Viscous or Kenlowe

[topchef]

Hi all, just done the viscous (should be vicious?) fan again. Still overheating, so elected to use 10,000 cst silicone oil (5,000 last time) Bought over t'internet from RC shop, sold as 10000cst silicone oil for diffs/shocks. Job done and took her for a test drive. Overheating within 5 miles, on the flat doing about 60mph. Took her gently home and had to nurse her up a gentle slope as temp was seriously redlining! Pulled over and gave the fan a spin by hand....absolutely no resistance whatsoever. I've never even seen one spin so freely before. Duff oil do we think? Put the correct amount in ~ 50mls. Gasket in place properly, all screws good and tight, no leaking apparent. Turned by hand when cold and slight resistance as to be expected before driving off...big smile for a couple of miles...big disappointment again.
Am awaiting new thermostat and rad cap from Roughtrax to fit later this week and thought I'd get the fan done in readiness so all cooling issues would be sorted. However, if fan shot then all to no avail. Having spent many, many hours trying to sort out these problems over last couple of years, am beginning to think that a Kenlowe fan should/could be the answer? Anyone fitted/used/heard of any problems or good things to say about them?
Perhaps I've got the oil weight wrong? Anyone got a reasonably definitive answer for what I should use>
Thanks in anticipation

[popuptoaster]

Fans a fan really long as it's big enough to shift the amount of air you need.

When i put the 220bhp engine in my old Ford Cortina i used a Granada air conditioning fan with an after market thermostat in the top hose and it cooled that thing just fine even with serious abuse.

If you are reluctant to spend the money on a kenlowe get down the scrappy and find something with an electric fan and a similar sized engine and it should do the job.

[shokenore]

Firstly how much oil did you put in?

Secondly the viscous fan will not be locked at 60 mph.
The fan locks when it gets hot opening small valves via a bi metal thermostat to allow silicone fluid to move from the reservoir to the clutch section and by friction allows the fan to lock up.

At 60 mph nearly if not all engine cooling will be provided by airflow moving
through the rad from the air pressure caused by the speed of the vehicle

At the first instance with the engine cold ie over night some resistance should be felt when trying to spin the fan by hand.

My fan moves air even when not locked up and at idle speed you can feel air being pushed out of the bonnet gaps.

I would suggest that your symptoms may be of another coolant system issue.

[shokenore]

Iirc the toyo tubes are 18ml each and three are recommend so your 50ml ain't enough I'm happy to be proved wrong.

The last time I did my fan I used the full 60ml tube also from a RC place and also went for the 10000cst
When it locks up when hot I get the roar from the fan and the temperature of the coolant drops from about 88 to 84 pretty quickly
I have an accurate aftermarket gauge so I knew what temperature the coolant is.
I don't think running the engine into the red zone is recommended.

[topchef]

Shokenore, checked oil bottle when I got home....60ml bottle..thought I had squeezed enough out but bearing your comments in mind it seems only 45 ish mls left the bottle! It is so thixotropic, loads must have clung to bottle side. Fan back out tonight (1o mins out, more oil in, 15 mins to refit...getting really quick on it now lol) test run and marked improvement on cooling. Not brilliant but better. Will get cap and stat changed next and see if that makes any difference. Will keep this post updated with progress...and thanks for your input.

[shokenore]

Shokenore, checked oil bottle when I got home....60ml bottle..thought I had squeezed enough out but bearing your comments in mind it seems only 45 ish mls left the bottle! It is so thixotropic, loads must have clung to bottle side. Fan back out tonight (1o mins out, more oil in, 15 mins to refit...getting really quick on it now lol) test run and marked improvement on cooling. Not brilliant but better. Will get cap and stat changed next and see if that makes any difference. Will keep this post updated with progress...and thanks for your input.

The 10000cst is pretty thick stuff, I took the pour spout off my bottle and left it upsidedown overnight to fully drain into the housing.
I did find as you probably have done too that initially that the fan feels pretty stiff to turn, but after the engine has run for a while you could almost get the fan to spin by hand.
But when it locks up it is pretty solid.
Have you checked the coolant level via the cap?
May also be worth flushing the radiator/coolant system with a hose too.
You could also adjust the lock up temperature to come on a bit colder although it may decrease mpg.

Hopefully the extra fluid will make the difference

[Dobbslc]

I think that if it's overheating at 60mph you have another problem. The fan is really only cooling anything at a standstill.
Airflow through the rad at 60mph should be keeping everything at a normal temperature.
Remember the standard temp gauge on surfs is not very good, once its near the red your engine is already well overheated.
My standard gauge reads the same when my digital one is anywhere between 55°& 99°
It doesn't move!

[bundubasher]

Derek - don't really know you but have you got a lot of stuff blocking the airflow across your rad? Winch bumper etc? Before I shipped my 3.0L to Africa I had a new rad made - 3 core to 5 core, nearly doubling the capacity. Because it was so much wider I had to loose the viscous coupling to get the new rad in. I then holed the radiator and cracked the head.

My problem now is that when I had my vehicle repaired the first mechanic I used took the rad out and then died. So I lost both! The latest guy working on my truck has fitted a regular rad and I'm thinking to get a larger rad made when I next go home.

Anyway, tell us how the Kenlowes get on.

[bundubasher]

Just checked the date...feel like a ###### idiot now...

[Bogus]

If its any consolation , you look like one too

[bundubasher]

Tw@t!

[topchef]

Anyway, tell us how the Kenlowes get on.[/QUOTE]

Hi there, no worries about date....still working on it!!

Nothing blocking rad except spotlights so I took those off and gave it some beans up my usual long hill, not a jot of difference. Carefully jetted through rad fins with washer but still no difference. Spoke to Kenlowe who told me that although the electric fan would pull enough air through to keep everything nice and cool, for long trips (over 100 miles) towing the horse box would be best suited to a viscous fan!!! I got the impression that they were not entirely confident in their product. So, with colder weather imminent and hence colder flow over the rad, I elected to leave the kenlowe for a while and concentrate on working with what I had. I took the vicious (sic) fan out (again) and put more of the magic oil in. Now it is pretty much running from the off, almost locked up I guess, and the airflow/blast is phenomenal, not to mention it sounds like a double decker bus! Even so, it still gets the needle travelling on hard pushes uphill not quite in the red but close. I could do with knowing what the actual temp is from 'normal' on the dial to approaching the red zone. It may be that when its close to red the fan locks up properly and really pushes air through thereby keeping it within tolerances although still hot. Another thing I note is the intercooler is mounted in front of main rad and of course the aircon fan et al is there too so maybe a point to re-site the intercooler and free up more rad area. Maybe even scrap the aircon. Thought also about fitting another small rad (pre-cooler?) just before main rad as well. Warmer weather will have to appear before I start any more tinkering though. Just finished major oil clean up in engine bay. Left cap off last Sunday and didnt notice till Fri all the oil shooting down the wings, small puddles after parking on road etc. Flipped the bonnet and it looked like someone had painted black hammerite everywhere lol. If I hadn't felt such a t##t I'd have photographed it to laugh at later. However, 5 litres of Gunk and a trigger spray bottle later it looks pretty good now.
Will keep on top of electric fan issue and maybe mount in front of rad and retain viscous which should be a 'boost' as and when it gets a bit hot.
All the best mate...

[bundubasher]

Defo the intercooler will be blocking the rad. Top mount it if you want to keep it. Bigger rad allowed me to drag a fully loaded vehicle and trailer 4000km when we moved house: Joburg to Nairobi!

[popuptoaster]

It's possible that towing is heating the autobox fluid up enough that no matter how much air you put through the rad the heat transfer from the autobox cooler is warming up the engine coolant to the point where the rad can't lose the heat.

I have a manual radiator and separate autobox cooler ready to go into mine for heavy duty use.

[Jameswallace]

Is the rad blocked at all and the stat working ok?