noodels

What about some nice new LMAs 14820-PCX-003

ncrx

timing chain guides if worn

Jub

Why? Honest question. Have people noticed wearing them out < 200k miles. My car has autocross time but not really track time. If it's something that makes sense to do, I'd do it but I'm not familiar with anyone really needing those. Also wouldn't require the head be removed to replace them though the cams would come out again.

noodels

The top caps wear,was a little worn on my old engine <115k>and getting the alignment on replacement is the only issue,not spring wear.Maybe shop will recommend it ?
may have a less noisy engine if replaced.
Can see wear on link >
DIY LMA removal/replacement writie up. - Honda-Tech - Honda Forum Discussion
compare with new not same engines but just to show LMAs
ScienceofSpeed Lost Motion Assembly (LMA) Kit - NSX, 1991-99 - Internal Engine Components - Engine Products - NSX, 1991-05

oooS2ooo

its always 1st or4st one, once you sit valves back it will totaly different car(in better way)

Jub

Valve looking obviously bad and cylinder walls looking good. Is there any real reason to clean off the piston tops while we're in there? Any downside to not doing it? I'd do it myself if I was the one doing the work but am questioning if asking someone else to do it is a good idea. I don't want to risk having cleaner or debris in the cylinder. Then again, the shop should know what to do.

I'll be happy to get it back at full power for sure! I'll be having the tune re-checked out as well once it's all complete. It was tuned a year and about 5k miles ago. I doubt it was leaking down like this at that time but still better safe than sorry. I've had the valves checked 3 or 4 times in the 20k miles I've owned it. I bought this car for a steal at 88k miles (now 110k) and did not have documentation of a valve adjust prior to my ownership. I expect that must be the reason.

Slowcrash_101

Ashy white exhaust valve, characteristic of a burned valve that has turned the carbon deposits to ash due to high heat.

Clean that ring ridge to make installing the pistons with the rings a little easier.

Iyan112

Yes you can clean the positions. Actually I do them all the time on J series engines for piston rings and part of the procedure is to clean the tops of pistons. We use brake clean or stuff we use for Induction services that is made for breaking up carbon. Spay it and let sit for a few and use a soft bristle brush and scrub away. Don’t use a steel brush because you’ll scratch them. Brass brushes are ok too.