427 foam in valve covers

[Richard L.]

I have just put back together a 427 L88, with aluminum heads, aluminum rockers and stud girdle. I used GM assembly lube and Royal Purple break in oil. I have run it for about 20 miles and liquid started to come out the valve cover breathers. I took off the valve covers and there is a coating of foam on the inside, picture attached. Also I noticed, what looks like water in the valve covers, see other picture attached. I drained the oil and there is no signs of water in the oil in the pan or filter. Has anyone had this problem? Is the Royal Purple not compatable with the GM assembly lube? Is the GM assembly lube breaking down with the oil and making the foam and also what looks like a bit of water in the valve covers?
Comments before I start pulling things apart looking for a water leak.

[Thomas H.]

Re: 427 foam in valve covers

I used to see this happen in our racecar when the head bolts were not sealed well allowing water to wick up the threads into the head. Did you use a good thread sealant?

Tom

[Richard L.]

Re: 427 foam in valve covers

Tom, yes I used the recommended GM sealant. But maybe I did not put enough this time!! I did cover the threads as I alaways have.

[Domenic T.]

Re: 427 foam in valve covers

Richard,
I agree with above, water is getting in your oil. Good news is that aluminum heads usually do not crack, they only warp. Don't rule out another source ( other than bolts) for the water because the water has to go thru the oil pump to mix with the oil to foam.
It then can come up thru the push rods.
Dom

[Joe L.]

Re: 427 foam in valve covers

Tom, yes I used the recommended GM sealant. But maybe I did not put enough this time!! I did cover the threads as I alaways have.

Richard------


It takes VERY little sealant on the threads. Usually, folks use more than they need to.

The GM lube is completely compatible with Royal Purple or any other modern motor oil rated for gasoline or diesel service.

There are other places water could be getting in. The interface between the intake manifold and cylinder head water ports is one obvious one.

Also, what head gaskets did you use?

[Richard L.]

Re: 427 foam in valve covers

Joe, I remember that they were thicker than standard as I wanted to reduce the compression ratio. Got them from Summitt. Will try and find out what I bought.
Thanks

[Stuart F.]

Re: 427 foam in valve covers

Was there any machining done on the block like an over bore that could have led to a cracked block? Were you using coolant instead of water? If so, get the problem fixed ASAP as if allowed to persist could lead to a spun cam bearing. Happened to me with a small block.

Stu Fox

[Richard L.]

Re: 427 foam in valve covers

Stu, no machining, everything stock. Short Block was brand new. Yes using coolant as the heads and radiator are aluminum. Definitely looking to find the problem as soon as possible. In all the engines I have built, never ran into this problem before. Will start the process of elimination this weekend.
Thanks

[Joe L.]

Re: 427 foam in valve covers

Stu, no machining, everything stock. Short Block was brand new. Yes using coolant as the heads and radiator are aluminum. Definitely looking to find the problem as soon as possible. In all the engines I have built, never ran into this problem before. Will start the process of elimination this weekend.
Thanks

Richard------


What do you mean by "brand new"? Is this an NOS short block assembly?

[Thomas H.]

Re: 427 foam in valve covers

Richard,

At this point many things become suspect. Any mating surface that seals the coolant could be the source. Head gaskets, intake gaskets and any bolt where the threads penetrate into the water jackets.

Depending on the type of head gasket used, it may require a retorque after the first heat/cool cycle. I usually check them after the first cycle anyway.

Was the head surface checked for flatness? How about the block deck? A thicker head gasket will usually compensate for deck irregularities, but only so much.

Another area is where the intake mates to the heads. If any significant milling was done to the deck or heads, the intake may not be sealing properly. I usually run some permatex around the coolant passages on the intake gasket during assembly.

One time I was able to find a leaky head bolt by bringing the engine up to operating temp (rad cap off), shutting it down, removing the valve covers and pressurizing the cooling system with my pressure tester. Didn't take long before I saw bubbles coming from around one of the head bolts.

Let us know what you find out.

Tom

[Richard L.]

Re: 427 foam in valve covers

Joe, yes the shortblock is brand new, over the counter. I bought it from a guy that had it stored since 67. I took it all apart, cleaned all parts and put it back together. The short block was well protected with no surface rust when I got it.

[Richard L.]

Re: 427 foam in valve covers

Tom, nothing machined, everything is new. I tried to retorque the head bolts, as is noted in the manual for aluminum heads, and the bolts would not move. Will be doing the pressure test, hopefully, this weekend. Will post results on what I find.

[Joe L.]

Re: 427 foam in valve covers

Joe, yes the shortblock is brand new, over the counter. I bought it from a guy that had it stored since 67. I took it all apart, cleaned all parts and put it back together. The short block was well protected with no surface rust when I got it.

Richard------


OK. I'd still like to know what head gaskets you used. The brand and part number is important. Engines with aluminum heads require composite head gaskets or MLS (multi layer steel) head gaskets. Original L-88's used a composite head gasket as did L-89's. All other big blocks originally used steel shim type gaskets.

It's also very important that you used gaskets designed for Mark IV big blocks. If you somehow got Gen V gaskets, you'll wind up with problems just like you have.

[Richard L.]

Re: 427 foam in valve covers

Joe, it took some digging but here goes. The gasket set for the engine was a FelPro HS-8180 PT5. The head gasket in this set is # 1017-1 which I still have and did not use. The one I installed is FelPro # 1017-2 that I bought separate. It is marked for the Mark IV engine as I found the box as it has some additional gaskets in it that I did not use.

[Joe L.]

Re: 427 foam in valve covers

Joe, it took some digging but here goes. The gasket set for the engine was a FelPro HS-8180 PT5. The head gasket in this set is # 1017-1 which I still have and did not use. The one I installed is FelPro # 1017-2 that I bought separate. It is marked for the Mark IV engine as I found the box as it has some additional gaskets in it that I did not use.

Richard------


Well, you don't have an incorrect gasket problem. The 1017-2 should work perfectly for your application. This is also a Permatorque-type gasket which does not require re-torque. I have used this type gasket with great success.

By the way, why didn't you use the 1017-1 that was supplied with the gasket set? That's the one I've used and prefer.