Foamy Oil in new Crate Engine

Oct 7, 2018 11:45 AM - 1065 Views Create A New Thread

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Blaine, WA

Just found it this morning
I pulled the valve covers off my new crate engine this morning (it's Chev 350, 385 hp version that GM bumped up to the 430 hp version for me and I changed the cam after that. It turned 456 hp on the engine dyno).and found heavy foam on the inside of the valve covers. The car hasn't been on the road yet, but the engine was broken in on the engine dyno. I did have the intake off to change the cam, otherwise, nothing has been touched. It's had maybe an hours worth of running in the car while setting things up. It still has it's break in oil in the engine, is it possible that foams up like that? I doubt it. Wondering if the intake gaskets are leaking water into the engine. The oil on the dipstick looks clear and isn't above the full mark. I'll drain the oil this morniing and see what's in the pan, but I suspect I'll at least have to pull the intake off to check things. Any ideas? Thanks, Bill

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  • mountain-mike
    Dec 14, 2018 at 12:07 PM

  • Also did you retorque the head bolts after break-in? I have had a few that some forgot to put sealer (like NAPA headbolt white sealer) on SBC headbolts that are open water jackets.
    Steam come through the thread gaps.
    MM out.

  • blade58
    Dec 5, 2018 at 6:26 AM

  • Good fine , those details are important

  • Bill33
    Dec 4, 2018 at 8:56 AM

  • Turns out in my case it was a minor leak in the intake to head gasket. It was a GM 430hp crate engine, but I opened it up to change the cam and used Felpro gaskets when I put it back together. They were too thin to mate up properly. The GM ones that I bought to replace them were nearly twice as thick. Once I changed the gaskets, everything was fine.

  • dixie
    Dec 4, 2018 at 6:33 AM

  • Same thing happened to me ,ran engine around town couple days always got it up to operating temp & yes it went away . Is the temp cool where car is kept ?

  • will547
    Oct 7, 2018 at 5:24 PM

  • I think you will be ok. Run the car and change the oil in a few days.

  • tazhog54
    Oct 7, 2018 at 3:09 PM

  • Just what you said the engine is not up to operating temps and that's just condensation built up till you run it more to burn it out .

  • Bill33
    Oct 7, 2018 at 1:04 PM

  • One more pic of foam from inside cover

  • Bill33
    Oct 7, 2018 at 1:03 PM

  • Could it be condensation from only running the engine a few minutes at a time? I had it fired a quite a few times when trying to check my Ron Francis Ice Box Fan control, but shut it down each time before it reached full temp as the fan wasn't coming on. You'll see in the last photos, the oil on my finger is quite clear. I'll let it sit for a couple days and see if anything separates out of it, but still nervous.

  • Bill33
    Oct 7, 2018 at 12:24 PM

  • Just drained the oil. No visible water, the oil looks quite clear......puzzled. I did notice yesterday when I was running the engine to finalize timing etc, there was a trace of steam residue on the valve cover under the breather, which I thought was odd.

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