The Stovebolt Site Forums The Shop Area Engine Shop 283 Intake Gasket Leak

I have a 1960 stock 230 hp 283. Long story short, I have problems with oil sucking up from the lifter galley into all 8 intake runners. I'm on my 3rd set of gaskets trying differnet things. Everythuing is flat, clearenced, angles matched etc. On the last set of gaskets, I run it for about 5 minutes and quit for the day. When I looked at it the next day, I could see looking between the valve cover and the edge of the intake, that the gaskets were wet for about 1/2" out from each of the intake runners. Now I'm almost wondering if the carb is bleeding down, and soaking the bottom of the intake gasket, and this is why they are leaking? It seems strange that all 8 leak through the same amount. I use sealer on the ends of the intake, not gaskets. I'm running an Edelbrock Performer carb on it that I bought new. I don't have another one to try out. Also on a side note, years past the intake gakets used to have stamped on them "this side up". I don't see this anymore, what was the reason for that? When they are leaking, I get smoke when I start out, and it will go through a quart of oil in about 250 miles. It will be alright when I first change gaskets, but then start up again in about 300 miles,Any thoughts or suggestions would be greatly appreciated.

If the heads have been milled at some time, it's possible that the intake passages in the heads and the manifold aren't lining up right anymore. Are you using a stock intake, or something aftermarket? It's not uncommon to have to mill the manifold-to-head flanges and the end gasket surfaces to make a manifold fit right, especially if you're dealing with angle-milled heads and/or an aftermarket manifold. It's usually necessary to take 3X the cut from the ends that is removed from the sides when fitting a manifold.

Try putting the manifold on the engine without gaskets, and see if you can slip a feeler gauge between the manifold and the heads anywhere. There should be no gaps on a properly-fitted manifold.
Jerry

Jerry: Thankns for the reply. I am running all stock intake, block, heads, etc., and I feel confident that when I first took the engine apart, it had never been apart before. All mating surfaces still have planer marks. I did try the intake with no gaskets, and run a feeler around it, and it seemed good. I checked heads and intake with a straight edge and feeler, checked good. I checked the road draft tube canister for clearence, and even elongated the bolt holes upward a little bit, just to make sure.

Could there be a hairline crack in the bottom of the intake manifold (all 8 runners oily?)
Maybe scrounge up another intake to try.

The last time I had the intake off, I plugged the runner ports and carborator bore, and hooked some air to it, and no leaks from under the heat shield or anywhere else for that matter.

Are you placing thread sealent on clean intake manifold bolts before you assemble

PCV.

cm

It's not leaking around the bolts, and yes, I tried putting on a PCV rather than the current road tube, and no difference. I am at a total loss on this thing. I didn't build it up, because I didn't want to mess with it, just drive, and I have had nothing but problems from day one. Thanks for everyones help.

I mean the PCV system could be the source of oil inside the intake manifold. If your rings are blowing by a lot, you'll have a lot of pressure inside the crankcase, which the PCV system is trying to relieve. Was there smoke & oil coming out of the road draft tube?
I just can't picture "oil sucking up from the lifter galley into all 8 intake runners".

cm

any pictures of the situation? maybe leakage someplace that the fan is spreading back across the engine? most high mile 283's will put some misty smoke out the oil filler .... could it be bad valve cover gaskets and valve seals? ["smoke when I first start out"]

Bill