Well folks, here goes…
Having messed about trying various things with little or no success, and being determined to do something about the higher than ideal temperatures, following a conversation with an old mate who does a lot of race engine stuff etc. we decided that the issue is not enough radiator or an issue with the new radiator and fan (Coolex FatBoy). Can’t see anything wrong with the Coolex one, but it is still very narrow which means all the cooling air hits the front of the engine. We also noticed when checking and topping up the coolant (it also has the Coolex revised thermostat housing with cap) that it seems the car fills very slowly, despite having an1/8" hole drilled in the thermostat.
Left a message for Alex at Coolex to call me, but by the time he did a few days later I’d bitten the bullet and ordered the Tony Thompson S4 version of the 26R alloy rad, plus the header tank and the hoses. Partly because TTR maintain that you don’t need the recuperation bottle with their system, just a catch tank (I’ve actually left it fitted as the rad cap they supplied for the tank was a double seal air valve type anyway). When Alex did call, we had a conversation about my issues and he offered to do me a deal on his alloy full width rad in exchange for the FatBoy, which was very good of him, if I chose to send the TTR one back but I wanted to do the job this weekend so I stuck with it.
Didn’t order the fan from TTR, as I’ve dealt with Revotec a lot over the years and William certainly knows his onions regarding fan choices etc. Following a chat with him about my issues and restricted under bonnet venting and engine bay pressure, he supplied me a 10" high power fan and his adjustable electronic controller that fits in the thermoswitch boss on the radiator - I’ve used them before, they work well and I’ve never had one go wrong. Interestingly the TTR fan switch comes on at around 87* and goes off at 79* which fits with his preferred engine temperature.
Sunny day on Friday, so I whizzed the car to the workshop, and set to! Stripped out the old rad, fan, relay, wiring etc. and started again from the beginning.
Rad fitted really well, lined up perfectly with the bonnet foam etc. : I did have to make new lower mounting brackets but they’re only L shaped bits of 16 gauge so no biggie, the header tank not so. TTR had supplied the long version which wouldn’t fit between the thermostat housing and the rad outlet. A quick phone call and the very helpful Charlie sent me the +2 one which is shorter but taller for Saturday delivery FOC (I’ve spent quite a bit with them over the last year
) - I’ll send the long one back next week. The rad is wider, it does have side tanks however the core is still appreciably wider and taller than the FatBoy, which means that the core on the passenger side now extends in front of the alternator and exhaust. More of which later. Mocked up with the tank (with the cap on…) replaced the Coolex thermostat housing with the original, a new 74* stat just in case with a 1/8" hole drilled in it. Not everyone’s choice, but I like it as it lets the air bleed through when you fill the system/lessens thermal shock and it fits under the bonnet with no issues.
Trying to fit the lower air deflector (Sue Miller fibreglass one) was a bit of a pain (the new rad is thicker) until I had a brainwave and remembered that the rad has the bottom bosses in it for mounting in an S1/S2. Fabricated a couple of alloy strip brackets to stick out in front of the rad, drilled some holes in the deflector and got the zip ties out! A bit more buggering about with the bonnet spring aperture in the deflector and all was well.
Ran a power feed from the starter solenoid area (I have a plastic B+ stud on my car as I have fitted the co-axial reduction drive starter previously so deleted the solenoid) as the high power fan needs 12A and I didn’t want to trust the car wiring as I have no idea what the cable size is in the harness…plus to remove the rad you need to be able to disconnect the Revotec controller as it’s dedicated harness and relay are all one piece. Wired it all up, all worked first time including my over-ride switch inside the car so happy days.
All done by yesterday afternoon but it was getting tired so I called it a day and went back this morning. Checked all the hose connections, took off the cap and started pouring in the coolant. Immediate difference - the coolant filled up quickly and easily. So quickly, you could hear the water rushing into the block and head. Filled it to just above the perforated pipe in the header tank, heater valve open, start up, top up a bit as the air comes out of the heater, cap on, watch the temp gauge and check the rad: slight warmth in the rad immediately as you would expect with a hole in the stat followed by the stat opening at around 78* on the gauge and sitting at around 80* fully open. Temperature gradually climbs to 90*, adjust the controller to bring the fan on, the temperature drops after a second or to and goes down to 82* and the fan shuts off. No obvious leaks, all seems well. Refit the bonnet and try again: same results. Time for a road test…
What a difference. Engine temp. stable at an indicated 80* regardless of how you drive it. Spiritedly - the same. 30mph in 3rd gear - the same. Up hill - the same. sit at the traffic lights, temp goes up to 92* fan comes on and after a few seconds the gauge starts to drop until the fan cuts out at 82*.
Problems solved. The car drives so much better at 80* than it does at the previous 90 -100* . No increase in the coolant bottle level after a reasonable run. Sharper performance, nicer idle, better in every way. And that’s with the heater off - I had to keep it on before to keep the temperature anywhere near reasonable.
From the way it all fits in the car, I think that the biggest difference is that the cooling air flowing through the passenger side of the rad (the hottest part) now goes straight past the alternator and past the exhaust manifold then out underneath the car. The cooling fan is also blowing through here. There are also the factory modded holes and mesh in this area. This plus the much more efficient rad has completely solved my issues and made the car a pleasure to drive. Not cheap: around £950 plus my time (a lot of time - I like things to fit “Just So”) but I’ve spent a lot of money previously on things that haven’t worked. The TTR radiator is so nice you could hang it on the wall and admire it. As is the header tank.
I apologise for the length of this post, but it became clear to me that when I asked in various places if anyone else had had these issues a lot of things were suggested, but no-one seemed to have a definitive answer ( I appreciate that not everyone issues are the same, but Elans running hot seems to be a perennial subject). Some said it must be air. Or water pump (new, TTR type assembled meticulously by me) . Or poor circulation (Block has been stripped, all core plugs out, all galleries cleaned. Same with the head). Some said the narrow rad is fine unless you have some other issue. Some said it isn’t. Some said the FatBoy is sufficient - it wasn’t for my car. Some said twin fans was the way to go mounted behind a wide radiator - I didn’t like the idea of that, it makes access to any of it really difficult and I didn’t need that in the end, just a single 10" high power efficient fan blowing towards somewhere the air could actually get out from through a decent sized efficient radiator. Thanks for everyone’s input, it all made me think about it from various angles, but eventually my initial thoughts turned out to be correct. In retrospect I wish I’d gone the TTR/Revotech route in the first place (or possibly Alex’s Coolex wide alloy rad.) but having bought the FatBoy as the received wisdom was “That’s all you need for a road car” I was reluctant to start over however now I have, the car is as it should be. If I was starting from he beginning again, I’d go straight down this route, no question. Experience is hard won, and expensive!
In conclusion, if you’ve got similar issues my advice would be fit a 26R alloy radiator, a swirl/header tank, a high power 10" fan from Revotech with their controller, and your problems will disappear. Yes it’s an expensive option but if it doesn’t solve your problems you most definitely have other issues. Your problems may disappear using a smaller rad and a smaller/lower power fan, but if they don’t it will be money (and time while you try all sorts of things to try and make it work getting more and more frustrated…) wasted that could be better spent elsewhere and some very nervous journeys in the summer which certainly spoil the enjoyment. Oh, and it looks great when it’s done as well, which is also very important!
Thanks for reading, I hope this helps someone else, and thanks for all those who helped me with their advice especially Shaun at Bateman’s, Ike at Ike Engineering, William at Revotech and Charlie at TTR.
This is, of course, my own experience and YMMV.
Have a great Bank Holiday, I’m off to the pub in the car with my wife.
Regards, Phil