Redtop Fan Cut In

[kevin the chicken]

At what temperature should I set my electric fan to cut in on my redtop? I don't have a problem but the fan does seem to come on quite a lot so I was wondering if it's set too low.

[Bob Tucker]

Depends what thermostat you have.

IIRC the standard one is very high...I think 97 deg.

I have installed one at 87 deg & the fan cuts i at 95.

The sensor is in the pipe from the thermostat.

[kevin the chicken]

My sensor is in a joiner between the thermostat and the radiator. Does running the lower temperature thermostat make any difference to the running temperature? I don't know what stat is in mine, perhaps it would make sense to put a lower temperature stat in and set my fan the same as yours. At least then I would know it was right as you have run a lot more miles with yours than I have with mine, although as I said I haven't had any overheating issues since I put a header tank on. The redtop does seem to run a bit hotter than a lot of other engines

[Bob Tucker]

I put the lower temp thermostat in purely because the engine & engine compartment was almost glowing.

It never overheated or blew out any coolant.

Just a precaution on my part before setting off for LeMans a few years ago when the weather

was stonkin hot.....up to 37 degrees on a few days.

[Guest 2b cruising]

The thermostats job is to give a quicker engine warm up from cold, and to assist to maintain the designed running temperature of the engine.

On production cars this is for a balance in peak performance and fuel economy.

The fan is for cooling the coolant in the differing local climate.

The fan should be set to come in above normal working temperature as the thermostat and radiator should manage under normal conditions.

This of course can be altered by yourself to adjust the running temperature to suite your own driving style or indeed as Bob has done his for personal comfort. The fan should still be set slightly higher than thermostat though. You don't want continuos battery drain from a powerful motor. Some are in excess of 120 w.

Make sure the other parts of the system are functioning correctly first. ie are your radiator fins clear.

Is there enough draught allowance to get through your,rad,

Is there enough exit,route for the hot air to escape from under the bonnet.

Last year I tried many things to stop mine from running hot.

After I cleared a good air path in the nose cone, and added a small deflector to force the air through it from under the front of the car. I have had no problems since.

Before this I was almost at the point of removing the cylinder head to look for nasty problems.

[kevin the chicken]

I have already done the things you mention, it has a new radiator which has deflectors to ram air through it rather than around, the bonnet has louvred, all the hoses are new. It does seem that the engine compartment is thermo-nuclear hot when you remove the bonnet though not as hot as it was before I wrapped the exhaust . I may however prop the rear of the bonnet up slightly to see if that makes any difference.

I was tinkering today and had a look at the fan setting and it is set too low, I think my rolling road man turned it down as he mainly works with pintos or maybe he did it just for the rolling road run. Anyway I will turn it up higher and see how often it comes on then.

Thanks for your comments