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Yup, I'm waiting for the other shoe to drop too. Which side?

3/4 side only. I dont' get it?

Could be casting sand in the cam blank. I've seen it on a couple of engines fitted with standard lifters and Scat cams.

Phil69 wrote:Could be casting sand in the cam blank. I've seen it on a couple of engines fitted with standard lifters and Scat cams.

In the ACVW, the same four lobes operate the valves on both sides of the engine. Any defect in the cam would manifest as near-identical damage on each opposed pair of lifters - here we have lifter problems only on one side of the engine, and on all four - since it seems unlike that half of them were bad and concidentally all managed to end up on the same side, it's more likely that the cause is somehow related to the head or case on that side.

Did you measure everything on both sides when building it?

Sometimes, only one side will be used to determine pushrod length/geometry, etc.

So many times i have ended up with four pushrods for the 1-2 side and four more for 3-4....

Marc wrote:

Phil69 wrote:Could be casting sand in the cam blank. I've seen it on a couple of engines fitted with standard lifters and Scat cams.

In the ACVW, the same four lobes operate the valves on both sides of the engine. Any defect in the cam would manifest as near-identical damage on each opposed pair of lifters - here we have lifter problems only on one side of the engine, and on all four - since it seems unlike that half of them were bad and concidentally all managed to end up on the same side, it's more likely that the cause is somehow related to the head or case on that side.

I wasn't aware that it was only one side of the engine that had suffered lifter damage.
The examples I viewed the lifters where all OG lifters so the lifter quality was not in question.
The camshafts however showed distinct offsets in there castings and even on the cam lobes.

I've seen that sort of damage happen when too slack on the valve clearances, some builders will specify over large gaps for the first 500, say 010" ex & in, if it gets forgotten to be re adjusted at the 500, it kills Brazilian lifters, if one side was slacker than t'other, could be the cause, I take a good few of these apart for oil burning problems, the same one dealer sets the gaps too wide and I see it on their motors.

buildabiggerboxer wrote:I've seen that sort of damage happen when too slack on the valve clearances, some builders will specify over large gaps for the first 500, say 010" ex & in, if it gets forgotten to be re adjusted at the 500, it kills Brazilian lifters, if one side was slacker than t'other, could be the cause, I take a good few of these apart for oil burning problems, the same one dealer sets the gaps too wide and I see it on their motors.

I set mine at 0.007" on a fresh build and reset them to 0.006" (0.15mm) after the first 500miles.
I feel 0.010" is a bit excessive.

What happens if they are too wide on valve lash is the lifter is knocked hard by the cam lobe as it's not on the 'soft' opening ramp, minimum clearance is good, but not if you don't maintain things often, loose zero on chromo p/rods should be kind on lifters but check clearances often.