Thread: where in the world is the oil coming from?

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Hello to all.

I have been struggling with an oil issue for some time.

Here's the scoop. Brand new 383 short block ( Eagle crank, rods , bearings ) 9.6-1 comp. This short block was prepared by a very reputable engine builder. Heads are cast iron with 2.02/ 1.6 valves, positive oil seals ,screw in studs , plates etc.

Thus far, I have tried three different manifolds, thinking the manifold(s) were warped. Not true. It was checked and it's a good fit.

Every single time that I pulled the manifold(s), the gaskets are soaked with engine oil!! The air/fuel charge is getting oil from somewhere. I've tried different gasket brands as well. I have unhooked the PCV ( using breathers for now ) to eliminate it being the cause. Same thing! The plugs are still wet and fouled. When the motor is running, it smokes when you gas it a bit.

The cam is fairly aggressive, but I doubt that has anything to do with the problem. The heads I had on this motor have been brought back to the machinist, and according to him, they checked out fine. The intake guides were also checked to see if any oil has been coming down the guides. Nope. Please advise!!

Dutchhotrod

Originally posted by dutchhotrod
Hello to all.

I have been struggling with an oil issue for some time.

Here's the scoop. Brand new 383 short block ( Eagle crank, rods , bearings ) 9.6-1 comp. This short block was prepared by a very reputable engine builder. Heads are cast iron with 2.02/ 1.6 valves, positive oil seals ,screw in studs , plates etc.

Thus far, I have tried three different manifolds, thinking the manifold(s) were warped. Not true. It was checked and it's a good fit.

Every single time that I pulled the manifold(s), the gaskets are soaked with engine oil!! The air/fuel charge is getting oil from somewhere. I've tried different gasket brands as well. I have unhooked the PCV ( using breathers for now ) to eliminate it being the cause. Same thing! The plugs are still wet and fouled. When the motor is running, it smokes when you gas it a bit.

The cam is fairly aggressive, but I doubt that has anything to do with the problem. The heads I had on this motor have been brought back to the machinist, and according to him, they checked out fine. The intake guides were also checked to see if any oil has been coming down the guides. Nope. Please advise!!

Dutchhotrod

ARE YOUR PLUGS OIL OR GAS FOULED?

Were the heads milled? Since you have tried different manifolds, that should eliminate them as a source. It really sounds like you are not getting a good seal between the manifold and head. If the head-block surface was milled and a corresponding amount was not removed from the manifold surface it could affect the seal. Just a guess on my part, but worth checking.

Pat

In answer to your questions:

The heads were milled. The plugs are heavily oil fouled.

I even had the machinist mill/match the intake as a last ditch effort to no avail. The machinist is buying me a new manifold to start again with.

The machinist is willing and ready to build another set of heads to try.

[QUOTE]Originally posted by Stu Cool
Were the heads milled? Since you have tried different manifolds, that should eliminate them as a source. It really sounds like you are not getting a good seal between the manifold and head. If the head-block surface was milled and a corresponding amount was not removed from the manifold surface it could affect the seal. Just a guess on my part, but worth checking quote by stu cool .yes it that is it the intake is not sealing up it may be stoping on the china wall the thin part of the block that go side to sid one front and one in back there should be some space here a bout 0.060 or more this holes up the intake gaskets and the intake may need to be cut sides and bottom .but i seen the bottom hit first. i do not know how this happen pat but two pat s are better than one

Pat

or lack there of

Denny, you said rings. hmm. That might be so, but then why does my intake runners, intake ports, and intake gaskets have oil all over them? If the rings were bad, how does the oil travel so high?

It actually sounds like you have two seperate problems, as far as your plugs oiling up this is either excessive valve guide wear or lack of seals "which as you said machinist has checked" or collapsed oil rings/incorrectly staggered oil rings/lack of a honed surface on the bore. As far as oil everywhere up top and when you pull manifold of its oil everywhere, where exactly are you talikng about on top sides of the gaskets/bottom sides or centre of gasket, if its topside then recheck rocker seals and have a good look along perimeter of manifold for any small holes from head manifold mismatch, I had a holley manifold/pro topline heads and they mismatched by a mm just behind the front water passage, when you gave the car a gutfull there was oil everywhere but couldnt work it out until I had a really good look, if its oil under the manifold thebn thats fine, if its oil on the mating suraface then thats a new one to me, hope this helps
Steve

no oil controll ring s or a piston burned down the side will make it smoke like hell

Originally posted by DennyW
The cam is fairly aggressive, but I doubt that has anything to do with the problem.

If the duration is long, this could very well have to do with the travel path of the oil vapors. As you know, a low vac cam, with long duration, heavy on the overlap, will allow the flow to back up almost to the base of the carb area. If the vacuum is low, and the cam is that aggressive, this would happen. The oil cause, I'm thinking is the rings. You have had the heads re checked, and have replaced gaskets. Are you sure the rings are ok ? I have also had a fricky thing where they would line up on a few cylinders on there own, sucking oil up into the chamber. I would re check the cylinder walls carefully. Maybe a leakdown test also.

HAVE YOU TRIED A CRANKING TEST YET?IF SO WHAT WHERE THE RESULTS?

poor ring seal and reversion

OK Gents.

When I yanked the manifold, there was oil on the intake surface, and the top of the intake gaskets. The bottom of the intake gaskets were still tacked on. Rings? The short block is brand new, but i would have to get my heads back and installed to check for leak down. This motor has maybe 200 miles on it!

Heads are ( were) also brand new , complete with teflon positive oil seals, new bronze valve guides etc. The block was bored, honed complete with all new parts. pistons, rings, rods, crank, etc.

I may have to yank that thing it sounds like.

Originally posted by dutchhotrod
OK Gents.

When I yanked the manifold, there was oil on the intake surface, and the top of the intake gaskets. The bottom of the intake gaskets were still tacked on. Rings? The short block is brand new, but i would have to get my heads back and installed to check for leak down. This motor has maybe 200 miles on it!

Heads are ( were) also brand new , complete with teflon positive oil seals, new bronze valve guides etc. The block was bored, honed complete with all new parts. pistons, rings, rods, crank, etc.

I may have to yank that thing it sounds like.

TRY A CRANKING TEST FIRST.

Originally posted by Bryan TTM
poor ring seal and reversion

REVERSION OF WHAT?

big cams with lots of overlap cause reversion....usually its black soot crap...poor ring seal would make oil

just an educated guess