Intake Manifold Question
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Drifting
Joined: Sep 2004
Posts: 1,414
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From: NC
Intake Manifold Question
I just replaced my cam in my 74 350. I bought a Performer intake and a cam change gasket kit from Summit. My question is, the intake gasket has a round hole @ 5/8" dia. on the center port (I believe it is an exhaust passage) and also has two stamped pieces of thin sheet metal that looks like they are used as plugs. Do I need those passageways' or do I block them? What are the exhaust passageways for?
Thanks
Bill
Thanks
Bill
Le Mans Master
Joined: Sep 2001
Posts: 7,739
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From: Unreconstructed, South Carolina
Originally Posted by hayman
I just replaced my cam in my 74 350. I bought a Performer intake and a cam change gasket kit from Summit. My question is, the intake gasket has a round hole @ 5/8" dia. on the center port (I believe it is an exhaust passage) and also has two stamped pieces of thin sheet metal that looks like they are used as plugs. Do I need those passageways' or do I block them? What are the exhaust passageways for?ThanksBill
Next performance step up in heads & intakes have no such Xover at all.
If your climate permits you to eliminate choke function ... you should block the Xover ... it will make more power but you'll probably need to wire your choke "open". If you block Xover but don't modify the choke it'll always be choked and motor rich (bad). Most Qjets have plenty of accel pump ... that'll usually get one cranked & running by feathering throttle for minute or two.
*edit* this sort of thread is exact reason why everyone should list an APPROXIMATE geographic location in their profile here on CF.
Last edited by jackson; Nov 2, 2006 at 09:22 AM.
Le Mans Master
Joined: Sep 2001
Posts: 7,739
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From: Unreconstructed, South Carolina
Bill:
If you block Xover ... If those stamped sheetmetal "plugs" are Aluminum ... that Alum WILL burn through.
Our local CT rules require performer 2101 & production iron iron in most classes. Every racer around here with a lick of sense blocks Xover ... we do it with a THIN piece of STEEL sheetmetal "shim" cut to fit a bit larger than hole in head ... silicone it to head ... lay gasket over that ... then install intake. Heck, I've used a doubled up piece of Al bud can in a pinch ... but it burns though in a race or two. Do use steel if you're gonna block Xover..
If you block Xover ... If those stamped sheetmetal "plugs" are Aluminum ... that Alum WILL burn through.
Our local CT rules require performer 2101 & production iron iron in most classes. Every racer around here with a lick of sense blocks Xover ... we do it with a THIN piece of STEEL sheetmetal "shim" cut to fit a bit larger than hole in head ... silicone it to head ... lay gasket over that ... then install intake. Heck, I've used a doubled up piece of Al bud can in a pinch ... but it burns though in a race or two. Do use steel if you're gonna block Xover..
