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stanjr41 11-28-2005 08:56 AM

engine blow-by
I have a 1965 Rambler wagon that I put a 350 Chevy engine in. The motor runs well, but I have a lot of blow-by.(the heads are 1972 with a 1970 short block) I initially started with a pcv valve on one side and a breather on the other.I got a lot of oil seeping out the grommits and out the breather.Next I replaced the breather with a hose which I routed under the car by the lower ball joint to try and lessen the oil on the motor. When I drive the car and get on it even just a little bit I can see a large trail of blue smoke and the smell of oil is overwhelming. Would changing the breather to a PCV valve and tying it in with a tee to the other help any? I am currently using 20/50 oil, and I tried a can of restore to no avail. I am retired on disability and cannot afford any major repairs. Any ideas would be greatly appreciated. Thanks, stanjr41

johnsongrass1 11-28-2005 09:09 AM

Unfortunatly if you route that oil fog into the intake, fouling plugs and low power with reduced fuel milage will result.

farna 11-28-2005 09:10 AM

A PCV valve AND a breather on each valve cover, with both PCVs on a T, might help. Other than that I'm afraid you're talking about an overhaul. It's obvious that the rings are letting to much compression slip into the crankcase. Hmm... with so much going past the rings, maybe two PCVs and no breathers will be okay.

Check the bottom of the valve cover though. There should be a baffle that keeps oil from going directly out of the hole. At least most cars have a baffle there (usually just a plate over the hole with space on each side between the plate and valve cover to suck in/out air). I know that AMC V-8s have a problem sucking oil up the PCV when the baffle isn't installed (it doesn't come with most aftermarket intakes -- they expect you to pull the factory baffle off the original), but they pull the PCV from the intake instead of valve covers.

stanjr41 11-28-2005 11:34 AM

I have chrome valve covers, and I don't believe they have baffles. Also.each cover has only one hole;one has a PCV, and the other a breather. Hope that straightens out the two hole misunderstanding. Thanks for the input and I'll take as much as I can get. Stanjr41

cboy 11-29-2005 07:32 AM


Go here for a pretty good discussion of blowby. If you scroll down to the first entry by NXS and then the following entries, you'll find a quick/easy method of diagnosing potential PVC valve and blowby problems.

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