Carb Wedge Plate |
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Riley
Grand Poobah Joined: January-19-2004 Location: Portland, ME Status: Offline Points: 7946 |
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Posted: November-12-2013 at 6:02pm |
We have what I guess is called a dual plane intake? It has one divider going front to back down the middle. We need a wedge plate and I am wondering if I need a specific type to match the intake?
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Gary S
Grand Poobah Joined: November-30-2006 Location: Illinois Status: Offline Points: 14096 |
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I think you need a plate to match the carb Bruce. Holley's need a plate that has equal size holes,Quadrajet's have different primaries and secondaries
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lewy2001
Grand Poobah Joined: March-19-2008 Location: NSW Australia Status: Offline Points: 2234 |
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Gary, normally referred to as "Spreadbore" where the primaries are smaller than the secondaries.
"Square bore" primaries and secondaries are the same size |
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If you're going through hell, keep going
89 Ski <a href="http://www.correctcraftfan.com/diaries/details.asp?ID=5685" ta |
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TRBenj
Grand Poobah Joined: June-29-2005 Location: NWCT Status: Offline Points: 21109 |
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Yep, like they said- the type of intake (dual vs. single plane) is independent of the carb mounting style.
You need a square bore spacer for that AFB. Something like this will work, if 5 degrees is in the ballpark: Moroso 5 degree wedge |
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Riley
Grand Poobah Joined: January-19-2004 Location: Portland, ME Status: Offline Points: 7946 |
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Matching to the carb make sense. Summit has this one which looks good as if this AFB doesn't work out, we'll probably go with a Holley. Lack of a wedge may be part of our problem.
http://www.summitracing.com/parts/trd-2028/overview/ Edit, Tim I saw your post after I posted this. Is the Moroso better than the one above? |
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baitkiller
Platinum Member Joined: October-11-2011 Location: SW Florida Status: Offline Points: 1693 |
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All I know is that an AFB type, no matter whose name is on it will flood without a wedge when used on these straight inboards. With the wedge it works very well.
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Jesus was a bare-footer.............
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JDD33
Senior Member Joined: October-20-2012 Location: Natick, MA Status: Offline Points: 499 |
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Would a PCM 351 with a Holley 4160 benefit from a wedge plate? Help keep things level and improve performance?
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Old school goin back to school!
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Gary S
Grand Poobah Joined: November-30-2006 Location: Illinois Status: Offline Points: 14096 |
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What year boat and what trans,Borg Warner or PCM?
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JDD33
Senior Member Joined: October-20-2012 Location: Natick, MA Status: Offline Points: 499 |
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It's in a 1987, with the Borg Warner trans. Thanks!
Sorry Bruce, not trying to thread jack! The topic came up at the right time! |
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Old school goin back to school!
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TRBenj
Grand Poobah Joined: June-29-2005 Location: NWCT Status: Offline Points: 21109 |
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If your floats are set properly you don't need a wedge on a Holley. PCM never put them on the fords.
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JDD33
Senior Member Joined: October-20-2012 Location: Natick, MA Status: Offline Points: 499 |
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Great! Thanks for the information Tim!
Get all the boats winterized? John. |
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Old school goin back to school!
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backfoot100
Platinum Member Joined: January-03-2007 Location: United States Status: Offline Points: 1897 |
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Bruce, I have this exact wedge on my stroker. Only difference beteen this one and the one Tim posted is this one is 8 degrees, Tim's is 5. I must say that the carb does sit real nice and level with this one on my motor. Tim is correct that one should not be needed and just adjusting the floats should fix any angle problems. The only reason I put one on my motor is that it had one from the factory so I replaced it (my motor was an Indmar). As for performance pro's and con's....that's debatable. Theory indicates that a spacer of 1-2" can provide some performance advantages. I have seen dyno numbers supporting this (in books, not real life so take it for what it's worth). I seem to remember something like 5HP can be gained. Not a lot but enough to add to the overall scheme of things when you start modding an engine. If you think about it, this theory must make some sense as most all aftermarket intake manifolds are higher than stock and the plenum right below the carb base is where the extra height (usually) is. They aren't made like that for show. It's similar to adding a built in spacer, albeit a small one. Then there's the debate of a 4 hole spacer or a single hole spacer. Supposedly, the 4 hole spacer will help the bottom end and the single hole spacer is more advantageous on the top end. Theory is that the 4 hole spacer will increase the flow velocity and the single hole spacer will provide a larger plenum which helps at the upper RPM ranges. Kinda like the difference between a single plane and dual plane manifold. Look at the plenum area of each one side by side and you'll see it immediately. Hope this helps. |
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When people run down to the lake to see what's making that noise, you've succeeded.
Eddie |
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TRBenj
Grand Poobah Joined: June-29-2005 Location: NWCT Status: Offline Points: 21109 |
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Yep, what Eddie said! Except for the part of the spacer being required- which should be caveated as being specific to Holleys. All of the AFB style carbs Ive seen have been mounted pretty darn level. Chrysler built the angle into the marine intake manifold, so it didnt require an extra wedge.
John, all the boats are getting there- not fully winterized, but at least drained, so freeze protected anyways. I keep checking the forums waiting for the big announcement, as I see a green Mustang for sale on CL in MA and have heard rumors of a '87 disappearing from N3's stock, but have yet to officially hear the big news. |
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Riley
Grand Poobah Joined: January-19-2004 Location: Portland, ME Status: Offline Points: 7946 |
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That's great info. I think we have the 4 holed one on our 312 and it sits very level, and that engine runs great.
The intake doesn't have much, if any of an angle to it and there is currently only a 1/4" level spacer on there now. I figured while we had the carb off we might want to add a wedge, but now that I hear these comments about AFBs needing them, we'll definitely add one. We're going to compare our carb to another AFB that came off a 427 and compare the jets and accelerator pump linkage set up. The engine seems to be starving for gas on hard acceleration. |
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lewy2001
Grand Poobah Joined: March-19-2008 Location: NSW Australia Status: Offline Points: 2234 |
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Carb Spacer Performance Eddie, I too have seen the same information about these spacers. I think the type of manifold they are bolted to would also determine how effective they are. |
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If you're going through hell, keep going
89 Ski <a href="http://www.correctcraftfan.com/diaries/details.asp?ID=5685" ta |
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Nautiquehunter
Platinum Member Joined: December-31-2008 Location: Lake Lanier GA Status: Offline Points: 1010 |
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I just installed one on my 84 Supra Comp 351 Holley 1to1 trans.
After rebuilding the carb I couldn't get the floats quite right since there are no specs for a tilted carb. After 4 times I decided to just level the carb and set the floats to spec. This one is a full 12 degrees. It runs better now than ever I'm glad I made the change . Only problem was the engine cover hit the flame arrestor so I had to build a new lower engine cover 1 1/4'' taller. |
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Gary S
Grand Poobah Joined: November-30-2006 Location: Illinois Status: Offline Points: 14096 |
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When mine had a 2bbl on it,it was a cast plate with a HM logo on it. It also
was the vacuum port for the pcv. When I put the 4bbl on I was able to find one that is some form of plastic,supposedly keeps the carb cooler since it does not transfer heat as well. I needed it because I carved the vacuum port with a dremel to match the HM one. Here you can see the angle of my engine and how close to level the carb is |
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backfoot100
Platinum Member Joined: January-03-2007 Location: United States Status: Offline Points: 1897 |
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Very true Mark, as well as how the engine is built. An Edlebrock Performer intake (for SBC anyway) is built with a spreadbore carb base so you have to make sure that you have the appropriate spacer to fit that. The RPM intake is a squarebore. Again, you need to make sure that the right spacer is used. Where the engine is built to make power is also a factor. Joe's rocketship has a single plane manifold which traditionally can be tough to make idle and looses something in the bottom end as compared to a dual plane manifold which is great on the bottom end and looses something at the upper RPM ranges. The theory of the spacers could help compensate for each applications shortcomings. A four hole spacer on a single plane manifold might help that engine on the bottom end and a single hole spacer on a dual plane might help the top end. Then again, the spacers might do the opposite thing for that particular engine. It's purely trial and error to see what works and what doesn't. Then you also have to worry about clearance when you start adding spacers like Mike stated. An RPM Air Gap manifold w/spacer on my engine is about an inch too tall for my engine cover. Something that you need to keep in mind when adding spacers. |
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When people run down to the lake to see what's making that noise, you've succeeded.
Eddie |
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Xer86
Newbie Joined: May-29-2015 Location: Texas Status: Offline Points: 6 |
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Hello,
I was reading through the forum and came across your post about the 12 degree carb wedge spacer that you installed. I am having an issue with my '88 PCM 351W and Holley 4160. The carb is dripping fuel after shutdown and thought that this spacer may help the issue since the floats on these are difficult to set properly. I have been looking with little success to find the 12 degree spacer. Do you recall where you were able to locate one? Thanks in advance! Matt |
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KENO
Grand Poobah Joined: June-06-2004 Location: United States Status: Offline Points: 10650 |
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This was said earlier in this same thread.and it's quite true What makes you think the floats are hard to adjust? Have you changed the inlet needle and seat assembly? They wear over the years and tend to leak by. You don't notice it till you develop a case of the drips after shutdown If the inlet is leaking you can adjust the floats till cows fly and it won't do you any good You're just trying to put a band aid on your problem without fixing the real problem. Like TRBenj said above, PCM never used one on your engine and there are plenty of them out there running just fine with no wedge. |
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8122pbrainard
Grand Poobah Joined: September-14-2006 Location: Three Lakes Wi. Status: Offline Points: 41040 |
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Xer86
Newbie Joined: May-29-2015 Location: Texas Status: Offline Points: 6 |
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This is going to be a bit of a novel but maybe if I provide a little background on the issues I am experiencing you may have a better idea of what might help me get this thing running again. The boat sat in a garage for 13years with 199 original hrs before I bought it. Because it sat so long I immediately replaced the mechanical fuel pump, all fuel lines, fuel filter, cooling hoses, thermostat, RWP, impeller, spark plug wires, rebuilt the 4160 (needle/seat assembly included) and put in a new battery. This was about a year ago and since then I have only added 40hrs.
The previous owner had replaced the points system with an old E.I. conversion module. I got the boat running but it was not consistent at all. Some times it ran well other times it would sputter, lose power under load etc. Carb was not dripping at that time so I looked into the E.I. setup. Replaced it with a newer Pertronix Ignitor I system and a Flame Thrower (40kV) coil. The boat ran well for a few weeks, then I had a backfire while driving. The next day the boat started and ran fine cruising down the lake at ~3000RPM then all of the sudden it started stuttering and almost died completely. I backed off the throttle and limped it home at 1200 RPM. Any attempt to increase speed and it started sputtering. I got home and checked the fuel filter and cleaned it. Tried it again and now it would idle fine and rev in the dock but lost all power when attempting to throttle up beyond 1400RPM under real load. I called pertronix and they said to try some troubleshooting techniques which didn't make any difference. They then informed me that I should also remove the ballast resistor since I had matched their E.I. module with the flamethrower coil. I did so and tried it again. No change. I got it back to the dock and shut it down. I took the flame arrestor off to check things out and noticed the starboard primary on the carb dripping continuously. I pulled the plugs to check them out and all 4 on the starboard looked fouled and smelled of unburnt fuel. The port side plugs looked a little better and did not have the same strong smell of unburnt fuel. I subsequently changed all of the plugs and now am looking at a new E.I. pertronix ignitor II module with the matched 45kV coil. I feel like I am chasing my tail on this one and would like to establish a methodical plan of attack to get this thing running again. Any additional advice? |
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TRBenj
Grand Poobah Joined: June-29-2005 Location: NWCT Status: Offline Points: 21109 |
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Did you drain and clean the fuel tank after it sat? Or did you run the old cruddy gas through your new fuel system? I would take a good look at the tank end (including anti siphon valve) and rebuild the carb since it's drippy. Look for signs of sediment to confirm the bad fuel theory.
Cap/rotor and plugs new? What spark plugs and what gap? Wires all good? Timing set properly and advancing as it should? I don't like pertronix but that's just me. |
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KENO
Grand Poobah Joined: June-06-2004 Location: United States Status: Offline Points: 10650 |
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Like Tim said, you got the drips, you need to clean/rebuild the carburetor.
The fuel leaking down the starboard carburetor throat doesn't go only to the starboard side cylinders either. It'll go to both. You could also run it on a temporary tank plumbed right to the fuel pump after the clean/rebuild to see if it runs good. Like Tim said you have the anti siphon valve and suction line in the tank to check along with fuel tank cleanliness. And like he said cap and rotor need to be good. You could have had your backfire due to a bad cap causing misfiring/cross firing of cylinders But any way you look at it, the carburetor needs work and then clean fuel going to it |
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KENO
Grand Poobah Joined: June-06-2004 Location: United States Status: Offline Points: 10650 |
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By the way, that was only a short story you wrote
Better doing that than giving little or no info |
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gt40KS
Gold Member Joined: August-05-2017 Location: Wichita Kansas Status: Offline Points: 943 |
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Just what I was thinking. If it sat for 13 years gasoline will not only break down - which can happen in just one year - it can leave a residue inside the tank, worst case even get sort of crusty. Over a long period of time I've seen these deposits become fairly hard, almost like a lime deposit on the walls which can dislodge later and start contaminating the new fuel. Just a side note - your posts might get a bit more attention if you start your own new thread.... this one lost traction years ago and doesn't really define your problem in the thread title |
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JCCI
1995 Ski Nautique GT40 |
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GottaSki
Grand Poobah Joined: April-21-2005 Location: NE CT Status: Offline Points: 3327 |
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Additionally to the solid advise above, the PV is also now suspect since the backfire, which i presume was carb side, not exhaust side.
If PV is blown it will dump fuel just when the boosters come on, around the rpm you indicated. IT will often pop out the carb when a lean condition occurs due to fuel restriction, even when everything else is on spec.. |
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