a70duster
Well-Known Member
Hello all, so I have a freshly rebuilt 383 that I've been assembling over the last couple of months. Last Wednesday I fired her up to break in the cam. The engine started right away. With all these issues of flat tappet lifters failing, I proactively made a vertical paint pen mark on all the pushrods.
Anyway the engine is running good, oil pressure at 70 and the engine running at 2500ish RPMs. A friend was helping out observing the rotating pushrods. After 10 seconds we noticed that the pushrod for #7 exhaust was NOT turning. I shut down the engine and dug into the issue.
I pulled out both lifters for cylinder #7, intake on the left and exhaust on the right. One can immediately see the wear pattern on the right lifter. It is straight down the middle.
I cleaned up both lifters, marked the bottoms with a Sharpie, reinstalled and cranked the engine over roughly 5 times. The wear pattern is right down the middle of the lifter. That ain't gonna rotate the lifter.
So both the pushrod and lifter rotated smoothly in their location. Next I'll need to measure the crown of the lifter. It's unfortunate one has to go to such lengths to break an engine in. At least there's no damage.
Anyway the engine is running good, oil pressure at 70 and the engine running at 2500ish RPMs. A friend was helping out observing the rotating pushrods. After 10 seconds we noticed that the pushrod for #7 exhaust was NOT turning. I shut down the engine and dug into the issue.
I pulled out both lifters for cylinder #7, intake on the left and exhaust on the right. One can immediately see the wear pattern on the right lifter. It is straight down the middle.
I cleaned up both lifters, marked the bottoms with a Sharpie, reinstalled and cranked the engine over roughly 5 times. The wear pattern is right down the middle of the lifter. That ain't gonna rotate the lifter.
So both the pushrod and lifter rotated smoothly in their location. Next I'll need to measure the crown of the lifter. It's unfortunate one has to go to such lengths to break an engine in. At least there's no damage.
