Engine mounted cooling fan options

[vtauto]

We have recently acquired an early S3 Elan with a yellow plastic 7 blade fan that has damaged tips, probably from hitting the crank pulley. It still cools well and we'd like to not go to some version of an electric pusher fan. The parts manual shows a waterpump mounted fan that looks like ours, if you could believe the drawing. Others have claimed that cars of this vintage could have come with everything from a two bladed metal to an eleven bladed plastic fan.

It would be nice to have something close to whatever original is, but finding something that works is the first priority. Even if we had a new version of the current yellow 7 blade, we could probably space it out to miss the crank pulley. I've seen someone on the forum use a fan from a Triumph Spitfire, but he claimed that only 2 of the 4 fan attachment holes lined up with the waterpump flange.

Anyone have a suggestion and possible source for a replacement fan?

Thanks

[2cams70]

The original source will most likely be Ford and probably Escort from what you are describing but please post a picture to more positively identify.

[Ray419G]

If you can't get a good used example locally, Burton in the UK (www.burtonpower.com) still list a yellow seven blade fan for Ford crossflow engines, this is what I suspect is fitted to your car.
For a S3 sold in Britain, I would expect it to have originally been fitted with a 2 blade pressed steel fan, Lotus part no. 036 E 6000. These seem to have come from the Cortina Mk 1 or another 60s Ford fitted with the pre-crossflow engine. I don't think they are available new but used ones may come up on ebay and such sites.
For some applications a 4 bladed version of this fan was fitted; this is made up of the original 2 blade fan, plus what the Elan workshop manual lists as an “outer fan” (part no 36 E 6001), fitted at 90 degrees to the original.
I suspect this arrangement will have been fitted to some export cars going to warmer climates, perhaps standard on a US spec car?

Ray.

[vtauto]

Thanks for both replies. It's hard to get a good photo with it in place, but here it is. It looks like maybe it could have started life as the 290mm diameter Burton fan. Clearly someone has trimmed the ends and it now measures about 270mm.

[2cams70]

That fan looks suspiciously like a bodge. To me it looks like a Ford fan that has been obtained somewhere from a scrapyard and installed. The giveaway is that appears to have been mounted around the other way to the correct way in order to gain clearance to the radiator for the Elan application. Ford had a number of different fan specifications at the time. The one Burton lists looks like UK domestic one which was different to the export one for use in warmer climates. The fitted fan looks like the export one but can’t really be certain based on the picture alone. Perhaps others can chime in about what was the correct original specification for your vehicle.

[Andy8421]

Its your call, and of course if you want originality then stick with the mechanical fan, but there were good reasons Chapman spent extra money on later cars on an electric fan rather than a bent bit of tin from Ford.

You only need a fan when the car is moving slowly, or stationary. When the car is travelling, there is more than enough air through the rad to keep the engine cool. I race(d) an Elan, the electric fan was only switched on when stationary on the grid, and coming back into the pits.

The mechanical fan robs the engine of HP. We don't have a great deal to play with, and depending on conditions (fan size, rpm etc) it can be up to 5HP you are wasting.

The fan is sized to keep the engine at an acceptable temperature when the car is stationary at tickover, or crawling in traffic when the engine is at low revs. Although the engine cooling requirement is relatively low, the only airflow is coming from the fan. At high revs on a highway, not only is the fan not needed, it is spinning away madly sucking up power.

Modern cars either have some form of thermostatic clutch on a mechanical fan, or use electric fans to avoid this HP (and fuel) wastage.

Just as an aside, an interesting case is my old Landrover Defender, where there is a reasonable expectation that the engine will be under heavy load with the vehicle at very low speed (low range gear, plugging through mud or up the side of a mountain). On the Landrover, the mechanical fan is enormous, and looks like it belongs on a helicopter - it does also have a thermostatic clutch.

[2cams70]

Bent tin fans were only used by Ford on Mk1 Cortina so I doubt Lotus would have used them beyond 1966 when the Mk1 was discontinued. The later plastic fans had more offset and probably wouldn’t fit a Lotus unless installed the wrong way around. Part of the reason for going electric may have been because they were forced to because the off the shelf Ford parts bin no longer existed.

[rgh0]

The water pump mounted metal fans were used until around 1969. Two bladed in cool climates and 4 bladed in hot climates. My Late 68 Elan originally had a two blade fan as it was UK deleivered. Lotus switched to an electric fan from around 1970 with the Sprint and Plus2S 130

cheers
Rohan

[2cams70]

The water pump mounted metal fans were used until around 1969. Two bladed in cool climates and 4 bladed in hot climates. My Late 68 Elan originally had a two blade fan as it was UK deleivered. Lotus switched to an electric fan from around 1970 with the Sprint and Plus2S 130

cheers
Rohan

What was the block number in your car? It’s also a possiblity that 120E blocks were linked to metal fan and 681F and later linked to something else because that’s how it would have aligned with Ford’s regular engines at the time. 120E blocks were only in Mk1 Cortinas and not Mk2

[rgh0]

The original block was a 681F

[alan.barker]

If you start chopping a Fan to reduce dia it will be out of balance. The Water Pump Bearing won't like that lol.
Also if you have an electric Fan infront of the Rad you can see Timing Marks easy.
+ no Fan to wrap around clothing when doing dynamic Timing with Strobe.
Alan

[2cams70]

The original block was a 681F

Lotus made the change independently from Ford in that case.

[MartijnElanS4]

Hi,

My 1971 Elan Sprint has a yellow plastic fan.
Don’t know if it is original but it looks similar.

Martijn

[2cams70]

Interesting fan. Does not appear to be Ford derived. May be Lotus unique. Perhaps others can comment as to it's origin. Judging by the number of blades Lotus did seem to have quite a bit of problem getting airflow through the radiator and that might not just be with getting the air into the engine bay but also getting it out of the engine bay. Getting air in but not being able to get it out is just as bad as not being able to get it in in the first place,

[Andy8421]

Interesting fan. Does not appear to be Ford derived. May be Lotus unique. Perhaps others can comment as to it's origin. Judging by the number of blades Lotus did seem to have quite a bit of problem getting airflow through the radiator and that might not just be with getting the air into the engine bay but also getting it out of the engine bay. Getting air in but not being able to get it out is just as bad as not being able to get it in in the first place,

It appears to be off a Mini.

https://www.minispares.com/product/Classic/12G2129.aspx

Which is interesting, because fans in a Mini blow, they don't suck (so to speak). If the picture of Martijn's fan is the actual fan from the car, and if my mental gymnastics are up to it, if would appear to be going the wrong way for an Elan and trying to blow air through the rad instead of sucking it from the nose plenum.