Friend has a 66 401 engine that was completely rebuilt and shortly after cam break in within about 30 minutes run time the driver's side lifters were very noisy. Oil pressure on the gauge was good but it appeared the driver side lifters were not getting much oil. Engine was pulled out of the car and completely torn down and there is nothing visually wrong that we can see. Front Cam bearing holes are aligned properly. He was thinking maybe he had a cracked oil passage but it would seem to me that would drop pressure in both sides. Any ideas?
I had a similar thing going on right after I built my Nailhead. I primed up the lifters and then torqued down the rocker shafts. What eventually happened was the rocker on the driver's side wasn't torqued down enough and broke into 3 pieces. It also didn't help the I had 2 different sizes of lifters in the kit, I was in a hurry to reassemble and didn't line them all up prior to assembly. The resulting mess came apart after about 1000 miles; - at first it started ticking, and then knocking and rattling, and then at speeds less than 60 it began misfiring and running very rough. This all happened on a 600 mile trip home across the Rockies in the middle of the night. By the time I made it home the car was running on 5 cylinders. I thought I had shot-gunned the motor, but I got lucky; only the one rocker shaft was destroyed, no pushrods were bent and the cam somehow survived. There was one Chevy lifter (concave bottom) and one other oddball I wasn't able to source in that kit. Of course a lot of the kit's components originated in China. Both incorrect lifters wound up on the same side. The guy who torqued that side down was hammered out of his skull at the time and likely stoned. (It wasn't me, I was in the can when he took the initiative). So there were a lot of lessons learned. Once properly sealed up and torqued down properly the oil was getting further up the and squirting properly. A set of rockers from the wrecker and a new set of lifters and I was on my way. Now it's 20,000 miles and 10 years later and the engine is still running strong.
Make sure the notch in the rocker-shaft is oriented as described in the Chassis Service Manual. Cheryl
I could see how an incorrectly orientated shaft could cause a problem with the rockers getting enough oil but would it make the lifters starve also?
that's what I thought. He put all of the components from this engine in a different block and the issue was resolved.
