Ahh yes that too, thanks Les I was waiting on your confirmation on this one... It feels weird to go do a compression test with the engine completely dry, but I have the engine hanging now just need to bolt up the starter and get this show on the road!

 

That is a VERY sexy motor!!!! Your gonna make girls drool when you pop your hood

 

You aren't going to EVER want to get rid of this Blazer after all the work that you did! And it was your first!!! All I can say is it looks fantastic and I'm quite confident you have it fixed. Compression test will tell. Don't forget to take out all the spark plugs when doing the test, have a fully charged battery, and to prop the throttle wide open. And don't test it to death!
Exact numbers aren't important at this point with the lifters collapsed and the engine dry and cold.

 

I could say something quite off color (double entendre), but as a Mod I probably shouldn't.

 

Don't worry... we are all on the same page here lol!!

 

Better put a seat cover on that passenger seat!

 

Hahaha thank you guys! Alright, so I did the compression test last night and got to see her work again!!!! 2 cylinders were a little lower than the rest but it could be because of short crank time or other reasons previously mentioned, I tried to crank until it stopped going up but also wanted to be as fast as possible because of course it has no oil in it. Still within 70% of the rest so I'm happy with it.
Cylinder 1 - 165 psi
Cylinder 2 - 165 psi
Cylinder 3 - 180 psi
Cylinder 4 - 190 psi
Cylinder 5 - 190 psi
Cylinder 6 - 190 psi
I guess the next step is putting it back in the blazer now!!

 

Great! Actual compression will be dependent on intake valve closing time, which in turn is dependent on how much the individual hydraulic lifter is collapsed. So I'm sure you will be much closer to each other if you check compression after running it.

Think about it.... if your lifter is collapsed, then intake valve closes earlier in the compression cycle, you compress more air, and you may actually get an artificially high compression reading on a cylinder with lifter that is more collapsed.

In racing, cams with same duration but earlier intake centerlines (typically narrow LSA) give higher compression readings for the same reason - but they really don't like to idle well because of increased valve overlap with narrow LSA. Their torque is increased at lower RPM but the torque curve is "peakier" and high RPM power can suffer. I think it's all interesting stuff.

 

Thanks, Les!! That is some interesting science there. I haven't done much lately as it's exam time, I should be pretty much ready to drop the motor back in when I'm done with my last one on Thursday! I just have a few hoses and bolts that I need to replace too but I'm working on getting those now.

 

I understand. Good luck on the exams! We will be here when you are done