Any news on the Melling Helical Asymmetrical oil pump?

[roc]

flathead Ford v8 symmetrical helical pump gear.jpg

Sorry Kevin, I don't get it, can you please elaborate?

[PackardV8]

Maybe what Kevin was showing is helical gear oil pumps aren't exactly new news. Some Ford flathead V8s and the '51-53 Studebaker V8 used them, as probably did many others.

jack vines

[Dutchman]

I just finished up a 1937 Cadillac lasalle v-8,it had helical cut gearsin the original pump,the replacements were spur type.
Anybody know of any earlier examples?

[Walter R. Malik]

flathead Ford v8 symmetrical helical pump gear.jpg

Sorry Kevin, I don't get it, can you please elaborate?

The leading side and the trailing side of the gear tooth is NOT the same.
A symmetrical gear tooth is the same on both sides.

[roc]

flathead Ford v8 symmetrical helical pump gear.jpg

Sorry Kevin, I don't get it, can you please elaborate?

The leading side and the trailing side of the gear tooth is NOT the same.
A symmetrical gear tooth is the same on both sides.

Walter, thanks for the explanation, now I understand. The asymmetrical gear looks like it has 'bent' teeth.

Am I the only skeptical here whether this wouldn't produce measureable difference on the engine dyno?

[Circlotron]

Maybe asymmetrical teeth are optimised for drive side loading only, at the expense of the overrun side which is not used anyway in an oil pump.

[GARY C]

The SBC version is currently available.

http://www.ebay.com/itm/NEW-Melling-Sel ... 1912949719

I saw the demo at the PRI show. The rep. at the PRI show indicated that the design would be available for other engines, but he did not know when. I also asked if the helical gears would fit in the original straight cut gear housing. He indicated that they would not.

I have not personally tried one because of the whole cost/benefit ratio thing. It probably cost them a buck more to make it, but they want an extra 100 bucks for the pump.

$160.00? THATS CRAZY! We have always run stock BBC pumps in our SBC's and have never had an oil related failure. We ran a very loose 377 nitrous engine for 5 years with one re ring and head change and reused the bearings it never saw more than 50lbs of pressure shifting at 7000.

I do feel Melling screwed the pooch when they went to the weaker SBC casting but I think they rethought that... or maybe I'm wrong.

This must be for circle track are endurance racing?

I hope we get to see some independent testing on this, I would like to know why they feel it's that much better.

[Kevin Johnson]

Engineers designing the Ford Flathead V8 and earlier automotive examples of helical gear pumps would have been familiar with the Ancient Greeks as a standard part of their education in the Classics: the gear sets are simply more elaborate counter-rotating and meshing examples of Archimedean screws.

The twist of the helix would be designed to attempt to maintain as constant as possible a continuous equal positive displacement due to the tooth volume being introduced to the pressure plenum leading to the oiling circuit. This would help ward against large peak to peak pressure variations or pulses.

The asymmetrical Melling pump tooth is optimized for the Chevrolet pump housing where the pressure plenum is offset. The gear and its leading tooth surface that provided the most direct in-line reaction force aimed at this plenum was maximized and the corresponding and mating tooth surface of the gear pair was minimized.

The images below show a Melling pump so this can be visualized more readily. The included oiling diagram of the Ford Flathead V8 appears to employ artistic license with respect to the arrows showing flow of the oil through the pump being counter-rotational to the actual path.

Melling_Performance_Shark_Pump_ISO_view_BK.jpg

Melling_Performance_Shark_Pump_top_view_BK.jpg

V-8Oiling1-445x525.jpg

Interested readers should view the Mercedes SAE paper 750051 to read the discussion on pages 6-8 and see Figure 21 with respect to the power consumption of various pump designs.

[GARY C]

Yeah, I was reading their literature earlier, http://hotrodenginetech.com/melling-deb ... -pri-show/

A lot of what they say is the same reason we went to BBC pumps.

I would think this new pump would be good for any racing where you were on and off the throttle a lot, it seams like it would have far less gear chatter in that circumstance.

[dwilliams]

Back in the day some people used a stock-volume big block Chevy pump instead of a high-volume small block pump. The BBC pump had 9 teeth per gear instead of 7, or something like that... plus it was cheaper and in stock at the local parts store back then.

There have been a few aftermarket SBC pumps with gerotor rings instead of spur gears. Cosworth used to make some, among others.

[pamotorman]

Back in the day some people used a stock-volume big block Chevy pump instead of a high-volume small block pump. The BBC pump had 9 teeth per gear instead of 7, or something like that... plus it was cheaper and in stock at the local parts store back then.

There have been a few aftermarket SBC pumps with gerotor rings instead of spur gears. Cosworth used to make some, among others.

they said the 9 tooth BBC pump caused less spark scatter.

[dirtracr5]

$160.00? THATS CRAZY!

Am i missing something? It's about $100 for the performance pump and $60 more for the design with helical gears. Since when did $160 become alot of money?? Especially for something so important???

[DaveMcLain]

$160.00? THATS CRAZY!

Am i missing something? It's about $100 for the performance pump and $60 more for the design with helical gears. Since when did $160 become alot of money?? Especially for something so important???

That sounds like a lot to spend vs the regular stock pump. It would be interesting to dyno test them back to back to see if there is any difference in performance.

[Kevin Johnson]

Yes, $60.00 more for optimized helical gears. If I were Melling I would very much want to know whether there was a customer base for further investment in improvements or to just let the technology to improve distributor performance fade away to stock replacement parts.

I think the typos in the Ford Racing catalog in the distributor gear installation section might be an unintended subtle message.

[GARY C]

$160.00? THATS CRAZY!

Am i missing something? It's about $100 for the performance pump and $60 more for the design with helical gears. Since when did $160 become alot of money?? Especially for something so important???

Yes, your missing the next line in my quote about a stock BBC pump.