new timing set

cowboycadillac556 · #1 (**permalink**) 07-14-09, 08:15 PM

I am kinda learning as i go here and am trying to get my new timing chain in and am wondering what cylinder should be in "firing position"? please excuse my mechanical grammar or lack there of. I have read that #4 should be in firing position, does this make the marks line up? and also how should the distributor be set?

cadillac_al · #2 (**permalink**) 07-14-09, 08:59 PM

Whew, it's been a while, but I'm positive #1 has to be at top dead center with both valves closed

cowboycadillac556 · #3 (**permalink**) 07-14-09, 09:34 PM

it might be helpful to know that the engine is a 74 472, also my heads are at the machine shop till friday and i am trying to get this done together before they come back.

steelybill · #4 (**permalink**) 07-15-09, 01:39 AM

On the 472/500 engines, when the timing marks on the chain sprockets are lined up, #1 is NOT at top-dead-center. It's on the exhaust stroke. You have to rotate the crankshaft 1 full turn (to the timing mark) to get the distributor timed to the #1 firing position.
Kinda strange why it's that way, but even the firing order and cylinder numbers are different than most engines, with number one cylinder being on the right-front. Firing order FYI is 1-5-6-3-4-2-7-8

cowboycadillac556 · #5 (**permalink**) 07-15-09, 02:11 AM

will it run if I just line the marks up?

BRUCE ROE · #6 (**permalink**) 07-15-09, 02:17 AM

Right, Cad lines up on cylinder 4. I wrestle the old timing marks to line up, then take the cap off the distributor & mark the exact position of the rotor to the distributor. The distributor to engine can be marked also to get you on the same tooth. But expect that to move a little due to the new chain (if the rotor is exact). Bruce Roe CLC #14630