26R differential cooler

[wbmoore]

Pardon my ignorance. When a differential cooler is talked about on the 26R is it..... Just a hose leading from the side scoop vent and blowing colder air over the differential (as seen in the kit from KelSport), or is it an actual oil cooler with a pump to circulate the oil which is cooled by the scoop/hose gag? I believe I have read about both. Thanks.

[vstibbard]

I have s2 26R which was delivered from factory with diff cooler which has bendix type pump and oil cooler under the boot floor i will post a photo when on computer next.

[wbmoore]

Perfect.... Thanks in advance for the photo. brad Moore.

[elj221c]

The (much improved) advanced search is your friend but this will start you off....

lotus-gearbox-f37/diff-oil-cooler-photos-t22060.html?hilit=diff%20oil%20cooler#p133460

V's installation wasn't the only solution.

There is a description only (sorry, no pics) of one on an Ian Walker rally Elan that I had dealings with.

'tis all there.......

[RayBoulay]

We had a 26R purchased at the Earl's Court show in 65 (maybe 64) that we ran in Germany for which Lotus Components supplied a retrofit kit with a Bendix fuel pump. Small cylindrical pump, maybe 3" diameter, maybe 7" long. (Please excuse my fading memory!).

I had some concern about using a fuel pump to pump gearlube, and contacted Bendix in the US. Their engineering department replied in writing that, although they couldn't endorse such an application, they saw no reason that it wouldn't work, but to be sure to use the "Blue Cap" model. It worked fine, and solved the diff problems on the 'Ring.

I subsequently used an identical setup SCCA racing in the States for years, with good results. Good luck, Ray.

[Greg Cozier]

Would any kind of diff. cooling be necessary on a rally car? Stages rarely exceed 15 minutes hard driving.

[rgh0]

With modern synthetic gear oils with much greater temperature resistance, a cooler is certainly not needed in short races of less than about 30 minutes which is the maximum duration i run. I still have the orignal diff in my Elan after 30 plus years of racing to prove it.

For longer endurance events of a few hours it may be a wise investment but even with these i suspect its not really needed these days.

cheers
Rohan

[elansprint71]

As an aside, has anyone actually got a copy of homologation papers for the diff cooling system(s)? It does not get a mention in any of the stuff I've managed to collect over the years.

No mention of an ally gear-box casing either, but these seem to pass scrutiny without comment, anyone got a copy of the papers for that too?

Cheers,
Pete.

[vstibbard]

Photo's as promised

Original differential oil cooler installation with bendx pump along side fuel tank, cooler under floor.

Cheers
V

[Greg Cozier]

The Alan Mann Twincam Escorts in the 68/69 BSCC ran similar cooling for the same diff in the Escort axle, not sure about the Broadspeed 1300cc cars. As far as I know, diff cooling was not required for Atlas axles in later Escorts.

[msd1107]

If you get your ring gear REM or RF85 processed, you will not need a differential cooler ever. These processes reduce the friction of the ring gear, thus leading to less heat buildup.

David
1968 36/7988