Lateral-g Forums - Melling oil pump warning

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Like the fella said on the first thread Jody posted... is the HV55 the same as the M55x casting?

It might be in there but I can't seem to find anything confirming or denying this

The new M55HV pumps are the thinner wall thickness castings too (you shouldn't be needing an HV pump for 99% of applications anyways but that's another story entirely...)

The only way to make sure you're getting the good THICK wall thickness pumps is to buy any of the pumps in their "Select" line.

All spur-gear type oil pumps will experience some amount of cavitation at some point in their operating range. This cavitation, coupled with general vibration in the engine will induce a cyclic load on the pump body. If the pump body isn't thick enough it will eventually crack and fail.

I have seen several of the new "thin" pumps fail now in roundy-round applications but I also know several other roundy-round guys who have an entire season on the thin pumps with no cracks of any kind even after a penetrant inspection. They are switching to the "select" pumps for next season though.

It's only a few bucks more for the original thicker casting pumps-- why take the chance?

Melling's wrongdoing in this case was not getting the word out to the "performance" crowd in a better manner.

Word has it that sometime in the near future Melling is going to be releasing a gerotor-type pump for Chevy's under their "select" line... that will be cool.

Quote:

Originally Posted by JUSTANOVA

dirt circle track racing comes to mind, with rough tracks, and the occasional wreck, that could put a serious jolt to the oil pump. I haven't had one break yet, but you can bet that the oil pan wil be coming off of all our motors to check the wich oil pump we have. It doesn't take long to destroy alot of parts at 8000rpm's for 3/8 to 1/2 mile track.

Yeahs for sure,I haven't had any pumps fail,but we are switching everything to the new performance pumps they came out with.For the Modified and Late Models I use a billet pump for them.

Is This One Of The Bad Pumps

So Ive read through all the links, but im still not sure if this is one to be concerned with? m155hv. I had a local shop put in the new pump and I did not get to look at it. I dont have solid motor mounts so if it is one of the questionable ones do I even need to be concerned with this? Thanks for the info. Jay.