Jarrod

Well, Today, I got bored, so decided to do a compression check. I did it with a Snap-On compression checker, and I did it with a couple of friends.

A bolt on 00 Integra Type R--220psi, except #3, which was 215psi
Built LS/Vtec--220psi across
My b16--190 across, except for #3, which was 180psi.

I want to figure out how to find my compression ratio. I have searched, but came up with the wrong places. I thought it was something simple like 190/14.7(atmospheric pressure) but I know I don't have 12.9:1 compression.

Also, for Honda people. Is 190 good for a b16?

Thanks in advance
Jarrod

neogenesis2004

All compression numbers look fine. 190 is probly from carbon buildup. Only thing I'd keep an eye on is the cylinder that is 180. 10 lower isnt bad at all but if it goes much over 15 in difference then you need some work.

Jarrod

Thanks.

I was told number 3 runs the hottest. And I have also heard it is pretty common for that to happen.

Jarrod

I read on the All Data we have at school, that 180 is normal for a b16. So, I'm lucky.

220 for a Type R isn't good either, it should be 270. But he has a larger headgasket for boost.

HatefulMechanic

compression gauge readings are not "exact" you can test it tomorrow under different conditions and it will be different.

there is no way to compare the pressure reading to a compression ratio, CR is not definitive to PSI.

15psi difference is common. general rule of thumb is anything more then a 10% variance from highest to lowest is an indication of trouble, and a leakdown test should be performed to determine the cause.

and Snap-On diag equip=teh overprice. i got my Mac kit with diesel gauge and adaptors for what Strap On wanted for just the gauge and auto hoses.

dont even get me started on the Modis.....

sk8rmike

snap on is hella overpriced for diagnostics...but when it comes to hand tools and what not you cant fuck w/ 'em. mac shit breaks so easy it's unbelievable. but yeah you said it how i wanted to say it but didnt know how to word it. just because a motor may put down 220 across the board doesnt mean it's stronger than a motor that puts down 180psi across the board. there are too many variables like cams and timing and what not.

Jarrod

Yah. I know. I was just asking if there was a formula to figure out compression ratio. Thanks though, to the both of ya'll.

I understand that just because the psi is higher, it doesn't mean its a stronger motor. But in this case, they are. ITR and Ls/Vtec own my b16.

I didn't pay for the snap-on compression checker

Yah, In the alldata it said 38 psi difference between all of the pistons combined is safe. Thanks on the 15 psi info, I thought it was 10.

Thanks ya'll.

I wish I was ASE certified, lol. One day.

sprack

fc735: how long does it take to usually get your test results? i took 2 last night....the website says a month but people said 1-2 weeks.

HatefulMechanic

3-4 weeks usually. when i passed my L1(first try btw ) i heard back in 12 days

one of my techs took three this week, i told him it will be 3-4 weeks. first time is always longer, they have to put you in the system and suchforth.

DONT take all at once. i have to recert about 4 a year which pretty well shoots my week to hell. plus, i am still taking truck certs too.....

Master L1 in auto (9 tests)
3 certs in truck

4 more to go in trucks if i recall, and then i will be a massah in trucks too

sprack

sounds like you got your hands full...i just took engine repair and brakes