[95 Truck]

Ok here’s tonight’s question.

350 +.060, flat tops, dart aluminum heads, stock GM intake and sniper EFI. Cam is summit 1102. Fresh rebuild with about 700 to 1000 miles on it.
This thing has been burning oil like mad, like a quart every 100 miles.
Today I pulled motor to find problem. I took intake off and the egr/cross over pocket was full of fuel/oil. Now the EGR is not used and I covered the head to intake ports with the fel pro gasket(black with blue bead). The cylinder head runners look clean, Now the egr pocket on the heads was full as well, even though the gasket between head and intake had not cracked or showed no hole in it on either head. 6 of 8 cylinders had heavy oil goo on pistons, not full hard carbon yet, wipes off easily. Now the only place with oil/fuel mix is intake and EGR pockets on heads, oil under intake, valve covers and pan is pure oil. It is very black like heavy combustion blow by, oil only had about 250 miles on it.
Cylinders look ok no marks from bad rings, engine looks clean in bottom end.
Anyone seen this before, bad rings? Crack in intake manifold? Crack in exhaust area on head? View attachment 613802 View attachment 613803 View attachment 613803 View attachment 613804 View attachment 613806

 

[ericnova72]

Three possibilities come to mind.
Does the stock intake cover and seal the larger Dart ports openings really well?

What does the PCV system look like?? PCV valve in a cover with a baffle that isn't up to the job results in a PCV that sucks oil badly.

Second rings installed upside down, turns them into oil pumpers...they are meant to glide over a oil film in one direction, seal going in the other direction....if upside down the direction of oil travel in the cylinder is reversed.
These do trip people up, sometimes rings are marked dot up for top ring but dot down for second ring, and assembler doesn't notice the instructions.

 

[BogiesAnnex1]

That much oil sure sounds like broken or incorrectly installed rings. I‘d expect to see the number 2 in particular as it is as much an oil squeegee as compression ring. A common error on the 3rd oil control ring is getting the separator ends overlapped.

These are things that will pump oil psst the compression ring and into the combustion chamber.

Bogie

 

[95 Truck]

Ok time to pop a piston, I will report back when I get one out, sounds like I may have missed something in the instructions.
On a curve ball note, would the 2nd ring being up side down lead to 1) low compression say 140 vs 160/170? 2) would it lead to increased crank case pressure or fumes? More then PCV system could handle? When I had this running and was troubleshooting issue, I pulled the PCV valve out of valve cover and it looked like an old electric train with the stack you would put oil in to make smoke.
Eric to answer your question, valve covers are stock GM.
Also do you guys think there is another problem as well? How did EGR area get full of the oil/fuel buildup?
Eric I will take another look at the intake seal.

 

[2old2fast]

Somewhere on line I remember an article by , I think, Hastings. They ran tests demonstrating what happened when common assembly errors were made . Iirc , they inverted one second ring & recorded how much oil consumption that caused . Interesting read ...
You do have a pcv system of some sort , right ?

 

[95 Truck]

Yes stock PCV valve system

 

[95 Truck]

ok here is an update pulled all pistons and all rings look to be installed correct, I am going to call Hastings tomorrow and double check with them, I need the install pdf sheet from them to confirm.
I will say this (its been a while) I can/could turn this assembly over by hand, meaning it had almost no drag or resistance with all 8 pistons in it. If i remember correct with all 8 pistons in cylinders there should be enough resistance to require a screw driver between 2 fly wheel bolts to help turn engine over. leading me to think rings did / do not have enough tension.

 

[johnsongrass1]

CHeck the ring gap and ensure the rings are the right bore size.
I believe those heads have the rockers studs go all the way through the intake ports. Check those for leaks.
I'd also be checking the valve guides and seals.

 

[2old2fast]

If it turns over that easy , something's amiss !

 

[95 Truck]

Well here is an update on this oil issue, I must admit, I have errored in my reading of online article's and not paying attention to the many words of wisdom shared on countless other post or perhaps I did not put 2 & 2 together too visualize the issue or my failure.

JohnsonGrass called it or the main cause, it is the rocker studs and my leak of using proper sealer, this caused the oil to get sucked in and intern flooded the rings and caused them not to seat, which lead to heavy blow by and which then lead to high crank case pressure and forced the vapors in and out every place it could.

So current plane is to clean everything up, put new rings in (cheap insurance), seal the rocker studs and start reassembly. I am going to use this oops on my part to swap in a new cam seeing I have it out of the car.

 

[blwn31]

Had the same problem with my Brodix heads, live and learn. By the way, I used The Right Stuff to seal my studs.

Keith

 

[95 Truck]

Well here’s another little update and confirms one thing I asked about. I started reassembly today, got the crank and pistons(new rings cast iron, no molly) back in and wow what a difference in ring resistance. As I had said earlier that this engine when assembled the first time, it seemed to turn over easier then I remembered it should, but it had been quite a few years, so we went for it. Now today with it back together, it is like I remember, need two bolts in back of crack and about a 15” long screw drive to over come the ring friction/tension.

I am looking forward to seeing who this car runs now.