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Either way you have no quench , the 452's will flow better than the 516's .





This is where I get totally lost. This "quench" thing everyone keeps bringing up. So what happens when there is no quench and how do I get it. How can I not have it if I'm using just stock type parts??? Is there somewhere that I can read about to get an understanding?
Does not having quench lead to pinging in the motor? Thanks, Alex



Quench wasn't a big deal when you could buy hi octane fuel at the pump on any street corner for pennies a gallon , now it's what you need to achieve if you wnat optimum performance to run on the piss available on every street corner.

Yes it can lead to detonation (pinging) especially with higher compression ratios .

What you want is .040-.045 between the piston and the head on the side of the chamber away from the valves , to achieve it with open chambers leads to aggressive head milling or step dome pistons , with closed chamber you want the piston no more than .020 below the deck with a steel shim gasket or zero deck with a composite gasket and a closed chamber head.

I have 2 friends with almost identical built 440's both using the same cam and 906's, one with KB step domes and .060-.065 quench distance , his compression ratio was 9.3 and it would ping with anything less than 93 octane , other was a motor I did a lot of machining to achieve .040-.043 with the same step dome pistons. The heads were something I had bought from another member with big valves and milled about .050 initially and compression ended up about 10.3, this one ran with no pinging on 93 octane with 38 degrees total timing.

As far as why you don't have it using stock type parts , mopar didn't do anything to really achieve it so it's a mix and match to get it if possible , unfortunatley you are working with something you can't mix and match with .

I don't know what hughes has for pistons but to get it with your 452's will be impossible without a custom piston , which is easily doable. I'm getting ready to have a set made up by diamond and it's not as pricey as you would expect for a 440 build I'm doing using 452's. Or you need a flat top with about 2.060 CH , that'll be .020 in the hole on a 10.725 deck , steel shim gasket and a closed chamber head of your chosing .