385 series 502 total iginition timing?

[NIsaacs]

My son is getting ready to fire his custom built 502 in his new pulling truck and the engine builder (local) is telling him 25 degrees total. That seems really slow to me but I know nothing about a 460 engine. I know the builder well and want to question him about this but I don't want to insult him either so that's why the question. I know build specs are important but is there a ball park #. I can get more specs but I don't have much right now (sorry).

I do know it is about 13:1 compression, ED heads that flow 350, victor intake with 1150 dominator carb, msd ignition, big solid roller cam and 112 octane fuel,  about 700 hp.

Thanks, Nick

[blykins]

I'd say 32-34. 

That's one of those things that you'll have to experiment with though. 

Generally speaking, a modern combustion chamber, higher compression, and a few other variables dictate lower total timing.  If it's been dyno'd, pull the plugs and look at the timing mark on the ground strap.  You'll be able to get it close based on that. 

[NIsaacs]

Thanks, that makes more sense. I would think that with a 20 degree bushing for the mechanical advance and 5 degrees initial it would not even idle. We have local spring dyno days here tomorrow so he is trying to get it ready enough to test. It has not been started yet.

Nick

[Joe-JDC]

Don't be surprised if it likes 36-37* total.  I would start at 34*, and add two, and if it likes it, add two more, and then back off one, try that, and if it likes it, tighten it down.  If the chambers were CNC'd, then it may like less, but you should be safe with the above advice.  Joe-JDC

[4twennyAint]

Pulling is different than drag racing - the engine is at WOT and under severe load for 20 seconds avg., way longer than a 10 second drag race or dyno pull.  You need to watch EGT and if you can't, be methodical as you increase ignition advance.