So I'm rebuilding an F22c t due to overheating & block/head warping. The engine has less than 50k on it, used exclusively for hpde/tt days for the last 3 years. No valve contact or jumped time, just lost compression.

Any reason to replace the timing & oil chains & guides with new, or just re-use them?

 

I think there is a measurement spec on the chain for stretch, but I'd be very surprised if you were anywhere near being out spec, you would have plenty of life left in that chain IMO. I'd keep it.

 

The service manual doesn't show any specific length that the chain needs to be. But clearly if the TCT is able to keep tension on it, it's fine to reuse. The only reason I can see for replacing it would be a damaged link or if the TCT is fully extended and there is still "schlop" in the chain. (Highly unlikely)

 

My chain was 1/8" longer than a new one at 115k miles.

Change it. Makes a big difference in TCT tension.

 

Thanks, changing it then.

Billman, your opinion on:

Oil pump chain?

The nylon guides for the timing chain?

Thanks.

 

Im taking mine out @170k miles, gonna measure it and see how much abuse it shows.

 

Please do report back. I got 160,000 miles on the chain with a lot of 9k VTECING!!

 

I would replace, and did on mine:

-Timing chain
-timing chain guide on the TCT side. The nylon itself was totally unworn....but the BUTTON on the TCT side guide that contacts the TCT piston was smashed flat from the years when my TCT was bad (before my modified TCT) I have learned that part or most of the TCT noise is the BUTTON getting hammered flat. This further reduces chain tension (one style of my TCT addresses flattened buttons)

Oil pump chain and guides you are totally ok to leave them alone.

 

Timing chain replacement requires these parts to be removed:

oil pan
crank pulley and timing cover
valve cover
upper cam caps and camshafts
TCT
camwheel
i
The only reason I did my chain is because my timing cover had a broken top mount for my Ingalls ETD (the cover broke because a bolt was galled up/ seized) and I had to replace the timing cover.

I would likely have done the chain at 150k if I didn't need to change the timing cover.

 

yeah at 50k the chain is still pretty young in it's life, it could easily go another 100k, but it isn't an expensive part so it's up to you if you feel better doing it now.