weatherman

I'm having a valve job done on my car this week. Should I pay the extra money to get the timing chain(or chains) replaced too? The shop said there are two chains that should be replaced. I plan to drive this car for another 150K miles.

SgtB

Has anyone measured the chain stretch at that millage? I'm just curious. I'm wondering how much tooth wear there is on the sprockets too.

zeroptzero

I would say not necessary but it will give you some peace of mind over the next 150k and you won't likely be in that part of the engine again.

jimnasty23

ouch! not good to replace worn parts on a worn engine. Your only going to make things worse if you only have the valves replaced, especially with 170k miles. If you want to fix things do it right and rebuild both the top and bottom end at THE SAME TIME. Otherwise your looking for trouble..your just going to ruin both the brand new parts and accelerate the death of your worn engine parts.
just some food for thought.
you dont have to listen to me...but its a good idea just to do a complete overhaul..IMO

SgtB

I wouldn't worry about valve replacements as long as they're lapped into the seats. Honestly I can't think of anything besides crank and rod bearings that would make a huge difference as long as runout and endplay are good on the particular part..

jimnasty23

true, i just like to be on the safe side and do both dop and bottom...you just figure if youve got a weak valve train and bottom end, the new valve train would wear the bottom end faster because now the top end is much more stronger...idk, ive never done a s2k engine overhaul but i mean ive always been taught that when you do the top, you better do the bottom...i mean i dont think it would matter as much if the OPs car had maybe 80k miles or less but since its got 170k....idk id feel much better doing both top and bottom..but thats just me, like i said ive never done an s2k engine(yet) and im no master.

slowpokeS2K

Jimnasty23, that makes no sense to me. obviously, if you never touched the engine yourself, id stay quiet about it.

to the OP, if by valve job you mean a valve adjustment, then i dont see anything wrong with leaving the bottom end just the way it is. You should definitely do a compression/leakdown test to see how things are going. if numbers are not in spec, then i would suggest looking into an overhaul. but if your numbers are consistent and within a safe range, just leave it alone.

like the saying goes, if it aint broke, dont fix it...

theres someone on this forum that has over 270,000 miles, and still rocking stock internals...

weatherman

This is not a valve adjustment. An adjustment was done at 110K. This is a complete valve job. The shop doing the work has been in the car racing business for many years, and the owner tells me they would do valve overhauls on cars after only a couple of races. I talked to him Friday about the timing chain. He said not to replace it. He sees nothing wrong with it. I have complete confidence in this shop. They are located in Palm Beach and work on the most expensive cars in the world...daily.

As a side note, the first shop I took the car to told me the piston rings were the issue(I had lower compression 100psi in cyl 2) I had a gut feeling the guy didn't know what he was doing, so I got a second opinion. Good thing I did. Second shop did a smoke test and clearly showed smoke coming out other valves. He said the first shop likely didn't lock down at TDC as the leakdown test was done.

weatherman

Went into the shop to see my car today. It will be another 2 days before it's ready. The head is at the machine shop but everything else was is amazing shape. The mechanic said other than machine shop work for the valves(and replace one valve) nothing else needed to be done. Cylinders, pistons, cams all looked brand new. Very good to hear.

My mechanic has never worked on the F20 engine, but said it was very unique design and worth keeping forever. I trust his opinion, considering he has an Indy car out back