hi guys i was wondering if this is normal or really good numbers, i did compression test on my motor the other day and results were like this all 4.

My set up is usdm itr block 81.5 pistons with gs-r head.

 

no thats bad you should sell that motor for quick lol

 

lol ok so buy it i want to sell it.

 

ok $5 shipped lol

 

those number are good as long as thier isnt a huge difference between any of the cylanders.

 

Good numbers. As long as you dont have a 10% difference from the highest and lowest cyl, your engine is in good healthy condition

 

No all 4 were same 240 across I did twice, I was wondering what's the compression on stock usdm itr motor

 

Haha sure also 5ft long tuna from subway eat fresh $5 shipping including lmao

 

my jspec put 245-250 across the board if that helps

 

that's actually on the high side. what's the compression ratio in that motor, i would guess at least 11:5-1

 

Yes those are good numbers. 240 is fine. You engines comp numbers say the engine is in good internal condition.

 

its 11.1.1

 

well its usdm itr pistons with gs-r head... so i dont know what exactly my cp and i'm using oem 3 layer gasket. I like to know stock type r numbers with itr head.

 

damn lol

 

you comp ratio should be somewhere in the neighborhood of 10.5 to 11.1......................like i said i have a bone stock jspec itr with no internal mods and stock head gasket and according to honda mines 11.1

 

cool, now cAn I sc my motor with this comp? Is it safe or not I know I can't boost it for sure

 

ive been daily driving mine with a turbocharger and im only boosting 8psi and i havent have 1 major isssue with it. you can safely supercharge it just make sure u have the supporting mods so you dont lean out. fuel system,ecu,and a good tune on a high compression force induction motor is key!

 

agreed. my ITR is boosted too. stock B18C5. ~235psi

did my buddies 50k mile stock B18C5 at ~240psi

and my old JDM ITR (97) was ~245psi.

all done on the same gauge.

 

honestly should be measured but a gsr head with oem valves is just a touch over 11:1, 250 is a really high cranking number though. if any metal gets shaved in that engine build or flat face valves are installed it's definitely north of 11:1

 

i wouldnt say 250 is high........i would say i have great ring seal though with numbers like that

 

 

oh there's nothing at all wrong with it, it just may mean higher compression and something to keep in mind when you're adding timing in the tune

 

my stock usdm b18c5 checks out at 245 across and its been boosted for sometime now

my jdm R motor i had in my 97 R read 255 across

 

well as of now my car is tuned on chrome and it made 196hp 136tq.

 

does this compression tells me how good my rings seated? Should i do leakdown test?