timing chains-i shoulda stayed w/big block
Thread Starter
Joined: Sep 2007
Posts: 4,188
Likes: 292
From: woodbine, md
timing chains-i shoulda stayed w/big block well, after buying a double roller chain, melling 296 pump, and finding they dont like the front cover (i dont think i can grind enough to make it fit) i went to the chevy dealer and figured i would go back to a single roller chain, and use the melling pump-based on some advice, i got a #12586482 chain (made in france), a #12576407 cam gear, and a #12556582 crank sproket-figured this ends that problem-wrong, the chain is way to loose, and the block is not line bored-i wonder what crap i have now, is the chain supposed to use some kind of tensioner? now im not new at this s%$#, done lots of motors over the last 40 years, just never touched a gen 3, and like an idiot i thought it would be cool to put in my 69-of course, with the motor rebuild, front acces dr, procharger, i am in to deep now-i really wanted to button it up and install this weekend, can anyone tell me what went wrong on the GM parts, and can i use the gears and maybe a diff chain! and to think i just unloaded my
489 procharged chevelle for this-boy, am i getting dumb!
489 procharged chevelle for this-boy, am i getting dumb!
The timing chain has a good bit of slack compared to an old school chevy. Aluminum expands when it's heated, so the slack is taken out when the engine is at operating temperature. They do make a tensioner, but you may have drill the block to use it. You can pick one up from Scoggin-Dickey if you want the added protection.
Cloyes I believe makes a single that is 0.005 over if you have too much slack. Check their catalog. If you can measure the slack (depress the chain) and get a measurement I think their catalog will convert it to the required increase required.
Thread Starter
Joined: Sep 2007
Posts: 4,188
Likes: 292
From: woodbine, md
when i had the comp double roller on, it was perfect-i am going back to that, and using a stock replacement oil pump, port it, shim the spring, hope the front cover fits (it did with the orig pump and d/r) and let it eat-been an expensive week, prob. bought over $500 worth of stuff i cant use on the car, trying to paint the car and reassemble it, along with putting the motor together, build the freak trans(switch pitch turbo 400) and have it done by the end of march-aint enough beer in the world at this point, lol
