Is there a formula? 4.030 pistons 308 heads. It’s almost 11:1 want to go to 9:1. Use: pump gas and nitrous.
Not an option. $$$$$$. I got screwed on these ones.Sell the race pistons & buy the correct pistons for your application. I'm sure there are people here who are building race engines that would buy the .030 high compression units.
Probably $200-$300. Aftermarket pistons have pretty deep valve reliefs and thick tops so I'm guessing it could be just milling and you're good to go with no valve relief work if you're going with a smaller cam for the 9to1 deal.Thanks guys flat top srp. Pics Friday. What would it cost to shave them and valve reliefs.
I don’t want to run hi cr with nitrous.
Needed info post 1Tbere are three ways (at least) to reduce compression ratio. Mill the pistons to reduce deck height or dome, enlarge the combustion chamber (minimally effective) or a thicker head gasket.
If you have open chamber heads, and dont have a quench dome piston, you dont have any quench now to lose. A set of thick head gaskets can lower your compression quite a bit. Cheapest, easiest ,simplest solution.
If you post your calculations and engine specs that say you are at 11 to 1, we can better advise what we would do.
Have you ever used nitrous? Just asking, because having more compression is really not a problem. To safely run nitrous you will need to retard your timing AND use high octane fuel (like race gas). The compression is a non-issue in my opinion...and I ran nitrous for quite a few years on motors that I built specifically for nitrous use.Needed info post 1
I’ll want to go as cheap as possible as there will be a compromise between cr and nitrou efficiency. Depending on where you want the sweet spot, with high duration and compression with the high duration cam I have will put power in mid to top end. With nitrous, you need to retard the timing. So with what I just described I would need to pull even more timing out of the equation. Thus reducing power. So I’m hoping that I can find a head gasket thick enough to get down to 10:1
Aren't there ways to reduce compression by changing the cam specs??????Tbere are three ways (at least) to reduce compression ratio. Mill the pistons to reduce deck height or dome, enlarge the combustion chamber (minimally effective) or a thicker head gasket.
If you have open chamber heads, and dont have a quench dome piston, you dont have any quench now to lose. A set of thick head gaskets can lower your compression quite a bit. Cheapest, easiest ,simplest solution.
If you post your calculations and engine specs that say you are at 11 to 1, we can better advise what we would do.
Is there a formula? 4.030 pistons 308 heads. It’s almost 11:1 want to go to 9:1. Use: pump gas and nitrous.
Take them to a machine shop & have them milled to a dish... I haven't done the math on your engine but probably a 12cc or more dish will get you there. Problem maybe if they're milled & you're using nitrous you'll most like make a very large gas port about 3 inches around because they were to thin.Is there a formula? 4.030 pistons 308 heads. It’s almost 11:1 want to go to 9:1. Use: pump gas and nitrous.
Yes & no, you can change the dynamic compression but cannot change the static (which is the accumulation of the mechanical parts)Aren't there ways to reduce compression by changing the cam specs??????