what compression are you running?

chrisb · #1 (**permalink**) 02-08-2008, 01:02 AM

just like the title says what compression are ya guys running and what kind if any promblems are you having? im n/a and run 93 octane how high could i go without any knock? just lookin for a base line im think 10:1 cause i dont want to have to much milled of the heads. any concerns are welcome!
(if i could, i go with 13:1 or sumthin crazy lol)

thanks

Lever · #2 (**permalink**) 02-08-2008, 04:35 AM

currently ..iam running stock cr.

GP_Pimp · #3 (**permalink**) 02-08-2008, 05:24 AM

I think you're going to have a hard enough time getting much over 10:1 anyhow without some significant motor work.

chrisb · #4 (**permalink**) 02-08-2008, 11:32 AM

yeah i heard that if you mill to much of the bottoms it throughs valvetrain harmonics out? would i have any problems ruinin 10:1?

dbtk2 · #5 (**permalink**) 02-08-2008, 06:36 PM

While I'm not N/A anymore, I have ~9.75:1 compression using an L36 bottom end, .052 head gaskets, and .010" milled heads. Even with a 2.55 pulley and spraying a 75 shot I haven't had any issues with head gaskets or warping heads, so on an N/A app. with significantly less cylinder pressure milling the heads a lot more than that shouldn't be an issue.

For an N/A setup, 10:1 is pretty easy to achieve, much more than that and you will have to buy shorter pushrods and start milling the intake and whatnot and/or change out the pistons. With .045" head gaskets and a .020" mill, (total of .037" shorter than stock), you will have just about exactly 10:1, the heads won't be weakened a whole lot and you can mostlikely still run stock pushrods. If you want to mill more than that, you'll probably need to change out pushrods. And with over .050" mill you'll also likely need to mill the LIM.

FWIW, ZZP had a .100" mill on their N/A car with .045" gaskets IIRC. Using a stock bottom end this would put compression somewhere around 11.3:1.

chrisb · #6 (**permalink**) 02-09-2008, 12:37 AM

i thought for every .006 taken off you add 1 point to your total number for compression? so .037 would be 10:1:1 i think

chrisb · #7 (**permalink**) 02-09-2008, 12:40 AM

Quote:

Originally Posted by Lever

currently ..iam running stock cr.

what kind of power are you putting down? and what else do you have done to the car? (nice run by the way against sleeper ls)

Lever · #8 (**permalink**) 02-09-2008, 06:58 AM

the major stuff done is in my siggy ...there are a few thing small thing like plugs engine oil and filter stuff like that wasnt listed

but the spring/early summer up grades ....
1 stage 3 cam
2 stage 3 heads
3 zzp hv3 insert
4 intense trans with Lsd
5 intense dyno tune

the dyno #'s listed i was told was kinda low due to several pulls that where made adjusting the car
i should be a little more closer to 200 whp than what listed in my siggy and on paper

thanks fore the nice words about my car that you and other folks have said

i really take great pride in my monte carlo

i was totaly in shock and aww when i saw sleeper's car get 2nd gear tire chirped that was the 1st time i ever saw a fwd do that
i thought that was rwd thingy only
sleeper's is very quick and the blower whine ..hehehe its beautiful music to hear
i may do a power adder in years to come after the monte is paid off and /or is not a daily driver, as it is now

chrisb · #9 (**permalink**) 02-10-2008, 12:30 AM

2nd gear wow?! thats sweet.. what modd made the biggest improvement on your car?