Not all EDM lifters have the hole centered. Case and point. CROWER.
Lets look at this logically. Take rocker arm to valve stem tip contact, for example. If there was no oil present there, the rocker pad and valve tip would burn up in short order. The oil there is not pressurized. It is splash/dripped, yet, somehow, the rockers and valve tips last a very long time. Several hundred thousand miles if the engine is properly maintained.
To argue that there is no oil film there I think would be futile, since the rockers do not burn up, nor the valve tips.
While it is true, what the cam lobes and lifters normally see is only splash lubrication, IMO it cannot hurt a thing if they get some oil that is purposely directed for the particular purpose of intentionally lubricating and cooling both the lobes and lifters.
The cooling effect seems to be something that has been left out of this discussion. That's how things die. Through lack of lube and heat. It seems to me that direct oil lifters, whether they actually provide a "pressurized cushion of oil "or not, are a great idea.
The holes are not large enough to negatively effect oil pressure, but they are large enough to provide a much needed (IMO) extra bit of oil to areas that (also IMO) should have had specific oiling designed there from the start.
IMO (yet again) if engines have relied on splash lubrication to the lobes and lifters for all these many decades, there must be oil filming going on there. Be it pressurized or not, must make no difference, because before the zinc reduction/elimination, engines ran several hundred thousand miles properly maintained with narry a camshaft or lifter failure.
Now that the zinc is all but gone, I don't believe a little more oil there will hurt a thing. Even if you run a high zinc content oil, what will it hurt to run EDM lifters? I say a little added protection is well worth the extra cost.
Who gives a flying whooptydoo if they offer pressurized oiling or not? They help lubricate and cool the cam lobes and valve lifters. Stop arguing the point. It's doing nothing to help anyone. A newbie would come on here and not know what to do. That's not why we're here last time I checked. Can we put the penises up and all agree that EMD lifters are a good thing? Run them if you want.
