Interpretation please

I received a new-to-me dauntless 225 ('65, milage unknown) to go in my 2A today and ran a compression check on a cold engine. The numbers were
120, 130, 110, 120, 130, and 120.
I know these cylinders are not within 10% of each other but I would really appreciate anyone with experience giving me their thoughts.
Tommy

 

carboned valves ?
burnt valve ?
rings on the one cylinder ?
who knows, a leakage test would be helpful by introducing compressed air into the cylinder, then listening thru the exhaust or the crankcase.
personally, I wouldn't worry about it and go ahead and run it

 

I've put ~10K miles on mine in the past 4 years with compression ratings of something like 125, 75, 125, 130, 120, 125. R)

I think you'll be fine :v6:

 

The lowest reading is the cylinder that had a valve open to the air while it sat. Nothing to worry about, and the general specs are 10-15%. Those #'s look good to me!

 

I would certainly run it.

 

#'s look real good to me,squirt a little wd40 or something simular in the low cylinder and i would bet that the compression reading will come up to the rest or maybe higher,got any way to test fire it on a engine stand for about 30 seconds? hook up a oil psi gauge,and you will have a good idea about the bottom end before you install it into the jeep,careful running it very long will heat it up quick without coolant

 

I would do a wet compression check , check the oil pressure and if all seems good(compression not bad as it is now) install and run it. For whats its worth I would run some Marvel Myst. oil in the gas and crankcase for the first couple hundred miles or 5 hours operating time.By the way look over the water jacket soft plugs real close ....it's a lot easyer to change them now (if needed) than after the installation into the Jeep. Look over the front and rear mian seals too.

 

Folks,
Thanks a lot for your input. I feel much better now. Sounds like I can avoid an expensive teardown.
I think I'll clean it up and install it.
Tommy

 

If I was in your position, I would just clean the exterior of the engine and run it. For being given and engine, those are good compression numbers! Be glad it didn't have a gaping hole in the side!

 

I'd pull the valve covers off to check for sludge, depending on the results the oil pan as well. easy to check since it's not installed.

 

It's an odd fire, you'll never notice.

 

Depends on your definitions. If it's plus or minus 10%, then they are in spec. The mean is 121.8, and the range then is 109.5 to 133.8. Even if 10% means a total of 10%, or +/- 5%, they are still pretty close to in spec (115.6 to 127.8). I'd say drive it.

 

I also say put it in and run it. The readings aren't all that accurate on a cold motor that hasn't been run for who knows how long anyway. At least you know there's nothing major wrong. Nickmil