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excessive crankcase pressure in 68 327F

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ridemech

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I've just recently aquired a 68 cavalier futura with twin 327F's, and the port engine seems to have been very recently rebuilt, but I dont hjave any info on the boat as it came from an auction. Both engines appear to run fine, except the port is blowing oil and some smoke out of the tube on the side of the filler neck. I suspect that there is a ring that has not seated, a friend suggested egr valve, but I dont seem to see one! any advice??
 
Worn piston rings that are allowing compression/combustion gasses to enter the lower end.
Worn exhaust valve guides may give similar results.... but this may be more prone to exhaust gasses entering the lower end.
Your engine oil is very likely turning dark prematurely.

Either way, it sounds as though an over-haul is imminent.
 
thanks ricardo, this was my first worry, I have discovered that the engine in question has 15 hours on it since total overhaul, so I suspect it is either a stuck or incorrectly installed ring. I am going to do a compression test this week, and yes the oil sure did turn black in a hurry, compared to the the other engine which is original with 1460 hours on it, and cleaner looking oil
 
I have just completed a compression test and there are 3 cylinders at 135 psi, 3 between 140 and 145, and 2 that made 150, most plugs were dirty and 3 were very oily, but they were on the higher compression cylinders, being a fairly new motor I am wondering if it is just stuck rings, and whats the best way to try to free them up?
 
Thanks Dave, I spoke to a mechanic who had this same problem with a 305 in a caprice, that plate under the manifold actually got pushed out from a build up of carbon, he almost guarentees this to be my problem, next week I will be pulling the intake for sure! Thanks again!
 
The temporary fitting of a pcv valve from a passenger car of the same era would go a long way toward scavenging some of the blow by gasses...it involves a ten minute installation and is totally removable if not needed...this may get you through the season and allow you to trouble shoot when the season is over...if the cylinders are as oily as you say, I'm not sure of the validity of the compression test results. If it is burning oil, the exhaust should have some blue smoke coming with it.
 
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