<VV> Advice on Rings (was Help - Oil Out Dipstick Tube)

[Tony Underwood]

At 08:33 AM 9/10/2010, Brian wrote:
>Total Seal rings!  What grit size were the cylinder honed to?  I 
>once had a very similar problem.  I called the Total Seal Tech 
>Center and before I could even finish the story, their rep told me 
>that unless I used a minumum of 400 grit the rings would never seal 
>and I had destroyed them.


Those "old school" iron rings were quite hard and they would seal up 
ok with those old 280 grit stone glaze buster "hones".   Modern rings 
don't appreciate a coarse surface like that.


>The cylinder which I had bought from the big NE guy were at 280 
>grit.  Ever since I've used a 400 grit ball hone without any 
>problems.  Just a thought.


I wrap the glaze buster with 600 grit wet-or-dry sandpaper to give 
cylinders a fine tooth, since I use moly-filled rings for the most 
part when I do this sort of thing, and I do check piston-cylinder 
clearances as a matter of course.


Jay's additional info posted is starting to sound like he's going to 
need to have the engine taken down again and corrected.   Brian's 
suggestion of the wrong glaze buster stones sounds very plausible... 
especially if the compression rings were not very fond of a coarse 
tooth on the cylinder walls.

There ARE still a lot of ring kits out there with cast iron 
compression rings that do need a coarse tooth to seat properly... but 
modern ductile rings with a moly-channeled center seat quickly with a 
fine tooth finish... and suffer if the surface is coarse.



>THAT 65 NUMBER IS FROM DIM MEMORY. I RECALL THAT THE PASSENGER BANK
>HAD TWO LOW AT 90, AND THE ONE ON THE DRIVER'S BANK WAS SIGNIFICANTLY
>LOWER THAN THAT.


So, it appears that the differences are pretty much random.   This 
tends to bypass the point of only one bank causing the problems.



>THESE ARE TOTAL SEAL MOLY RINGS FROM CLARK'S. I ALSO PURCHASED NEW
>FULL-FIN .030 JUGS, NEW FORGED PISTONS, RODS, AND BOUGHT THE CLARK'S
>PISTON PRESS-ON SERVICE.


This is now beginning to get interesting... did your engine builder 
hone the cylinders himself before assembly?   If so...  and if he 
used the "standard" 200-300 grit stones, this could be part of your 
problem.   It may have damaged the rings in short order.   I can't 
figure much other than that, or that perhaps by some fluke there was 
an error in the parts you received, and something was out of wack 
regarding cylinder clearance wither by mismatch or manufacturing error.

> > When the pistons went into the cylinders, did they go in from the 
> top or the
> > bottom of the cylinders?    What sort of ring compressor was used?   This
> > could be important...
> >
>I DON'T KNOW THE ANSWER TO THAT.


It's possible to install the pistons from the bottom of the cylinders 
but it's "iffy", and can result in ring cracks and/or gouging, or 
even a bent ring land if the assembler was a bit ham-fisted.  I still 
have a set of TRW forged pistons that I took out of an engine that 
had been assembled this way and ruined because someone forced the 
pistons up through the bottoms of the cylinders without using the 
right "tricks" and the rings actually hung on the notches of the 
cylinders and bent the ring lands badly enough to pinch the 2nd 
compression ring and leave the 1st ring sloppy loose in places... it 
actually ran like that but scuffed up the cylinder walls a bit and 
the engine started using oil bigtime.   It required another set of 
pistons, rings, and some hopeful optimism about the rehoned 
cylinders... AND some careful assembly.   It ran ok then.

I'm beginning to think you're gonna need to pull it apart again and 
take a close look at the cylinder walls and the condition of the rings.


>I CAN'T SAY WHAT CLEARANCES WERE CHECKED, BUT THIS GUY DIDN'T FALL OFF
>THE TURNIP TRUCK YESTERDAY. HE'S BEEN WORKING AT THE SAME GARAGE - AND
>NOW OWNS IT - FOR OVER 30 YEARS.


Now:   If he assembled the engine with the parts as-supplied, no mods 
(like a re-hone) and was careful about which end of the cylinders the 
pistons went into, it SHOULD have worked out ok.   It MIGHT still be 
that something was amiss in the parts themselves.. but only a partial 
teardown will tell.



>MICHAEL LEVEQUE PUT NEW BRONZE GUIDES IN. I AGREE THAT IT'S HIGHLY
>UNLIKELY THE HEADS ARE THE SOURCE OF ALL THAT OIL SMOKE.


Agreed, the heads are unlikely to be the cause of your problems.


>ONE OF THE REASONS WE STRUGGLED TO SAVE THE BLOCK, DESPITE THE UPPER
>STUD PULL, WAS THAT IT MIC'ED OUT SO BEAUTIFULLY ON TOLERANCES. LARRY
>CLAYPOOL'S INSERTS WERE A GODSEND. I BOUGHT SIX, AND WE ONLY USED TWO.
>I'LL STORE THE REST AND 'PAY FORWARD' TO SOMEONE ELSE WHO NEEDS THEM.

And, the crankcase would have to be pretty bad off to be so distorted 
as to cause the issues you're experiencing.


Again, I hate to say it but I think you're going to end up pulling it 
apart again.   Your compression issues are too far out of bounds to 
be a "delayed seating" thing.   Compression that low on the bad holes 
isn't gonna correct itself without a minor miracle.



tony..

PS:  sorry about the late reply