RPI of England reported many years ago that there were head gasket issues with the Rover engines that had 14 head bolts. Took Rover 25 years to correct it by deleting the lowest four bolts per head. Apparently, the lowest row puts pressure on the top row & causes compression to leak into the lifter valley causing excessive blowby. RPI documented this with photos.
My MG with a Buick 215 is famous for excessive blowby. I have been blackflagged multiple time at track days for severe smoking. Since it wasn't burning all that oil & it was blowing it out every orifice it could, I was sure that this was the problem. Since I had removed the right side header for Jim B. to TIG weld the crack that had developed due to the crappy sagging engine mounts, I figured "Might as well".
So, here is a pic of the right side head gasket, Pretty obvious.
Passengersideheadgasket.jpg
I wonder if Olds 215's had this problem. I have an Olds 215.
Now we know. Wonder if the other side looks the same?
Jim
Edit:
Not so much, since you get even clamping. On my boosted engine I still got some leakage but it wasn't at the top.
Jim
Olds 215 should not. They have a better head retention pattern.
Here are photos of a set of copper head gaskets showing leakage patterns with 8.5 CR and 16+psi of boost.
http://forum.britishv8.org/file.php?2,file=1729,in_body_attachment=1
http://forum.britishv8.org/file.php?2,file=1728,in_body_attachment=1
Jim
Carl, have you calculated what your new compression ratio would be if you kept everything as before but took this opportunity to install Rover 4.0 (smaller cavity / bigger valve / ten bolt) cylinder heads?
No, I haven't, Curtis. It already rattles on anything less than good quality 93 octane.
Swapping to these better Rover heads that I have had for a long time was the plan....before I found the broken piston skirt. Way to close to the WV Meet to do much.
Jim B., are those solid copper gaskets ? Not too much "compliance", if so. The 215 heads and blocks were weaker than their cast iron contemporaries. They weigh only 266 lbs., for a reason ! They were build for a limited displacement and output, without an abundance of safety factor, like say the early Chrysler hemi at 672 lbs.
Art, the main thing with that high boost was that the threads in the block could not hold it and the gaskets would begin to leak after awhile. I tried double stacked helicoils in the block but that only slowed it down a bit.
Admittedly I was running pretty close to the ragged edge. On teardown one piston has some nibbling away of the top ring land in one spot. But for cast pistons I felt they had held up rather well.
Jim
Here is the Driver's side. Significant leakage on both sides.
215driversside.jpg
That's about the best clear evidence you could hope to see.
Jim
PSA:
https://gm.oemdtc.com/1895/00-06-01-012f-use-of-surface-conditioning-disks-when-cleaning-engine-gasket-sealing-surfaces-andor-reused-engine-parts-2017-and-prior-gm-passenger-cars-and-trucks
Considering Carl had to use 75 ft-lbs of breakaway torque to loosen his head bolts, this is darned near irrefutable evidence of the 'head cocking' we have heard of caused by the extra lower row of head bolts. Note that all leakage was towards the top and none was towards the bottom.
The GM bulletin was interesting. Like most things it isn't exactly gospel, but a useful guideline. I quite agree that introducing grit into the innards of an engine is a bad thing. And, those ROLOC finger discs can do that. I'm not convinced it means you can't use them though. The question is what you do to prevent the swarf from going where it isn't wanted, and there are ways to keep it out, ranging from the crude to the effective. For instance, laying a bead of grease down around the top of each piston gives a pretty good chance of being able to wipe up/blow out any grit that gets in the cylinder, and the lifter valley could be masked off. Just one possibility. Guess it'd void your warranty, but that may not concern a few of us.
Jim
Went with the old, slow method; razor blades & carb cleaner, followed by brake cleaner.