Timing chain and FE
 

anyone ever document FE before and after a timing chain/belt service. my olds just hit 100k miles, and sooner or later i'll have it done. i realize it can go many more miles, but would consider sooner over later if greater FE would result.

any opinions and/or links are appreciated.

and clencher, before you tell me to do it myself, i'd like to invite you to florida to help me(you work, i'll supervise). no $, but all the beer you can drink w/ a one day limit. and NO doggie containers to go. it's really nice this time of year(mid 70s right now). or come in january when it's 50s and 60s when you have what? 10 and 20 BELOW.

Unless your chain has s t r e t c h e d to the point of changing your valve timing (stretching would retard it, which is bad for FE because it would lower effective compression... I believe), you won't notice any difference in fuel consumption.

That said, does the free-beer-in-Fla-in-the-depths-of-winter offer only apply to clencher??

Under the terms your proposing, I don't think you should be counting on the work acutally getting done. The primary incentive you are offering would seem to lean the participant towards the chugging side of things, not the working side.

Shhh!

Let's not forget the crash on the drive home as an added benefit, :p

Don't think a swap would net you any fe benefit.

depending on where the tensioner is located, a worn timing chain may advance or retard the cam timing.

i've asked the top guy in our shop about this very thing, not for mpg, just for wear. i had a 94 olds, but it goes for the series2 3.8s also. he says they're lifetime chains/gears, had never seen any in need of replacement from wear. or heard of any ever replaced for reason other than customer requesting it or complete engine overhaul/rebuild. i was asking because mine was over 200,000miles at the time, he said hes seen +300,000mile chains that were just fine.

long story short, wear doesn't seem to be an issue on these engines timing chains.

there isnt one, pushrod engine, so it has a short chain.

I am not sure exactly how important the timing belt is to a gasser. I do know that with my car, a TDi, that if you neglect to change it according to schedule, that you risk destroying your engine. I have never heard of such a risk with gassers, but it makes sense to follow the owner's manual for items such as this. The manufacturer usually has reasons behind their maintenance schedule.

I say you should change it, whether it affects your FE or not. Just do a good job, as a bad install could cause problems for you.

If the car has an interference engine (which many do these days) a snapped belt will fubar it.