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have a 68 Ford truck with a 70' 302. when throttled up black smoke comes out of tail pipe, also leaves carbon residue on garage floor when ideling. prior to this last weekend the truck has sat for sometime. changed all the fluids, added some good gas (got rid of the bad gas), replaced spark plugs and wires. pulled the new spark plugs to do a compression test and all of them were fouled. the results of the compression test are as follows: 1-140; 2-145; 3-150; 4-145; 5-140; 6-155; 7-135; 8-120.....there are a number of oil leaks in the the engine (this weekends project to start tackeling them). from the compression test does it appear that the rings are good and the oil on the spark plugs is from the valve seals? any help or advice would be greatly appreciated....
I think you're on the right track , have you tried putting a little oil in the cylinders and then running your tests to confirm that the valve guides are shot. If they are then a head rebuild is called for.
any good compression tester set will have a set up in it to pressureize the cylinder in it.take that and rotate the engine so that bolth valves are closed then put pressure to it and spray the valve seal area with some oil.if the valve seals are shot you should get some boubiling.
any good compression tester set will have a set up in it to pressureize the cylinder in it.take that and rotate the engine so that bolth valves are closed then put pressure to it and spray the valve seal area with some oil.if the valve seals are shot you should get some boubiling.
If you pressurise the cylinder and get blow by on the seal, you have either improper valve to guide seating or worn guides, which will allow the air to pass through the guide to the seal.
I'm probley posting this in the wrong place, I am very new to computer. anyway, I recently bought a 1966 F100 that has had a V-8 with a c-6 auto trans installed in it. It runs great right now but I don't know how to tell the exact engine size or year model. What do I look for on the engine that would give me that information. Also am looking for a wiring schematic for the entire dash area. Need all the help with either problem I can get.
Thanks; Bluetracktor
I'm probley posting this in the wrong place, I am very new to computer. anyway, I recently bought a 1966 F100 that has had a V-8 with a c-6 auto trans installed in it. It runs great right now but I don't know how to tell the exact engine size or year model. What do I look for on the engine that would give me that information. Also am looking for a wiring schematic for the entire dash area. Need all the help with either problem I can get.
Thanks; Bluetracktor
You are correct, this is the wrong year forum for your post. If you look a little further up the list you'll find your year model truck. Post a new thread and not to an existing one unless you're replying to it. I'll mark this for TheWiz to move. And welcome.
Last edited by LoosMaster; Apr 8, 2004 at 08:52 AM.
Reason: wrong direction
simple test, run a compression test then squirt a little oil in the cylinder and re run the test. If number rise then the rings are probably worn, if they stay the same look at the valv area. The 302 valve stem seals will harden and start leaking pretty often on the older motors. Good news they are easy to change. Another test is to see if you blow smoke out the exhaust on startup and quik acceleration. Both of these are signs of valve area leakage, if smoking all the time more like the rings.