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Old 02-18-2013, 12:39 PM
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ggevaert ggevaert is offline
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Initial timing

Hello,

I'm working through retiming an engine with minimal engine information (i.e. don't know compression) and I need some assistance on determining initial timing.

Is there a way to determine how much an initial timing an engine can handle through some sort of procedure? Most articles and threads I read talk about trial and error if you don't know items such as compression and that is fine but how do you know when too much is too much? How do you know how much the engine 'wants'?

I have a 350 SBC (had been rebuild when I bought it 4 years ago, has about 10,000 miles on it) with 450 lift, 224 duration cam, 416 heads, dual plane edelbrock intake, quickfuel 680 carb (with slightly larger idle air bleeds), long tube headers, 2500 stall, MSD 8365 distributor,

I have run it at 18 degrees all the way up to 22 degrees (currently at 22) and it starts and idles fine at 800 rpm. I have a custom limiter installed in the 8365 that gives me 14 degrees of mechanical advance for a total of 36. I also have a custom 10 degree one and then the typical MSD advance kit 18 and up ones if needed; vacuum advance currently totally disconnected and plugged. Advance kit springs starts timing at 1200 and all in at 2800.

I was provided a procedure by an old timer as below but couldn't really see any of the conditions he indicated all the way up to 22 degrees so not sure if I was doing it wrong or if I need to keep going up:
* get engine up to operating temp.
* turn off and let the temp spike (about a minute)
* Start engine back up and if the starter has problems getting the engine to start or if you have air coming up the carb then decrease timing by a couple of degrees and that's your initial timing otherwise keep increasing the timing a couple of degrees at a time doing the above temp spike method each time.

Final note; truck does not have any windows in it so I can't take it to a road drive just yet so need to do most inital setup in the garage.

Before I move onto vacuum setup and carb tuning I want to get initial timing and total timing correct so any help is greatly appreciated.

Ps. Truck is a street vehicle but not a daily driver; more of a fun learning environment which may yet get to see some strip action just for the fun of it.

Last edited by ggevaert; 02-18-2013 at 12:46 PM.
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