I'm replacing the intake/ exhaust manifold with one with a working heat riser and it might be the right time to check on the head gasket. I have had the 55.1 3600 six years. one of the first things i did was sent out the head for a rebuild and over the years adjusted a little here and there and got the engine running strong. i do use alot of oil and the spark plugs toward the rear (#5 and 6) are always oily. there is also oil seeping below the spark plugs(5 and 6) where the head meets the block. i did a compression check and it was 120 at all cylinders except #3 (105) it also seems to burn more at high revs and less after fully heating up. Since i will have the parts off the engine do you think it a good time to look into this or is this not a head gasket issue. thanks Brian
A leakdown test will tell you where the compression is going- - - - -something a compression check won't do. Get each cylinder up to top dead center with both valves closed, chock the wheels and set the parking brake with the transmission in high gear, and put air pressure into the cylinder. Listen at the carburetor, exhaust, and oil fill for air escaping. If you use an air pressure regulator and adjust the pressure to 100 with no air flowing, you'll also get a "percentage of leakdown". For instance, a cylinder that holds 94 PSI with air applied has a 6% leakdown rate. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
i have most of the needed supplies for the leak down test and did some research on how to do a leak down test. other than some saying it is dangerous there was not much about the procedure. could anyone give a link on how to do it safely. (do all the plugs come out? , does the coil get disconnected?) details are much appreciated. thanks Brain
Hotrod Lincoln gave you the information you need. Taking all plugs out would make it easier to turn over bringing the next cylinder to TDC. Wouldn't hurt to disconnect coil, nothing wrong with an extra level of safety, but if ignition is off you shouldn't get any spark. I'm not sure what's dangerous about it. It can be dangerous on an airplane engine as there is a large prop on the front and it can swing on you if you're helper isn't careful to hold it at TDC.
