S4 SE Engine Mounted Fan

[peterexpart]

I hope this is not a stupid question !!!!
Should the S4 SE have an Engine mounted Fan or just the Electric Fan ?? I only ask as mine has not got one fitted, and I am not sure if it was removed by PO or if this is correct.

[m750rider]

An S4 SE would have had both fans, one electric in front of the radiator and one four blade on the water pump shaft.

Rob
1969 S4 SE
45/8842

[peterexpart]

Due to lack of response to my question I telephoned Miles Wilkins and received the following reply :-
The Early Elan S4 with the full width Radiator did have an Engine Mounted Fan the later UK Spec ones, such as mine with the Narrow Radiator "Never had an Engine Fan Fitted" they were only fitted to cars destined for warmer climates.
Well at least I now know that there is nothing missing !!!

[69S4]

Well I'm glad you've got a definitive answer. My mid 69 S4 SE with a narrow rad didn't look like it ever had an engine mounted fan fitted but as it was 12 yrs old when I bought it who knows what could have happened in the interim. I'd have thought you'd leave any factory fitted engine blades in place given how marginal the cooling is with the smaller rad but there's no accounting for previous owners whims.

[peterexpart]

Stuart
Thanks for that, like you I would have thought if any one of them would have not had a Fan it would be the one with the wide Radiator not the one that had marginal cooling in the first place !!!

[oldelanman]

Not an SE but my Stromberg S4 (narrow rad) never had an engine fan either.

[rgh0]

Due to lack of response to my question I telephoned Miles Wilkins and received the following reply :-
The Early Elan S4 with the full width Radiator did have an Engine Mounted Fan the later UK Spec ones, such as mine with the Narrow Radiator "Never had an Engine Fan Fitted" they were only fitted to cars destined for warmer climates.
Well at least I now know that there is nothing missing !!!

Interesting but like most things Lotus you can never make defintive claims around some of the details even if your name is Wilkins.

My early S4 elan 36/8555 was UK spec standard equipment car made around August 68 and came with a narrow radiator and engine driven fan from new. It did not have an electric fan until I fitted one- my belief is the electric fans were not introduced until around 1970 in late S4's.

S4's fopr hot climates came with the S3 style wide radiator and the engine driven fan though to arounf 1970. Late S4's and Sprints in Australia came with the narrow radiator and electric fans. I have never seen a car with both but that does not mean Lotus did not make it

cheers
Rohan

[saildrive2001]

My UK spec 69 S4 SE came with the narrow rad and electric fan only. Car is fitted with the UK spec Strombergs.

[cliveyboy]

I think another way to look at whether a car came with an electric fan as standard is to think how would it have been triggered.
I currently have examples of three different radiators for the Elan:- S1/2, S3 full width and a narrow radiator (off my Sprint) only the narrow radiator has a boss for an otter switch to operate an electric fan. The narrow radiator on my Sprint also had an electric fan fitted.
I might be wrong but I cant remember anything in the manuals referring to switches for operating an electric fan other than the late S4/Sprint and Plus 2 which used the otter switch. If there is no switch there is not likely to be an electric fan and so an engine mounted fan is more likely

[69S4]

There is a hole in the top of the rad on my car that looks like it might have held an otter switch but it has a threaded plug screwed into it blanking it off. The electric fan is triggered from an aluminium casting fixed into the top hose - at the top in the picture below. It's been there ever since I've had the car and I'd guess it's probably an aftermarket addition - Kenlowe or something like that but better quality. It easily looks like it could be original equipment though.

[oldelanman]

Hi Stuart,
According to the workshop manual Lotus did supply the electric fan as an aftermarket accessory and the switch was then fitted in an adaptor in the top hose as you have. However the manual also states that Stromberg engined cars had an electric fan as standard and the illustration shows the switch in the radiator where you have the threaded boss.....and that's where mine is.
Your car looks like another Lotus production anomoly
The original screw-in Kenlowe switch was later replaced in production and service by the push-in Otter switch.

[DJ908]

My Elan 36/8507 had an engine driven fan, and wide radiator when supplied as a kit car in December 1968. The car has the bulge in the bonnet for Stromberg carbs although Webber carbs were fitted to this car.

It would seem to have been delivered from the factory to the Sheffield UK dealer some months after Rohan?s car although it has a lower serial number. I do remember that the factory was having all sorts of quality issues at the time, hence my car was ?late? on delivery. The standard of finish on car, when received, was appalling.

Robert

[69S4]

Hi Stuart,
According to the workshop manual Lotus did supply the electric fan as an aftermarket accessory and the switch was then fitted in an adaptor in the top hose as you have. However the manual also states that Stromberg engined cars had an electric fan as standard and the illustration shows the switch in the radiator where you have the threaded boss.....and that's where mine is.
Your car looks like another Lotus production anomoly
The original screw-in Kenlowe switch was later replaced in production and service by the push-in Otter switch.

Roger - thanks for that. With all of these little anomalies I've often wondered whether Lotus ever actually produced two cars that were exactly the same

Not having an otter switch I don't know but presumably they trigger the fan at a fixed preset temperature? The Kenlowe-alike lump that I've got has an adjustment screw in the centre of the sensor so you can vary the cut-in point but sitting where it does at the highest point in the cooling system if the water level drops even a little for any reason it's left high and (more importantly) dry so it either stops working or cuts in late. It doesn't seem to affect the car but it certainly affects me so I gave up with it many years ago and fitted a manual override switch. It might have been easier to retrofit the otter switch as that sits much lower in the rad.

[Robbie693]

On early Plus 2's there was a Kenlowe switch in the rad before the introduction of the Otter type. The Kenlowe unit was adjustable for cut-in temp, the Otter has a fixed activation temp but i think at one time units with different cut-in temps were available. Presumably the Elan was similarly fitted...

Robbie

[fasterbyelan]

Hi Stuart,
However the manual also states that Stromberg engined cars had an electric fan as standard and the illustration shows the switch in the radiator where you have the threaded boss.

When Stromberg carried out the development work for the use of their carbs on the Twin Cam they recommended the fitting of an electric fan as the hotter running made the cooling rather marginal (probably an understatement as far as some are concerned!)

My S4 SE came to me in 1984 virtually in an original condition and yes, it had an electrical fan with the otter switch mounted in the radiator (top, offside).

As a slight aside, the cooling is OK in normal conditions and I only ever become concerned in traffic jams.

Edit - Checking my source once home, Stromberg recommended the electric fan for the SE version (they were using an engine fitted to a +2) as boiling occurred within 24 minutes.