Incredible Performance
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=1435
Printed Date: January-15-2025 at 4:50pm
Topic: Incredible Performance
Posted By: skyhawkflyer
Subject: Incredible Performance
Date Posted: April-11-2005 at 3:29pm
| I test drove my 87 Ski Nautique yesterday after installing a Holley Trick Kit, a new power valve, and a new Acme 540 prop. I cannot believe how much improved the performance is. After driving it for a bit and making idle adjustments I threw on a wet suit and wet skiing. This boat rocks. All it needs now is a coat of wax and some warmer weather here in Virginia!!! |
Replies:
Posted By: swamp demon
Date Posted: April-11-2005 at 3:46pm
| Tell us about the carb kit. |
Posted By: skyhawkflyer
Date Posted: April-11-2005 at 4:19pm
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It's a 4160 Holley Trick kit from Vince at Discount Inboard Marine. ------------- |
Posted By: 79nautique
Date Posted: April-11-2005 at 4:31pm
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The kit is just a standard overhaul kit, just Holley's marketing dept at work calling it trick. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique |
Posted By: skyhawkflyer
Date Posted: April-11-2005 at 6:01pm
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Well 79nautique, you're almost correct. You seem to know all the answers so whats different in the kit. You tell us! ------------- |
Posted By: 79nautique
Date Posted: April-11-2005 at 6:35pm
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What's different between what? a Holley trick kit and a regular carb kit? ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique |
Posted By: 79nautique
Date Posted: April-11-2005 at 8:24pm
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If your engine is stock then there really isn't a need to spend the extra money on a trick kit. Which is a universal carb kit to start with and not a kit for a specific model carb. If I was racing and had to change boosters, accell pump to meet changing weather condition then ya but I don't think you'll be doing that on the lake. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique |
Posted By: 64 Skier
Date Posted: April-12-2005 at 9:37am
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Skyhawkflyer:
How did the new prop affect your skiing RPM's versus your old prop. What was your old prop? Did you use a prop puller or a small gear puller. Thanks for any help at all! ------------- 64 Skier 66" HO VTX and 67" HO Triumph http://www.correctcraftfan.com/diaries/details.asp?ID=1071&sort=&pagenum=3&yrstart=1971&yrend=1975 - 71CC |
Posted By: skyhawkflyer
Date Posted: April-12-2005 at 10:51am
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64 Skier!
To be perfectly honest I really didn't notice any engine rpm change through out the skiing range, or at top end. However, for the same top end rpm (4400) I noticed an increase of 2 mph on the top end. Keep in mind that this is only indicated on the speedo's, and the speedo's are 17 years old, but this has got to be somewhat close. I calibrated my speedo's last year to 36 miles per hour (not top end) using a hand help (aviation) gps and there are certain speed errors above and below that speed. The 540 prop is probably the best single upgrade you could do for the 2001 hull. All hull vibration is virtually gone, and out of the hole performance is comparable to the 90's nautique line. I wanted to take a few stop watch accelerations readings from 0-36 mph for comparison but I forgot my stop watch. I can assure you accelerating through 36 mph seems less than 6 seconds, but I won't make that statement until I've actually performed the test. Prop removal is always a struggle no matter what puller you use. I used an old OJ c-type puller and it was difficult. When istalling a puller first of all make sure it's on straight, tighten, tap with a hammer, use heat on the prop, any other trick to help out. If it won't come off reposition the puller and try again (I've done this several times). My old prop was a federal 13x13. The 540 Acme is 12x13! ------------- |
Posted By: 64 Skier
Date Posted: April-13-2005 at 7:09am
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Thanks...that really helps me out with some of my decisions!
I'll grit my teeth while pulling the prop and try not to chip any. Good Luck ------------- 64 Skier 66" HO VTX and 67" HO Triumph http://www.correctcraftfan.com/diaries/details.asp?ID=1071&sort=&pagenum=3&yrstart=1971&yrend=1975 - 71CC |
Posted By: skyhawkflyer
Date Posted: April-13-2005 at 11:26am
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64 Skier!
Good luck with the prop removal. Don't chip any teeth  Leave a little bit of the prop nut threaded on to so that when it breaks loose it stays on the shaft with the puller somewhat intact.
The Marine Holley Trick kit and a standard Marine Holley overhaul kit are not the same. The old overhaul kits gave you all new gaskets and a #25 power valve. Conservative and workable. The Holley Trick kit gives the same Marine gaskets, but you get a #65 power valve instead. Much more aggressive results from a dead start on acceleration. Much better for slalom starts. So the kits are not the same, as the power valve can make or break carburator performance. Correctcraft also recommended throwing out the standard #25 that comes in most kits and replacing with #65. Thats for a 4160/351 installed on a 2001 hull with all else being stock. I haven't heard what power valve comes in the Holley RENEW kits, I suspect it's a #25, maybe someone out there has a kit on hand and can shed some light on these kits. ------------- |
Posted By: 882001
Date Posted: April-14-2005 at 12:49am
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i got the acme 542 and the performance your seeing is mostly prop. ------------- kemah texas http://www.correctcraftfan.com/diaries/details.asp?ID=163&yrstart=1986&yrend=1990 - 1988 skinautique "2001" |
Posted By: skyhawkflyer
Date Posted: April-14-2005 at 10:42am
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882001,
The prop helped out a bunch (I also put in a new shaft, coupler, and strut bearing) from nicking a rock while idling in a channel- it bent the tip of the tapered shaft ever so slightly. This boat has had some serious carburator problems for the past 2 years that I have been putting off. Starting out for a slalom run last fall the boat would hesitate, cough, and slowly accelerate with what seemed little help from the secondaries. The carb was dirty with belt dust, had some badly worn parts inside. It really has the punch out of the hole now, but at least part of that has to be the carburator working for a change. If the weather holds out I'm going to make some 0-36mph acceleration tests and time them with a stop watch, how fast are your boats accelerating to 36mph? ------------- |
Posted By: jameski
Date Posted: April-14-2005 at 11:29am
My boat accelerates faster than my speedometer . It takes a few seconds for the stabilizer tube to pressurize, so I don't know how I would get a good 0-36mph time... maybe I could bypass the stabilizer tube for the test? Am I the only one with this problem? Maybe I need to replace my pitot hose, I've cleaned it out the best I can with water and compressed air. It's not REAL slow, just 2 or 3 seconds behind.------------- current boat http://www.correctcraftfan.com/diaries/details.asp?ID=1977 - 94 Sport Nautique previous boat http://www.correctcraftfan.com/diaries/details.asp?ID=601 - 78 Martinique |
Posted By: 79nautique
Date Posted: April-14-2005 at 1:47pm
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The holley renew kit I bought 2 years ago had the #65 power valve in the kit already. The only thing I had to buy was the choke stat which isn't encluded in brand of kit. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique |
Posted By: skyhawkflyer
Date Posted: April-14-2005 at 1:53pm
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I know they have been playing around with their kits and the names changed. the old kits had a #25 which wasn't the best. I bought my trick kit in 98, so it's been sitting for a few years. I don't think you can get a trick kit anymore, but it sounds like the renew kit is the same. Did you get a new secondary diaphram with the kit. I didn't. ------------- |
Posted By: 79nautique
Date Posted: April-14-2005 at 4:25pm
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Jegs lists the trick kit on their website still. I got my kit from rex marine. I used holley's website to get the correct kit number first. I don't remember if the kit had the diaphram for the secondaries or not, my dad did the overhaul at his shop, he did have to get something that wasn't in the kit and maybe it was the diaphram. On me carb it doesn't have all of the interchangable cams for the accel pump and all of the other goodies that the double pumper models have. I have thought about getting one but what I have has worked well. I had to re-jet it after all of the engine mods I did so it wouldn't run lean. I just put on my new ACME prop and a shaft seal yesterday and should be able to take it for a spin this week-end to see if I got the right pitch and dia to bring back the RPM's to 5k-5.5k and I'm looking to top out around 65mph on smooth water. My buddy is bring up his bass boat this week-end so I can find out what the top end is. I killed him out of the hole last year and hope to still be able to with the new prop. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique |
Posted By: skyhawkflyer
Date Posted: April-14-2005 at 4:43pm
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I only saw the automotive trick kit for 79.99. I see they have a marine repair kit or a marine renew kit. What I installed was a Marine Trick Kit. ------------- |
Posted By: 1time17
Date Posted: April-15-2005 at 2:07am
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for those that want to replace your prop overtons has a prop puller 99.99 its well worth it to have if you ever ding your prop or need to change a friends. ------------- gotta love those old school nautiques http://www.correctcraftfan.com/diaries/details.asp?ID=1138&sort=&pagenum=1&yrstart=1981&yrend=1985 - custom2001 |
Posted By: Guests
Date Posted: April-15-2005 at 9:13am
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In my experience, a power valve 5.5" or higher causes a lean dull spot when you launch hard, forcing some to over-accel pump to compensate, or just live with it. Then too much accel pump can then cause a rich stumble when just accelerating easy..
I have gotten the best results with a 4-4.5" power valve and quite certain I would not be satisfied with a 6.5 . (The number equates the vacuum required to actuate the valve and permit gas to the main jets.) |
Posted By: jameski
Date Posted: April-15-2005 at 10:38am
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Gotta Ski, that sounds backwards, the higher your power valve number, the earlier (and more often) it opens and enriches your mixture. You have high vacuum when you are idleing or holding steady RPM, but when you open your throttle plates and put your engine under load, your vacuum drops and your power valve opens. If you have a low number power valve, it will not open unless you put a HUGE load on your engine (like wide-open-throttle from stop) and your vacuum drops WAY down. If your have a high number power valve, it will open more often and under less load. ------------- current boat http://www.correctcraftfan.com/diaries/details.asp?ID=1977 - 94 Sport Nautique previous boat http://www.correctcraftfan.com/diaries/details.asp?ID=601 - 78 Martinique |
Posted By: skyhawkflyer
Date Posted: April-15-2005 at 10:48am
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Jameski's got it down pat. That's why you want to keep your eye open for the #25 power valve that might be floating around in some of the older kits sitting on the shelf, throw it out, it's terrible. (I actually had it installed on my carb)
I think the "renew" kits replaced the old trick kits. If you spray your gaskets with silicone they won't stick like the originals. ------------- |
Posted By: Guests
Date Posted: April-15-2005 at 12:39pm
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Yah, I think you're right I described it backwards, and probably experienced the same symtoms as you guys before I sorted it out..
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Posted By: Jim_In_Houston
Date Posted: April-15-2005 at 1:00pm
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How do you get to the power valve? Is looking to see what power valve you have a 3 minute project? Are new gaskets required when checking? ------------- Happy owner of a '66 and a '68 Mustang |
Posted By: Guests
Date Posted: April-15-2005 at 1:14pm
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Yes, the bowl and primary metering block has to come off, for a 4160 model. New gaskets are required.
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Posted By: skyhawkflyer
Date Posted: April-15-2005 at 1:16pm
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Go Here: click to enlarge:
http://holley.com/HiOctn/TechServ/TechInfo/4150-60.html It's threaded into the primary metering plate behind the fwd fuel bowl. You will have to disassemble, and may take some time for gasket clean up. New gaskets required unless fairly new ------------- |
Posted By: 79nautique
Date Posted: April-15-2005 at 2:31pm
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If they are the blue holley gaskets you should be able to remove them without damage just be carefull. I pulled mine off about four or five times with no problem when I was change the jets last year. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique |
Posted By: Jim_In_Houston
Date Posted: April-15-2005 at 4:09pm
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Thanks all. Good info. ------------- Happy owner of a '66 and a '68 Mustang |
Posted By: 64 Skier
Date Posted: April-17-2005 at 5:16am
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Jim,
I recall you putting a HP cam in that rebuild...you may want to get a vacuum gauge and measure your engine vacuum from idle to Max RPM...dead starts with a skier etc and then talk to Holley before you buy. I can't remember and maybe one of you guy's know, but under a hard start you may not want the secondaries flooding in more fuel to quickly so a lower # power valve may be better??? Isn't there some type of rule of thumb for the vacuum and RPM you want the power valve to unload more fuel??? ------------- 64 Skier 66" HO VTX and 67" HO Triumph http://www.correctcraftfan.com/diaries/details.asp?ID=1071&sort=&pagenum=3&yrstart=1971&yrend=1975 - 71CC |
Posted By: SS 201
Date Posted: April-17-2005 at 8:12pm
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Put a vacum guage on and get the vacumn reading at different RPM with and without a load. The guage will give you the reading. The more load less vacumm, most marine carbs are inistalled 6.5, however depending each situations,conditions and engine performance it can vary.
|
Posted By: 64 Skier
Date Posted: April-18-2005 at 6:20am
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SS201....about 6 months ago you helped me fix my carb problems...she's still running great.
------------- 64 Skier 66" HO VTX and 67" HO Triumph http://www.correctcraftfan.com/diaries/details.asp?ID=1071&sort=&pagenum=3&yrstart=1971&yrend=1975 - 71CC |
Posted By: skyhawkflyer
Date Posted: April-18-2005 at 1:45pm
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Ok, Here's what it did...
I took 2 acceleration times (from 0 to 36mph) with a stop watch after warming the engine up a bit. This is still burning last years fuel in the tank, and there is speedometer lag. The first acceleration test to 36 mph from a dead stop was 8.02 seconds. The second time was 7.97 seconds. I think it's pretty good for 18 year old boat (1987 2001) with 700+ hours on it!!!! We skied afterward too, the water temp is 60 degree at Lake Anna, Virginia! ------------- |
Posted By: 79nautique
Date Posted: April-18-2005 at 8:30pm
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I got mine in the water this week-end and tried out the new prop and did a little stopwatch test as well. It was a little tricky doing it myself with the cell phone, not enought hands to hold the trottle, phone and wheel all at once. But I timed mine a little differently as well, I went from a dead stop to top RPM (5K) or WOT or top speed what ever you want to call it and it took just under 8 seconds on last years gas as well. My speedo's never read over 40-45 mph and need adjusted. But I figure the first time I peg the speedo they'll have to be re-adjusted again anyway so I haven't done it. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique |
Posted By: Guests
Date Posted: April-18-2005 at 10:35pm
| Don't confuse the secondary diaphram spring with the power valve, different annimal |
Posted By: SS 201
Date Posted: April-19-2005 at 8:02am
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to figure speed.
RPM X prop pitch X .00946 then divide that by the prop diameter that gives you the speed at 100% then subtract at least 10 - 20 % it gives the speed. However most CC subtract 15 - 18%. ex. 4800 rpm X 14 = 67200 X .00946 = 6357 minus 18% 521.26834 or 52 MPH. |
Posted By: skyhawkflyer
Date Posted: April-19-2005 at 10:22am
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Gotta ski
As I understand it, the power valve only provides supplimental fuel to the primaries, where as the the colored spring used on the secondary diaphram determines opening rate for the secondaries. I'm my case I had a purple spring which I believe is medium. Correct? ------------- |
Posted By: skyhawkflyer
Date Posted: April-19-2005 at 10:27am
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The power valve is a key component of the power enrichment system of Holley
performance carburetors. The power enrichment system supplies additional fuel to the main system during heavy load or full power situations. Holley utilizes a vacuum operated power enrichment system and a selection of power valves is available to "time" this system's operation to your specific requirements. Each Holley power valve is stamped with a number to indicate its vacuum opening point. For example, the number "65" indicates that the power valve will open when the engine vacuum drops to 6.5" Hg, or below. An accurate vacuum gauge, such as Holley P/N 26-501, should be used when determining the correct power valve to use. A competition or race engine which has installed a long duration, high overlap cam will have low manifold vacuum at idle speeds. If the vehicle has a manual transmission, take the vacuum reading with the engine thoroughly warmed up and at idle. If the vehicle is equipped with an automatic transmission, take the vacuum reading with the engine thoroughly warmed up and idling in gear. In either case, the power valve selected should have a vacuum opening point about 2" Hg below the intake manifold vacuum reading taken. ------------- |
Posted By: skyhawkflyer
Date Posted: April-19-2005 at 10:29am
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The opening rate of a vacuum secondary system is controlled by the diaphragm
spring located in the vacuum secondary diaphragm housing. A "lighter" spring will allow the the secondary throttle plates to open more quickly. A spring assortment kit, Holley P/N 20-13, is available to help you "tailor" the secondary opening rate to your application. A "quick change" kit, Holley P/N 20-59, is also available for fast and easy access to the spring. It consists of a two-piece secondary diaphragm housing cover which, after it's installed, can easily cut in half the time required to change the secondary spring. ------------- |
Posted By: 79nautique
Date Posted: April-19-2005 at 4:01pm
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bill is the formula correct? it seems to be off when I plug in the numbers it comes up 5 mph lower than what I would expect. What effect would cup have on the calculation? ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique |
Posted By: skyhawkflyer
Date Posted: April-19-2005 at 4:32pm
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same here, 5 mph off. ------------- |
Posted By: SS 201
Date Posted: April-20-2005 at 7:49am
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The formula is correct, depending on how severs the cup.In some cases it can add to the pitch a extra pich. Ex a prop with a 15 cup pitch could be in theory a 16.
Stock 81 CC 13 X 13 X .009469 = 59.0340 -20% = 47 MPH as I said you have to rate your hull, Bass boats or flatbottom are 10%. Rermember if you havea 123 tranny you subtract 23 % from the engine RPM. |
Posted By: 79nautique
Date Posted: April-20-2005 at 12:28pm
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what would .105 cup have on a 12.5x15 at 5k ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique |
Posted By: SS 201
Date Posted: April-20-2005 at 8:46pm
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BC,
I am not familar with Acme props, sorry. |
Posted By: Guests
Date Posted: April-20-2005 at 10:23pm
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79 Nautique,
Zero slip would equate to 74.5 MPH. After 20% slip you would be looking at 59.5 MPH. You 1.05 cup makes the prop cut at a pitch of 15.75" per rev |
Posted By: 79nautique
Date Posted: April-21-2005 at 1:23pm
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thanks
I'll have to compare with my buddies boat and see how close it is. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique |