Compession test

[trueno_20v]

Done a compression test on my silvertop 4age today and got:

160 150 160 160 psi

sound right??

i wound it over about 4 times maybe it wasnt enough?

[Jebus]

Pretty good

[matt9ball]

i got 175 180 175 170

[matt9ball]

sorry just checked i actually got 170 175 185 185 psi

[Malcolm]

main thing you're looking for is variation, they should all be within about 5% of each other, 5% of 160 is 8, so your minimum should be 152, I'd say you're probably fine, might have slightly worn rings or maybe just did a bad test. I wouldn't be concerned unless you're having overheating problems

[AE85coupe]

wow thats really interesting, my smallport has 250psi across all cylinders

surprises me how much more pressure i seem to have

[Punter]

wow thats really interesting, my smallport has 250psi across all cylinders

surprises me how much more pressure i seem to have

It can vary hugely, ie throttle open or closed, cam overlaps/timing etc. etc. Infact 4afes will sometimes test higher than 4ages.

[AE85coupe]

wow thats really interesting, my smallport has 250psi across all cylinders

surprises me how much more pressure i seem to have

It can vary hugely, ie throttle open or closed, cam overlaps/timing etc. etc. Infact 4afes will sometimes test higher than 4ages.

yeah that makes sense, i wonder what smallports usual compression is

[trueno_20v]

well i done mine with open throttle..

[craigt]

Actual readings between different gauges cant be compared. They all read differently, whether its because of design or gauge calibration, I dont know.
Compression tests are only useful in comparing the readings between cylinders.
I actually quite like leakdown tests but they are a bit more time consuming to do.

[CAMB01]

i have 180psi across the cylinders on my GZE