Compression test numbers: Thoughts?
#1
Compression test numbers: Thoughts?
Rebuilt engine, 450 miles on it when this was done.
S5 TII irons, with 0.002" step wear
Very low mileage FD housings
Low mileage FD rotors
New OEM 2 piece Apex seals
Side seals were all @0.0025"
Stock ports.
#1
![](http://i27.photobucket.com/albums/c185/funkjaw/1015871_10203341177673658_155268365_o_zps1c7e5847.jpg)
#2
![](http://i27.photobucket.com/albums/c185/funkjaw/1912060_10203341178473678_525731947_o_zps50d6b64c.jpg)
Vacuum at cold idle ~750 is about 14. Vacuum at warm idle ~1050 is about 17.
Any input on if these are ok/not ok numbers for the amount of miles on the rebuild at the testing RPM?
Thanks!
S5 TII irons, with 0.002" step wear
Very low mileage FD housings
Low mileage FD rotors
New OEM 2 piece Apex seals
Side seals were all @0.0025"
Stock ports.
#1
![](http://i27.photobucket.com/albums/c185/funkjaw/1015871_10203341177673658_155268365_o_zps1c7e5847.jpg)
#2
![](http://i27.photobucket.com/albums/c185/funkjaw/1912060_10203341178473678_525731947_o_zps50d6b64c.jpg)
Vacuum at cold idle ~750 is about 14. Vacuum at warm idle ~1050 is about 17.
Any input on if these are ok/not ok numbers for the amount of miles on the rebuild at the testing RPM?
Thanks!
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#2
640 kPa = 92.8 psi
650 kPa = 94.3 psi
680 kPa = 98.6 psi
620 kPa = 89.9 psi
650 kPa = 94.3 psi
640 kPa = 92.8 psi
8.7 psi variance
The difference between the highest and lowest reading is low (good) but the numbers are low and the vacuum at idle is low for stock ports. Was there any flaking on the edges of the housings? If it starts fast hot/cold I wouldn't worry about it. What numbers are expected for a new engine read with that type of tester?
650 kPa = 94.3 psi
680 kPa = 98.6 psi
620 kPa = 89.9 psi
650 kPa = 94.3 psi
640 kPa = 92.8 psi
8.7 psi variance
The difference between the highest and lowest reading is low (good) but the numbers are low and the vacuum at idle is low for stock ports. Was there any flaking on the edges of the housings? If it starts fast hot/cold I wouldn't worry about it. What numbers are expected for a new engine read with that type of tester?
#3
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at 450 miles that isn't bad.
I've seen numbers lower than that on engines in cars at meets..
#4
Good info thanks peeps.
Yeah I agree the vacuum is low, and it doesn't start up right away. I have starter issues right now, and I also have tune issues, as it's very rich on start up. Need to go through the microtech settings and see if I can get a better startup. I'll also triple check for any kind of vacuum leaks to see if I can bring the idle vacuum up higher.
Yeah I agree the vacuum is low, and it doesn't start up right away. I have starter issues right now, and I also have tune issues, as it's very rich on start up. Need to go through the microtech settings and see if I can get a better startup. I'll also triple check for any kind of vacuum leaks to see if I can bring the idle vacuum up higher.
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