Bobby_80s

iTrader: (2)

when is it a good time to change out the timing chain and cam

and don't say whenever or do it for more power

i just want like a factory spec almost like change oil every 3,000 mile kinda answer

like every 100,000 miles or what>?

its not hard just very time consuming and just a pain to me so im jsut curious when i should be gettign ready to do it to my v8 tpi trans am 1986

Air_Adam

For the cam, either flat tappet or roller - if theres nothing physically wrong with it, then theres no reason to replace it. If its the factory cam, then I wouldn't worry about it, as they have a tame enough grind and weak enough valve springs that they don't really wear out if they get somewhat regular oil changes. Especially true of roller cams ('87+ V8 cars, not sure what year for 6 cyl cars).

For the timing chain - it depends whats there. They actually last a really long time with the V8 engines, and don't really have a replacement interval like a timing belt would have, because they very very rarely break (basically never) they just stretch a bit. If you take the cover off, and you can feel a fair amount of slack in the chain, then its probably due for replacement. If you are looking for a number though, 100,000 is probably safe.

Bobby_80s

iTrader: (2)

my v8 has 102,000 on it i really dont want to take it apart again but you answered my question

is it true if the chain does go the engine stops before it does any real damage and jsut replace the chain or once the chain goes everytihng gets meshed and the engine is ruined?

Air_Adam

With an interference-engine (common in Japanese cars), if the timing chain/belt breaks, then the pistons can slam into the valves and cause alot of damage.

BUT - these are not interference type engines, so that doesn't happen. It will just simply stop running. You'll just have to realign the crank and cam for the proper valve timing, install the new timing set, and your good to go. But it is EXTREMELY rare for a timing chain to snap in a SBC engine, unless you are running some really gnarly valve springs and a VERY big cam - more possible, but even then still rare. I wouldn't count on it ever happening to you. The chains stretch over time, and once it gets to a certain point, then the valve timing is off enough that the engine will be hard to start, run poorly (if at all), and make no power. If not for chain stretch, there would really be no reason to ever replace the chain, as it is so rare for it to actually break (assuming correct assembly, etc).

I've seen a few SBC engines with well over 200,000 miles on them, with the original chain, and still working just fine. With only 100,000 on yours, I really wouldn't worry about it too much.

AsphaltAssalter

I've seen the chains get so loose they start chewing a hole in the timing cover, then oil starts getting over everything, that's when you know it's really wore out. But they commonly go 200,000 + miles, might not run as good as new because the timing does retard some but they run OK. The exceptions are the old timing sets GM used in the 70's with the nylon teeth, they might not last 20,000 miles, pure junk.

TheBigJ

iTrader: (1)

My 88 sportside has over 240,000 miles, seems to run good. Chain stretch has def. occured since it shows signs of being retarded

jamon8

iTrader: (3)

change it

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