| Author | Message | ||
     Bill Lengkeek Posted From: 216.217.210.218 |
I have an Oliver 77 that has a good compression reading on all 6 cylinders, back three cylinders foul the plugs in a graduating degree with the rear being the worst. Could this be caused by oil return passages being blocked? I have replaced the valve guide seals. | ||
| cordell Posted From: 159.83.252.234 |
I have 15 years experiance as a mechanic, not on tractors. I would be checking the head gasket. These can leak oil without leaking water depending on head & block design. old chevy v-8's did this but it was due to the intake gasket leaking. | ||
| kurt miller Posted From: 24.75.5.232 |
I am inclined to agree with cordell there is an oil port in the rightrear of motor can leak in or out ps i have a brand new gasket hanging on my wall i also have one complete 77 and one parts tractor | ||
| John Schwiebert Posted From: 209.143.51.212 |
To me you are not looking at the big picture. First of all remember your piston has more than one ring on it. You have compression rings and oil rings. If the compression rings are good and the oil ring is worn than excessive oil can get in the cylinder. You said you replaced the valve guide seals. Which type of seal did you have? Also have you take the manifold off and looked in the ports with a flashlight and had someone turn the engine over to see how oily the valve stems are? On your rocker arm shaft, does the oil line go in the center of the shaft or is it close to the back cylinder. Return oil from the rocker arms is and returned through the same holes as where the push rods go through the head. If those hold are pluges, you have a 77 that has not had the oil changed very well. More questions? John | ||
| Bill Lengkeek Posted From: 216.217.210.218 |
John, Cordell & Curt: Thanks for your info, I still feel that it is a clogged oil passage as the engine has a slant to the rear and the last three cylinders graduate in quantity of oil in each combustion chamber per the build-up of oil residue on each spark plug. When I changed the Valve stem oil seals, I did not have the head off the engine so I was unable to look into all of the ports. Also after the motor has been shut down for a few days, it takes a while before the smoke once again starts back up. Thanks again. | ||
| John Schwiebert Posted From: 209.143.51.150 |
Take the valve cover all. There are 12 holes for the push rods. Those are the only drain holes and they have nothing to do on the oil enters the combustion chamber. If the push rod moves oil will fall down the hole. Do you know how to do a cylinder leak down test? What kind of oil seals did you use? If you want get my phone number and call me. Merry Christmas! John | ||
| John Schwiebert Posted From: 209.143.51.204 |
Think about this: If you have the rocker arm assembly with the oil line that is not centered maybe you have enough waer in the back rocker arms that you are getting too much oil over the valves and it is draining into the combustion chamber. Remember seals do not correct excessive wear. Like I said lift the manifold off and shine a good mag light in there. John |
