TCS Radiator - I did this

[Dilkris]

Thought I’d post what I did with this – the photo’s hopefully tell most of the story. It is not 100% finished as yet as I have to disassemble and spray the components. I also have to make a plan for a stone guard – and with this I need some advice. (See end of thread).
I know the common approach is to replace the whole assembly with an aluminum unit, but the car has done 73,000 miles with this radiator so I first wanted to confirm if it was at all “usable”.
I found a radiator specialist some 30 miles from me, (West Mercia Radiators - which I highly recommend), and I took the radiator to them for an opinion; he pressure tested the unit while I waited and advised that  it was a “good piece of kit” and well worth keeping. Interestingly, when they first saw the radiator they thought I was rebuilding a classic bus as they believed originally this was where the unit would have been from. 
I’m not competent enough to take on soldering around the radiator myself, (I would have melted everything…), so I made up all the associated components and returned them to the radiator specialist for soldering. (4 corner brackets plus a proper arrangement for the otto switch).
Once soldering to the radiator was completed, everything basically bolts together. (I did learn during this stage that you can soft solder mild steel with a mini gas torch, which I found very helpful for producing “captivated bolt” fixings)
Now my query, the original stone guard (woven wire mesh as shown) surely must be highly restrictive in terms of reducing air flow through the radiator so would not a louvred style panel mounted to the inside of the wheel well be better?  I’m thinking of molding one in glass fiber.
Anybody got any thoughts please as I don’t want to reinvent a wheel.                       

[EuropaTC]

I don't think the original mesh does have a serious restriction to air flow, mine was original when I got the car and I drove it regularly for several years in and out of Huddersfield and commuting traffic without any problems. In fact the otter switch had broken when I got the car and it had a manual override which I very rarely used unless stuck in a traffic jam.

Having said that, when I decided it was too rusty I made a guard out of polypropylene filter cloth support. Being in the chemical industry I noticed one day that when the plant guys were replacing filter cloths, the underlying polyprop support just happened to have the same sort of mesh that my rusty steel one had. It's been there since the 80s and still looks fine !

Apart from stones, this mesh also cuts down on the direct spray in wet, salty weather so I've no doubt that a custom made louvred panel would work equally well and also keep away the salt spray from our roads.

Brian

Edit to add - well done for resurrecting the original radiator, good job !

[Bainford]

Nice work on the rad. Nomex honeycomb mesh makes a great, low weight, very low restriction stone guard for the rad. I fitted one with velcro, but my fixings weren't sufficiently robust and I lost it on a run shortly after installing. I bought some more of the stuff and will be attaching it with the zip-tie method or similar.
https://www.speedwaymotors.com/Nomex-Honeycomb-Radiator-Guard-Mounting-Kit-15-x-22,475853.html?_br_psugg_q=nomex

[BDA]

Here is my radiator screen. I used stainless steel screen and my fabricating buddy made a frame for it. I don't remember exactly how the upper screws held it but I think it would be pretty obvious if I took the time to look at both sides. The bottom screws go into tapped holes on the bottom of the radiator "frame." Sorry other than core and ports, I don't know parts of a radiator! Anyway, I have an aluminum radiator and there is sort of a frame for the core where the bottom of the frame looks a bit like a tray. The edges are turned up and it's thick enough that I was able to CAREFULLY drill the holes and tap them.

Not as cool as Nomex honeycomb!     (seriously, that really is cool!) But it seems to work.

While you have your radiator out, you might want to consider a radiator shroud like Joji did (http://www.lotuseuropa.org/LotusForum/index.php?topic=5485.0). I've heard from people who implemented them that the motor runs cooler but there is less hot air washed into the back bone or cabin so it's cooler inside too!

[Dilkris]

Bainford - Nomex Honeycomb looks a possible fix - does it trap mud and general road debris and when it does, is it difficult to clean? I assume however they are installed in some easily removed way for this purpose.
BDA - did you forget the picture??  I read with interest Joji's approach and I have mixed feelings about that - I understand the effectiveness of the shroud when the fun is "pulling" (as most automotive applications are) but we are all "pushing" - so the shroud in this case surely just decreases radiator area to that of the swept area of the fan. No ?         
   

[GavinT]

There's this idea which I quite liked. (stolen pic)
Looks like a neat job.

[Dilkris]

There's this idea which I quite liked. (stolen pic)
Looks like a neat job.

  For me that's it !!  Now all I have to do is sort out how to make it   
I'll post when its done - could be a while 

[BDA]

BDA - did you forget the picture??  I read with interest Joji's approach and I have mixed feelings about that - I understand the effectiveness of the shroud when the fun is "pulling" (as most automotive applications are) but we are all "pushing" - so the shroud in this case surely just decreases radiator area to that of the swept area of the fan. No ?         

Oops!!! Here are my pictures although they are anticlimactic after the interesting ideas others have posted.

As for pulling fans, I'm pretty sure a couple of us (not I) on this forum use pullers mounted in the wheel well to good effect.

As of Joji's writeup, he hadn't tried it on the road yet but a few years ago, I met a fellow Europa owner at our Lotus Ltd. LOG (Lotus Owners Gathering) who did the same thing and claimed his car ran cooler and the cabin was cooler. IIRC, he said that air from the wheel well would blow through the areas of radiator not covered by the fan. This heated air would find its way into the cabin. I don't remember his rationale for cooler coolant temps. I was skeptical too but I seem to remember another person implementing this other than Joji so I feel much more confident that it is worthwhile trying it.

WRT hot air getting into the cabin, the factory addressed this by putting a piece of foam rubber that covers the access hole in the backbone under the elbow pad. Mine is long gone (I might expect most of them are long gone by now) so I need to find a replacement.

Another, more elaborate cooling mod I've thought of is to run a large duct directly from the front grille to the radiator pretty much as described in the Jensen Competition Manual (http://lotus-europa.com/manuals/misc/jensen.pdf). Since this was for a competition car, they deleted the fan. This duct would negate the need to make sure holes in the forward compartment are sealed as well as eliminate any air from the radiator getting into the cabin but would require some method of dismantling it for radiator service. I think it's way overkill anyway since my car doesn't overheat anyway.

[Grumblebuns]

Outstanding job on resurrecting the original radiator. I did the same for my TCS. The only advantage to going with an aluminum radiator in my opinion is cost. I paid $600 to recore my stock radiator. I could have bought two or three aluminum ones for that cost.

When I put my stock radiator back in I took a look at the stone guard and thought it has to restrict flow somewhat. It didn't look as crusty as yours did but I thought that there has to be a better alternative. than the large gauge mesh used. I actually counted the number of wires in the stone guard and calculated an area that the guard took up. I but don't remember the percentage now but it was a surprisingly large amount of blockage. For a cooling system in tip top shape, it wasn't a problem. It's when the system starts to degrade with time that all of these little things start to have an effect on the amount of heat that can be rejected. To eliminate any possible future air blockage I also decided to use a nomex honeycomb mesh for my rear stone guard. The nomex is just thin enough to fit inside the lower lip of the lower frame. My photos show my system to secure the nomex in place. I'll need to tighten up on two of the cables before putting it on the road. 

[GavinT]

Back in the late 70' when I first acquired my S2, the radiator seemed partially clogged. The car had lots of other problems – carb literally rattling because the bolts came loose all the time, a piece of water pipe used as a rear axle bearing spacer . . lots of things.

Anyway, I took it to the radiator guy who said he'd need to remove the end tanks and rod it out.
Living in a hot climate (similar to California), the conversation turned to potential improvements. He suggested a four inch core with staggered tubes & increased fins was the maximum that could be done within the existing package & end tank size, so that's what we did - can provide a pic if anyone is interested. The car never overheated again but this can't be fairly compared to a stock unit working correctly.

Perhaps others have noticed, but when travelling on the highway at steady speed and waiting for an overtaking opportunity behind a semi-trailer, the temp creeps up a little.
Air flow rates even at speed seem to be detectable.

Initially, I also wondered about the ally fan shroud as per Joji's implementation but it's quite common with modern auto manufacturers. All the air now goes through the circular shroud, so the reasoning appears sound.
Below is a pic of a Toyota Corolla radiator fan in just such a pusher configuration.

I can believe there's flow restriction from the wire screen mesh but if it flows more than the already restricted radiator core itself, what has been lost? . . perhaps nothing?
This could be tested.
Immerse the end tanks in water and measure the volume.
Immerse the whole radiator in water and measure the volume.
Subtract the end tank volumes from the whole and deduce the area taken up by the tubes & fins – thanks Archimedes.

[Dilkris]

Below is a pic of a Toyota Corolla radiator fan in just such a pusher configuration.

Hi GavinT - I'm not familiar with the Toyota Corolla but is this really a pusher application? 

[Dilkris]

The only advantage to going with an aluminum radiator in my opinion is cost. I paid $600 to recore my stock radiator. I could have bought two or three aluminum ones for that cost.

Hi Grumblebuns - totally agree. I continued with the stock radiator after the pressure testing proved good - it took me probably 2 days to straighten out all the bent fins though...   

[EuropaTC]

One thing to bear in mind whilst comparing the modern Al units against the old copper ones is that while Al is lighter and cheaper, copper is a better conductor. So if you replaced a dimensionally identical unit without increasing fins/rows then you'd likely have less efficient cooling.

So take comfort in that repairing your original one might be expensive and not as light or "cool" (see what I did there    ) as an Al replacement, it's going to be efficient as when the cars were new, and they didn't overheat back then, did they ?

Brian

[GavinT]

Hi GavinT - I'm not familiar with the Toyota Corolla but is this really a pusher application?

Ooops, I think you're right, Dilkris; it's a puller.
The same principal applies, though. In this instance, the fan is pulling from the entire surface of the radiator, not just the circle described by the fan motion.

[dakazman]

  I love it.
 I had to go back to the Jan 01 post to get the just of it, but trust me, I'll re-read many more pages.
Dakazman