crx1856

i went to dsr today to get tuned with poor results. after doing a leak down test, i had a 3% 12% 12% and a 7%. but when i do a compression test, i get high 190's all across. this is on a 84mm 9-5-1 motor. what does it mean when you have good comp numbers with poor leak down tests. my tuner said it might be the rings still trying to seat. the motor has 650 miles on it right now. the highest dyno run was a 170 whp. this is with a revhard 2c kit. anyone have any awnsers???

crx1856

ttt

boosted_dc2

valves??? what kinda head work do you have???

crx1856

port flow three angle valve head from import builders.

InTeGrA B18b1

you have good compression but why you making only 170 hp? how much your boosting?

crx1856

i was boosting 6lbs.

crx1856

i went and bought a good comp tester since i was using one from harbor freight. here's what i got.#4 220,#3 210,#2 200,#1 220. does this sound about right for a motor with 600 mi on it. what could the bad leak down be caused by? my tuner at dsr said number 2 had the best leak down results. is it possible to have the highest comp and the worst leak down on the same cylinder? what should my next step be?

Quick 200k Mile Motor

Make sure the leakdown test is done correctly at TDC (not BDC) for the piston you're testing. I suspect those 12%'s happened with a valve open. BDC can be mistaken for TDC. Setting the piston to TDC is probably the toughest part of the test.

With 12%, you should've heard air leaking into the problem area. But if the crank turned, the test isn't true (reset piston to TDC before pressurizing).