B7100 Rebuild

[Schmotown]

I am reassembling my B7100 engine (liners, pistons, rings, bearings, cylinder head) and did a compression test on #1 cylinder while the engine is still on my bench and was very disappointed with the reading of 240# on Cyl. #1. This seemed very low to me so I did a leakdown test on all 3 cylinders and they all show about 4% leakage. I squirted a bit of oil into #1 cylinder and got a reading of 380#. The starter was connected to my car battery and turned over quickly.

With the very good leakdown test and 380# on Cyl #1 do you think I can proceed with completing the installation or does something seem wrong with my results? I did not do a compression test on #2 and #3 as I left the lifters and pushrods out as I just wanted to see what compression I had with an aftermarket head gasket before installing the Kubota head gasket for the final assembly.

Attached is a pic of my gear assembly showing the timing mark alignment.

Thanks in advance, Larry.

 

[North Idaho Wolfman]

Well there is a lot at play here.

The rings need to be run a bit to set and get proper compression numbers.
The aftermarket head gasket will throw all the numbers off, that's why you need an OEM gasket.

I personally wouldn't worry about those numbers.
Finish up the build.

 

[Schmotown]

Thanks, Wolfman. I'll finish it up and report back with my results.