Compression Test Results

[SmItZ]

Hi,

Looking at buying an engine from Japan and compression results came out at:

Cylinder

1 - 9.3

2 - 9.5

3 - 9.5

4 - 8.5

5 - 9.5

6 - 9.5

9.5 is equivalent to 135psi if I remember correctly (realise some may say this is low, b/c it should be about 150-160psi). However, my big worry is cylinder 4 with lower compression than the other 5.

Your help and opinion would be appreciated. Thanks.

[AngryRB]

Hi,

Looking at buying an engine from Japan and compression results came out at:

Cylinder

1 - 9.3

2 - 9.5

3 - 9.5

4 - 8.5

5 - 9.5

6 - 9.5

9.5 is equivalent to 135psi if I remember correctly (realise some may say this is low, b/c it should be about 150-160psi). However, my big worry is cylinder 4 with lower compression than the other 5.

Your help and opinion would be appreciated. Thanks.

sounds like a tired motor, does it have cams or alot of aftermarket work done?

[Hanaldo]

135 is a little bit tired, but I wouldn't worry about that too much. However you're correct about cylinder 4, there's a bit much variation there. Can you get a wet test done? Would stay away myself.

[SmItZ]

sounds like a tired motor, does it have cams or alot of aftermarket work done?

It's a stroker motor, ported head, 272s, etc. Reputable builder and seller that's the main reason I'm even considering it haha

135 is a little bit tired, but I wouldn't worry about that too much. However you're correct about cylinder 4, there's a bit much variation there. Can you get a wet test done? Would stay away myself.

Exactly, if it was 135 across all I wouldn't be too fussed could just do with a freshen up. Can't do a leak down, only have compression results to go by = (