Compression Readings: L28 Fuel Injection 77 280z

[MH77280Z]

Guys, when i bought the car i took a risk. I knew it was overheated and also later found the head cracked. So far we have replaced the head and car seems to run decent. Took these compression readings last week and wanted to share.

Cylinder 1: 130
Cylinder 2: 130
Cylinder 3: 135
Cylinder 4: 140
Cylinder 5: 130
Cylinder 6: 130

I have yet to see if it burns any oil. Not driven too much. But i expect older engine to burn a bit which is fine. I change every year and dont drive too much.

What do you guys think about these numbers? Personally i expected a bit worse but I think 130+ should be acceptable?

Any advises for on-going maintenance are appreciated as well?

 

 

[siteunseen]

Those look good to me but they could be higher doing the testing different.

Good read...

 

[Patcon]

Did you do a wet test? If you add a little oil to each cylinder and retest, if the numbers improve,  it's rings. Could be worn or poorly seating...

PS: always hold the throttle 100% open when testing. Not doing so, will give lower numbers

Edited February 9, 2022 by Patcon

[Zed Head]

Which head and pistons?  You might have posted it somewhere else but it's been a while.  The combination will determine your CR.

If you use an adapter it will give you lower numbers than if you run the hose straight to the plug hole.  Your numbers are low.