225 V-6

I just bought a 48 CJ2a with a Buick/Jeep 225 V-6. ( I have not checked the casting numbers yet) It starts great, runs ok, a little lethargic IMO. I gave it a major tune-up today. This included; plugs,wires,cap rotor, points/gap/dwell, timing, carb adj., coolant system check and pressure test, and cylinder compression test.
The compression test revealed the left bank at around 60psi +- 2 psi. The right bank all were 0psi. I do not see any unusual bubbles in the coolant, oil does not look milky, and oil level is staying steady on the dipstick. No signs of oil in coolant either. Wet compression test did not improve the numbers.
I will be pulling the heads to have them freshened up. My question is are there any common issues or upgrades to address while the heads are off? I really do not think I will have hardened seats installed due to expected low mileage use.
Thanks for any input
Gregg

 

something fishy in your compression readings...shouldn't run at all with those numbers.
I'd recheck or try another compression gauge.
if the timing chain has jumped, I could see low readings...
I wouldn't pull the heads just yet.

 

I can try my diesel engine compression gage, but these readings might be too low for that gage. I did use a known good gas engine compression gage. Not like I borrowed or rented one.
The left bank held steady after cranking. The right bank would go up to about 70 and just as fast go back down to 0 with each compression stroke.
When I took it for a test drive it didn't want to pull down low in the rpm range.

 

I'd agree with Jim, with an entire bank at 0 psi, I doubt the engine would start and run.

The compression gauge is supposed to hold the max pressure and not leak down. You need to reset it manually to go back to zero. Even a bare piston (no rings) in the bore would give a reading higher than 0 psi. IIRC the gauge uses something very much like a tire core valve to hold pressure. I think your compression gauge is leaky/wonky somehow, or you're not following the directions. A new gauge is only about $25 at Pep Boys.

 

Jim and Tim you guys were correct. As soon as I wrote my first reply and said the gage bled down with each compression stroke it hit me and I became suspect of the gage. Plus it was way too late and I was very tired.
Today I found out it has a bad seal on the quick coupler that the hose attached to. Tomorrow I will take it to the Mac tools guy and get it repaired. My diesel gage read about 110 on the bank that I thought was 0 and 95-100 on the other bank. But this is at the very low end of that compression gages' scale.

 

i found i get better luck with the gauge, after i put a couple of squrits of oil in the bore before taking a reading.

 

Karl, you're skewing your readings by doing that.

The usual procedure is to test dry, then test wet (ie after adding oil). Then compare the two sets of numbers. The oil will fill in around the rings and should increase the pressure readings. The amount that the readings increase indicates how worn your rings are.

The wet/dry test can be very helpful in separating the effect of potentially leaky valves and worn rings.

 

I agree with Tim always do both tests, dry first then wet to get some idea of where the compression losses are (head v/s rings).