Fitting Rad fan?

[Grizzly]

Hi all.

I'm just planning how to fit an Electric fan to my UK spec S4/Sprint (Small rad) without causing issues with my bonnet sprint etc.

My original plan was to buy an S3 Rad and fit a Cliveboy kit to it http://www.cliveyboy.com/product/lotus- ... -fan-kits/ but after doing a bit of thinking about it i would prefer to keep my smaller S4 rad (i have things like the horn and catch tank fixed to the Rad wings) plus i have just noticed he's put the business on hold for a while.

So before i saw that kit i did some searching and read that if the fan is fitted to the front on the rad (standard position) modern Electric fans interfere with the bonnet Sprint so the fan needs to be fitted as far left in the car as the rad will permit. But i can't help going back to the Cliveboy kit where the Fan is fitted between the Rad and the Engine which made me think is this possible with the smaller S4 Rad?

I'd be really interested to hear peoples opinions on it, i have only placed the Rad in the front of the car then weighed it up against the position of the front pulleys, unless i'm mistaken i have approximately 2 1/2 - 3 inches that i could do some thing with. But on Cliveboys page is says there is not enough room?

I realise all these things must have been played with before and maybe there is a reason the fans are not fitted to the Engine side?

Cheers
Chris

[rgh0]

Many years ago I fitted a front mounted fan to my S4 soon after I purchased it that was similar in style to the electric fans fitted to Later Elan and Plus 2. I removed the Bonnet / Hood spring at the same time as annoyed me to hold the bonnet up with my shoulder while working on the engine and I have remove the bonnet completely anytime I need to open it for the last 40 years. Plus the spring interfered with the fan I fitted at the time. Not sure how the spring cleared the electric fan on later Sprints ( I assume they had an electric fan like my Plus2)

I fitted a layer of half inch closed cell neoprene rubber along the front lip of the bonnet. This provide enough "spring" to lift the bonnet and to secure it from being loose at the front. I have always use racer pins rather than the standard Lotus clips at the rear which makes the whole bonnet more secure and less likely to fly away. If using the standard Lotus clips I would install a cable at the front to hold the bonnet down if the clips come loose as they have a tendency to do at time if not adjust right.

I have never tried it but the narrow modern fans may fit even with the spring in place or moved slightly forward at the bottom end with a small bracket

cheers
Rohan


cheers
Rohan

[AHM]

I have never tried it but the narrow modern fans may fit even with the spring in place or moved slightly forward at the bottom end with a small bracket

Yes the modern fans fit - 4 zip ties and it is done.

beware - Cheap fans are cheap and not very well balanced.

[William2]

Hi Chris, I have just fitted a new fan to the front of my S4 standard rad using aluminium angle purchased from my local B & Q. I removed a fair amount of material so as to minimalise any airflow restriction. As my bodywork is currently not bolted to the chassis I can't be sure yet whether I will have any issues with the bonnet spring. The fans are not that deep so I am hoping it will be ok. I do also wonder that if necessary the spring bottom fastening could be remounted slightly further forward from the steering rack itself. If I had used the ty-rap fastening method it would have only bought the fan another 1/4" closer to the rad and I'm not keen on that method of mounting.

[john.p.clegg]

If your fan is standing off the rad you are loosing some of the efficiency...

John

[alan]

If your fan is standing off the rad you are loosing some of the efficiency...

John

i have original fan on my Elan Sprint and also +2S130, both are a distance in front of rad (original position), no problem.
imho if the system is flushed out, clean and a good quality antifreeze used i see no reason to modify for normal road use

[saildrive2001]

Depends on where you live & what model of Elan. I have a 69 S4 SE UK spec which I brought over with me from the UK when I came to Canada. The car has the narrow rad, original electric fan & Stromberg cabs. The car always ran hot in traffic here in Ontario in the summer & still does after my full restoration a couple of years ago. I have seen up to 105C on the temp gauge. I did check the sender & gauge during the rebuild & it is accurate at the boiling point. I have the other problem when the temp drops outside, I need to block off the air intake to get the temp up. The car has always been like this. I am the original owner.

[fasterbyelan]

Depends on where you live & what model of Elan. I have a 69 S4 SE UK spec which I brought over with me from the UK when I came to Canada. The car has the narrow rad, original electric fan & Stromberg cabs. The car always ran hot in traffic here in Ontario in the summer & still does after my full restoration a couple of years ago. I have seen up to 105C on the temp gauge. I did check the sender & gauge during the rebuild & it is accurate at the boiling point. I have the other problem when the temp drops outside, I need to block off the air intake to get the temp up. The car has always been like this. I am the original owner.

My S4 is exactly the same. You need to get the radiator re-cored so that there are 3 instead of 2 cores. This will hopefully overcome the hot running in traffic. Blanking off the rad in cold weather is the normal fix for winter months.

[saildrive2001]

I re-cored the rad with 3 cores after the first summer here many years ago. It helped with the cooling but it still runs very hot in traffic in summer.

[holywood3645]

Keith, what is very hot?
James

[collins_dan]

I don't recall the width of the original rad as I upgraded to an aluminum that was slightly wider and mounted with slightly narrower side wings. I have 2 8" fans http://www.summitracing.com/parts/prm-19128/overview/
which I really like. No interference with the spring, very high CFM and not too much of an electrical drain. Might be slightly too wide for the original rad. The debate as to whether the original rad is adequate seems to have no clear answer. I would love someday to have someone with a car using the smaller rad drive that says it never gets hot drive side by side with me and see if it is my car or the conditions where I use. All the best, Dan

[saildrive2001]

James, it will run at 105C or slightly hotter.

[Pistacchio sprint 72]

The small rad here in Nice would have never worked. I have also a caterham with a kent engine, so kind of similar you will admit. My seven use an aluminium thick rad and the kenlowe fan kicks in often, each time there is a bit of traffic ahead of me.
So i guess it depends a lot of the region weather you re living in...
I would have like to retain the original rad... It was just impossible.

[69S4]

Re the bonnet spring, I have an electric fan that looks pretty much the same as William2's mounted in much the same position and the bonnet spring has plenty of clearance - up to the point where the bonnet is close to vertical when it just touches. At the normal opening angle - 60 degrees or so, there's a couple of inches of clearance.

I had my original narrow rad rebuilt to a three core matrix some years ago and noticed a substantial improvement - in how long it took to overheat. In general it's fine for normal driving on an open road in temperatures up to about 30C. In stationary or slow moving traffic it just takes longer for the temperature to rise but rise it does. The original electric fan will put off the point when panic sets in but isn't effective enough to hold or reduce the temperature. I don't have enough experience with the new fan yet but in static tests on my drive it does actually reduce the temperature.

The one thing that's always worked is pulling the bonnet release so it pops up a few inches on the spring. Even the original fan will reduce the temperature under those conditions. The new fan brings it down quite quickly. That suggests the problem is something to do with getting air out of the engine compartment.

[William2]

One other option is to get hold of the wider S3 radiator which I believe was fitted to Triumph Heralds but with a modified tube angle for the top hose connection. The trade off would be that you no longer have the side plates which are useful for mounting associated hardware. It would be interesting to hear if S3 owners think their cars suffer less in the heat.