Join Date: Dec 2000
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Re: Considering used engine purch need advise :)
There is a diagnostic test called a cylinder leak down test. If you have access to pressurized air, you can pick up a leak down tester. Basically, you set the engine to top dead center, remove the #1 spark plug for that cylinder and use a fitting to pump controlled air into the cylinder. The beauty of this method is that you can find just about any internal problems that might suprise you before disassembly. If the rings are bad, you'll hear blow by past the rings, through the oil pan, up top by the oil filler, or through the valve covers. Bad/Burnt intake or exhaust valves will show up by air coming out of the carb, or exhaust. The point is, a good tight engine should not let the air out of the combustion chamber.
You can also check oil pressure easily in the 304 by hooking up a mechanical oil pressure gauge to the sender unit, removing the distiributor, and spinning the oil pump with a screwdriver end via drill. This will let you know what kind of main, rod, and cam bearing condition to expect.
This may be more detail than necessary, but you will definitely know everything about the engine without disassembly. Depending on your mechanical and engine repair ability, please be careful doing these diagnostic tests. Ask someone if you are unsure to avoid damage to yourself and the engine. Let me know if i can help. Scott
1979 CJ: 304, 3spd, tires, rust, miles
1989 XJ: has seen every state except Hawaii
In search of lost paths and distant locations...