Quote:
Originally Posted by May70
Saw your post last night, usually its a good idea in my general experience to start a new thread (as you did). Case in point my forum thread has definitely had a 'paper trail' tracing down some things. No telling where you will end up on these, ha ha. Funny someone mentioned, he thought I had 292 (numerical value amount) questions.. turns out I just might 
Was there oil in the intake manifold? Its my understanding you will get higher(false) compression readings if oil is leaking into the cylinder via rings/seals and is helping the rings seal, causing increased compression. Or in extreme cases there is so much oil in the cylinder it is actually decreased the volume enough to increase pressure (probably not the case here just a statement).
If your manifold has the nipple from the valve cover (pcv), ensure you have baffles of some sort. Steeveedee pointed that one out to me on my setup. I believe a am getting some oil into the manifold via that pathway....
Another thing to consider with 5/6 being 'wetter' ( i assume you mean with oil) than 3/4 is that the motor is mounted with a bit of an angle and if oil is getting into your manifold it could be running down the back 2 intake holes.
3/4 plugs were the worst on my truck and it so happens that is where the oil was sitting in my intake as you probably saw. Im hoping its just oil passing through those hoses but it wouldn't surprise me if the valve seals are gone.
Is it smoking? If its not smoking I doubt oil leakage into cylinders (causing false compression reading) is the case. If no smoke I wouldn't worry about it with those compression numbers. Im not super knowledgeable though.
Also in the pics I see a stud in place of where a bolt should be, maybe you said it and ive missed it but that head has been off before and odds are they had a little bit of trouble so just be ready and careful if you go to take it off. |
Thanks for popping over to check this out! I learned a lot from your thread. There isn't pooled oil in my intake per say, just a bit of a coating. I agree that the front intake ports were dry due to the angle of the engine.
I do have the baffles inside the valve cover and the truck doesn't smoke so that's a plus.
I didn't even notice that head stud until you pointed it out so nice catch. I figured someone had messed with it at least a little before as the valve cover and inspections covers had been removed and painted. Now with the 1970 block casting I am thinking it's likely not even the original motor. Does your block have a date cast in to it?