New Build 340/420 Questions

I’m going to say this again.

Your cylinder head materiel does NOT matter when it comes to compression ratio. NOTHING.

I’m not going to explain (again) why this is, but the fact is aluminum heads do not change how much compression you can run, nor do they reduce detonation with the exception of absolutely loading the engine for long periods of time.

Just like in the Engine Masters test, they had to heat load the engine similar to what would happen in the real world if you were pulling a 7% grade for several miles and never down shifting.

If someone does that then to me that’s a driver abuse issue.

You should always use the highest grade if pump fuel you can get. Premium pump fuel has much more strict controls on the garbage the blenders can use.

I would not even back the car out of the shop without knowing total timing and at what rpm that is.

With your cranking numbers you better make double damn sure the curve in the distributor is spot on.

For you, that means probably less initial (I’m going to guess you’ll need 16-18 initial) and then you need to keep the curve so that at peak torque you have 22-24 at peak torque. After that the curve should be 1.5-2.0 degrees per 1000/rpm to peak power.

You’ll need to get a vacuum gauge on it and figure out where you can start the VA but I suspect you’ll need to delay it’s start and reduce its total advance.

You say your cam is on a 109 CL. Are you saying it’s on a 109 ICL or is it on a 109 LSA?