Pumba

Gentlemen,

Over the past few days I have had an opportunity to discuss LS gerotor oil pumps with an engineer who designs and tests such pumps.

Before I go any further, I need to warn that some of the data I am going to present will confound and upset some of you. So, if you decide to read on, don't throw darts.

• All three of the Detroit OEMs are working on improving their crank mounted gerotor pumps.

• Ford is having problems with their supercharged modular engines and gerotor oil pumps. It seems that the belt load of their supercharger is deflecting the snout of the crankshaft and putting a high load on the inner gear of the oil pump. So, if you have or are looking at putting a supercharger on you LS engine, be certain that you have a good fully counterweighted, internally balanced forged crankshaft, with the appropriate ATI damper on the snout to minimize the deflection of the crankshaft and its snout.

• Chrylser is also looking at the design of their gerotor oil pumps on their HEMI engines for improved output.

• GM is looking at improving the output of the gerotor oil pump for the LS7, LSA, and LS9 engines.

The following chart gives a comparison of oil pumps that are available for the LS engine:

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It is obvious from the data that the Melling M10335 or M365 pumps are a major improvement over the original and even the improved LS7 and LS9 oil pumps. They are available from JEGS and Summit.

If you are having an engine built that will use a gerotor pump have your engine builder install either the M10335 or M365 pump. For less than $150, it's a great engine life improvement.


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SteveDoten

great info, thanks bud

Blue Angel

Adding a supercharger to an existing engine using the OEM serpentine belt shouldn't affect the load on the crank. It still uses the same type of belt with the same tensioner operating at the same tension, so I can't see how that would significantly increase the crank load/deflection?

I would imagine if Ford is having problems it's because the supercharger setup they're using adds an additional belt, so the crank load would increase as there is now loading from the accessory belt as well as the supercharger belt.

This is just speculation on my part, I don't have a supercharger and I'm not a powertrain Engineer.

Good info on the oil pumps - Thanks!

SteveDoten

NO, C5 SC systems use a much stronger than oem tensioner, I have experience installing dozens of SC systems

But...the C5 does benefit from having such a short crank pulley

Bill Curlee

WOW! Excellent data. Glad I went with that melling pump when I did my last set of mods! Its an excellent pump and looks well built! That flow data is impressive compared to stock!

Thanks for the data.

BC