Head's coming off tomorrow and thought I bump the CR while its off. My setup:
B20 stock head gasket, 0.040 milled head, Jun3 cams, 85mm 11.5:1 je pistons.

My final compression is about 10.8ish:1 which I think is way too low for my cams so I want to raise the CR a bit. --someone please help me calculate my exact CR as I do not know how to --

Now, my question is what would you do to raise the final cr to be at least 11.5:1? This is the absolute max I'm willing to raise it to as I'm afraid it might ping if I go any higher on 91 octane gas.

 

Since you have 11.5:1 pistons and you have done an LS/VTEC (which usually raises the compression) with a milled head doesn't that mean you are above 11.5:1 or did you mean 10.5:1

In any case make sure you check the valve clearances before you bring the combustion chamber closer to the block or you might get some piston to valve contact.

 

I have stock cam gears on the engine right now. Still debating whether spending money on cam gears to squeeze out whp is worthy because I don't think it'll make a big difference.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Calavera &raquo;</TD></TR><TR><TD CLASS="quote">I have stock cam gears on the engine right now. Still debating whether spending money on cam gears to squeeze out whp is worthy because I don't think it'll make a big difference. </TD></TR></TABLE>

tuning makes a HUGE difference.. buddy of mine w/ jun3's lost to a stock gsr before tuning.. after tuning.. it pulled on a stock R by 3 cars... and i have cam gears for you.

 

Damn!! You got all that engine work done and you have stock cam gears? Adjustable cam gears and some time on the dyno will unlock a lot of potential out of that engine. Not like it will give 50whp or nothing but, it will make a bigger difference than you might think.

 

okay, I'm looking into some adjustable cam gears.

Anyways, I really need to raise the cr though. Flat head valves, thinner head gasket, mill the head some more, get higher compression pistons....argh.... I dunno what to do, I don't wanna spend another few bills.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Spoonin &raquo;</TD></TR><TR><TD CLASS="quote">Damn!! You got all that engine work done and you have stock cam gears? Adjustable cam gears and some time on the dyno will unlock a lot of potential out of that engine. Not like it will give 50whp or nothing but, it will make a bigger difference than you might think.</TD></TR></TABLE>

I'm still thinking which way because considering the nature of jun 3 cams' high lift and duration, does 1 degree difference justify me spending 120~200 bucks on cam gears? Jun doesn't recommend going past +1 on cam timing I think. And it seems most jun3 owners make power at stock 0,0 settings anyway. decisions decisions decisions.

 

You never know. You might get more out of the cams since you have a different setup. It's not like you are putting them into a stock engine. Your compression is different than stock and your displacement is different than stock. The best thing to do is get a thinner head gasket if you want more compression (cheapest way) if you are really into keeping the car's longevity then get a copper one. Then check your valve clearances. Then cam gears and dyno tune. You never know what it might do. Every engine has it's own personality; even if you have two B18Cs, one could have totally different results than the other just from some tuning.