By Loren Cross
Originally published in the Austin-Healey Magazine
Does your Healey give out with smoke when first started or upon hard acceleration, but no other until...? Do you have oil in or dripping from the rear air cleaner? Is the oil pressure abnormally low? If the answer is yes to any or all of these it is possible that the problem could be a worn rocker assembly.
Case In Point: 1963 Engine Prior To Rebuilding Assembly.
Oil Pressure (Hot) At 2000 Rpm: 40 Lbs
Oil Pressure (Cold) At 1500 Rpm: 55 Lbs
Oil Pressure (Hot) At Idle (950) Rpm: 20 Lbs
Oil Consumption - One Quart Each 500 Miles
Oil Dripping From Rear Air Cleaner.
Same Engine After Rebuilding Assembly.
Oil Pressure (Hot) At 2000 Rpm: 60 Lbs
Oil Pressure (Cold) At 1500 Rpm: 65 Lbs
Oil Pressure (Hot) At Idle (950) Rpm: 40 Lbs
Oil Consumption - None
No Oil In Rear Air Cleaner.
Please do not interpret me wrong. A worn rocker assembly is not the only cause of oil consumption or low oil pressure. This is just the way it affected my car. Obviously mine was quite worn. A simple check - remove rocker assembly cover. Oil should just barely ooze out of the hole in the top of each rocker. A steady stream or spouting indicates wear.
The book says:
Diameter Of Shaft Bore Of Arm: .8110 Minimum At Wear Point
Bore Of Arm: .909 To .910
I/D Of Bushing After Ream To Fit: .8115 To .8125
Clearance: .005 To .0015
Note: if the diameter of the rocker shaft at point of wear - if less than the above minimum the shaft should be replaced. Good luck and have fun.
Not what you were looking for? Don't forget you can check our back issues using the AHCUSA Magazine Index.