UPDATE ON MY DONOR GENERATOR LHEAD

[boucher]

I installed the rear plate to accomodate the starter , this past weekend. So last night was time to try a compression test and the results are less than impressive:

#1 30 PSI
#2 0 PSI
#3 60 PSI
#4 30 PSI

Note: these result are with a small amount of oil in each cylinder

Is there anything I can do prior to pulling off the head? If the answer is to pull off the head was is the best way, I had a hard time on my original engine?

Thnaks

Peter (Ottawa)

[Bill_F]

ouch

[ocwd]

I was sad to see that the compression in my RMC was 75 to 90 psi. I'll be interested to hear comments on your situation.

[wesk]

With coolant showing at the top of the radiator run the engine and look for bubbles in the coolant. If she's not running yet see below.

Are you sure the head is actually torqued down properly?

This is the perfect time to employ a leak down tester. This is a set of test gages that you use to pressurize each cylinder (one at a time) with about 80 pounds of air pressure so you can better observe where the pressure is leaking to. Some examples of what you may find are:
1- Thru another spark plug hole you hear air hissing from an adjacent cylinder indicating a blown head gasket between them or a crack.
2- You hear air hissing at the exhaust pipe indicating that exhaust valve is leaking.
3- You hear air hissing at in the carb indicating that intake valve is leaking.
4- You hear air hissing at the oil dipstick tube indicating rings are leaking excessively.
5- You see bubbles in the coolant indicating either a blown head gasket or a crack in the water jacket.

Record all the symptoms you find on a note pad then pull the head and start a thorough visual inspection again noting on your pad all symptoms.
Since none of your compression result figures seem to indicate any pairing of cylinders, odds are you dont't have a leaks between cylinders. Remember a detailed visual inspection must include using at least a 10 power magnifying glass to look for small cracks. These normally occur at bolt holes, between bores, between bores and valve seats and around spark plug holes.

Pull the side valve cover and spray penetrant on valve stems while turning the engine. Look closely for valves that aren't getting full travel. If you spot one concentrate on it and see if you can get them loosened up. See what that gives for compressions.

[boucher]

Thanks Wes, as always you provide excellent feedback.

Peter (Ottawa)