The year of the carb...
Printed From: CorrectCraftFan.com
Category: Repairs and Maintenance
Forum Name: Boat Maintenance
Forum Discription: Discuss maintenance of your Correct Craft
URL: http://www.CorrectCraftFan.com/forum/forum_posts.asp?TID=16764
Printed Date: September-25-2024 at 8:42am
Topic: The year of the carb...
Posted By: vondy
Subject: The year of the carb...
Date Posted: March-10-2010 at 5:48pm
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I'm going to break down this year and actually get a "real" carb for the Mustang. That would be the Holley 4160, 450 cfm marine carb. http://www.summitracing.com/parts/HLY-0-80364/ - Carb
Hopefully this will take care of any starting issues. Plus any safety issues. My current carb must be leaking and flooding the engine because all last year I had to open the throttle wide open to start her after running a while then sitting a wile. Could also smell fumes. My idle mixture screws never seemed to do much either. I could shut one all the way down and the idle kept on going. So looking for any info up front on installing this thing? Anything I should know? I rebuilt my last one twice so I'm familiar with the basics. Would the new carb fit right on top of the spacer my current one sits on? These things usually come with the gasket needed? I plan on getting the metal fuel line from Skidim. http://skidim.com/prodinfo.asp?number=RA085002B - Fuel Line Other than the carb I plan on getting new plug wires and a cap. Hopefully she'll be running very smooth this year. Thanks for any help! ------------- http://correctcraftfan.com/diaries/details.asp?ID=4645&sort=&pagenum=1 - 69 Mustang HM |
Replies:
Posted By: kapla
Date Posted: March-10-2010 at 10:40pm
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sounds like the floats were set to high thus flooding the carb..I'm also thinking on a foulty power valve? ------------- <a href="">1992 ski nautique |
Posted By: Gary S
Date Posted: March-11-2010 at 2:40am
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Sebastian,Dave has the original carb on that motor which is either a Ford or a Motorcraft. They were the same as what came on the cars of those years, kinda of a real basic carb, 2bbl no power valve etc. Getting a new carb will really make a difference as it did for mine.
Dave are you planning on using a 4 bbl? If so I think you'd be best to change the manifold too,rather than using an adapter. I guess it would be good to look at your link before posting--- ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1711&sort=&pagenum=1&yrstart=1966&yrend=1970" rel="nofollow - 69 Mustang HM SS 95 Nautique Super Sport |
Posted By: vondy
Date Posted: March-11-2010 at 11:10am
Yes my current one is an motorcraft. Standard auto. Gary, I can't even remember what the top of my manifold looks like. You think a 4 barrel wouldn't work? I wouldn't just need a new spacer? I'm calling it a spacer, never was quite sure of it's purpose. Except for venting. Here's a pic.  ------------- http://correctcraftfan.com/diaries/details.asp?ID=4645&sort=&pagenum=1 - 69 Mustang HM |
Gary S wrote:Posted By: vondy
Date Posted: March-11-2010 at 11:30am
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Something like this?
http://www.summitracing.com/parts/EDL-2121/?rtype=10 - Manifold ------------- http://correctcraftfan.com/diaries/details.asp?ID=4645&sort=&pagenum=1 - 69 Mustang HM |
Posted By: GottaSki
Date Posted: March-11-2010 at 11:33am
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A spacer is a poor compromise, best buck up and get a nice 4V manifold.
And your new 4160 should have the PVC port built right in, so an adapter is not required unless its a new edelbrock manifold. I would also look into your fuel filtration system, best have that right before putting on virgin hardware. Gasket, best get a nice fel-pro; I forget the number. ------------- "There is nothing, absolutely nothing, half so much worthwhile as messing around with boats...simply messing." River Rat to Mole |
Posted By: TRBenj
Date Posted: March-11-2010 at 12:43pm
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Vondy, in case it wasnt clear, it appears you have a 2 barrel 302. You cant just slap a 4 barrel carb on it. You'll need to get a 4 barrel manifold. Like Gottaski said, the new 4bbl Holley will have a port for the PCV, no need for a spacer. If youre interested in really improving the performance of the engine, a 4 barrel cam would be a nice upgrade. Of course, while youre in there, a better flowing set of heads would be nice as well. It all comes down to how much you want to spend! Either way, an aluminum intake can be found cheaply used (~$100-125)... Id keep on the lookout for an Edelbrock Performer. If your budget is starting to look a bit thin, then shoot me an email- I have a few spare 4bbl 302 intakes Ill never use. Theyre heavy (shipping wont be cheap) but Id be happy to send you one. TRBenj@gmail.com ------------- |
Posted By: vondy
Date Posted: March-11-2010 at 1:31pm
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See this is why I posted this, knew there was going to be more to it than simply buying a carb. Is the difference in the 2 barrel manifold and 4 just the openings? I guess I was thinking mine was just an open square that would accept either.
Why do I need an adapter to put the Holley onto a new Edelbrock intake? Is it a difference in the bolts or something? As I posted earlier I was looking at this one. http://www.summitracing.com/parts/EDL-2121/?rtype=10 - Intake I can swing $160. TRBenj, thanks for the offer, I'll keep that in mind. My goal here is to get everything running as smoothly and safely as possible. I'm not looking for tons of performance increases. That would be a nice "side effect". But I of course want to do things right. I'm on a budget, but like I said, I can swing and extra $160 for a manifold. ------------- http://correctcraftfan.com/diaries/details.asp?ID=4645&sort=&pagenum=1 - 69 Mustang HM |
Posted By: TRBenj
Date Posted: March-11-2010 at 2:21pm
The Edelbrock Performer usually requires the adapter plate (p/n 2732, available from Summit) because it will prevent vaccuum leaks. I know this is required if running the PCM 1" spacer, as the Performer has narrow surfaces on the side, and the spacer is open on the bottom. The adapter would cover the area outlined in red, preventing a vaccuum leak in the green areas. If bolting a Holley up directly, you may or may not need it- but for $6, Id grab it just in case.
Id look around for a used Performer before plunking down cash on a new one. My sister found a used Performer RPM last week for $80 on craigslist for their Mustang. If you want a cast iron one, just shoot me an email. For reference, here's an overhead shot of what your 2bbl intake manifold looks like:  ------------- |
Posted By: 79nautique
Date Posted: March-11-2010 at 3:09pm
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the reason you have to use the adapter is because edlebrock likes to use a spread bore carb on their intakes, it matches their carbs and the holley typically is a square bore carb so you have to have the adapter to seal it. Use an edlebrock carb no adapter required.
spread bore carb two small holes primary two larger holes secondary's on the base of the carb square bore four equall size holes on the base of the carb ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique |
Posted By: DrCC
Date Posted: March-11-2010 at 3:36pm
| I've got a 4bbl intake. 50.00 if you wanna cover shipping. |
Posted By: DrCC
Date Posted: March-11-2010 at 4:03pm
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It is originally from (I believe) a 1969 Ford Thunderbird.
It was used briefly on a 260 Interceptor, then two seasons on the OMC 302. |
Posted By: kapla
Date Posted: March-11-2010 at 4:04pm
I always wondered what was the difference!! thanks Chris ------------- <a href="">1992 ski nautique |
Posted By: TRBenj
Date Posted: March-11-2010 at 4:05pm
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A few links for your consideration:
http://dallas.craigslist.org/dal/pts/1634986649.html - stock 80's Mustang intake (4bbl aluminum) http://dallas.craigslist.org/dal/pts/1615123481.html - Edelbrock Performer RPM ------------- |
Posted By: vondy
Date Posted: March-11-2010 at 4:51pm
Thanks for all your help! 
Would a newer aluminum edelbrock perform better than the old cast iron? I like the idea of a fresh new one with no rust buildup. Am I correct in thinking that they moved the thermostat housing on later models? When getting an new manifold, do I want to install new bolts? I see Summit offers Stainless and Steel. Obviously I'll need a gasket kit. Summit has the Fel-Pro. What's the difference in the regular Edelbrock Performer and the RPM Performer? According to the description on Summit for the manifold, it uses as Square Bore. At least that's for a new one. http://www.summitracing.com/parts/EDL-7121/ - Manifold ------------- http://correctcraftfan.com/diaries/details.asp?ID=4645&sort=&pagenum=1 - 69 Mustang HM |
Posted By: vondy
Date Posted: March-11-2010 at 4:51pm
Thanks for the Links! ------------- http://correctcraftfan.com/diaries/details.asp?ID=4645&sort=&pagenum=1 - 69 Mustang HM |
Posted By: 79nautique
Date Posted: March-11-2010 at 5:01pm
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the RPM version has a higher RPM range that it's designed to work best with, typically a pretty stout motor turning over 5K which isn't going to help you much if your not changing cams and heads too, but it won't hurt if you do use one if you got it at a good price, but spending extra money to get it really is a little waistefull if you ask me. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique |
Posted By: vondy
Date Posted: March-11-2010 at 5:15pm
I see. So if I find a used one for $60 that happens to be an RPM, it wont hurt anything with my engine. Just don't spend any extra money on one. ------------- http://correctcraftfan.com/diaries/details.asp?ID=4645&sort=&pagenum=1 - 69 Mustang HM |
Posted By: 79nautique
Date Posted: March-11-2010 at 5:21pm
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correct ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique |
Posted By: TRBenj
Date Posted: March-11-2010 at 5:39pm
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Agreed. Many here run the slightly more aggressive RPM (or the similar Weiand Stealth). Like Chris said, thats usually with an upgraded top end (heads and cam) but such upgrades help the holeshot as well as the midrange and top end- so I wouldnt expect the RPM to hurt your performance over a lesser intake if you were to find one cheap. The standard Performer is really more of a stock replacement. Dont expect to pick up any hp with an intake upgrade alone- the stock 2bbl cam and heads are still a major choke point. If you dont plan on any future upgrades, just grab a stock 4bbl manifold for cheap. Clean it up and paint it Ford blue and it will look like new. Intake bolts can usually be reused (inspect them first), but a new set wont do any harm. Head bolts, on the other hand, should always be replaced.
All of the aforementioned intakes are square bore. They dont look anything like the spread bore manifolds Ive seen. The adapter is a spread-square adapter though- it just happens to solve the vaccum leak with that manifold when using the spacer. ------------- |
Posted By: vondy
Date Posted: March-11-2010 at 6:47pm
So would I need a spacer for any reason?  If the carb and the intake are square bore?
I didn't realize how far down the line the 4bbl upgrades went. The heads on this engine where replaced at one point. Any chance they used 4bbl? Would that work if they still had a 2bbl on it? So am I going to see any increase in performance with just upgrading to the Holley 4bbl and intake? Should I stick with a new marine 2bbl and save a few bucks. Upgrade to a 4bbl later down the line when I rebuild? ------------- http://correctcraftfan.com/diaries/details.asp?ID=4645&sort=&pagenum=1 - 69 Mustang HM |
Posted By: TRBenj
Date Posted: March-11-2010 at 7:11pm
Yes. See my post above with the red/green diagram. For $5, just get one if you run an Edelbrock.
The whole top end is tuned together. Cam choice is always dictated by the components its controlling (intake, heads, exhaust) so the whole package works well together. To see a significant performance increase, all parts will need to be upgraded... I dont know much about the heads, but the cam is probably pretty tiny. Here's my take: Option A: upgrade the whole top end now. Heads, intake, cam, carb. For under $2k you'll have a 275hp monster that will pull your arms off and run in the low 50's (at least). Option B: Buy a 4bbl carb as planned. Get a cheap/free 4bbl intake. This will make the boat more reliable and safe, even if it doesnt improve performance much. Spring for an Edelbrock intake if youve got some cash to burn. In the future if you want to upgrade the heads and cam, its that many fewer pieces to buy. Otion C: Buy a 500cfm 2bbl Holley and go skiing. This is the cheapest route. I would not do this if you ever plan to upgrade the top end and convert to a 4bbl somewhere down the road. You'll never recoup the cost of the new 2bbl carb. Based on what youve said, Id lean towards option B for now. Id get a cheap/free 4bbl intake and a new 4bbl carb. Get an Edelbrock intake if youre feeling saucy. It wont break the bank for now, and it will vastly improve safety and reliability, and will support future growth. ------------- |
Posted By: 75 Tique
Date Posted: March-11-2010 at 7:33pm
I really shouldnt contribute here since all you guys responding have more knowledge/expertise than I, so I will offer this as much as a question to you guys as it is a suggestion to Vondy. But Vondy, if you are on a budget, why not consider an http://www.summitracing.com/search/?keyword=edelbrock%201406&dds=1 - Edelbrock Carb . I know the Holley is the standard around here, but there are also a number of proponents of the Edelbrock. I had a Holley for 11 years and have run my Edelbrock for 6. I find it much less fussy, more reliable and easier to work with. And the main reason I mention it, is its close to half the price of the Holley. I only put this out for discussion/consideration...although I have a feeling it will go something like the points vs electronic discussion aka "my way or the high-way"  ------------- _____________ “So, how was your weekend?” “Well, let me see…sun burn, stiff neck, screwed up back, assorted aches and pains….yup, my weekend was great, thanks for asking.” |
Posted By: Gary S
Date Posted: March-11-2010 at 10:22pm
Larry anything will be less fussy than that old Ford carb he has now He will really notice a difference in how it starts and how much smoother it is once he gets rid of it. I had the exact same setup on my HM.------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1711&sort=&pagenum=1&yrstart=1966&yrend=1970" rel="nofollow - 69 Mustang HM SS 95 Nautique Super Sport |
Posted By: Gary S
Date Posted: March-11-2010 at 10:28pm
Wish mine would  ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1711&sort=&pagenum=1&yrstart=1966&yrend=1970" rel="nofollow - 69 Mustang HM SS 95 Nautique Super Sport |
Posted By: vondy
Date Posted: March-12-2010 at 3:47am
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Oh decisions, decisions.
Unless my engine blows up, God forbid, I don't plan on doing anything to it that I don't have to, other than painting, for several years. Probably like 5-10 years. My next big project will be stringers, hopefully this coming up winter. So with that in mind, I can spend right at $400 on a 2 barrel and bolt her right on. Or spend a bit over $500 for the 4 barrel, plus lets say $50-$180 on an intake, plus gaskets, spacers etc. Hummm? Guess I'll have to think about that. Forgive my lack of knowledge but what's the difference between a 2 barrel and 4 barrel head? Do they just allow more air to pass through? As I mentioned above, the heads on this were replaced, is there any way of knowing what might have been put on? Thanks again everyone! This, as most things, is a bit more involved than I originally expected. ------------- http://correctcraftfan.com/diaries/details.asp?ID=4645&sort=&pagenum=1 - 69 Mustang HM |
Posted By: eric lavine
Date Posted: March-12-2010 at 10:13am
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whats the difference between a boy and a man? nothing better than the sound of the secondaries opening.....go for the 500.00, and i think if you search you can find good used.. Sam57 has a good used one he may part with (carb) ------------- "the things you own will start to own you" |
Posted By: GottaSki
Date Posted: March-12-2010 at 11:36am
On the Windsor engines, almost nothing. The difference in VE is minimal. I suspect the bigger difference is compression ratio. Either way, its inperceivable to the buttometer. ------------- "There is nothing, absolutely nothing, half so much worthwhile as messing around with boats...simply messing." River Rat to Mole |
Posted By: TRBenj
Date Posted: March-12-2010 at 12:37pm
Gary, have you given your cam specs to Alan to run in his desktop dyno? Im curious how good that Crane cam really is. The last guy that posted his set up with a Comp SBF grind didnt impress me... the specs looked similar to my Cam Research stick, but it was a good 30hp down... thats leaving a lot on the table. Also, any idea what your compression ratio is? Was your H-M originally a 210hp 2bbl or the 235hp 4bbl? Something doesnt add up since youre only running 45mph or so... even my bone stock 4bbl 302 Skier runs 46-47, and I consider that to be an underperformer! Tom, thanks for clueing us in on the 2bbl heads. Glad to hear theyre not terrible- at least not much worse than the 4bbl heads, haha. Regardless of whats on there, it wont be a powerhouse- all stock 302 heads are pretty wimpy. GT40, GT40p or D0OE heads and a matched cam would really wake it up, I suspect. I am curious about the CR though- what size chambers do the 2V heads have? Vondy, it sounds like youre very tempted to stay 2bbl and save a few bucks. Thats certainly a consideration. I will warn you though- once you have a good running boat, you may catch the bug to upgrade sooner than you expect! With a bit more power, these small boats are an absolute riot... so avoid riding in one if you want to stay stock. Even with no plans to do so in the near term, the extra $150-200 to go 4bbl might be a good investment. Since youre still on the fence, Id recommend a 4bbl carb and a cheap/stock 4bbl intake, rather than new Performer or otherwise. ------------- |
Posted By: hotboat
Date Posted: March-12-2010 at 12:59pm
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Did anyone mention the difference in hood clearance from performer to rpm? I dont know if thats an issue in this app. or not? ------------- Brian |
Posted By: 79nautique
Date Posted: March-12-2010 at 1:01pm
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your just going to be running rich all of the time if you don't change the cam so stay away from a 4bbl carb if all your going to do is get a new carb.
if you want to change the cam and upgrade to a 4bbl that would be your best bet the heads are a wash you'll never tell a difference, without a cam change it's not going to gain anything been there done that when I was 17 big waste of cash. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique |
Posted By: TRBenj
Date Posted: March-12-2010 at 1:10pm
Chris, I dont know if I agree with this. You realize the engine in question is a 210hp 2bbl Holman Moody, right? That came with a 500cfm 2bbl... Its a different animal than the 165hp 2bbl Interceptor (which came witha 350cfm 2bbl?). I dont see why a 450cfm 4bbl would cause it to run rich. I agree a cam swap would optimize its performance though.
With a new carb (which has a vacuum port for the PCV) he can eliminate the spacer if need be, so height should be a non-issue. The RPM is ~1" taller than the regular performer, but it may not be an issue at all with his big wood motorbox. ------------- |
Posted By: Keeganino
Date Posted: March-12-2010 at 1:17pm
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Good reading! I have nothing to offer- just another fly on the wall soaking it all in. ------------- "working on these old boats may not be cost effective but as it shows its what it brings into your life that matters" -Roger http://www.correctcraftfan.com/diaries/details.asp?ID=4897" rel="nofollow - 1973 Skier |
Posted By: hotboat
Date Posted: March-12-2010 at 1:18pm
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Doesnt a carb meter the fuel depending on air flow/velocity? If there are further upgrades in the future you will already have some of the pieces ------------- Brian |
Posted By: 79nautique
Date Posted: March-12-2010 at 1:23pm
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if your going from a 500 2bl to a 450 4bl do you plan on runing on the secondaries all the time or just running lean all the time on the primaries?
the cam drives the air flow not the carb so there's no need to re-invert the engine unless your doing other major changes like the cam and rockers. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique |
Posted By: TRBenj
Date Posted: March-12-2010 at 1:32pm
Wait, which is it? 
I agree that the carb wont likely be the limiting factor- the cam will be the most likely culprit... though everything from the carb to the exhaust (intake, heads and cam in the middle) will have an affect on the amount of airflow (and thus, the A/F ratio). The carb is the only thing metering fuel though, yes? Youre saying it will be impossible to dial in a 4bbl on a motor spec'd as a 2bbl, even though the carbs have similar CFM's? Seems like it wouldnt be too tall of an order. Really, how different can the longblocks be between a 210hp 450cfm 4bbl Interceptor vs. the 210hp 500cfm 2bbl H-M? ------------- |
Posted By: 79nautique
Date Posted: March-12-2010 at 2:02pm
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well you've taken comments out of context to combine them in to one, so if you look at the context, you'll maybe figure it out.
So we have engine that wants to see 500 cfm all the time and you are suggesting using a 450 cfm 4bl carb that is going to allow 225 cfm all of the time and then 450 cfm if you use the secondaries. Sure seems like your creating a restriction to me. I just love a guy that has all the answers and takes stuff out of context but when it comes down to the show part they're look at the rear of the other boats ahead of them because his can't keep up, stay with them out of the hole for about 30 seconds then fades. HHHMMMMmm use a 500cfm 2bbl carb and call it a day. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique |
Posted By: TRBenj
Date Posted: March-12-2010 at 2:13pm
This makes no sense to me whatsoever. The air and fuel needs of an engine vary across the RPM band. Neither scenario requires the max CFM until you get close to WOT. Explain to me why the cam (or the rest of the engine) would care whether a 500cfm 2bbl or the front 2 barrels of a 450cfm are feeding it air and fuel at 2500 rpm's. Its only going to need 175cfm of air at that speed. So long as the A/F ratio is correct, its going to run good. Explain to me why a 4bbl cant be dialed in to work. Youre right, when we lined up at GL07, I only held you off out of the hole for 30 seconds. Pretty poor performance on my part. I would have been to the end of my home lake and back in that time! Bring any inboard ski boat you want to GL10 and we'll see if you can keep up... I promise you that you wont. ------------- |
Posted By: 79nautique
Date Posted: March-12-2010 at 2:27pm
so then if it only needs 175 cfm at 2500 why will the secondaries open with the throttle completely open and your only doing 3000 rpm? load is why and it doesn't care what rpm your at. Far from the need for the max CFM rating and max RPM of WOT ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique |
Posted By: TRBenj
Date Posted: March-12-2010 at 2:36pm
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Yes, the secondaries are controlled by a circuit that is affected by both vaccuum and RPM. Yes, they will open well before youre at max RPM. Clearly there is a crossover point on a 4bbl application where the carb needs to open the back 2 barrels. That doesnt mean it cant run well on the primaries at lower RPM's with low to medium load... and that would just as easily apply to an engine that originally shipped with a 2bbl carb. The heads and cam that came on a H-M 2bbl cant be that radically different from an Interceptor 4bbl since its rated the same exact 210hp. If he wants to upgrade the top end in the future, he'll have a heck of a time finding a performance 2bbl manifold to match the 2bbl carb youre proposing he buy.
Am I way off base here? ------------- |
Posted By: 79nautique
Date Posted: March-12-2010 at 2:43pm
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you have a guy that has a carb problem that's not the sharpest tool in the box when it comes to carboration. He states he doesn't want to modify or change any part of the engine that is going to require a different CFM rating or style carborator. So since the compression ratio isn't changing, the stroke isn't change and the cam isn't changing, why ignore the orginal engine builders specs and change the carb, he only wants better starting and engine operation for the whole day instead of the continued issue's he's been fighting with the current carb. What You know more than Holman or Moody.... maybe... probaly not would be the better answer.
So instead of suggesting he gets a 2 BBL 500 CFM carb to replace a 500 CFM unit, lets change the intake to a 4bbl, use a smaller carb to boot and then expect the guy to figure out the jetting and mixture issue you created because he took your advice. Are you going to be there to rejet the carb, adjust the floats and all the other crap that will need to be done? I doubt it. So I suggest getting a new 500 CFM 2 bbl carb, and save the head ack after all isn't that why he wants to change the carb in the first place because he can't figure it out and get it to work properly? What the F am I missing here? ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique |
Posted By: 79nautique
Date Posted: March-12-2010 at 2:45pm
they are called vaccum secondaries for a reason not RPM secondaries. They open because of vaccum not because you just hit 4000 rpm. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique |
Posted By: Keeganino
Date Posted: March-12-2010 at 2:51pm
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BZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ The reading gets even better. ------------- "working on these old boats may not be cost effective but as it shows its what it brings into your life that matters" -Roger http://www.correctcraftfan.com/diaries/details.asp?ID=4897" rel="nofollow - 1973 Skier |
Posted By: vondy
Date Posted: March-12-2010 at 2:56pm
OK now I'm really confused... 
According to Chris it seems like I could update my carb, intake and cam to 4bbl and be good. No heads needed. If I'm reading correctly, and I may not be. If that's the case, whats a good cam usually run? Is it a simple enough swap or terribly involved? If it's not a huge deal I could update the carb and intake to 4bbl this year and do the cam next. One thing I don't want is to get a 4bbl and waste a bunch of fuel and not get anything extra out of it. So basically if I have to change the heads down the line to see any advantage to a 4bbl I might just stick with a 2bbl cus I'm not planning on spending that kind of money any time soon. But, if it's not going to hurt anything, fuel economy, performance, reliability, etc., to have just a 4bbl intake and carb for a year until I get a cam then I might go that way. ------------- http://correctcraftfan.com/diaries/details.asp?ID=4645&sort=&pagenum=1 - 69 Mustang HM |
Posted By: 79nautique
Date Posted: March-12-2010 at 3:05pm
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Vondy your correct.
about 500-800 bucks maybe a little more if you going all new, but for a used intake, new cam, new carb 500-600 depending on what carb you choose. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique |
Posted By: vondy
Date Posted: March-12-2010 at 3:09pm
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Wow, look what I started...
Chris is right that I'm looking for an easy way to get her "running right". Any gains in HP were secondary thoughts. That being said, I do not want to limit myself for future upgrades. But if it's going to be a PITA to get running right in the meantime, I would rather keep it simple and just bight the bullet years form now when I decide to really upgrade. ------------- http://correctcraftfan.com/diaries/details.asp?ID=4645&sort=&pagenum=1 - 69 Mustang HM |
Posted By: TRBenj
Date Posted: March-12-2010 at 3:23pm
I dont care what you call them. Yes, vaccuum is a key. So is RPM. I dont know exactly how they work, not having designed the circuit. I do know that if you try to pull up 10 skiers, the secondaries still wont open... they have to be close to the RPM they normally open (3500-4000) regardless of load for them to activate. And yes, they'll open at a very similar RPM even with minimal load (eg, a lightly loaded boat, slowly creeping up to speed). Yes, he would have to check the float levels and verify the jetting on the 4bbl- he'll have to set the idle too. Youre saying he can just bolt a 2bbl on with no adjustment at all? I dont think so. He'll have to dial in either one. Dont confuse the issue here- a 302 will not be choked by a 450cfm carb any more than a 500cfm, so calling the 4bbl a "smaller carb" and implying it will hurt performance and economy is not accurate. I would think both would be improved with the 4bbl- especially when he's only running on the primaries. No need to run on on larger jets and throat sized for WOT operation (like the 2bbl would have to be) when he's only cruising. The issue here is he's dealing with a worn out Autolite automotive carb. Safety and reliability are the top 2 concerns, yes. I think either a new 4bbl or a new 2bbl would improve that. With no other changes (save for an intake manfold with the 4bbl), performance between the 2 wouldnt be very different. Economy might be a little better with the 4bbl. The real difference is if he ever wants to upgrade the cam and heads... he'll want a decent flowing intake to match them, and all the decent/cheap ones are 4bbl. Why buy a new 2bbl carb (expensive!)that wont support a future upgrade? Vondy, no I wouldnt upgrade the cam unless youre doing the heads. Youre only looking at picking up 20hp or so at best- not worth the $250 and extra work. Do it all at once if youre going to bother. ------------- |
Posted By: 79nautique
Date Posted: March-12-2010 at 3:35pm
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Tim your so wrong the heads are not the limiting factor so changing the cam is going to get you way more than 20 hp.
Also explain where your engine's vaccum and RPM comes into play on a four barrel carb with mechanical secondaries? if the secondaries only work based upon the engines rpm and vaccum needs as you want to argue? Step on the gas peddle and the secondaries open up the engine is allowed to breath in more air and the RPM takes off. Keep reading your websits and books maybe one day it'll sink in. Good old teachings from a master tech don't mean *************** I guess that's why I'm so lost. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique |
Posted By: 79nautique
Date Posted: March-12-2010 at 3:42pm
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It's pretty darn funny someone complaining about 302 heads not being good enough, but the same old fool is using 302 heads on there 351W that's all beefed up? where the hell's the logic in that? isn't that why the head bolt holes have to be opened up so that it fits on a 351W block that uses a larger bolt diameter. HHHHHHMMMMMMM maybe not so bright maybe the heads are better than one might think?
Vondy get a cam, used in take, a new carb and enjoy the added perfomance. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique |
Posted By: TRBenj
Date Posted: March-12-2010 at 4:08pm
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All this coming from a guy that dropped in a longblock instead of building his own engine.
Yes, the stock 302 heads suck. They put similarly awful heads on stock 351w's. Thats why the GT40 and GT40p heads are an upgrade. Yes, both of those heads were designed for and originally installed on 302's. Theyre not in the same league as the stock marine heads though- we're talking a 30-40 bolt on hp difference. Yes, they work well on a 351w that doesnt see much over 5k RPM's. If the stock 302 heads were so good, why were the 4bbl's only rated at 220-235hp? You think you can get a 2bbl to perform significantly above that level with a cam and intake change? That would surprise me, but hey, youre the Master Tech! Would a cam upgrade alone help? Yes. Would a head upgrade alone help? Yes. Would I do the cam without the heads? No- add the heads later and you'll probably want to change the cam again to take advantage of them. Would I do heads alone? Not in this 2bbl application- but others, maybe. All for the same reason Im recommending he go 4bbl now- support future growth, prevent buying the same part twice. Im not following you on a your mechanical secondary reference. I thought we were talking vaccuum secondaries, which 95% of people here are running. The 450cfm that Vondy is proposing to use (the stock 4bbl 302 carb) falls into that category. Even with vaccuum secondaries, theyre not going to open based purely on load- theyre RPM dependant as well. Like I said, attempt to pull 10 skiers out of the water- youre only going to get 2500-3000 RPM's with a 1:1 (at best) and no matter how much the engine struggles, the secondaries wont kick in. ------------- |
Posted By: 79nautique
Date Posted: March-12-2010 at 4:52pm
your correct it was a long block, was it the same long you can buy? NO it wasn't, as it was custom built to my specification's by the same engine builder my Buddy used to build his race engines for is top sportsman car and his super comp rail at his sponsor's facility and at his cost not retail. So penny earn penny saved smart buy maybe Very much so and a better engine than you brought to the show to boot. It pays to invest wisely and get what you want in return, but then I was never looking at the back of your boat either or looking for you to pay the bill for the parts, pretty nice motor for 3K all in all and I could spin it at 5500k all day long with no worries, but that's why I could spin a bigger wheel too, because the stock wheel pegged the tach. so you missed the piont where you state that vaccum and rpm drive the secondaries on a carb, but that's not really true it's true only for a holley or a carb with vaccum secondaies so they can open up but it's not a requirement to have vaccum secondaries now is it and if you had mechanical secondaries the engine would come up to speed faster pulling those ten skiers because it lets the engine breath more quicker than waiting for the vaccum to build and open the secondaries up? So to say you can't get any horse power out of an engine unless the heads are changed along with the cam is horse dung. Might be in your book because you don't know of any other way to do it because thats how you've always done it, It doesn't mean everyone does or everyone should because there are many out there that can and do get around that issue ask a bracket racer where they spec out everything yet some are fast some are slow wonder why, maybe they way they massage the parts the engine the components that compliment all of the other parts so that they create the most HP given the rules and size limits? ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique |
Posted By: Keeganino
Date Posted: March-12-2010 at 4:58pm
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bbbzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz ------------- "working on these old boats may not be cost effective but as it shows its what it brings into your life that matters" -Roger http://www.correctcraftfan.com/diaries/details.asp?ID=4897" rel="nofollow - 1973 Skier |
Posted By: vondy
Date Posted: March-12-2010 at 5:10pm
 Oh I'll never get a carb now... ------------- http://correctcraftfan.com/diaries/details.asp?ID=4645&sort=&pagenum=1 - 69 Mustang HM |
Posted By: TRBenj
Date Posted: March-12-2010 at 5:11pm
Chris, just poking at you about the Jasper longblock! 
My comments regarding the vacuum secondaries and the need to upgrade both the cam and heads together were specific to Vondy's predicament. In case you forgot, he's trying to improve safety and reliability of the 2bbl 302 H-M in his Mustang with a new carb, while still allowing for future growth (without re-purchasing parts). All of my advice is good! Yes, I know you dont always have to upgrade heads to see an improvement. Im going through this right now on our BFN... we're picking up 90hp with a cam change alone- but thats only because it was the ONLY bottleneck in the system. I just dont see how upgrading either the cam or heads alone on a 2bbl 302 is going to make a big enough difference to justify the cost. Theyre BOTH bottlenecks. Vondy, long story short: Like Ive been saying from the beginning, Id upgrade to a new 4bbl carb. Grab a cheap/free 4bbl intake and go skiing. This will improve safety and reliability, and should improve performance over the worn out Autolite. If and when you ever decide to upgrade to upgrade the top end, pony up for a new set of heads, a cam upgrade, and a performance manifold. Spec the cam last to match your other components. Reuse the 4bbl carb that youve previously purchased. Chris, let me know if this is bad advice!!! Oh, and yes you did see the back of my boat- for the first 30 seconds of that race! If you want to line up again, bring a fast one- the BFN will be running 60 this summer.  ------------- |
Posted By: 79nautique
Date Posted: March-12-2010 at 5:20pm
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never saw you get a length on me but oh well your story,
So maybe you should read up a little more since your suggesting using a 450 CFM carb BIG *************** Mistake going smaller and then if you want to upgrade your buying a new carb too. So the question is what actuall heads are on it? what are the valve specs what? are the runner specs? then a good cam and carb can be selected to get the most bang for the buck without changing the heads. But you better get atleast a 650 CFM carb if your going 4 BBL and want to up grade at a later date, much easier to restrict the flow than not have enough flow to start with, so Read up Tim, your a little off. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique |
Posted By: Air206
Date Posted: March-12-2010 at 5:23pm
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I hope you 2 don't have day jobs!............... How can you get a day's work done posting so much? Well , you guys are certainly multi-taskers.......... Too funny!
No matter how old you get, it still comes down to comparing whose long block is bigger and better. Ha! ------------- https://tinyurl.com/y6t5e3bu" rel="nofollow - 04 Air206 http://tinyurl.com/9urzgls" rel="nofollow - 91 Barefoot 78 SkiTiq |
Posted By: TRBenj
Date Posted: March-12-2010 at 5:44pm
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Come on Chris, try to keep up!
Like I said, the 450cfm that Vondy picked out is the stock 302 4bbl (220hp) carb. That wont be a limiting factor, even if he wants to wind it up to 5200rpm (and thats assuming 100% volumetric efficiency). Some have gotten a 600cfm carb to work great on a 302 (like Reid's baby blue), but others needed to finesse it more to get it to run right (like Doc's 331 stroker). The 600cfm carb isnt holding back my 351w from turning up to 5400, so I feel its overkill in this application... especially if Vondy is keeping the 2bbl heads and cam for now. And dont try and pretend you hung with me out of the hole! Id tell you how many boat lengths I put on you, but it was hard to judge... how many boatlengths are there in a football field?  ------------- |
Posted By: vondy
Date Posted: March-12-2010 at 6:05pm
 ------------- http://correctcraftfan.com/diaries/details.asp?ID=4645&sort=&pagenum=1 - 69 Mustang HM |
Posted By: 8122pbrainard
Date Posted: March-12-2010 at 6:17pm
I feel the confusion here is due to misinterpretation. Tim, you just need to take the Chris course of spelling!!
------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
Posted By: Gary S
Date Posted: March-12-2010 at 11:29pm
The only thing I could add is, I doubt this piece of junk could be anywhere near 500cfm
 ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1711&sort=&pagenum=1&yrstart=1966&yrend=1970" rel="nofollow - 69 Mustang HM SS 95 Nautique Super Sport |
Posted By: vondy
Date Posted: March-12-2010 at 11:32pm
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Has anyone here actually replaced the carb on their 302 HM from the autolite to a new 4bbl or 2bbl marine? Replaced without changing cams or heads? If so, what were the results?
When I was discussing this with my brother he said, "you want MORE power in that thing?". ------------- http://correctcraftfan.com/diaries/details.asp?ID=4645&sort=&pagenum=1 - 69 Mustang HM |
Posted By: Gary S
Date Posted: March-12-2010 at 11:55pm
In all honesty Tim, after I put the heads on,I didn't have much time to mess with it, too busy filling and wet sanding. Next up is new rub rail,original windshield,more filling and sanding! Alan has the info,but as you know he's busy too. The new and old heads are within tenths of each other cc wise,but I neglected to check anything on the engine as to cr. I have flat top 30 overs and a 450 cfm Holley. I don't know how much a difference it makes, but 45 is with just me onboard.I want to advance the timing and check to make sure the secondaries are opening. The hole shot and midrange is much better and a prop change is next up. I would be very happy with 50,51 tho.It was originally the 210 hp ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1711&sort=&pagenum=1&yrstart=1966&yrend=1970" rel="nofollow - 69 Mustang HM SS 95 Nautique Super Sport |
Posted By: eric lavine
Date Posted: March-13-2010 at 12:52pm
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a few years back, in an old Mach one, (this is from memory) so please do correct me if im wrong. it had a 351 with 2v heads and being not so wise, i bought a 2v manifold and 4 barrel....it ran worse once installed...the heads couldnt take that much gas. I still have the old manifold up in my attic and need to take a look at it ------------- "the things you own will start to own you" |
Posted By: vondy
Date Posted: March-15-2010 at 11:33am
I believe I'm going to go with the 2 barrel on this one. Really it comes down to me wanting the easiest an most cost effective solution. If I do an engine upgrade it will be years down the road. And if I have enough money to upgrade then, I'll have enough to buy another carb. Perhaps make a couple hundred on the new 2 barrel. Or who knows, maybe I'll have another boat by then and need the 2 barrel 
I appreciate everyone's help on this, I'm certainly not taking any sides or saying anyone is right or wrong. This solution I believe will fit me best. Now that I know what I'm going to do, what should I be looking out for? First there's the fuel line. Skidim has one for the 4 barrel but it looks like the fuel inlet on the carb is slightly different on the 2bbl than the 4bbl. Can I get an angled fitting so that I would be able to use the Skidim line? I really don't want to have to bend another line, that was a PITA. Other than a gasket, and fuel line, can anyone think of anything else I might need for installation? http://www.summitracing.com/parts/HLY-0-80402-1/ - 2bbl http://skidim.com/prodinfo.asp?number=RA085002B - Fuel Line Thanks again everyone! ------------- http://correctcraftfan.com/diaries/details.asp?ID=4645&sort=&pagenum=1 - 69 Mustang HM |
Posted By: 79nautique
Date Posted: March-15-2010 at 12:12pm
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I would think that you can tweek your current fuel line to get it to work, that is unless it's a little to short. Another option is a braided flexable hose with AN fittings on each end. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique |
Posted By: vondy
Date Posted: March-15-2010 at 3:14pm
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I might go with the flexible line. That would be the easiest solution.
Do I definitely want the 500 CFM? They have a 300 as well. I assume my Autolite is 500 only because that's what everyone on this thread has been saying. ------------- http://correctcraftfan.com/diaries/details.asp?ID=4645&sort=&pagenum=1 - 69 Mustang HM |
Posted By: TRBenj
Date Posted: March-15-2010 at 3:28pm
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Yes, the 2bbl Holman Moody came with a 500cfm carb. Thats why it was rated at a strong 210hp- the same as the 4bbl Interceptors. The 2bbl Interceptors used the smaller carbs, I believe- as they were rated at 165-190hp. ------------- |
Posted By: vondy
Date Posted: March-16-2010 at 11:27am
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Ran across something interesting yesterday. I was looking at my HM manual and noticed the two engine options were a 302-4v and 351-4v. The v stands for venturi right? 4 barrel carb. Looks like the manual was published in the early 70's. I assume HM had the 3 barrel option before that? ------------- http://correctcraftfan.com/diaries/details.asp?ID=4645&sort=&pagenum=1 - 69 Mustang HM |
Posted By: TRBenj
Date Posted: March-16-2010 at 12:00pm
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Im not quite certain what the V stands for, but yes- 4v indicates 4bbl. Im assuming your hand slipped off the 2... Ive never heard of a 3bbl!
I think youre correct- the only 2bbl H-M's Ive seen or heard about were from the mid 60's through '70. Everything newer than that was a 4bbl- the 302 being rated at 235hp and the 351 being rated at 290. I dont think that H-M manual is on the site... would you care to scan it and share it with the rest of us? ------------- |
Posted By: vondy
Date Posted: March-16-2010 at 1:15pm
Yes, slip of the hand, only had 1 cup of coffee in me at that time. I would love to scan the manual but I actually bought it so I assume it's copyrighted. Got it from http://www.marineengine.com/manuals/holmanmoody/index.html - Marine Engine Now that I look back at that site, there's another 302 manual, wonder if that's an earlier version like mine? I can't remember if I asked the guy when ordering which one was specific to my boat. That was a couple of years ago. ------------- http://correctcraftfan.com/diaries/details.asp?ID=4645&sort=&pagenum=1 - 69 Mustang HM |
Posted By: Gary S
Date Posted: March-16-2010 at 2:20pm
Not me and I still have it here in my garage. It's float bowl is marked 1.14 which makes it a 300 cfm. It's definitely the original and the same as the picture you posted in the past David.Look on the float bowl under the push rod for the accelerator pump Here is what I finally found- This is the Autolite 2100 series two-barrel carburetor. Look for throttle bore size cast into the body . The type of carburetor is determined by the venturi diameter size which is cast in the left-hand (driver’s) side of the carburetor body beginning in the 1960 model year. What you can expect to see are numbers like .98, 1.01, 1.02, 1.14, 1.23. This is the venturi diameter in inches. The higher the number, the larger the venturi diameter in inches. The 221ci small-block was fitted with eight possible 2100 types, all with .98-inch diameter venturis (190cfm ). The 260 and 289ci engines were fitted with 2100 carburetors with 1.01 (245cfm ) and 1.02-inch (240cfm) diameter venturis, depending upon application. Venturi size originally depended upon transmission, vehicle application and original sales district. California emissions carburetors, for example, were jetted differently. This was also true for vehicles delivered to high elevation areas like Denver. For 1964, the 289 received a larger throttle bore 2100 with 1.14-inch (300cfm ) venturis. This gave the 289 improved low-end torque. About the manuals,the parts manual has all models in it,only the owners manuals are seperated by size. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1711&sort=&pagenum=1&yrstart=1966&yrend=1970" rel="nofollow - 69 Mustang HM SS 95 Nautique Super Sport |
Posted By: TRBenj
Date Posted: March-16-2010 at 2:29pm
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Very interesting, Gary. I have an old email from Reid where he said they were 500cfm, but maybe we got our wires crossed. The carb cfm calculator Im using says that 300cfm wouldnt be enough air for a 302 spinning to 4400, even at a low 83% volumetric efficiency. I know the 210hp is legit, as the 2bbl H-M 'stang on our lake would outrun my Skier (220hp 4bbl Crusader) and our old '68 Mustang (210hp 4bbl Interceptor) back in the day. Something doesnt add up! ------------- |
Posted By: vondy
Date Posted: March-16-2010 at 3:20pm
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Back to square one.
I'll take a look when I get home tonight and see what's on there. If it is 300 cfm. I assume I should stay 300? If this is the case then the 450 cfm 4 barrel would have been closer than the 500 cfm 2 barrel huh? ------------- http://correctcraftfan.com/diaries/details.asp?ID=4645&sort=&pagenum=1 - 69 Mustang HM |
Posted By: 79nautique
Date Posted: March-16-2010 at 3:29pm
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I believe Gary is missing one key point it's a H&M and not just a stock ford motor which he seems to be quoting from a ford manual.
Bottom line get the mubers off of the carb and know what you have and stop guessing what you have. It would be much easier if people would get the model numbers of the actuall part than asking what everyone thinks is on it. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique |
Posted By: vondy
Date Posted: March-16-2010 at 3:53pm
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The tag says Autolite C9ZFG A949. That's the only info I have at work on it.
Guess I figured there were plenty of HM 302s out there that people would have changed out the carb on. I knew Gary had but he also upgraded more than I plan on. ------------- http://correctcraftfan.com/diaries/details.asp?ID=4645&sort=&pagenum=1 - 69 Mustang HM |
Posted By: Gary S
Date Posted: March-16-2010 at 4:46pm
I would agree Chris,those numbers are out of a Ford manual but 1.14 is what is marked on the float bowl of my old HM carb. I don't think CC was popping out more cash for custom HM's. I understood that the HM conversion was nothing special.At Mr Meloon's River run talk he basically said they got their engines from different sources so they would not be interupted by strikes up until the PCM's came out. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1711&sort=&pagenum=1&yrstart=1966&yrend=1970" rel="nofollow - 69 Mustang HM SS 95 Nautique Super Sport |
Posted By: vondy
Date Posted: March-16-2010 at 5:48pm
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Gary did you ever install your new fuel pump? Remember, way back when, I got mine and the vent tube was hitting the oil pressure sending unit? I still have not addressed it.
Curious if you ever did yours. http://www.correctcraftfan.com/forum/forum_posts.asp?TID=11565&KW=&title=my-new-fuel-pump - Old Post ------------- http://correctcraftfan.com/diaries/details.asp?ID=4645&sort=&pagenum=1 - 69 Mustang HM |
Posted By: TRBenj
Date Posted: March-16-2010 at 5:57pm
Gary, any chance the float bowls are interchangeable on different sized Autolite carbs? I know they are on Holleys... the thing that determines the cfm is the size of the venturies, obviously. ------------- |
Posted By: Gary S
Date Posted: March-16-2010 at 9:04pm
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No David,I'm keeping it as a spare, I http://correctcraftfan.com/forum/forum_posts.asp?TID=16010&KW=fuel+pump&PID=188207&title=1969-span-classhighlightfuel-span-span-classhighlightpump-span-rebuild#188207 - rebuilt my old one for now.
Tim here is a pic, the carb is more like an Edelbrock in that the top comes off and the bowl is cast as one with the venturies and base. You can see on the bowl the number cast into it. I thought it was a pretty cheap carb,but I see on some Ford sites,they were well thought of. When I changed over to the Holley it runs so much better particularly after sitting for a few days.One thing I just thought of, is mine started out as a 289 which was rated at 200 hp with the 2v,the 302 was 210 hp. I wonder what Davids is? Can you post the serial # off the bellhousing David? Then look at the carb's float bowl to see what size it is.Reid is probably right as the parts book dated 9/74 also a holley type carb,does not say Holley,but sure looks like one, they might have been changed for later models.  ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1711&sort=&pagenum=1&yrstart=1966&yrend=1970" rel="nofollow - 69 Mustang HM SS 95 Nautique Super Sport |
Posted By: vondy
Date Posted: March-17-2010 at 1:04am
Here's the info.
 ------------- http://correctcraftfan.com/diaries/details.asp?ID=4645&sort=&pagenum=1 - 69 Mustang HM |
Posted By: Gary S
Date Posted: March-17-2010 at 2:00am
Now that is confusing,a bigger engine,higher compression and a smaller carb not even listed! Must be a different listing for the 302's,but it must be less than 300 cfm. My opinion would be to go with the 4bbl 450cfm and manifold,you'll cruise around on the smaller 2bbl side and when you want to open it up the secondaries will kick in.
 ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1711&sort=&pagenum=1&yrstart=1966&yrend=1970" rel="nofollow - 69 Mustang HM SS 95 Nautique Super Sport |
Posted By: 79nautique
Date Posted: March-17-2010 at 10:14am
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the carb cross references a 69 mustang 302 in the auto world from the quick search I did yeasterday. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique |
Posted By: eric lavine
Date Posted: March-17-2010 at 10:35am
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for some reason i can remember 2v or 4v stamped on the heads somewhere, dont quote me cause in no way im a ford genius, but from what i remember the engine couldnt handle the 4 barrel, i blew black smoke when the secondaries opened, but nothing like experimenting ------------- "the things you own will start to own you" |
Posted By: GottaSki
Date Posted: March-17-2010 at 11:29am
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Eric i think the typical holley 'universal' carb is what gives them a bad rap, they belch black when romped on because thats the way they are set up, so no kid frags his pistons and blames Holley.
Yes, those windsor heads did have casting ID's 2/4V but I'm almost certain they were not the root cause of your experience. I've used the performer/4V holley on a '68 302 with 2V heads, but found the 'universal jetting ' is just that; universally mediocre until corrected. It appears only h-carbs wth very specific listings work well out-of-the-box. I think either carb, if marine specific, will work in this application. However, i suspect the 2V could have more precise throttle responce at 36 mph, because there is some lag in the vac seconday's responce, and the 450cfm's primary is likley past 70% open at those speeds. ------------- "There is nothing, absolutely nothing, half so much worthwhile as messing around with boats...simply messing." River Rat to Mole |
Posted By: vondy
Date Posted: March-17-2010 at 11:40am
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My search is showing the 1.08 to be 287 CFM. And apparently, like Gary said, these Autolite carbs are highly thought of.
------------- http://correctcraftfan.com/diaries/details.asp?ID=4645&sort=&pagenum=1 - 69 Mustang HM |
Posted By: vondy
Date Posted: March-17-2010 at 3:11pm
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So sounds like the 2 barrel Holley 300 cfm might be the way to go.
How would you go about tuning in a carb to get optimal performance? Other than the initial adjustments. ------------- http://correctcraftfan.com/diaries/details.asp?ID=4645&sort=&pagenum=1 - 69 Mustang HM |
Posted By: GottaSki
Date Posted: March-17-2010 at 4:03pm
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[QUOTE=vondy] So sounds like the 2 barrel Holley 300 cfm might be the way to go.
[QUOTE] Not unless you like a slow boat. Like tim sez, above 4000 rpm, you'll be making unneccesary manifold vacuum. While you would likely exceed 4000 or more rpm, it will be like having a restrictor plate on, and the power will go flat for no good reason. I feel 300 is just too small. ------------- "There is nothing, absolutely nothing, half so much worthwhile as messing around with boats...simply messing." River Rat to Mole |
Posted By: vondy
Date Posted: March-17-2010 at 5:30pm
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My carb now is rated at around 287 CFM. So I would want more than 300 CFM?
How about a poll from the experts, which I am obviously not. 2bbl - 300 cfm 2bbl - 500 cfm 4bbl - 450 cfm (with only intake upgrade) Sorry if I'm running this into the ground. Everyone seems to have a different opinion and mine doesn't count because I don't know what I'm talking about. So I put my trust in the good people of CCF. ------------- http://correctcraftfan.com/diaries/details.asp?ID=4645&sort=&pagenum=1 - 69 Mustang HM |
Posted By: 79nautique
Date Posted: March-18-2010 at 10:28am
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if you can acurately measure the carb, then we might be able to verify the research so far and be 100% right. But there is a possibility that the carb was changed at some point in it's life. What does HM state should have been on the motor? the 500 cfm? has anyone actually seen this in print form in a manual?
Seems like a very small carb for a high compression engine. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique |
Posted By: vondy
Date Posted: March-18-2010 at 11:25am
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My manual only shows info for the 302-4v. It specs at 480 CFM.
Turns out the manual I have was published in 74. I'm wondering if marineengine.com sent me the wrong manual. I emailed them and asked if the 289 and 302 manual was for earlier engines than the 302 and 351 one that I have. This manual also states it's a Holman Moody carb. Not and Autolite. ------------- http://correctcraftfan.com/diaries/details.asp?ID=4645&sort=&pagenum=1 - 69 Mustang HM |
Posted By: vondy
Date Posted: March-18-2010 at 12:45pm
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Yesterday I emailed the source on this topic. Here's what they said,
"Hello, Summit offers some marine carbs on their web site. I would go for the 500 CFM 2v or the 450 4V for a bit more top end. It does need to be a real marine carb for safety. The marine units have an overflow into the ventures so a stuck float will not fill the boat with fuel. Lee Holman" ------------- http://correctcraftfan.com/diaries/details.asp?ID=4645&sort=&pagenum=1 - 69 Mustang HM |
Posted By: reidp
Date Posted: March-18-2010 at 5:46pm
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Asleep at the wheel again, that's me, and missed all this. First, an apology to Tim if I stated or implied that the 2V was or should be a 500cfm as I don't think that to be the case either.
One quick note on Gary's: That engine tag says yours is a 289 built in 1968! I'll jump back on later, not that Vondy needs any more help. ------------- ReidP /diaries/details.asp?ID=231&yrstart=1971&yrend=1975 - 1973 Mustang |
Posted By: vondy
Date Posted: March-18-2010 at 6:08pm
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Reid I can use all the help I can get. ------------- http://correctcraftfan.com/diaries/details.asp?ID=4645&sort=&pagenum=1 - 69 Mustang HM |
Posted By: Gary S
Date Posted: March-19-2010 at 12:41am
Yea my block was changed out at sometime with a 302,don't tell Pete it's not original ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1711&sort=&pagenum=1&yrstart=1966&yrend=1970" rel="nofollow - 69 Mustang HM SS 95 Nautique Super Sport |
Posted By: Gary S
Date Posted: March-19-2010 at 1:20am
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Here's your choices http://www.summitracing.com/parts/HLY-0-80364/Application/?prefilter=1 - 4 bbl and http://www.summitracing.com/parts/EDL-2121/?rtype=10 - manifold or http://www.summitracing.com/parts/HLY-0-80320-1/ - 2 bbl 300 cfm , http://www.summitracing.com/parts/HLY-0-80402-1/ - 2 bbl 500cfm each has it's own merrits but one thing I noticed is the 2bbl 500 is a universal carb,the other 2 are for a Ford 302 ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1711&sort=&pagenum=1&yrstart=1966&yrend=1970" rel="nofollow - 69 Mustang HM SS 95 Nautique Super Sport |
Posted By: Gary S
Date Posted: March-19-2010 at 2:18am
I posted these pic's Dave of my installation of a 450 cfm 4 bbl to show you what was involved with the change.If you change to a 4 bbl,you'll need the manifold,gaskets and pipe plugs (those blue plugs in the pic's) to fill holes you don't use.I bought a 4bbl wedge spacer to match the one that Holman Moody used. Some here say you don't need one,but I put one on just for the pcv hose connection.I then fabricated a bracket for the throttle,which I'm changing over to a Pleasure Craft Marine (PCM) bracket since I like the adjustment better,and I think I needed a new cable because it needed to come under the motor from the back and up to the carb. I think the original 2bbl had the cable going over the front of the motor to the carb. Or you just pretty much bolt on the 2 bbl and maybe just change out the cable and the cable mount. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1711&sort=&pagenum=1&yrstart=1966&yrend=1970" rel="nofollow - 69 Mustang HM SS 95 Nautique Super Sport |
Posted By: vondy
Date Posted: March-19-2010 at 3:25am
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Thanks Gary. Pretty certain I decided on the 4bbl. I did notice on Holley's site the the 450 4bbl was calibrated for the 302.
Does the carb not have a pcv port? ------------- http://correctcraftfan.com/diaries/details.asp?ID=4645&sort=&pagenum=1 - 69 Mustang HM |
Posted By: Gary S
Date Posted: March-19-2010 at 10:41am
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In a word, no. But I think and others will conferm that you could take that pcv hose fom the valve cover and use a hose fitting instead of one of those blue plugs in the manifold. I think you'll be happy with your choice. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1711&sort=&pagenum=1&yrstart=1966&yrend=1970" rel="nofollow - 69 Mustang HM SS 95 Nautique Super Sport |
Posted By: vondy
Date Posted: March-19-2010 at 12:48pm
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One of these days Gary, my engine will look that good!
Is your flat cap a standard Mallory Marine? http://www.summitracing.com/parts/MAA-9-29416/ - Cap I'm looking to replace that as well. I also like the yellow wires on the Ford blue. ------------- http://correctcraftfan.com/diaries/details.asp?ID=4645&sort=&pagenum=1 - 69 Mustang HM |
Posted By: TRBenj
Date Posted: March-19-2010 at 2:42pm
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Gary's carb may not have a vacuum port for the PCV, but a new Holly will. ------------- |