Cooling a 7 engine in high ambient temperatures?

[DougBaker]

For the cold weather you could use the traditional method of physically covering part of the radiator. My fathers vintage car has a fitted leather cover for the radiator with a number of sections which can be removed depending on how cold it is.

This is the closest I remember seeing on a Seven though I suspect it was not done to improve insulation 

http://www.strangely.org/7club/meetings/200407/furry7-441.jpg

[rj]

[Jonathan Kay]

For the cold weather you could use the traditional method of physically covering part of the radiator.

Yes. And reports of overcooling seem to be getting more common. 

(I've just driven home from Nottingham on uncongested dual carriageway: needle hardly lifted.)

Jonathan

[7 wonders of the world]

If your looking at improving the cooling system its worth remembering that the oil does at least 60% of the cooling, indeed its the only thing to contact all the hot working parts on the engine and so look at improving this side of this the system with a thermostatic cooler and or increased capacity etc, don't just assume the cooling is soley down to the water in the rad.

[Golf Juliet Tango]

I found my car overheating when I leaft it in the pit to cool down following a trackday session.

This was completely sorted when I fitted an external water pump to circulate the water in idle.

As an additional circuit this is a great idea as it prevents hot-spots. The whole engine may not have too much heat but localised high temperatures are likely, I would have thought.

[CageyH]

There is a dry sump system fitted, so I do have an increased oil capacity. I don’t have an oil cooler though.

I am going to run my car with the high performance fan and see what happens. I do know that the fan cuts out much sooner than the Spal did, as it seems more capable of dropping the water temp in the radiator quicker.

If I were to fit an electric water pump, would I need to remove the mechanical pump impeller?

[CageyH]

The Spal fan spec is 779cfm, and the Revotec is 1060cfm. A useful gain in my opinion, while keeping the current draw to a sensible level.

[7 wonders of the world]

The OE water pump is more than capable, fit a correctly sized and oriented oil cooler in the scavenge hose.

I assume you have the oil temp sender located in the DS pan too in order than you can accurately see the difference, this way you we massively increase the ability of your lubrication system to dump excess energy thus giving your normal cooling system somewhat or an easier time.

[CageyH]

Oil temp sender? 

I will be honest, I don’t have an oil temp gauge, and therefore have no idea what my oil temp is.

[rj]

Nope, the OE water pump is not capable at idle. I suspect it's heat from the primaries that disturbs the water rail fitted just above, but the water was boiling and escaped from the expansion tank cap.

I have brazed in a boss to accept an 80 deg thermoswitch in the water rail. When I fitted the PRRT I replaced the old thermostat housing with an alloy tube which I have extended to match up with a Craig Davies EWP 80 that starts at the 80 degrees. The OE water pump is complete and intact as it was just when I left the circuit after less than three cooling down laps I had the problem the EWP has made no difference to the temperature when running - it's rock steady at 75 degrees. In the pit it will reach 85 degrees before the fan kicks in, then it'll go down to 75 where everything turns off again.

The car had wet sump, but when it comes back into one piece it'll have dry sump with the kidney shaped tank in front of the engine. This partly to compensate for the missing apollo tanks cooling of the oil; the oil temperature never exceeded 110degrees (which even was rare) Temp sender in apollo tank.

[CageyH]

As for fitting an oil cooler, I thought that these were only really necessary for track use?

If I am wrong, where is the typical mounting point with a Caterham dry sump system with external tank? It makes sense for it to be thermostatically controlled, but will it ever be used?

[CageyH]

I have been reflecting on the wise words.

I think an oil cooler would be a good idea, but it would need to be thermostatically controlled to avoid overcooling of the oil in winter. For this, the easiest solution seems to be a thermostatically controlled take off plate. Two options are available - 80 degrees and 92. Which is most suitable?

After that I need a cooler, a couple of hoses and a mounting kit. I may add a temperature gauge later, as I would have to replace my current mech oil pressure with a dual gauge.

Somtotal cost is about £200? Where is the best place to get all of the bits? Redline?

I am planning on a cam belt change and water pump soon, so may as well,add a few more parts to the list.

[Tazio]

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