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How to read compression test results?

  • Thread starter Thread starter gideup
  • Start date Start date Apr 25, 2004

gideup

Member
Dec 28, 2002
114
0
17
fort myers, fl
Apr 25, 2004
#1
  • Apr 25, 2004
  • #1
Just got my first antique 1965 2 +2 mustang with a 289 motor. Did a compression test to see where things are.

Low was 130, high was 145, with average of 134.5 over all eight cylinders.
Not sure if this is OK, so-so, or acceptable.
any thoughts from you restomoders out there?
 
R

Ronstang

New Member
Apr 4, 2004
1,294
0
0
Houston Texas
Apr 25, 2004
#2
  • Apr 25, 2004
  • #2
It isn't terrible, but it isn't great. Some people say that all cylinders need to be within 10%, which your's barely is, and some say 5%. If it runs ok then let it go until you have the time and $$$ to do a quality rebuild.
 
A

akd67

Banned
Apr 6, 2003
231
0
0
Small Town Illinois
Apr 25, 2004
#3
  • Apr 25, 2004
  • #3
It isnt the #s but how consistant they are. 10% of each other is what you are looking for.I checked mine pulling one plug at a time (I now know the correct way) and got close to 140 in all but one, which was 0. Push rod was bent bad.Is yours running ok?
 

gideup

Member
Dec 28, 2002
114
0
17
fort myers, fl
Apr 25, 2004
#4
  • Apr 25, 2004
  • #4
it starts right up, I put new plugs in today. It runs kind of rough, could be that it needs new wires. If youjump on it, wants to stall. The gas is old too. The point gap is right on, but the carb hookup is kind of rigged. I have not had a chance to check the timing.
 
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