Thread: Small Block 400 Head Leak

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I was hoping someone could point me in the right direction with an issue.

My father has had oil leak issues with a small block 400 Chev engine with aluminum heads. The heads he's using are aluminum Edelbrock Performer RPM heads, 6073. The oil leaks from between the cylinder head and the block on the outside (on both sides, same place).

My brother has practically the same issue on a Chev 350 small block with a Vortec head.

They are using the appropriate gasket and have put the heads in to spec.

Any solutions? He's getting ready to put different heads on but I convinced him to give the forum a go.

JP

Assuming the deck of the block is not warped ,nor the heads are warped,assuming that the correct gaskett is being used and everything matches up......some people use the copper coat spray and have good results....might want to give that a try.

1. Are you using a sealer on the head bolts that go into the water jacket?
2. Did you drill the heads on the 400 for steam holes?

Thanks for the responses so far. Appreciated.

techinspector1, yes to both questions.

Any idea?

Thanks in advance,
JP

OIL leak . not water ? on the lower part of the head there no returns in the block so if the head gasket was leaking down at the lower row of bolts it would be water not oil , if the upper back then it could be the pipe plug in the deck . it sound s like to me you have some very bad valve covers or bad set of valve cover gasket ,even if no sealer on bolts your going to see coolant/water no oil .this is a 350 deck is about the same other then bore and steam hole as you can seen all water holes in the deck

He could be leaking from the gallery plug at the top of the block right side, under the head....

Originally Posted by 406Rich

He could be leaking from the gallery plug at the top of the block right side, under the head....

yep i said that ? and that is why i posted the photo ? well i was thinking i did say that ?

sorry missed that....!

Originally Posted by 406Rich

sorry missed that....!

hey thats ok i was thinking i was having a twilight moment

I concur with all of the above - one additional possibility is a bad intake seal (typically at the front or rear of the manifold where it meets the block) and the oil drips around the head so it looks like a leak at the base of the head...

No Pat, it was my turn for a twilight moment. He said oil, I was just hung up on water....DUH!

yep would be the end rails . they must be very clean if you use RTV only use that to bead up a gasket with RTV for end gaskets . warm oil likes to be on the move with air movement so it very well could leak one place and end to drip at another . could be a leaky oil sended to could be one thing or more then one spot as well. bad Dist gasket too

Thanks for the feedback. I'll keep you posted. Thanks.

JP