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By Jack Groat - 5 Months Ago
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I have a 292 with Edelbrock 357 tri-power manifold. I have 3 Holley 94s that were rebuilt by Vintage Speed (Charlie Price). He removed the idle circuits and the choke from the end carbs. It runs fine on the center carb with the end carbs blocked. I turned it over to a restoration shop who I asked to install the progressive linkage and get the end carbs functional. Well, after 2 months and a $5000 bill they returned the car in the condition I gave it to them and they said it is impossible to get it to run right. By the way, I don't know what they mean by "running right".
FYI I am handicapped and can do none of the work myself, but my son can change parts. He is no carb expert.
Two questions:
1) Anyone and expert on Holley/Stromburg carbs with some suggestions.
2) Speedway Motors sell a replica set for $800. Any opinions on how well these work.
P.S. Don't tell me to just convert it to a modern 4bbl. I had a Mummert manifold and Edelbrock 650 cfm 4bbl and it ran great. I am old old old school and I insist on a tri-power set-up. I sold the 4bbl and manifold.
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By miker - 5 Months Ago
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When you say the carbs were blocked, I assume there was a plate under them and the linkage was not hooked up. ? Was the fuel connected?
Charlie’s got a pretty good reputation, I had one of his units 30 years ago.
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By Ted - 5 Months Ago
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I understand the ‘WOW’ factor of the 3X2 set ups so no argument there.
I wouldn’t consider myself an expert on those 3X2 setups but I have tinkered with quite a few of them over the years. Recently had to set one up to dyno test the new prototype Offenhauser three deuce intake and for that test, I used three Holley 94 carbs (model 2100’s). For those carbs, I simply left the center carb pretty much stock with #51 jets and the power valve intact. For the end carbs, I removed the power valves and upped the jetting to 55’s but left the idle circuits intact. The idea behind leaving the idle circuits intact is so that the fuel does not stagnate in the bowls from disuse. The engine idle speed is still controlled by the center carb with the throttle blades on the end carbs being completely closed in the idle position. The idle mixture screws are about ½ turn out on each carb. That 3X2 setup idles good and with the progressive linkage adjusted so that the end carburetors come in at approximately half throttle, accelerates under a load just fine without any issue.
Here are pictures of that setup as it ran about six weeks ago.
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By Jack Groat - 5 Months Ago
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To answer the question about being blocked, yes, we fabricated plates to fir at the carb mounting surface.
The car was driven for hundreds of miles on the center carb only with my only complaint was very black tail pipe. No black smoke but 14 mpg, so it was a little rich.
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By pintoplumber - 5 Months Ago
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Do you know what size jets you have in now? I bought an old offenhauser tri power at Carlisle years ago. It had .57 jets in all 3 carbs. My eyes would burn standing behind the truck. I now have .51 jets in all 3 carbs in an Edelbrock 354. I have a 283” 239. Works pretty good.
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By Jack Groat - 5 Months Ago
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Don't know the jet size but they are the size recommended by Charlie Price. I will see if I can find a jet kit with multiple jet sizes some where on the internet.
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By 1946international - 5 Months Ago
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Don't worry, it can be done, just takes a little tinkering. I run 3 94's on my 292 and it runs fine. I have 59 jets in the two end carbs and 57 in the center. All three still have the power valves and the the idle circuits but the two end carbs have the idle screws all the way in. Also running a progressive linkage.
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By Ted - Last Week
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Jack.
Had another thought on your 3X2 setup. I am in the process of testing the new Offenhauser 3X2 intake manifold and that particular manifold was not sitting flat on the intake gasket as it should. This came to the forefront when the engine was not idling correctly and had a couple of cylinders running cold at the headers.
The engine this was being tested on had an aftermarket aluminum valley cover but what I am going to bring up could likely occur with any valley cover, aluminum or otherwise. The intake manifold was bottoming out on the valley cover bolts and but there was still some clearance between the thermostat housing and the valley cover at this point. I machined the valley cover bolt heads so that they were thinner and then removed a small amount of material on the bottom of the intake to achieve the necessary clearance without an intake gasket between the parts. With the intake manifold back on the engine without any gaskets, the thermostat housing was now keeping the intake from sitting square on the heads as it was hitting the front flange on the valley cover. The thermostat housing was then ground at its bottom to provide some clearance between it and the valley cover. Now with the gaskets in place, there is some daylight between all the previously interfering parts.
With all this done and the manifold bolted back in place, the engine cranked up and now runs as it should. The idle on this setup is all controlled by the center carb with the end carbs having the throttle blades closed at both idle and normal driving. The end carbs (Holley 94’s) have the power valves removed and the jetting increased to 0.055”. The center carb still retains the stock 0.051” jetting and the power valve is retained on that one. Idles good and with the progressive linkage set so that the end carburetors start coming in after the center carb is at half throttle, the setup performs as it should. On the dyno, the wide band oxygen sensor is still showing slightly lean and that’s likely a result of using gasoline with some added ethanol. Before this setup gets released, I will try jetting the center carb to 0.053” and the end carbs to 0.057”.
With all this being said, an improper manifold fit may be happening on your end.
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By Hoosier Hurricane - Last Week
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Ted:
Thanks for posting this. I have found interference with the front valley cover bolt and my '56 factory EDB-C dual four manifold. This resulted in a broken ear on the manifold. I re-used an old grommet on the bolt, which is thinner than the present grommets in the gasket kits. That allowed the bolt to be seated deeper and clear the manifold. I also have an ECZ-B manifold with a repaired (by a previous owner) ear. I assume it happened by interference with the bolt head. I wonder if the valley bolt and the water pump bolts were originally slightly different lengths and the water pump bolts were longer and bottomed out when installed in the valley cover by accident. I have never thought to compare the lengths, but I always check for clearance when I install an intake manifold.
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By KULTULZ - Last Week
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By KULTULZ - 8 days ago
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This info from previous thread -
"A pass on note, posted here some time back by John, the Hoozier Hurricane. He noted that in some gasket sets, the rubber bolt rocker cover gaskets are apparently thicker than the original valley cover ones. He says that can result in some intake manfolds bottoming out on installation.. I trimmed the front one on my ECZ--B install, because it looked to be to close on clearance..."
THREAD - http://forums.y-blocksforever.com/Topic147904.aspx
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By 1946international - Last Week
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Hey guys, be carful sinking those valley cover bolts in lower by using thinner grommets, I understand if those bolts are run in too far they may hit the cam below. I don't know how much you can go without hitting just be careful.
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