Electric Fan
- Dean and Kaye Howells
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........"I suffer from overheating since my Oka (XT) air tunnel is stuffed with a/c condensers and fans so air flow is already impeded, especially pulling hard over slow terrain, but more importantly, on a hot day with the a/c on full blast .........".
What I was trying to say is that the LT has an improved cooling system (compared to the XT) with a larger radiator and ease of access/removal for maintenance which make it a better system. As Rick points out though, a well maintained XT cooling system does the job well. I guess the LT cooling system has a bit more 'wriggle room'.
And yes, "believe it or not" #403's temp gauge didn't rise above its usual 'one needle thickness into the green' position. This could of course mean that the temp gauge is faulty , a very common OKA problem (they usually read high) but I don't think so as it was replaced along with the thermostat, viscous coupling and coolant just prior to this trip so the cooling system was in pretty good nic.
What is noteworthy is that all three OKA's viscous couplings failed within a couple of months of each other. Mine just prior to leaving, David's along the way (but fortunately he was able to affect repairs) and Dave's on the return to Perth. Just bad luck maybe ?, but something to consider when planning an extended trip.
Deano
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- TH
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I'd love to see some pictures of your new system.
Good to see you have found a solution
Cheers, Tony
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- mort
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For the members who don't know the beginning,I had a need to move away from the std perkins fan to an electric one and at the same time I also installed an electric water pump.
For the record my background is in the field of Air Conditioning, ventilation and hydraulics or simply the movement and treatment of air and fluids, although I may have left the industry some years ago dementia hasnt set in yet.
I have been running the electric fan and water pump now for 2 years, am I happy? yes it runs better than I had expected, would I recommend? Yes.
What I did and why.
I chose a fan from USA only because it had an output of some 3600 cfm. Why? not knowing what resistance through the radiator and down the tunnel I had allowed for a 30% loss in performance so at 3600 cfm less 30% leaves a lot of air through the radiator.
Now for the water pump, I chose the Davis Craig pump at 150 Lpm again not knowing how much would be needed so go for the largest.
The controller I had first tried was one from the states but didn't like it so tried the Davis Craig electronic all in one fan and pump controller and it works brilliantly.
For your info Davis Craig invented the electric fan and water pump which is now used on most vehicles today but maybe not their brand.
So what is so good about it well it takes up less room but the controller is the key, when you start the engine the fan runs for 2-3 seconds just to test and then shuts off and will only start again when the temp reaches 3 deg above the temp you set and run until the temp drops below your set temp. If the engine is cold like icy the fan as a safety will continue to run until it registers a temp change then turns off so it checks to see if the sender unit is working.
The pump will start when engine started but will run for 5 sec and stop for 30 sec then on for 5 sec etc but as the engine warms up its on for 5 sec and off for 25 sec on 5sec off 20 sec on 5 off 10 on 5 off 5 and so on until engine reaches set temp then on continuously until temp drops below set temp and so it continues.
Another good feature is when you turn off the engine the pump keeps running for 2 minutes circulating coolant allowing the engine to cool down evenly.
gotta go back soon
Martyn
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- mort
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With the controller you can set temp from 75 deg to 95 deg this is a good feature because if say your in very hot temps or your crawling and the engine temp is going up you can set temp at say 80 deg and this will cause the pump to cycle quicker or even run continuously keeping the engine cool or if lets say your up in the highlands on a cold winters day and the engine isnt getting warm enough then set a higher temp and that allows the pump to cycle slower.
After 2 years of operation including the desert trip last year and the trip up north this year excluding the initial start up the only time the fan came on is climbing the 5 rivers lookout at wyndham which is a very steep slow climb and half way the set temp was reached the fan came on brought the temp down to 90 and it stayed there till I finished the climb so provided you have sufficient forward movement the fan doesnt come on.
Since installation I had to play with different settings till I learnt what suits the OKA and the engine.
I would convert over again even if I didnt have a reason that forced me to.
If you go direct to Davis Craig you can get the fan pump and controller individually or buy in a kit containing the lot I think I paid about $500.
Paul in your case you will remove the viscous hub and fan plus the fan hub right back to the front engine cover saving approx 30cm and then the electric fan will be about 13cm.
Martyn
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- Paul Scherek
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The Davies Craig 16" fan goes upstream, so that leaves heaps of space for the Perkins 6.
Would you let me know please what the American fan was? The Davies Craig is only 2120 cfm, and I probably want as much going for me as possible.
Thanks again,
Cheers,
Paul
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- Paul Scherek
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Thanks, Paul
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- mort
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The fan was a Zirgo Ultra High Performance Electric Fan Model HFM-ZFU16S I got it from Summit racing in US www.summitracing.com the price is $214.00 have a look at their range and other brands there is a lot to choose from but I am happy with mine.
Make sure when mounting you have a suitable cowl/shroud I can take a photo of what i did which is to cut down and reshape the existing OKA one but depends on the room you have to play with.
Martyn
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- mort
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The engine runs a bypass cooling system which is when the engine is cold/warm etc the thermostat hasn't opened yet the coolant bypasses the radiator and goes back through the engine to help heating up faster, so as the pump operates with the controller being on 5 sec off 30 0n 5 off 20 etc it has the same effect so you will need to remove the thermostat and maybe in your engine there could be 2 together.
I did take my pump off when removing impeller but if you have a suitable puller and room maybe leave it on its easy its driven by a cog and nothing to line up.
Martyn
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- Paul Scherek
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Many thanks for all that info. I had been wondering about a shroud for the electric fan - assuming a 16" fan, the swept area is about 200 square inches, while the actual radiator core area is 400 square inches. Already half the area is lost if the fan is close coupled without a shroud.
It is an interesting question - with the fan close coupled, the air volume per square inch of core is greater, but the number of square inches of core with air flow is less. With a shroud, the air volume per square inch is less but the number of square inches of core with air flow is greater. Intuitively I would think the shroud would be best.
Yes please, I would be very grateful for a picture of your shroud arrangement.
Cheers,
Paul
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- mort
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Having trouble with new phone and downloading photos but when I sort that out will post photo.
Martyn
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- mort
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Just brinning to the top so if any interested owners have forgotten or new owners dont know about it.
Martyn
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- dandjcr
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David
David and Janet Ribbans - Oka 148
Oka148 profile here.
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- Alister McBride
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cheers, alister
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- mort
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This is the post on the fan from a few years ago, you may want to read or not.
Martyn
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