Kenlowe Fan

Chris that controller would be of little use for a fan and apears to be for water pump control.
Not to sure how valid a proportional controler would be if the fan ran on a high duty cycle it would need a lower limit turn on point as you dont want too broad a hysteresis curve

graeme
 
I don't agree Graeme. I'll quote a couple of different scenatios for the fan duty to illustrate.

First, stationary in traffic, with the engine idling, and steady state heat dissipation / generation: Cooling speed 1

Next, stationary in traffic, after hard running - heat soak emerging from engine: Cooling Speed 2

Low traffic speed, up hill, Air movement insufficient to maintain engine temperature: Cooling Speed 3

HIgh speed low throttle opening (eg motorway) : cooling speed 4

Cooling speed 4 is likely to be zero if the radiator is correctly sized. Cooling speed 2 is likely to be flat out. Colling speeds 1 and 3 will be at different intermediate points.

If only full speed and zero are used then the engine temperature will climb beyond optimum and then fall below optimum. This effect is quite marked, because the overcooled water will flow for quite a while before the engine mass catches up, similarely in the other direction. A variable speed controller should maintain the temperature within a much finer error of optimum, ie coolant temperature entering engine very similar to engine mass temperature. Not only does this give more efficient running, it also minimises thermal shock on the engine.

Chris
 
Yes can see where you are comming from on that, I would like to think thast stae 4 was the most prevalent and that fan speed was Zero.
Thermostat opening point is a saviour in terms setting lower boundaries but how closely you manage to subsequent temperature rise maybe far more critical in the electric solution as we would not be pushing as many watts in to cooling mechanism as that whacking great mechaical fan.

Graeme
 
Actually, Graeme, I have a hankering to use this controller with an electric water pump. Apparently the power losses in the water pump are at least as great as in the rad fan! And with that sort of system you get to throw the thermostat away altogether. I just haven't worked out how to blank off the existing mechanical pump yet without leaving a staionary pump rotor in the way of the coolant flow.

Modern Mini's have this set up as standard - that was what the recent recall for water pumps causing fires was all about!

Chris
 
That sounds like a worth while endevour, surely just remove the impeller and blank off where the pump stem came out of the housing? or are there other ports internal to the stem housing?
Would be nice to see some quantified figures as to expected HP savings, I can see how this would make a large dent in fuel economy figures if the HP savings were equal or greater than the mechanical fan removal esp at highway (extra urban) driving.

Graeme
 
Shouldn't be to hard to design a controller that just works of the existing temp sensor, just a matter of a comparator circuit and a PWM circuit to drive the fan for proportional control. Relativly easy to do and no messing around with the Rad or hoses, I may give this some thought but I have been too busy with my work to find many spare moments but it is an appealing elegant solution.

Graeme[ /quote]

Sounds perfect. Surprised there isn't one available off the shelf though.
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rockdemon said:
I don't suppose you remember which size revotec you went for?

Rich.
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Ebay feedback thingy says - Revotec 38mm EFC Electronic Fan Control System / Swtich (#130392215726)

They can't spell 'switch' so I would measure it first like I did Rich.

Richard
 
AUTOMATIC TWO SPEED ELECTRONIC THERMOSTAT
Part No: KLM2455
Two speed high performance fans will be offered with our new fully automatic, two stage, electronic thermostat. When cooling is required the fan will start at normal speed but ramp up to boost speed if necessary to provide extra performance.
The thermostat comes pre-wired into the fan harness, complete with inline fuses and relays (it even has an input to allow connection to the air-conditioning system or where applicable). This will minimise wiring connections to be made when installing. All wires are clearly colour coded. The thermostat is fully adjustable to suit all vehicles. Once installed, the fan will be switched on and off and, if necessary switched up to “2nd Jet Boost Speed” (max fan speed) fully automatically. This will ensure that the engine temperature rises quickly to the correct operating temperature (fan off) to minimise wear and give an efficient fuel burn for power, economy and extended life of the catalytic converter. Should the ram air effect on the radiator be insufficient to maintain a normal engine temperature (e.g. in traffic jams or on long slow hill climbs), the fan will come on at the lower speed to stabilise the temperature. In extreme conditions of heat soak or high ambients, the fan will step up to boost speed until the temperature starts to drop. It will then step down to the lower speed until the normal temperature is reached and it will switch off.
The new two speed auto thermostat has a fast acting contact probe that can be simply inserted against a tube in the radiator matrix. A special Fastfit retainer is provided. There is no need to cut hoses or break into the cooling system in any way........................................................................................................
This is what i received back from Kenlowe, along with dimensions for the 13" heavy duty fan. This to me (a plumber i admit) seems good, but in the back of my mind is my "s" has had the mechanical fan in for 38 years, why should I change
 
38 years ago there was a lot less traffic.
Or so i hear :D
Depends how concerned you are with originality vs modern practicality.
MPG and power gains can only be a good thing to me.
I'm sure if Rover had this technology then, they would have used it.
Jim
 
I hear what your saying, I use my car daily, not had overheat problems, mpg savings surely will be minimal. Having said that im always a little concerned when i see a bit of traffic build up on motorways, just need to get my head in gear to see its worth it.
 
If you think about a modern car, certainly on mine, the fans rarely come on, only after standing in traffic for 10+ mins, even in the summer, they're really there just to provide cooling when there is no natural airflow over the rad.

(Asuming you remove your engine driven fan) Economy savings are two fold, firstly the engine will generally warm up faster without the constant airflow over the block from the engine driven fan reducing the need for choke, and secondly at speed the engine driven fan would be consuming a fair amount of bhp. Of course at speed you really don't need any fan as the naturaly airflow over the rad/block will be sufficient to keep everything cool.

They really are win-win, except for the initial installation cost. However I used a Citroen BX fan from the scrap yard on mine, which meant the whole install was about £10 :LOL: Lots of very good fans in the scrappy.
 
In Highway driving ie constant speed the savings in gas would be considerable as you are using minimal engine HP to maintain a constant speed. In this scenareo fan HP becomes a significant fraction of the total used engine HP so to remove the fan will make double digit HP savings ie 10% or more with the consequent fuel savings.

Graeme
 
Really as much as that. Well Kenlowe have said a 13" heavy duty is the one they would go for in the p6. It is 60mm thick so wont go in unless i cut right up and slightly into the slots which hold the grill lugs. Has anybody done this and was it ok. Think I will now go for the electric fan just deciding best one.
 
I'll get a chance to see what PAE has behind the grill tomorrow hopefully... i need to get that sorted too i think. Just one of those jobs that keeps getting put to the back of the queue.... Kenlowe's fans are supposed to be better than anybody elses - it's the controller that's their weak point.

Would be interested to know what you get the price down to with them...

Rich
 
webmaster said:
Interesting with the electric water pump, although replacing a generally very reliable mechanical pump with an electric one doesn't strike me as the greatest idea, not on something so critical to engine survival.
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Interesting, You should think that. They do it with power steering systems, and that is critical to
driver survival!!

Colin
 
Mr R/D they say for the next week or so total price for 13" heavy duty fan with the probe which pushes into the rad is £160, normally just under £200. So that's why I want to move on it sooner than later
 
Interesting, You should think that. They do it with power steering systems, and that is critical to
driver survival!!
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Ah, but the steering generally still works when the pump fails, albeit very heavy ! I've experienced that one myself.
 
Paul (testrider) has a kenlowe fitted to the front of his V8 rad. Pics on the first page of his project thread EMF. As you can see he has cut a section out of the front valance to accommodate the fan motor to get it to fit.

I gave up on electric fans when i couldn't get one to fit, especially with the thicker three core rad I now have. Mine now has the mechanical fan and a cheapo thin electric fan on the outside of the rad " just in case". To be honest, the difference in fuel consumption and power when removing the mechanical fan seems negligible on my car. I don't know if anyone has actually done any proper testing (ie rolling road) to see what the difference is. All we generally see are people reporting what they expect to find from removal of the mechanical fan. Yes I'm sure it does make a difference but in the great big scheme of things I don't think the return is worth the effort, or expense of buying the parts and re-engineering the car to get it to fit. I wait to be proved wrong, but we need data from proper testing rather than the usual "I took the car out and it felt a lot more powerful" etc. The placebo (not the correct term but I think you know what I mean) effect is a powerful thing.

Just my thoughts and experiences, I wouldn't want to put anyone off trying these things for themselves of course :D It's all good fun at the end of the day.

Dave
 
webmaster said:
Interesting, You should think that. They do it with power steering systems, and that is critical to
driver survival!!
Click to expand...

Ah, but the steering generally still works when the pump fails, albeit very heavy ! I've experienced that one myself.
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Me too Rich and the steering becomes a lot heavier than that from a non-power steering car when the pump fails or the belt snaps.

Dave
 
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