327 engine itake warped?

I have a 327 chevy engine from a 65 chevy supersport that is mostly stock except I'm running duel quads. The intake is a old edelbrock with 2 390 Holly cfm carbs. Problem is the intake was warped or so I think as the engine surged at different speeds and ran rough. I put a straight edge on and saw that there was enough light for a piece of paper to push thru. I took the intake down to a machine shop and they milled .003 off. I put it back on using Fel pro gaskets and it still is running about the same. I sprayed water along the intake to see if there was any change and it ran really rough for a few seconds. Torqued the intake to 15 lbs for a good seal which is probably a little too much. I know the problem is with the intake as the origional 4 barrel ran great and the 390 carbs are good with a total rebuild and are synchronized. Can't think what else I can do.

Use a handheld unlit propane torch, at the manifold to see exactly where your leak is, the engine wil smoothout or speedup, then maybe we can come up with a fix, insure its not at the carb base...

Sprayed carb cleaner around the intake and only noticedthe engine speed up at one of the runners. Maybe I have a cracked intake.

Yeah-the cracked intake was one thing I was thinking of.

check the china walls /cross gaskets if block deck/heads have been cut alot the intake will bottom out on the block before the intake gaskets seal on the heads if so bottom of intake needs to be cut gaskets are very thick .005 is not stopping the intake from sealing 020 yes intake just maybe over cut for milled heads /block and need a 060 gasket so intake is just to small think of the intake is a cork stopper and is now just to small

Pat-he posted he has another manifold that does seal.

I put back on my origional intake with 4 barrel and it runs fine. Have another intake for two carbs and will try that when it gets warmer. 18 degrees this AM.

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Originally Posted by 1gary

Pat-he posted he has another manifold that does seal.

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yes but liked i did post the intake old one could be to small could of been milled alot then you need thicker intake gasket . over milled it can bottom out on the block before sealing on heads

Pat thnks for the input. I don't think .003 off the intake is that much but I did use fel pro gaskets #1207 which are .060 thick with no bettter results. Bart

NO no no:D what i am saying is that intake could of been cut before on the 003 cut have a hard time buy that most of the time it takes more then that . i cut intakes it is not warp at 003 . go back if you want and read #5/#8 :)what i posted two things could be going on

I think there is a mix up on numbers---.003 is not enough warp to not seal---0.03 is enough for a leak--also if you take some off the head side you will probably need to take some off the bottom surface so the ENDS don't hold it up so it don't mate with the heads.

Some old timers used to cut the end of the block an amount coorsponding to the amount taken off the deck surface so manifild sealing wouldn't be an issue---for instance--I had 3 different manifolds that I ran on my motor, so trimming the block was the way to go--

Pat, Jerry. Thanks again for your input. Yes the intake was milled only .003 not 0.03 and yes I agree it's not enought for a warped to fix. Pat I understand you from what you say about maybe it was taken down before and .003 is not enough to make it straight. I put it back on a straight edge and completelyclosed the carb opening and put a flaslight inside in a dark room and cannot see any light coming from anywheres. I then put some dye the same used in magnafluxing, and it showed a crack on the front runner just before the carb opening so I'm not going to jerk around with this intake as it's old and I have another one I'll try when my garage warms up.

You could always have it welded then do a full polish job on it.

Too bad its not a Ford 289 or 302. I know where you could get a dandy intake for a mere 1,500 bux. :LOL::LOL:

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Originally Posted by chevy 37

Pat, Jerry. Thanks again for your input. Yes the intake was milled only .003 not 0.03 and yes I agree it's not enought for a warped to fix. Pat I understand you from what you say about maybe it was taken down before and .003 is not enough to make it straight. I put it back on a straight edge and completelyclosed the carb opening and put a flaslight inside in a dark room and cannot see any light coming from anywheres. I then put some dye the same used in magnafluxing, and it showed a crack on the front runner just before the carb opening so I'm not going to jerk around with this intake as it's old and I have another one I'll try when my garage warms up.

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A new one isn't that expensive...............