Are dished pistons OK for nitrous? Optimal? Not optimal?
#1
TECH Junkie
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Are dished pistons OK for nitrous? Optimal? Not optimal?
I'm probably going to be buying a forged shortblock that is already assembled for the most part, and it has dished pistons. I do have a nitrous kit and was wondering how dished pistons would affect the nitrous?
#2
The Bull
The piston itself will not totally help or harm the use of nitrous. It's mostly based on a couple factors. The first being total compression ratio. A motor at 13:1 plus will make the most significant gains on nitrous. Whereas a motor at 8.5:1 will work but just not as effective. You may not notice a substantial gain. For most of us with flat tops we are hovering around 11:1, which is a pretty good ratio for nitrous on a street car. A lot of this is really based on volume. Obviously with a dished piston you need a little more volume which really takes some power away at each jet size.
The second major factor is the flame front. If it's a true dish piston the flame front should be pretty close to that of a flat top. Guys with big dome pistons sometimes have them dimpled to change the flame front to get a little more even loading on the piston surface. Leads to more effecient horsepower gains from what I can gather.
So the net net of it all is no the dishes will not cause a problem, you just won't see the same gains as someone with a higher compression ratio.
The second major factor is the flame front. If it's a true dish piston the flame front should be pretty close to that of a flat top. Guys with big dome pistons sometimes have them dimpled to change the flame front to get a little more even loading on the piston surface. Leads to more effecient horsepower gains from what I can gather.
So the net net of it all is no the dishes will not cause a problem, you just won't see the same gains as someone with a higher compression ratio.