compression psi to ratio: compression test results!
 

im not exactly sure that this is where this belongs but this is where its going...im wanting to figure out how to turn a compression test into a compression ratio. ive looked around on a few different sites but i havent came up with much nor do i know if its even possible...?

Re: compression psi to ratio
 

I don't think its possible. Maybe rough approximation, but not exact. If your compression is low on all your cylinders, is you compression ratio drop? No. There's too many variable for compression ratio.

Re: compression psi to ratio
 

ok well then will...a d15 with 9.5:1 compression have different numbers than an h22 of the same compression ratio when a compression test is ran?

Re: compression psi to ratio
 

mabey due to bore and stroke

Re: compression psi to ratio
 

ok cool i dont feel quite as dumb now. im not the only one that doesnt know. the reason i ask i have an h22 hatch and im wating to turbo it. supposedly something has been done to it the guy i got the motor got it from a guy that got it from a guy... its supposed to have really high compresson and when i took it to get it tuned it put down like 225 and dan said hes never seen an h22 put down that much power that was stock. im gonna go run a compression test probably tomorrow when i get off work. im just trying to figure out what is done to this thing without pulling the head...

Re: compression psi to ratio
 

Well obviously the lower the compression ratio the lower the compression of the motor and vice versa. If your compression ratio is 10:1 you will have a much higher psi reading on the gauge than if you had a motor with a 9:1 ratio. All you need to do is find what the service standards are for a compression test on the H22 and see where your numbers sit at. ;)

Re: compression psi to ratio
 

maybe dew to leaks !! more wear different engien more blow by?

Re: compression psi to ratio
 

7.0 is like 141, 8.0 is 162, 9.0 183... and so on. thats just what my gauge says

Re: compression psi to ratio
 

huh? i said it makes more power not less?


well yes i understand that more psi means higher compression ratio. i would just like to know what the compression ratio is on this stupid thing to figure out whats been done to this thing. oh well thats cool i just didnt know if theres a formula or something. thanks for the info though!

Re: compression psi to ratio
 

lol

compression psi to ratio: compression test results!
 

ok...i ran a compression test today...i have 263 265 263 262...whats going on here...im only supposed to have somewhere around 180 what the hell?

Re: compression psi to ratio: compression test results!
 

Are you doing it right? I remember a post on hmt that was that high, I think the guy didnt open TB. But I really dont know, never did a compression test before...

Re: compression psi to ratio: compression test results!
 

dont open the throttle body and its usually slightly lower because it cant pull in quite as much air. but yes sir thats at approx. 250 rpm and the throttle body wide open with all 4 plugs out and i know the gauge is right because i went out to my lst crx just to check it and had 190 ish on all 4 im confoosered

Re: compression psi to ratio: compression test results!
 

Sounds like it has some pretty high compression pistons. My guess would be around 12.5:1 as that is a pretty typical number for people to use. Unless you plan on running E85, turbo charging that engine sounds like a bad idea. You are better off selling the engine to someone for a decent chunk of change and buy something else.

Re: compression psi to ratio: compression test results!
 

well untill here recently there wasnt anyone that had pistons for the FRM sleeves (mahle) correct? so that means this thing must be sleeved unless its just been decked all to hell? which i think the chances of that are slim to none? just out of curiosity how would this thing react to boost? i know thats uber high but what about like 8 pounds? i wish i had a bore scope... sounds to me that someone sleeved it. i may pull the pan off of it and see if it has aftermarket rods. i really want to know what went on inside this thing...

Re: compression psi to ratio: compression test results!
 

if its rocking a 12.5: to 1 it will respond to boost like a crack head to crack....

It will run like a ------- raped ape, however will probably die as quickly as a crack head who is HIV + due to being raped by an ape ???


But you will lay some great #s if you boost that motor, but if you don't have a GREAT tuner it wont last past tunning ;)

Re: compression psi to ratio: compression test results!
 

Mahle has had pistons for H22's for at least a couple of years now. I honestly know very little about H22's and the parts you can use on them so I can't really comment on how it got such high compression, but it is clear that it is well above stock. The best way to find out is take off the pan and head.

As for how it will hold up with boost, well, it will be very efficient(high hp/psi) but very volatile. Probably after 4psi you will be moving away from finding MBT because you are octane limited. 8-10psi you will definitely be octane limited and most likely on the brink of detonation even with a good tune. With E85, I wouldn't hesitate for a second running plenty of boost. I would start getting fearful once you got over 500whp but most likely wouldn't show any real concern until you were near 600whp.

Re: compression psi to ratio: compression test results!
 

First and foremost you wont get compression results that high with any stock honda piston and cam combo unless you've fucked with the cam timing and dialed out absolutely all the overlap.Even then thats high. The high spec on a 10.2 gsr motor is 235psi, so you have at least that high compression, most likely much more unless that motor is fresh as a mofo and you got extremely lucky. Dynamic compression (which is what you are measuring) is a function of cam duration and overlap, and static compression ratio.

Re: compression psi to ratio: compression test results!
 

welp i got to lookin around a little more today and it seems i do have somewhere around 12.5:1 or so. does anyone know of any good tuners NC im willing to drive some into VA and SC but not too far. i know of a bunch of people that tune cars but i dont trust any of them or myself to do THIS car. ive done a few street tunes on buddies cars as well as my own but for this much HP i dont want to... im going to look more into the E85 aka how to make it myself i assume its about the same as making corn wisky? if it is it wont be much of a problem ive made my fair share of that haha if yall have any good sites or anything to look at about it let me know.

bigwig thats what im running into myself...i dont know much about H22s this is the first one ive ever messed with actually probably even seen of with anything done so i reckon this will be a learning expirence for a few people. but thanks for yalls help and ill keep yall up dated on whats happenin with em. ill try to get some pics posted up of the truck the crx and the civic soon. thanks again

Re: compression psi to ratio: compression test results!
 

you should go to chirs (xenocron) he'll take care of ya... its only 6hr dirve to MD, and from MD only 4hrs to Xenocron. ;)

10 hr drive aint ---- when it comes to getting a good tune :1

Re: compression psi to ratio: compression test results!
 

well id like to find someone a lot closer than that but if it comes down to it! as long as hell let me set up bunk in the back bay at his shop for a night i might could haha

Re: compression psi to ratio: compression test results!
 

I'd suggest Matt Shue if you are semi close to the Richmond area. http://www.honda-tech.com/zerouser?c...e&id=999311607

Making E85 is pretty retarded though. It's something like $2.50 a gallon and you are going to use 30% more than you use gasoline so if you drive more than a couple thousand miles a year you are going to have a hard time coming close to reaching your demand. Not to mention the general inconvenience.

I should note, if you plan on runnning this thing on 93 octane, expect it to blow up. On top of that, any tuner that basically says they don't want to tune their car is saying the right thing so don't dismiss it and think they are an idiot. There is no way I'd touch a 12's compression H22 running 10psi on a typical T3/T4 if they were running 93 octane.

Re: compression psi to ratio: compression test results!
 

well the more i thought about it day i pretty much came up with what you just said...i think im gonna pull the pan off and see if its sleeved...if it is ill order some eagle pistons that are slightly less compression 9.5:1 or so and some rods if it doesnt already have some. the car needs an oil change comming up probably friday... so well see what happens thanks for all the help ill keep yall updated

Re: compression psi to ratio: compression test results!
 

WTF so you'd rather pay $4.25 for 93 octane then $2.50 for 110 octane? I dont give a ---- it takes 30% more, the stuff beats filling up with race gas just to drive back and forth to work. I dont ever want to go back to regular pump gas after getting use to e85. The ---- loves teh boost.

Re: compression psi to ratio: compression test results!
 

sick too bad CALI is gay no E85

Re: compression psi to ratio: compression test results!
 

whats the difference in mileage after the switch from 93 to e85? right now im getting between 185 and 275 to the tank. 275 being strictly highway of course.. 185 killing it around town

Re: compression psi to ratio: compression test results!
 

You're illiterate. Read things again. I've suggested using E85 the whole thread. I said making his own ethanol and mixing it with gasoline is stupid as he won't be able to keep up with his own personal demand.

Re: compression psi to ratio: compression test results!
 

looking into it a little more there seems to be a lot of waste. i believe theres like 10-30% of usable ethanol even off of straight corn and other starchy and sugary feed stock. it doesnt take long to make at all apparently being it doesnt have to be purified like drinking alcohol. i think i could possibly make enough to keep up. it would however be time consuming and thats something thats hard to come by at the moment. i think im better off paying 400 bucks for a stock closed deck motor and throwing 10 psi at it for the time being untill i can get pistons and rods. and spraying the 12.5 motor in the slow ass busted ring land turbo ls crx...