Leak Down test results-???
#1
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Test engine is a 1979 4.5L 16V USA model with approximately 175k miles...it sat without running for about 2 years. I was told it ran fine when it was removed.
tested on a COLD engine, well probably around 90F since it was hot in the shop...we tested the engine in firing order, here are the results
1: 5% 5: 5%
2: 6% 6: 7%
3: 9% 7: 9%
4: 8% 8: 6%
Since the variance between cylinders is at most 4%, I think thats pretty good and none showed significant leakage... 3-7 showed the most leak down, but also were the 2-3rd cylinder we tested?
I read some articles online that say 3% leakdown is about the lowest you can expect...& up to 20% is fine for street engines....what are your thoughts? Still I'm impressed for a 30 year old motor...but the bores I could see-feel from underneath were VERY smooth....
tested on a COLD engine, well probably around 90F since it was hot in the shop...we tested the engine in firing order, here are the results
1: 5% 5: 5%
2: 6% 6: 7%
3: 9% 7: 9%
4: 8% 8: 6%
Since the variance between cylinders is at most 4%, I think thats pretty good and none showed significant leakage... 3-7 showed the most leak down, but also were the 2-3rd cylinder we tested?
I read some articles online that say 3% leakdown is about the lowest you can expect...& up to 20% is fine for street engines....what are your thoughts? Still I'm impressed for a 30 year old motor...but the bores I could see-feel from underneath were VERY smooth....
#2
Done With Sidepatch
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IMHO, for cold numbers, those are very acceptable. Your homework is the same as I've read,
You may have other issues with a motor that hasn't run in two years but I like your compression numbers.
3% leakdown is about the lowest you can expect...& up to 20% is fine for street engines
#4
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#5
Shameful Thread Killer
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Run it. did you put oil in the jugs before the test? anything like that on a cold engine is perfect. Change fluids and go drive.
#6
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