Compression testing... the results.

[shiroitenshi]

Finally did that compression test today that I mentioned in the dyno results thread...

And I got these

Cylinder 1:195psi
Cylinder 2:205psi
Cylinder 3:195psi
Cylinder 4:215psi

And I thought cylinder two was leaking when I did it last time with 150 being the result of piston 2.. I must have made a mistake then.. maybe didn't screw in the gauge plug properly.

I wonder if you can estimate the dynamic compression ratio from this.. anyone?

 

[patpaty]

wer u do tis?? how?? by a machine?? cost??

Cylinder 1:195psi
Cylinder 2:205psi
Cylinder 3:195psi
Cylinder 4:215psi

which psi is normal?? y diff??

 

[shiroitenshi]

Nope.. just a regular compression pressure gauge and it's relevant fittings.. If you actually buy one, it's quite easy to use.. A good mechanic shop will have one, and it costs very little. Maybe about 20bucks or less, depending on how professional and reputable the mechanic is.

Disconnect distributor signal wire, remove all plugs, plug into one cyclinder at a time. Start the engine (it won't start, since there's no plugs!) and take the reading.. these are static compression pressure.. didn't have time to do a running compression test.

As to the purpose, it's to test cylinder sealing.. to see if your sleeves or piston rings are worn out or not, resulting in compression loss which = lost power = consume quite a heavy amount of engine oil.

The different numbers indicate that I do lose a bit off pressure on cylinder 1 and 3, which means that it's slightly worn out compared to the cylinder 2 and 4.

I'm told 140-150psi is normal... but as you can see... I get different numbers. From what I'm told, it doesn't matter much, just that if one of your cylinders is reading a lot less than the others, it means the cylinder isn't sealing well, either because of cylinder liner wear, or piston ring wear.

 

[patpaty]

i wonder that dyno machine can do running compression test?? if not, then...??

"140psi is normal" is it for all tpye of engine??

 

[hattech-v]

i did mine last time in may. 220psi for all 4 cylinder...

 

[patpaty]

i did mine last time in may. 220psi for all 4 cylinder...

http://i19.photobucket.com/albums/b159/hattech/library/comression.jpg

how 2 do it?? do it 4 me okie?? wat time suit 4 u to do d tiuning??

 

[hattech-v]

aisey.. i dun have the tester...planning to buy one soon...
will call u later....

 

[shiroitenshi]

your engine lagi healthy.. what engine B16A oso ah?

 

[hattech-v]

that time just plonk in new heart... hehe...
straight after installation going to do this compression test...
my engine is from hokkaido... i worried the piston get frost there before transfer to malaysia... haha

 

[shiroitenshi]

that time just plonk in new heart... hehe...
straight after installation going to do this compression test...
my engine is from hokkaido... i worried the piston get frost there before transfer to malaysia... haha

Hmm.. I forgot mine came from where.. should check.. I don't think it's hokkaido though.

 

[hattech-v]

better check... i'm going to pay visit to hokkaido and do some jejak kasih.. wanna find the previous owner... haha

 

[mrbear]

how much it cost to do compression test? or anyone here got free time.. hehehehe.. i can belanja makan after finish do compression test

 

[hattech-v]

sometime u can do it for free..

 

[shiroitenshi]

Wah.. all naik gila want to find out the condition of their engine.. :P

 

[hattech-v]

its good to know the all 4 cylinder healthy or not... later go to dyno.. power very low then do further mods without knowing the compression loss fr any of the cylinder... then wasting money n time..

 

[shiroitenshi]

its good to know the all 4 cylinder healthy or not... later go to dyno.. power very low then do further mods without knowing the compression loss fr any of the cylinder... then wasting money n time..

Actually the static compression test is just a basic one.. there's a more complete one, but I haven't attempted and understand it yet.. Another one is leakdown test, which even tests exactly where you are losing compression.. BDC? mid-stroke? TDC?

Will try that one once I find the time.

 

[Oderf]

yeah...wasting time...like my case last time lah...put this..put that..then kena tapau with stock 4G93...wth ????.....then only found out my compresen very the teruk one.....half of other fella b16a compression on all 4 silinders.....no wonder la....hahahaa...

 

[V8_nutter]

Finally did that compression test today that I mentioned in the dyno results thread...

And I got these

Cylinder 1:195psi
Cylinder 2:205psi
Cylinder 3:195psi
Cylinder 4:215psi

And I thought cylinder two was leaking when I did it last time with 150 being the result of piston 2.. I must have made a mistake then.. maybe didn't screw in the gauge plug properly.

I wonder if you can estimate the dynamic compression ratio from this.. anyone?

Low numbers,,that's why your low RPM tourque weak. Try doing 252+ static compression and feel the tires begging for mercy. Our last year machine have those figures but bcoz we have no good tires (that time only use toyo trampio) we can only launch at 1500rpm only !!! more than that is a waste of time.

Best achivement with 252 compression is with maxed ignition from bottom to top (no reading on the ignition pistols aka maxed out already). When we did 262 then only we have to retard it a bit,,,but still 90% maxed ignition. Feel free to examine our machine setup,,,,,:regular_smile:

 

[udengfahlawi]

can leaking in head gasket contribute to loss in compression?...

 

[lightningfield]

all of my cylinder compression is 14..not very healthy ykan