26R Diff Cooler

[jkolb]

Does anyone have any photos of the original diff cooler installed on a 26R. I am interested in pump and cooler location.

Also, I have seen many racing Elans that just duct additional air to the carrier. Was the cooler found to be overkill?

Jerry

[twincamman]

OK heres mine ----the pump sits in the trunk inside on the left [facing the trunk] wheel well --after discovering this worked guys put scoops to the rear brakes ---but I dont think the works did ---over kill ?? with about 6 hp loss in the tiny diff I dont think so -----nomex on ----ed

[jkolb]

Thanx

What is the cross section on the cooler?

Jerry

[twincamman]

well it was a trans cooler --I replaced it with a newer cooler as it was 40 years old -----it just sits in the air flow in the scoop ------ed

[twincamman]

front view---add a oil temp guage in the dash from the diff and an on off switch ----ed

[jkolb]

Thanx. Very helpful

Jerry

[elj221c]

Jerry,

It doesn't show the location but this list might be of use. http://www.lotuselan.net/wiki/Category:26R_Parts_List If only you could get hold of the quoted drawing!

I once worked on an ex Ian Walker rally prepared S2 26R . From memory, the oil cooler on that was behind a vertical slot cut into the front of the left rear wheel arch. The oil was pumped with, I think, two SU pumps mounted in the spare wheel well.

I seem to remember some racers of the peroid having them there too. AFAIK they were'nt considered necessary for UK 10 lappers but for endurance all sorts were tried, such as (illegal?) under diff scoops and scoops lowdown on the sills in front of the arch.

[msd1107]

A little different point of view.

The over heating you see is due to the sliding action of the pinion on the ring gear. A spur gear is said to lose 1% power at each mesh point. A helical gear will lose 2% or more, depending on the helix angle. The pinion/ring combination will lose 4% and more, due to the large helix angle and amount of sliding action.

A variety of techniques has been developed to decrease the the friction loss at each mesh point. F1 and other competition cars have been using these techniques for some years, and it is becoming popular enough so that some of them are commercially available at reasonable prices. One process is called REM and is a post production finishing process.

http://www.evansperformance.com/rem.html

On a race car, if you consider the cost and effort to install and plumb a pump, oil lines, and radiator, the cost of the REM process is less, with the side benefit of getting a small increase in power at the rear wheels.

The effect of using this is to obtain a substantial decrease in oil temperature, since less power is being lost to friction.

Studies I have seen seem to indicate a reduction in friction of around 50%, with lesser decreases being observed at light loads and greater decreases being observed at higher loads, just where you want it.

The REM process is licensed to third party shops, so is available from multiple sources, both in the US and Continet.

Remember, there are multiple sagas of magic treatments pushed by various classes of snake oil salesmen. Some race teams believe in one treatment, some in another, some in none. Do suitable due diligence to see whose lies you believe.

David
1968 36/7988

[cabc26b]

I run with out a cooler, - longest events are vintage enduros around at 60-90 minutes , most sessions are at 30min. sprints last 10-12 laps. no issues with diff , ever.

[elj221c]

I once worked on an ex Ian Walker rally prepared S2 26R . .

Here is Pandora's box, waiting to be opened.....

You've just given Ed a new thread, it would seem!

[twincamman]

yes --a new thread perhaps to patch an old seam --- -indeed -----lets hope there is some documentation this time and not just 'expert'opinions - [:lol: -ed