Offy 4BBL intake

According to my information the primary metering block is not interchangable with others. Hope that's wrong. I will park it on top of the engine and see what the AF says. I know it came off a 87 Mustang 302. I also have a smal 4bl with a single float, any ideas??
 
Yes Ron, I looked into it and you are right, the blocks will not interchange. On the other hand there are idle mixture screws, but Holley moved them into the throttle plate. They have them hidden behind plugs to make them "tamper proof". Apparently you can take a hack saw to the aluminum casting and remove enough material to get the plugs out and then the a/f mixture screws can be adjuusted with an Allen wrench.
Like you mentioned, put it on and try it, it just might be OK.
 
Walt I have 390 cfm Holley carb on a 51 flathead with a 3/4 cam,aluminum heads,bored .040 over and a offy 4 barrel intake.It works very well right of the box.
 
29AV8 said:
Walt I have 390 cfm Holley carb on a 51 flathead with a 3/4 cam,aluminum heads,bored .040 over and a offy 4 barrel intake.It works very well right of the box.
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29AV8, yea I know they work good but i'm not going to spend the money on a new carb. I find something that work and rebuild it myself. Walt
 
Walt, are you going to race this engine or street drive it? If your going to race it I'd use the 600 and try running it eith only the primarys, then both to see how well it preforms.
 
Walt>>>My son inlaw has a 600 Holley I can have. Do you guys think that is to big for my engine. >>>

Yes, unless you can somehow experimentally re-work or manually control the linkages to delay the secondaries to suit your engine in whatever you're trying to do with it. That would be an interesting project, Walt. I really think you should do it. Then report back to us on your results. 8^)

Jack E/NJ
 
Jack E/NJ said:
Walt>>>My son inlaw has a 600 Holley I can have. Do you guys think that is to big for my engine. >>>

Yes, unless you can somehow experimentally re-work or manually control the linkages to delay the secondaries to suit your engine in whatever you're trying to do with it. That would be an interesting project, Walt. I really think you should do it. Then report back to us on your results. 8^)

Jack E/NJ
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It's easy to ajust the secondaries, just take a small bolt and nut and put it through the slot that link goes in that pull the back barrels, you can ajust the bolt so the barrells open as far as you want them. Walt
 
Walt Dupont--Me. said:
29AV8, yea I know they work good but i'm not going to spend the money on a new carb. I find something that work and rebuild it myself. Walt
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Walt, go on ebay and search wcfb. Look for one that has the fuel inlet on the very back of the top cover. It will be a mid 50's Buick. You can pick up the un identified ones very cheep. I have used several by just cleaning and reusing the gaskets. They can't leak!
 
Jack E/NJ said:
Walt>>>My son inlaw has a 600 Holley I can have. Do you guys think that is to big for my engine. >>>

Yes, unless you can somehow experimentally re-work or manually control the linkages to delay the secondaries to suit your engine in whatever you're trying to do with it. That would be an interesting project, Walt. I really think you should do it. Then report back to us on your results. 8^)

Jack E/NJ
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If it's a vacuum secondary carb, and an 1850 should be, you can install a heavier spring in the secondary diaphragm housing to slow the secondary butterfly opening. Holley sells an assortment of those springs. I had 2 390s on a tunnel ram on a mild hydraulic cam 289 and it ran fast with 2 springs in each diaphragm, 1 real heavy black spring and one medium. The secondaries never opened all the way, stopped at about 2/3s at 4500 RPM, when I had it performing well. Less spring pressure and it bogged as soon as the secondaries opened. I could see the carbs through the windshield, that's how I know what they were doing. (Later built a hot 289 and it needed 2 600 double pumpers to make proper HP)
 
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I have a Carter WCFB Model 2361 from a 56 Merc Y-block on my 8ba. Also have a Mitchell manual with tech sheets for Carters. Its indexed by auto manufacturer.
 
Yoyodyne said:
If it's a vacuum secondary carb, and an 1850 should be, you can install a heavier spring in the secondary diaphragm housing to slow the secondary butterfly opening. Holley sells an assortment of those springs. I had 2 390s on a tunnel ram on a mild hydraulic cam 289 and it ran fast with 2 springs in each diaphragm, 1 real heavy black spring and one medium. The secondaries never opened all the way, stopped at about 2/3s at 4500 RPM, when I had it performing well. Less spring pressure and it bogged as soon as the secondaries opened. I could see the carbs through the windshield, that's how I know what they were doing. (Later built a hot 289 and it needed 2 600 double pumpers to make proper HP)
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Thanks for the tip on the heavy springs on the secondary diaphragm. Walt
 
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