DRIFTINGmy85
07-09-2008, 07:56 PM
Okay, at school I used a leak down tester and the way they taught us was to get the psi side to 100 and read the percentage side.
Not reading the instructions first..
I did it just how I did at school. I put the psi up to 100 and read the percentage side. 20% leakage.
Wondereding if I was on the wrong stroke. I turned the crank over one revolution and put the psi back up to 100. The percentage side went WAY past the 0% mark (stupid design!!) and it hit the back side of the 100% peg, where the needle should never touch.
Now it sits at 80%, instead of 100%, when not in use, I think I ruined the spring in that guage.
Confused again, I turned the crank over one revolution, read the instructions which read: "7.Turn the regulator knob clockwise until the leakage guage reads 0%. 8.You can now read the amount of leakage on the leakage guage as a percentage loss."
Doing it like this, lots of noise came out of the oil filler cap. With the percentage side at 0% the psi was at 25. The percentage side stayed at 0. This is why my instructors told us to put it at 100psi.
Wondering again, I turned the crank over one more revolution and did it again. Lots of air and noise came out of the intake manifold.
It was at TDC Compression, with 100psi the percentage loss was at 20%.
Note, the engine was not warmed up at all as per suggestion of the instructions, but I don't remember being told to do that at school.
I'm about to go back out to do the rest of the cylinders, but my question is:
What psi do you go to for your leak-down readings?
Is 20% leakage going past the rings sound normal?
Do you think My percentage side guage is now inaccurate because it's not resting at 100% peg but up at 80% (because it went way past 0% to the back side of the 100% peg)?
Thanks in advance!
Not reading the instructions first..
I did it just how I did at school. I put the psi up to 100 and read the percentage side. 20% leakage.
Wondereding if I was on the wrong stroke. I turned the crank over one revolution and put the psi back up to 100. The percentage side went WAY past the 0% mark (stupid design!!) and it hit the back side of the 100% peg, where the needle should never touch.
Now it sits at 80%, instead of 100%, when not in use, I think I ruined the spring in that guage.
Confused again, I turned the crank over one revolution, read the instructions which read: "7.Turn the regulator knob clockwise until the leakage guage reads 0%. 8.You can now read the amount of leakage on the leakage guage as a percentage loss."
Doing it like this, lots of noise came out of the oil filler cap. With the percentage side at 0% the psi was at 25. The percentage side stayed at 0. This is why my instructors told us to put it at 100psi.
Wondering again, I turned the crank over one more revolution and did it again. Lots of air and noise came out of the intake manifold.
It was at TDC Compression, with 100psi the percentage loss was at 20%.
Note, the engine was not warmed up at all as per suggestion of the instructions, but I don't remember being told to do that at school.
I'm about to go back out to do the rest of the cylinders, but my question is:
What psi do you go to for your leak-down readings?
Is 20% leakage going past the rings sound normal?
Do you think My percentage side guage is now inaccurate because it's not resting at 100% peg but up at 80% (because it went way past 0% to the back side of the 100% peg)?
Thanks in advance!