Alright fellow gearheads. The ring gaps we’re all in spec. I cleaned the pistons, and the bores with contact cleaner before I installed them. Good oil flow to the head (except the leaks). Where did I go wrong?
Twenty four years and I still have to learn things the hard way. Luckily I’m used to myself, so I have a backup-plan! Spare set of cylinders, and a JE 11:1 drop-in piston set on its way. Anyone care to place any wagers on the outcome?
September 27th, 2007 at 10:03 am
A couple of years ago I was coming to work down route 1 in the cobra and the steering froze. I went to adjust for the road and the wheel didn’t move! If I wrenched real hard it would jump to a new position and stick there. I was extremely lucky to get the car off the road safely. I took the steering rack apart and discovered that I had done a real good job of cleaning and rebuilding but I never lubricated it.
In your case it really looks like my steering rack, all nice and shinny instead of sloppy with oil when they were assembled. If it wasn’t lack of pre-lube then I am stumped, you are lucky that the plugs leaked.
The damage looks quite minor; I would give the pistons a quick scotch brite, run a hone back through the cylinders and save the new units for next season.
Years ago I rebuilt a V8 for my Vega and took it out for a test. Just about the time I noticed that I had no water temp it seized. Apparently the water temp gage needs water to work.
September 27th, 2007 at 10:28 am
I’ve checked it all three times now. The only thing I can think of (even though the piston-to-bore gap is within tolerance) is that I put the wrong piston in the wrong cylinder, but I don’t think that would have caused this much damage? These cylinders we’re sloppy with oil (and bits of the moly-ring) I just cleaned them off before taking photos. Frustrating and humbling all at the same time.
September 27th, 2007 at 11:00 am
What strikes me as odd is the wear pattern, it almost looks like two of the rings were butted, no gap, and doing a wavy expansion thing. Did you break a ring? How much running did the cylinder have?
September 27th, 2007 at 11:04 am
Didn’t break any rings. Running time was probably 5-6 minutes total. I’m not sure if I can save these though. I’ll need new rings at a minimum, but I’m not sure if a hone would clean up this scoring. Maybe a replate?
September 27th, 2007 at 2:45 pm
A guy I work with (who used to work on big trucks) gave me a different perspective which seems to make sense. Debris in the oil. Looking at the damage on the piston, it kind of makes sense.
September 27th, 2007 at 5:59 pm
Is it possible that it was debris left over from the dropped valve? If so I hope that the bearings are ok.
September 28th, 2007 at 11:58 am
Nope, I dropped the valve in the Husqvarna. This is the 900SS. I had four (not two) freeze plugs leaking. I’m wondering if the oil leak caused enough of a drop in oil pressure prevent oil from spraying into and through the piston…
September 29th, 2007 at 3:37 pm
Im really not even sure what im looking at.. so that being said, does it feel as bad as it looks? And despite looking bad I can still see some crosshatch through the dark spots.. bits of ring I would assume is normal when they are new, they are breaking in (ie cutting themselves up to fit into the cylinder perfectly)… perhaps this is just what it looks like if you start a break in and then take it apart well before its done?
nah probably not
did you lubricate of any that before installing it?
im trying to visualize how the heck it would end up with those perfect rectangles instead of just a mess of random cuts.. but even still I dont think debris would effect the cylinder walls like that so much as the bearings