Replacing Kenlow Fan Switch

[andyf]

Has anyone got experience of replacing one of the Kenlow capillary fan switches with a "standard" thermostatic fan switch? I'm wondering which temperature setting to go for.

[cabrioman]

Re: Replacing Kenlow Fan Switch

The Revotec fan controllers are good and they are user adjustable between 70 and 120c so you decide when the fan kicks in.

http://www.revotec.com/acatalog/EFC_Hose_Fitting.html

John

[stevejgreen]

Re: Replacing Kenlow Fan Switch

The Revotec fan controllers are good and they are user adjustable between 70 and 120c so you decide when the fan kicks in.

http://www.revotec.com/acatalog/EFC_Hose_Fitting.html

John

The temperature setting is dependant on many variables, primarily the pressure cap fitted to the radiator that determines the maximum temperature and the Thermostat that controls the minimum.

The standard 14 psi / 1 atm pressure cap will release at about 120C depending on antifreeze content, that changes the boiling point of water.

There is also a variable as to where the thermostat is located, the further it is from No4 cylinder the relatively cooler the temperature will be.

At the end of the day it's pretty much trial and error to find the best setting. There is no point in spinning a cooling fan whilst driving at 30mph, it will have little effect, it will only really be necessary when in slow moving or stationary traffic.

incidentally, setting oil temperatures aside, the hotter an engine operates the more fuel efficient it is!

[andyf]

Re: Replacing Kenlow Fan Switch

The temperature setting is dependant on many variables, primarily the pressure cap fitted to the radiator that determines the maximum temperature and the Thermostat that controls the minimum.

The standard 14 psi / 1 atm pressure cap will release at about 120C depending on antifreeze content, that changes the boiling point of water.

There is also a variable as to where the thermostat is located, the further it is from No4 cylinder the relatively cooler the temperature will be.

At the end of the day it's pretty much trial and error to find the best setting. There is no point in spinning a cooling fan whilst driving at 30mph, it will have little effect, it will only really be necessary when in slow moving or stationary traffic.

incidentally, setting oil temperatures aside, the hotter an engine operates the more fuel efficient it is!

Yes, we ran the Sunbeam at 90 and the fan never came on on stage it only kicked in when we stopped at the end. What I'm looking at is simplifying the installation and was considering using a switch that bolted into the radiator. I noticed a BMW part that switches at 90 and has two spade terminals so it would be easy to fit with a small modification to the radiator. What do you think?

[stevejgreen]

Re: Replacing Kenlow Fan Switch

Yes, we ran the Sunbeam at 90 and the fan never came on on stage it only kicked in when we stopped at the end. What I'm looking at is simplifying the installation and was considering using a switch that bolted into the radiator. I noticed a BMW part that switches at 90 and has two spade terminals so it would be easy to fit with a small modification to the radiator. What do you think?

Beware the electrical load of the fan, the BMW switch is unlikely to carry full fan motor load, and may even be designed for solid state switching so may not be able to support a standard relay.
The bottom of the radiator is the coolest part so 90C is probably fine.

[andyf]

Re: Replacing Kenlow Fan Switch

Beware the electrical load of the fan, the BMW switch is unlikely to carry full fan motor load, and may even be designed for solid state switching so may not be able to support a standard relay.
The bottom of the radiator is the coolest part so 90C is probably fine.

I think you're right, all of the wiring diagrams that I can find seem to include a relay to switch the power to the fan. I think I'm going to give this a go, I'm going to have to take the rad out to get to the water pump to replace it so while I'm at it I'll get the rad tested and a mounting fitted for the thermostatic switch. The power relay can then sit where the Kenlow thermostat is mow, except it will be a lot smaller.

[DamnedFrog]

Re: Replacing Kenlow Fan Switch

Regarding REVOTEC sensor:

IMHO you should always put the sensor at a place where it should read the most realistic temperature of the engine and would remain usefull even in case of coolant leak.

Don't put it on the return path, because if there is a massive leak, the coolant would remain cold in that part of the circuit because the pump could run empty and not flush the coolant anymore.

On the contrary, if you put it on the main hot duct, reasonabely near of the cylinder head, boiling coolant and even steam would heat it enough to switch the fan on, and maybe help a little before it's too late. Usually on modern engines, it is bolted on the block, or on the thermostatic valve output, or on the coolant pump, or just at head hot duct exit.

The standardized engine water-based coolant temperature in normal use is 85 Celsius for cars, and can be higher for bikes. It matters for oil viscosity, metal dilatation (hence size tolerence between moving parts) and polymers resistance.

Regards,
Christophe.

[andyf]

Re: Replacing Kenlow Fan Switch

This thread on the www.turbosport.co.uk forum had some interesting information on engine temperatures for Ford engines. It had the following list of intermotor thermostatic fan with some different thread sizes (I've saved it here in case it gets lost):

Part No. A/F Size Thread Temp °C

50480 19 3/8" BSP Taper 50-46 N.C.C.
50471 19 3/8" BSP Taper 77-74 N.C.C.
50460 27 3/8" BSP Taper 90-85
50370 27 3/8" BSP Taper 95-90
50372 27 3/8" BSP Taper 100-95
50010 25 3/8" x 18 NPTF 79-74
50080 21 3/8" x 18 NPTF 88

50172 22 M14 x 1.5 87-82
50042 24 M14 x 1.5 90-85/98-93
50041 22 M14 x 1.5 95-90
50173 22 M14 x 1.5 100-95
50040 22 M14 x 1.5 103-98

50481 21 M16 x 1.5 50 OFF N.C.C.
50475 17 M16 x 1.5 60 OFF N.C.C.
50430 17 M16 x 1.5 85 ON
50320 27 M16 x 1.5 85-80
50420 21 M16 x 1.5 85-80
50432 21 M16 x 1.5 85-80
50476 17 M16 x 1.5 85-80 N.C.C.
50300 27 M16 x 1.5 87-80
50317 22 M16 x 1.5 87-82
50321 22 M16 x 1.5 88-79
50310 22 M16 x 1.5 88-86
50301 22 M16 x 1.5 90-83
50474 19 M16 x 1.5 90-83 N.C.C.
50461 21 M16 x 1.5 90-85
50421 21 M16 x 1.5 90-85
50470 17 M16 x 1.5 90-85 N.C.C.
50390 17 M16 x 1.5 90-85 N.C.C.
50316 22 M16 x 1.5 92-82
50330 22 M16 x 1.5 92-82
50453 24 M16 x 1.5 92-85
50315 22 M16 x 1.5 92-87
50341 24 M16 x 1.5 92-87
50342 24 M16 x 1.5 92-87
50371 27 M16 x 1.5 92-87
50373 24 M16 x 1.5 92-87
50450 21 M16 x 1.5 92-87
50340 29 M16 x 1.5 93-86
50374 24 M16 x 1.5 93-88
50479 17 M16 x 1.5 93-88 N.C.C.
50332 22 M16 x 1.5 95-85
50477 17 M16 x 1.5 95-88 N.C.C.
50455 22 M16 x 1.5 95-90
50454 22 M16 x 1.5 95-90
50380 17 M16 x 1.5 97-92 N.C.C.
50478 17 M16 x 1.5 98-91 N.C.C.
50375 24 M16 x 1.5 98-93
50472 17 M16 x 1.5 98-93 N.C.C.
50473 17 M16 x 1.5 98-95 N.C.C.
50431 17 M16 x 1.5 100-95
50331 22 M16 x 1.5 102-97

50100 29 M22 x 1.5 82-68
50101 29 M22 x 1.5 84-79/88-83
50250 29 M22 x 1.5 86-76
50012 29 M22 x 1.5 86-77
50090 29 M22 x 1.5 86-81
50120 29 M22 x 1.5 88-79
50295 29 M22 x 1.5 88-79
50296 29 M22 x 1.5 88-79/110-102
50271 29 M22 x 1.5 88-83
50272 29 M22 x 1.5 88-83
50275 29 M22 x 1.5 88-83
50217 29 M22 x 1.5 88-83/92-87
50091 29 M22 x 1.5 88-83/92-87
50212 29 M22 x 1.5 88-83/92-87
50213 29 M22 x 1.5 88-83/92-87
50216 29 M22 x 1.5 88-83/92-87
50221 29 M22 x 1.5 88-83/92-87
50219 29 M22 x 1.5 88-83/92-97
50240 29 M22 x 1.5 90-80
50110 29 M22 x 1.5 92-82
50111 29 M22 x 1.5 92-82
50112 29 M22 x 1.5 92-82
50113 29 M22 x 1.5 92-82/95-80
50218 29 M22 x 1.5 92-82/97-92
50170 29 M22 x 1.5 92-87
50200 29 M22 x 1.5 92-87
50210 29 M22 x 1.5 92-87
50211 29 M22 x 1.5 92-87
50220 29 M22 x 1.5 92-87
50230 29 M22 x 1.5 92-87
50231 29 M22 x 1.5 92-87
50235 29 M22 x 1.5 92-87
50260 29 M22 x 1.5 92-87
50270 29 M22 x 1.5 92-87
50280 29 M22 x 1.5 92-87
50281 29 M22 x 1.5 92-87
50285 29 M22 x 1.5 92-87
50290 29 M22 x 1.5 92-87
50215 29 M22 x 1.5 92-87/97-92
50011 29 M22 x 1.5 93-88
50102 29 M22 x 1.5 93-88/97-92
50035 29 M22 x 1.5 95-85/102-92
50130 29 M22 x 1.5 95-86
50030 29 M22 x 1.5 95-90
50033 29 M22 x 1.5 95-90
50061 29 M22 x 1.5 95-90
50062 29 M22 x 1.5 95-90
50160 29 M22 x 1.5 95-90
50092 29 M22 x 1.5 95-90/100-95
50174 29 M22 x 1.5 95-90/100-95
50104 29 M22 x 1.5 97-92
50282 29 M22 x 1.5 97-92
50103 29 M22 x 1.5 97-92/101 -96
50214 29 M22 x 1.5 97-92/102-97
50190 29 M22 x 1.5 100-95
50195 29 M22 x 1.5 100-95
50196 29 M22 x 1.5 100-95
50197 29 M22 x 1.5 100-95
50198 29 M22 x 1.5 100-95/110-105
50000 29 M22 x 1.5 103-98
50013 29 M22 x 1.5 103-98
50014 29 M22 x 1.5 103-98
50191 29 M22 x 1.5 120-115