I just calculated compression ratio in LS/VTEC I'm bulding. I used c-speedracing on-line calculatior. The result was 11.6:1, when I used B16A with B18A and pistons from B16A USDM.

My question is: Is this compression too high for this engine to make reliable or I don't have to worry about it t all? Are there any necessary additional upgrades to the hybrid engine I shoud make to be secured with such compression?

 

Im not sure about the ls block's ability to hold up to high compression, but im sure if they can hold all that boost people throw at it im sure it will be fine. Im running 11.6:1 compression, and have had no problems, just keep the higher octane fuel in there:thumbup:

 

What kind of octane do you guys get over there in Poland?

 

We have 95 (normal) and 98 (super), but I think the real octane ratio is 2 points lower.

 

nice

 

guys, keep in mind that there are two different ways of rating octane

 

That compression is fine for a daily driver using US premium gas.

It usually isn't a concern until you get over 12:1, and then you just have to be a little more careful.

 

11.6 to 1 is what you are yielding from that. So approx my ls/vtec should be running 11.8:1 with b18a block b18c head and civic type r pistons? I heard with the GSR head you add .2 to the compression yielded from a b16 head. Thanks.

 

if you have that exact setup you are pushin more like 12.3:1

 

i have a b18b block w/gsr head. my cr is 12.8:1 using 100 octane. if the motor is built right, should be reliable. my motor is also daily driven too.