Hi Guys,

I now have the time to finish my Dart 225's and FAST intake LS2 Throttle body install and wanted to know what you guys think would work. I was thinking of
.040 Cometics and mill the heads to 59-60 cc. I know I will have to flycut the pistons as I am running a G5X3 on a 114.
Concerns I have are how much can I cut the pistons without weakening them or causing balance issues, and with the 2.05 Intake valves I don't know how much I can safely take out between gasket and milling without causing problems. I run 93 octane Mobil gas, no race fuel. I'm picking up an adjustable pushrod tomm. so I can start to check clearances with the stock gasket, so i really have no idea as to what i will find.
My car is not a daily driver it gets driven on the weekends around town and raced at Moroso maybe a couple of times a month. I'm looking for the most perfomance I can muster without getting into new pistons, and at the same time good compression and DCR. Can someone help me calculate my compression and DCR, I don't have a calculator for this, I tried the sticky but for whatever reason it won't open on my computer.
Thanks
John

 

up up up

 

You can safely flycut .120 out of the stock pistons. While you do have to cut deeper than what you actually need for clearance, cutting less is better for balance.

 

Thanks for the info. just want to make sure I don't upset the balance of the motor. I'm thinking with milling and thinner gaskets rducing by .028 or so, I should be somewhere around .045 to.070 to cut, with the 2.05's. I won't actually know till later today. Do you have a calculator for DCR?
John

 

I would start with a .075 flycut and measure from there. For reference, thats the thickness of a nickel. It wont upset the balance all that much. Heck, ive seen pistons with that much weight in carbon on em

 

Thanks, I'm looking to get the most out of this setup. Does anyone know how far down I can take the head before I run into quench problems or low lift turbulence with the valve being to close to the wall?

 

Milling or running a smaller gasket wont put the valve any closer to the cyliner wall.

Most people try to maintain atleast a .030 or .035 quench. Keep in mind most pictons are .007 out of the hole.

 

Cool, thanks again.

can anyone calculate DCR for me?

 

Gimme your head and cam specs...

Cylinder head CC's
What gaskets?
Intake closing point?

 

PM Sent
Thanks