I was just wondering how long do you actually turn the key while doing a compression test? A friend told me to crank it for 5-10sec until the guage stops...and do that 5 times. is that right?

 

I just keep cranking it until the needle doesn't go up any more. I then repeat the test and take the average of the two (though they're usually within 1-2 psi anyway).

 

Helm's says like 4-5.....I crank till the needle stops.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Mr Milano &raquo;</TD></TR><TR><TD CLASS="quote">Helm's says like 4-5.....I crank till the needle stops.</TD></TR></TABLE>yeah, i crank until i get the highest reading possible in all 4 cyl. Though I try to record how many crank each cyl. takes to get to the peak compression also.

 

should really be only 4.. because it takes four strokes to complete cycle..

 

6 times

 

i crank 6 times

 

We crank it 8 times,and usually it has stopped climing by then

 

it shouldn't matter the number of times you crank it, as long as the pressure is still rising. you'll definetly see it slow down. just don't forget to cut off fuel supply. it IS funny to leave everything hooked up though, one click and VROOM it has already started....hehe

 

Which reading counts the most the first crank or the 5th crank? Cause my first crank was 90 then the 4th crank was 150.

 

I go until the gauge stops...

 

I did 5 cranks in each cylinder and it all started at 90psi then by the 5th crank it bounced up to 130-150psi all across. So my rings are fucked huh?

 

I do 5 cranks, 210 accrost the board.

 

i do 7 cranks for a good happy medium. More, and it does seem to jam a bit more into the guage, but consistancy is what's important.

Its also good to see how many cranks it takes to get there.

d

 

make sure you open the throttle fully.. to get a more accurate test. needs air.. to build air pressure..

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mingchi69 &raquo;</TD></TR><TR><TD CLASS="quote">make sure you open the throttle fully.. to get a more accurate test. needs air.. to build air pressure.. </TD></TR></TABLE>

I crank it about 5 times as well and got 255 across. Should I crank it more, if so, how much more?

 

crank it until it doesnt go anymore.. but with an open throttle to get a more accurate reading... 255 is a very good number, what motor u have?? gsr?
for some reason, my jdm gsr read i think 285 across the board. around that, but if i cranked it without it on full throttle, it differs greatly. also my 12.1:1 compression b20 (b4 i sold it) got around 290 too.. weird how my jdm gsr has the same compression as my b20.. o well..

 

i dont crank it with the throttle open, i have got lower readins in the past with the throttle open. i crank til the needle stops and pull over 300 across the board on my friends compression tester and pull 270 across the board on mine.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 1 2 NV &raquo;</TD></TR><TR><TD CLASS="quote">i dont crank it with the throttle open, i have got lower readins in the past with the throttle open.</TD></TR></TABLE>

???

The proper way is to pull the F/I fuse, wide open throttle and crank 5 times. Accurate and consistant.

 

until the gauge peaks

mike