Reading valve color

nander · Post by **nander** » Sat Oct 16, 2010 12:25 pm

And here's the last set -- of the liners.

Again, the left sleeve has some black ring marks that I think are pretty visible in the photo. Both left and right have some vertical and cross-hatch scoring.

Like I said, my assumption, and that's all I have to work with because I didn't identify left and right pistons when I took them out, is that the more scored piston in the second set of photos came out of that lef tsleeve -- just because that sleeve has the more obvious wear. But, who knows?

LOUD MOUSE · Post by **LOUD MOUSE** » Sat Oct 16, 2010 1:40 pm

IMO the pistons didn't seize. ..............lm

nander wrote:And here's the last set -- of the liners.

Again, the left sleeve has some black ring marks that I think are pretty visible in the photo. Both left and right have some vertical and cross-hatch scoring.

Like I said, my assumption, and that's all I have to work with because I didn't identify left and right pistons when I took them out, is that the more scored piston in the second set of photos came out of that lef tsleeve -- just because that sleeve has the more obvious wear. But, who knows?

nander · Post by **nander** » Sat Oct 16, 2010 2:41 pm

LM
Yeah they didn't look too abused to me either. The scoring on the skirts troubled me though.

I just put some lacquer thinner in that cylinder head and there was a little moisture seepage around that whitened valve. So it looks like it doesn't seat well.

jensen · Post by **jensen** » Sat Oct 16, 2010 3:33 pm

Hi,

Indeed, pistons show normal wear, bores too.
Some stains due to condensation, but that ain't the problem you describe.

Jensen

teazer · Post by **teazer** » Sat Oct 16, 2010 4:00 pm

There is no sign of seizure on either piston as LM and Jensen already observed. There's quite a bit of scoring, but nothing to worry about. The burned oil on the bottom surface of the crowns indicates that the pistons are getting quite hot, and no sign of "death ash".

That stained liner is rust where the rings stuck to the liner, but I wouldn't get too excited about that either.

It is possible that something got hot and you stopped it before it seized.

There's one other possibility we haven't talked about and that's the transmission. How free are the shafts to turn and is there any play in the shafts?

LOUD MOUSE · Post by **LOUD MOUSE** » Sat Oct 16, 2010 8:32 pm

I don't see that. .......lm

"""The burned oil on the bottom surface of the crowns indicates that the pistons are getting quite hot""",

teazer wrote:There is no sign of seizure on either piston as LM and Jensen already observed. There's quite a bit of scoring, but nothing to worry about. The burned oil on the bottom surface of the crowns indicates that the pistons are getting quite hot, and no sign of "death ash".

That stained liner is rust where the rings stuck to the liner, but I wouldn't get too excited about that either.

It is possible that something got hot and you stopped it before it seized.

There's one other possibility we haven't talked about and that's the transmission. How free are the shafts to turn and is there any play in the shafts?

teazer · Post by **teazer** » Sat Oct 16, 2010 9:59 pm

Piston 1 has a small but easily seen stain under the crown. Not bad, but it's stained. Piston 2 has a slight discoloration. In neither case is it serious or a sign of an overheating problem.

At higher mileages, most pistons will have some build up on the lower surface, but my understanding was that these hadn't done many miles. Either way, it's not a problem and the top surfaces look fine.