Compression
Compression
Just a quick question i should have ask a couple years ago. 1984 305 Camaro, over a period a weeks and several days the power slowly but surely decreased, until the car would start but not rev over 1500. The winter before this car was ran repeatedly with WATER in the radiator and as such it would overheat. Now a friend and i tested the compression and it was like 30-35 and at some pistons it was like 16, and some manual said it was suppose to be around 120. Is this correct? As such i figure the engine is junk and a have left the car to sit in my garage for 2 years. So now was my assumption correct? Also i'm looking to finally to put a engine into this thing a figure my best bet was a Jegs GmGoodwrench with a engine package, any comments?
Thanks
Thanks
Supreme Member

Joined: Jan 2002
Posts: 3,852
Likes: 1
From: Valley of the Sun
Car: 82 Z28
Engine: Al LT1 headed LG4 305
Transmission: TH350
Axle/Gears: 3.73 posi with spacer
Did you measure the compression correctly? Did you follow the instructions? Those numbers are way low.
TGO Supporter
Joined: Oct 2002
Posts: 9,067
Likes: 1
From: Saskatoon, SK, Canada
Car: '83 Z28, '07 Charger SRT8
Engine: 454ci, 6.1 Hemi
Transmission: TH350, A5
Axle/Gears: 2.73 posi, 3.06 posi
It should be 120+psi, yes. 35 seems awefully low for something that actually runs, are you sure you did the test properly? Did you hold the throttle wide open when you cranked the engine over to read the compression? How many times did you crank it each time you tested a cylinder?
TGO Supporter
Joined: Oct 2002
Posts: 9,067
Likes: 1
From: Saskatoon, SK, Canada
Car: '83 Z28, '07 Charger SRT8
Engine: 454ci, 6.1 Hemi
Transmission: TH350, A5
Axle/Gears: 2.73 posi, 3.06 posi
Did you hold the throttle all the way open when you cranked the engine over?
You should try spraying some oil through the plug holes, and try the test again and see if it helps the compression... that might tell you if your rings are still sealing or not.
You should try spraying some oil through the plug holes, and try the test again and see if it helps the compression... that might tell you if your rings are still sealing or not.
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