Caught a lifter not rotating before cam failure

[a70duster]

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.

 

[Newbomb Turk]

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.

View attachment 1716490902

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.
View attachment 1716490904

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.
View attachment 1716490905

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.

What does the lobe look like?

Just because the lifter is rotating doesnt mean the pushrod rotates too.

By the look of the lifters you’ve got an issue.

 

[sr71mopar]

Thats the shitiest made lifter I've ever seen.

 

[Illahe]

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.

View attachment 1716490902

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.
View attachment 1716490904

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.
View attachment 1716490905

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.

Who ground the camshaft? Lack of lobe taper has been as issue with @#%* cams.

 

[a70duster]

So the cam is from Mopar. A 292 0.509 hydraulic, new in the box made 30 years ago. Here is a pic without any Sharpie marks.

 

[a70duster]

What does the lobe look like?

Just because the lifter is rotating doesnt mean the pushrod rotates too.

By the look of the lifters you’ve got an issue.

Well 15 other lifters were rotating the push rods. A rotating lifter is going to rorate the pushrod.

 

[jos51700]

Well 15 other lifters were rotating the push rods. A rotating lifter is going to rorate the pushrod.

Not necessarily, but finding that is a holy crap moment! I'm REALLY curious to see where this goes.

Good job on the root cause find!!!!!

 

[grjammer]

I went through this recently on my 440 with 2 lifters looking just like the one on the right. I dressed the lifter bores and swapped the lifters with known rotating lifters and all lifters would then rotate when turning over by hand. 1500 miles and no problems yet. I did use a dial indicator and a flat anvil to measure lifter crown and lobe tapers and all were good. If in doubt, send the lifters out to be machined. Apply new break in lube to all lifters. I use the Driven gel type.