were pulling the head in a couple of days to get some work done to it ill cc the chambers then and find out thanks for all the comments

 

Simple Compression Calculator Link

This does not give adjustments for the head being milled, but gives a reasonable starting point.

 

all of the compression calculation tools say 11.5 to 11.7 so if the head is milled .30 on top of that i think it will be higher thand 10.4

motor is a ls vtec with p30 spec pistons and b16 head milled either .30 or .40

 

I never said his was 10.4, just stated that 260 was 10.4-10.6 on a B-Series Vtec with stock cams. Meaning your typical B16, 17, or 18 Vtec. That is why I previously asked for the set-up. I know the above is correct do to recent experience, compression checked 2 customers cars, both JDM GS-R's, one with stock cams was 270-275 and jdm gsr's are 10.6:1 motors. And checked one with a Type-r Intake cam and his was 260. Most stock USDM GS-R's and B16's I have checked are all within that range also. When you stroke a motor (I.E. LS Vtec, the poor mans stroker motor but very affective for the cost) , a piston that will may only produce 10.6 may easily produce over 11.0:1 as the link I posted for the compression calculator shows. Not trying to call you out but don't try to make my information look incorrect. I hope the link to the compression calculator is useful to help end some disputes. It's one of the most simple ones I have found to use and with checking it against other methods it appears to be correct.

 

must have more power capatain

 

does somewhere in there really say 270-275 for jdm Gsr owell yes like i said with your head milled your around 12: with aftermarket pistons