[Steve C.]

Potential of not having the oil band exposed to the lifter bore feed hole 100 percent of the time. I know the base circle of the cam has a impact as does the lifter oil band location and/or width. If using them, it can have a impact on the Hi-Pressure Pin Oiler (HIPPO) system on Crower roller lifters because the small 0.024" hole that feeds oil to the needle bearings is located within the oil band. That means it is not getting 100 percent oiling thru that hole.
In some instances the lifter must raise quite a distance before oil starts flowing to the needle bearings thru the small hole. I have no specific number but it can equate to quite a few degrees of cam rotation before it does.

Related video: https://www.youtube.com/watch?v=JoU_hUgq4O0&app=desktop
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[PAUL K]

Originally Posted by Steve C.

Potential of not having the oil band exposed to the lifter bore feed hole 100 percent of the time. I know the base circle of the cam has a impact as does the lifter oil band location and/or width. If using them, it can have a impact on the Hi-Pressure Pin Oiler (HIPPO) system on Crower roller lifters because the small 0.024" hole that feeds oil to the needle bearings is located within the oil band. That means it is not getting 100 percent oiling thru that hole.
In some instances the lifter must raise quite a distance before oil starts flowing to the needle bearings thru the small hole. I have no specific number but it can equate to quite a few degrees of cam rotation before it does.

Related video: https://www.youtube.com/watch?v=JoU_hUgq4O0&app=desktop
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Did the lifter that had an issue on your engine have the oil band in the correct location?

There is a lot of oil being tossed all over the place in a running engine. The same oil that lubricated the lifter and lobe on a flat tappet cam is still provided to the bearing and cam on roller set up regardless of where the oil band and oil hole are.... It provides quite a bit of oil.

[Steve C.]

I've had two separate solid roller lifter failures that involved one lifter each time, both with the same .4300" lobe lift w/1.65 ratio and same Crower Cutaway Severe-Duty roller lifters with HIPPO pin oiling. One had needle bearings and the other bushing-style. We did not suspect either failure had anything to do with the lack of 100 percent oil flow thru the HIPPO system. Regarding that situation some suggest no issue if the needle bearings don't get oil flow 100 percent of the time under pressure, including the opinion of Crower when I called them years ago regarding the subject. That said, Crower tends to cover their ass on many issues. Agree, lots of oil splashing that is commonly called 'splash lube' but it was Mark at Luhn Performance who commented on the subject with a car at idle in a street application.

And a fwiw, after the first failure we modified the lifter bore with the groove like Paul Carter does so my lifters involving the second failure did see 100 percent oil flow to the bushed bearing thru the HIPPO system.


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