Quote Originally Posted by FAYLUR
I've never used domed pistons so I've never had a need to know this but can someone explain if you should be concerned as much about quench when using domes? If you go with .035"-.045" then the head combustion chamber will have to be the proper or 'matching' CC's? Or do domed require more quench? And,,,,if the pistons are designed to provide say,,,12.5:1 with 64cc then using a 76cc would give too much quench? Is this right?
I will give you my 10 cents on the subject.
What Richard says is true.
I really don't care that much about quench when we use a high comp. ratio.
I will say this.
If it where a "full on" race engine I would put the piston down in the hole .005 to .010 that way you have some room to clean up the block if you have any issues.
If you want compression try and make as much as possible with out shoving a dome in the combustion chamber.
When you do this you create a kinds of problems trying to "light off" the fuel and air charge you also create all kinds of vortec's when you do this.
In a 383 a 6.0 rod and a 58 cc combustion chamber head and a flat top piston you can make 11.8-11.9 for a comp. ratio,no this won't run on pump gas.
I would never fart around with a 12.5 to 1 comp. ratio.
If you are going to shove a dome up in the combustion chamber it might as well be a big one.
One of our USMTS engines this year will go over 15.5 to 1 on meth.
This really pushes the limits of everything.
If this engine was on "gas" you would have to run 116 octane.