Timing with Aluminum heads

[billetunderwear]

A friend of mine is running the TFS/Summit combo on a stock shortblock. Roughly how much timing should run with 91 octane? I seem to remember that you can advance timing a few more degrees with aluminum heads over irons because of their heat dissipating qualities.

Thanks!

 

[ILLKreations]

No more then 4 degrees! But u MUST run 90+ octane always! AND run as low of oil viscosity as possible! BUT keep in mind the thinner the more dangerous! Be careful!!

 

[StreetStang37]

I run 17-18* with 91 octane no problems.

 

[billetunderwear]

I run 17-18* with 91 octane no problems.

That's what I always thought was about right, but I wanted to double check before we went ahead and bumped it. Anybody consider that to be too much?

 

[Blue Thunder]

I run 36 degrees total timing (comes in full at 2400rpm) with the TFS race heat heads, close to 11:1 compression and a very aggressive cam profile. I can also get away with running 87 octane fuel if I have to, but the motor gets hotter, and I imagine it's detonating to some small degree that I can't hear.
Depending on your setup, you may or may not get away with more timing, it's difficult to know such things without testing the motor and monitoring its vitals. I would definately start conservative and see how it performs. Better safe than sorry.