What initial timing to run????

[Mikelly]

I know it really depends on the layout, and you want to shoot for a total of 36 degrees total timing, but... What initial timing are you guys running? Mine was set at around 11 degree.... thought that was pretty low... When people refer to backing off the timing they usually mean to reduce the number, but I found the car running much better when I advanced it...

 

Here are the exact specs..

383 with aluminum heads, straight plug, 1 5/8th ceramic (Thought they helped with heat issues??)headers. Valves are 2.05/1.6,cam is hydraulic roller with 282/294 duration w/ 110 lobe center. 1.5 rockers, intake lift is .530 and exhaust lift is .550. Overlap is 68 degrees. Running a BG 750 double pumper, with four corner idle circuit and a MSD billet distributor & 6AL box + 8.5mm wires...

 

Also, Pete, I still have a lot of heat under the hood so I'm gonna order some of the wire and line wrap for hi temps... that will hopefully resolve part of the issue, and I'm gonna relocate the remote starter to way up high and far back in the battery box area. This will mean extending the 1/0 wiring... how well do those welding grade butt connectors work for extending cable? Don't want to throw away $50 worth of 1/0 cable...

 

Mike

 

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"I will not be a spectator in the sport of life!"

mjk

 

[This message has been edited by Mikelly (edited May 20, 2000).]

 

[This message has been edited by Mikelly (edited May 20, 2000).]

[John Scott]

Mike, get the new car craft June edition. They have a great article on timing and carb tuning. Big cams, lower compression, high altitudes, like much more initial. I'd bet you'll be in the 16 to 18 degree range. Total advance in by 2500-3000. Some combos. will like more than 35 total, some a little less. This is where most people get into trouble. Most distributers have too much mechan. advance built in. They find the engine responds well to the new advanced initial, but forget or don't bother to check how much they've added to the total, say @ 3000 rpm. Get your initial set for best off line perf., then start working on the total. Probably need to reduce the mechanical with whatever limiters your mechanical advance requires. I've fabricated advance slot stops for stock HEIs. Aftermarket dist, like Mallory, MSD, should have a simple way of adjusting the total. Usually a tab or set screws. Too, much up on top is dissaster for an engine. As soon as any predet. is reached, power is gone, sometimes so are the pistons! I used to run a 265/256 @ .050, .600 lift, and 106(!) lobe sep angle. Talk about a radical sounding idle, up to almost 4000 before it got smooth! I had the red hot headers until I bumped it to 18+ degrees. I couldn't believe the low end it added to the already strong engine. It really cleaned up the throttle response, idle mixture/ speed also became adjustable.

JS

 

[This message has been edited by John Scott (edited May 20, 2000).]