Timing

Newbomb Turk said
Oh come on. Not this again. There isn’t one shred of evidence that says aluminum heads will take more compression than iron heads. In fact, engine master debunked that nonsense.

I’m betting my engine, which will be at least 12:1 on pump gas with IRON HEADS won’t be any more detonation prone than if it had aluminum heads.

And I’m betting that if the engine pulls to say…6800 that it will require close to 35 degrees of total timing.

This total nonsense that aluminum heads have superior heat conductivity THAT REDUCES detonation needs to quickly die.

There is no basis in fact that the aluminum head can transfer heat so fast it can get rid of heat in nanoseconds. That’s just straight horse crap.

The myth that Engine Masters debunked is that aluminum heads need more compression to make the same power/torque as iron heads which is untrue.

Aluminum has much less tendency to have hot spots in the chamber. Heat transfer away from the chamber is too slow to matter but localized heat buildup is a lot less with aluminum.

The 8.2:1 iron-headed 360 in my D200 pings with 34 degrees total timing but the 9:1 aluminum-headed 360 in my Duster is happy with 36. MANY factors at play there and I have yet to optimize the curve in the Duster engine (getting really sick of mechanical advance control!!) but overall the aluminum-headed 360 is far less sensitive to ignition advance.