I have a complete gsr swap that i got out of a non running gsr. To my knowledge the car hasnt been started in a few years so i ran a compression test and the numbers are 45 40 60 120.. i did not do a leak down test and i proceeded to drop the motor and begin to tear it apart. Now from what i can see no cracked cylinder walls, no bent valves or any major issues. Im new to working with motors and thats what i was expecting to see with such low comp numbers. So can anybody give some ideas on what it could be..i have searched and those are the main things i see along with piston rings. i am rebuilding the motor so just wanted to know what else to check for

 

It may have just been tight valves, [not closing all the way] a valve adjustment would fix that.

With that said, you already have it apart so glaze bust the cylinders and replace the rings.

I would also straight edge the block and have the head checked for warpage and have it machined if it is, it is also a good time to do a valve job, [new seals and maybe guides].

Better to do that now even if it was not needed then to put it all back together to find out you will need to pull it apart again to do those things. 94

 

Whats a glaze bust? I was planning on having the machine shop bore it out a bit for type r piston

 

Also called a cylinder hone... not needed if your having it bored out 94

 

If you are rebuilding there's nothing additional to check if your measuring everything as needed. Chances are the Rings were probably just Frozen and that's why your compression was low. I just a picked up an accord that has sat in the woods for two plus years producing 120 PSI 30 PSI 0 psi 0 psi. I had installed the engine less than 6 months prior to it being left in the woods. Put a small amount of transmission fluid in engine cylinder let it sit for a day or two and then fired it right up and drives perfect.