excessive crankcase pressure

[blkfordsedan]

Just to play Devil's advocate........

How would a leaking head gasket between the middle cylinders cause the excessive blow-by? The only oil return passages that I know are the 2 round holes in the front corners of the block and the two oblong holes in the back driver's side corner. Doesn't really add up considering the end cylinders had good compression. Seems to me that the only way for combustion gas/pressure to get in the crankcase is to go by the rings, or leak into the oil returns. I'm guessing the oil soaked areas are from the head bolt holes.
Not saying you don't have head gasket issues, or that isn't the problem, I just don't quite understand it. I hope it fixes the problem. If so, I may have the same issue with my B3 and I'll take a closer look at it! Good Luck!

[htchbck]

Well, I'm pretty sure the last HG job was botched... for one thing, couldn't find two rings that go around the outer rear head bolts that helps center the gasket. They were gone. And after careful inspection of the gasket I can tell that it was about an sixteenth of an inch off from where it should be. May or may not have been the cause of my problem, but either way, not good for proper torquing and sealing. I'm using a couple or spare ones I have from an old motor.

Blkfordsedan: I get what your saying, but I would think that a leak to any oil passage could cause excess pressure, not just the returns. But I could be wrong. I've had oil in each cylinder for the past couple of hours, and the oil doesn't seem to be dropping in any of them, still could be some leaking past the rings, but if it is, its not much, and certainly not as fast as it would be if a piston was toasted.

[blkfordsedan]

Flip the head over and look in the bolt holes for the locator sleeves. They get pushed up into the head. I spend hours looking for them once....thats where they were, LOL.

I'm not sure where the oil feed passages are, but I belive there's only one that goes from the block into the head. It feeds the cam towers first, then the rocker shafts, rocker arms and HLA's. I would think there'd be some HLA clatter and lots of bubbles in the oil if you had compression going into an oil feed passage. I sincerely hope I'm wrong and this solves your problem. If so, I may have the same problem.

[juryrigger007]

Yeah, your numbers point more to a head gasket. Good luck, on your fix!

Cheers,

Scott

[FestYboy]

Thanks Arty, I know how to do the HG, but I'm suspecting that whoever did this last HG job didn't lol.

not saying you didn't (actually figured you DID, but...) just putting it out there that you really want to use the spray and take the bolts to 70 (not the 60 they the book specifies). this is comming from experiance.

[htchbck]

Flip the head over and look in the bolt holes for the locator sleeves. They get pushed up into the head. I spend hours looking for them once....thats where they were, LOL.

Nope, they were gone completely, I had a couple spares though

And Arty, I wasn't taking offense to what you said about the install, just thanking you for the reminder And also making a point that while we may know how to do it, I don't think the last guy did :lol: At least thats what I'm hoping the problem was. If not, there's a '91 323 I've been keeping an eye on at the PaP

[htchbck]

Ok, this morning went down, and the oil had drained all the way down on the cylinder with 90psi, and I could tell it was a little down on the one with 115. The other two were fine. This was with two teaspoons in each cylinder over a 24 hour period.

[htchbck]

So, I have a (mostly) complete Aspire lower end, with an '88 Carb'd head on it in the basement. So I think I'll just use parts from that and a fresh ring kit and rebuild greens motor. Don't really feel like buying a swap right now, since this is more of a spare car right now anyway... sound like a plan?

[iceracerdude]

...just putting it out there that you really want to use the spray and take the bolts to 70 (not the 60 they the book specifies). this is comming from experiance.

I've used the copper spray, and the engine re-builder I know actually says to use the spray too. This from a guy who's professionally resufacing mating surfaces!

I've got cars with MLS gaskets however, and I don't use or recommend spraying them with copper, but the type of gaskets we use (b3 and b6 fiber and steel) I say use it too.
I do recommend pulling the VC after heat cycling the engine for a couple hundred miles and doing a retorque/check of all the head bolts, don't be surprised to find some of the bolts actually need it!

[blkfordsedan]

We use metallic aluminum spray paint on all the SBF head gaskets.
Never have any issues, even racing circle track.

[nitrofarm]

I've used the copper spray, and the engine re-builder I know actually says to use the spray too. This from a guy who's professionally resufacing mating surfaces!

I've got cars with MLS gaskets however, and I don't use or recommend spraying them with copper, but the type of gaskets we use (b3 and b6 fiber and steel) I say use it too.
I do recommend pulling the VC after heat cycling the engine for a couple hundred miles and doing a retorque/check of all the head bolts, don't be surprised to find some of the bolts actually need it!

Whats MLS ?

[rollertoaster]

Multi layer steel


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[iceracerdude]

Whats MLS ?

Read this, this is about mls gaskets WITH exsisting coatings, but not all have a coating either: http://www.dupontelastomers.com/Appl...otive/head.asp

[nitrofarm]

Read this, this is about mls gaskets WITH exsisting coatings, but not all have a coating either: http://www.dupontelastomers.com/Appl...otive/head.asp

Good reading thanks Dude. I'm sold-

[htchbck]

Alrighty, finally got around to dropping the oil pan and pulling the pistons this morning. Well, the middle two pistons were cracked bad, as in chunks came out leaving holes all the way through the sides. #4 also had about an inch long chunk of the lip between the two compression rings break off, but not a hole straight through like the middle ones. So... I'm going to tear down my spare motor and hope three of the pistons are good. I'm headed back down to pull the oil pan off the spare motor and get the pistons out of the spare motor (pulled the head the other day). So my biggest question is... why would three of the pistons have broken? And if I do put more pistons in, is it likely that they will break too?