LS3 Compression Numbers Results Question?
Thread Starter
Racer
Joined: Nov 2018
Posts: 459
Likes: 74
From: Oregon
LS3 Compression Numbers Results Question?
The first time I checked compression on my LS3 engine out of the vehicle using a battery connected to the starter, it was a little low on a couple of cylinders but rechecked them and they improved but I had a weak battery I was using.The 3rd time I used a charged battery for cranking and all the cylinders registered between 160-175 lbs. of compression. Thanks
Last edited by Z064me2enjoy; Feb 21, 2020 at 01:19 PM.
Drifting
Joined: Mar 2018
Posts: 1,365
Likes: 414
From: New Jersey
Not to burst your bubble but those are not really great compression readings. When you do a test you have to look at how the gauge comes up on the first full stroke. It should be around 60-80 lbs. It should also reach its final value pretty quickly. If it's increasing in small increments but still reaching 180 that's not good. I would say the variation between cylinders is higher than 20 psig so that's not good. The test results also depend on how you did the test and how good you battery is.
Last edited by C5MSG2004Vert; Feb 21, 2020 at 01:12 PM.
Thread Starter
Racer
Joined: Nov 2018
Posts: 459
Likes: 74
From: Oregon
Thanks for the information. I rechecked it again but with a newer battery since the first time the battery I was using was pretty weak. This time all 8 reached between 160-175 lbs.. thanks again
