Stock 440-6 barrel restoration engine, the PCV Valve is pulling in oil after rebuild wetting inside intake and fouling plugs. Engine holding 18 steady vacuum and I have done a compression check and find all cylinders at 165 psi. There is stock valve covers on the engine with baffle so there is no direct oil being splashed on the valve. I'm at a loss any ideas ?
Engine ran on dyno with no pcv and of course ran awesome, rings sealed right up and made 410hp 470 torque.

Thanks MLR426

Is this a fresh build.. if so let it break in then try the
PCV... sounds like the baffle isnt good enough

Crankcase should be running a slight vacuum at idle? Using the correct PCV valve? with Mr P. Sounds like it just isn't baffled well enough.

I did a catch can/puke can on mine- it would sometimes smoke when engine braking down from a high rpm blast. It doesn't do it any more!

hi, what type of rings are you using?? also, pcv new or old?

Are you sure that the oil is coming into the motor from the PCV or is it possible that the oil is sucking into the intake from the lifter valley pan? I've seen a lot of rebuilt motors, especially cast iron six pak motors, suck oil into the motor from the lifter valleys from a bad seal on the intake valley pans To test this remove the PCV from the valve cover and remove the hose from the intake or carb, you could leave the PCV sit outside the valve cover with a rag wrap around the bottom of the PCV to keep debris and dirt from sucing into the motor also and leave it hook up to keep the vacume the same I have taped a rag over the PCV hole in the rocker arm cover to see if crankcase pressure is blowing oil out of the valve covers to test issues like this also Lots of gremlins in these motors, dang it If you try this test drive the car long enough to suck all the oil out of the intake, if it doesn't dry up in 100 miles of street driving the valley pan may be your problem I now set the intake manifolds on the motors without the valley pans and use a feeler gauge to check the manifold to head fitment on all four corners at the top and bottom of each corner, I write it down on the intake corners for future reference I've seen some that have .015 on the bottom of one corner and have .007 at the top of that corner, I've also seen .000 on one corner with .025 on the bottom on the same corner I shoot for having the manifold cut to fit the motors with .002 max at the bottom and no more than .005 on the top so the valley pans will be pinched in tight at the bottom I also will use the thin intake gaskets to help seal up the intake from sucking oil into the motor IHTHs Let us know what you do and find

Complete agreement. Had identical issue on newly built 512 ci six pac fouling plugs badly which began some 800 miles after build. Thought might be pcv too. Vented it to atmosphere, no improvement. Pulled intake, all ports on intake manifold and head slathered with oil. Replaced turkey pan,,,could not add additional fiber gaskets as geometry too far off to get bolts started. Used silicone sealer liberally on turkey pan. Still had plug fouling. Very odd, no smoke from exhaust,,suspect fouling plugs so badly that they were not firing, hence no smoke.

Suspected significant head and intake incompat.

Replaced heads with Edelbrock Performers. Problem resolved perfectly. Using turkey pan only.

Valve guides of replaced iron heads upon inspection after removal were perfect.

Close inspection of intake turkey pan gasket, heads and intake each time after removal, never did demonstrate how the oil was being allowed to suck into ports. I now somewhat believe there was a very poor fit of intake to heads, silicon was sealing this gap temporarily, then it would 'tear' and allow oil to suck in. This phenomenon of the silicon tearing in the middle leaving no trace on postmortem

Imagine silicon between your forefinger and thumb. Pull them apart, the silicon tearing in the middle, leaving no evidence on either the thumb or finger.

In error I responded to incorrect post. This post should have been in response to Cal-Burge post on leaking intake/head geometry.

I also agree whit Cab statement but i discoverd the hard way that the 70 style and the 71&up PCV valves are made different as the 71 style have more of a restritction in the valve and the 70 is like no what so ever restriction if you suck thru them so on my 505 Engine my oil consumtion stopt but i dident have any screan under the valve before i started the investegation and found this out but Cab put me on the right track =) Also the restricted 71 style pcv valve works good as i have no loss of oil by the opend breather driping or smoking over the valve cover.

What valve seals are you running?

I used the Teflon PC seals originally on a brand new rebuild...kept on chasing strange oil-consumption issues showing up as oil residue in the intake runners, fouled plugs and occasional blue puff out the exhaust...went to the standard "go-to" place, that being manifold head port alignment, didn't find anything there.

Eventually I noticed the tell-tale oil accumulation over the valve head (after the engine shut-down and oil dripped down past the teflon seals and down the valve guide). Went to CompCams #529-16 Viton seals...problems gone...intake runners nice & clear, no more blue puffs of smoke, valve heads are staying clean.

Intake is sealed good it is totally coming in through the Pcv valve.
Trying to get customer to change out Pcv. This engine holds steady vacuum at 18 and doesn't waver stays steady. It also has 165 psi compression on all cylinders. Trying to get guy to change valve and change plugs.

Martin

What is stock vacuum for this engine

Mlr426

hi, what type of ring combination in engine? reason are they gapless rings?

Total seal standard rings. Engine is not puffing smoke it's sealed up. Vacuum is sucking hard on Pcv valve

Mlr426

I see what your talking about cab with free flowing Pcv the one on the car is not restrictive. So what gives here ? Before rebuild no oil being pulled in now I have oil being pulled in through the same Pcv. I know engine holds 18 vacuum don't know what it had before. I found a newer style Pcv that is definitely restrictive. Night and day difference.

Mlr426

the reason I asked about gapless rings , is you have to restrict the the pcv valve when using gapless rings. they pull a lot of vacuum!!! total seal wants a dowel in line , with a .060 hole in it. otherwise , it will suck oil out of engine!!