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Hot Running...and Kenlowe Fans


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I have recently had my engine completely rebuilt, and its clearly a lot tighter. In normal running the temperature needle stays very firmly in the middle. I have a Kenlowe fan which comes on in the normal way as the temperature climbs in traffic (I live in West London), however, initially the temperature remains broadly under control, but after a few minutes the temperature starts to rise, and putting the heater on doesn't help, it might make it worse. At the same time idle speed starts to climb from the normal 850/900 level, and will build to 1500/1700, before I turn it off to cool down. The engine fan has been removed, but with the old engine I had none of these problems.

 

The car runs great most of time, and has no real issues when running on the road. It does now have a new fast road cam from Kent cams, which make the low revs a little lumpy, but once the revs build its great.

 

I'm wondering if the electrical circuit is struggling to cope with the power required to run the fan, as the fuse box is getting very hot, and turning the heater fan on wont help this, I was thinking I might put in a relay here, to see what happens, as I suspect the idle speed rising is vaporisation.

 

Thoughts and comments would be welcome

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Have you still got he original engine fan?

Is the kenlowe blowing the right way? Odd that it runs fine in a run but overheats in traffic. This suggests that the there is unlikely to be too much amiss with the engine or rad.

Could be very lean mix or retarded timing.

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You need a 14" Kenlow to cool it down properly. Advise from Kenlow when I had my engine rebuilt. Mines a puller. Works perfect. Brings temp down and cuts off.

Steve

Edited by whatmore179
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Could be very lean mix or retarded timing.

+1.

Check points gap, if dry of grease they can close up in few hunderd miles and retard the spark. Retarded running leads to more heat in the water jacket and less put into pushing the pistons.

Peter

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The Kenlowe fan I put (1991) in my 1958 TR3A is a 12" puller or pusher depending on where you locate it. Mine is installed between the grille and the radiator. The 12 blades on the fan push the air through the radiator. When I put it in, I had the two wires reversed so it was pushing the air back out through the front grille. I swopped the wires over and it's been fine since. My TR3A starts to heat up when stopped for more than a few minutes in heavy stop-and-go traffic. I have a manual switch that I use to turn on the fan and in a few minutes it's right back to 180 deg. F (in the center). I also have the cardboard air deflector installed as well as the original fan on the front of the engine block.

post-1056-0-37859300-1437499151_thumb.jpg

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I had trouble with my "6" in traffic when I first got it - fan would cut in/out and seemingly control the temperature, but car would run rougher and rogher then eventually conk out. Once cooled down it would run fine again.

 

I too found that my fusebox had got hot around the terminal the fan was connected,, to the point that the rivet holding the terminal on became loose. With a trip to Le Mans pending, I replaced the fusebox and rewired the fan via a direct fused feed from the positive terminal of the battery.

 

I suspect that the mode of failure was high resistance due to corroded terminals, working with a relatively high current draw from the fan causing the terminal to heat up, and subseqently the voltage to drop, affecting the standard wired fuel pump.

 

I've not yet got around to re-cabling the fuel pump, but the car sits fine in traffic now.

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Check for an air lock. My rebuilt engine overheated a tad until I "burped" the system. Cheers

Tim

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Over the 43 years I've own my TR6 I've never experienced overheating...using the original fixed Fan! That includes living in North London and driving in Central London and driving in the heat of Spain too.

 

Over the years mines had 2 major engine-out rebuilds, and as the needle never ever got to the central 'N' I fitted a gauge with numbers, which never reaches the central 70 mark...In the winter I have to blank the Radiator with cardboard!

And yes, the Thermostat does work, as I recently had to change all the old Rad hoses as they were perishing, and I observed it open during air bleeding.

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Hi Farly6 (have you got a name),

 

what ever the problem is with the temp I'm sure somebody here will put you on the right TRack.

However in the mean time put a relay on your fan with a 30amp fused supply direct from the battery. The relay coil can then be run from the normal fuse box.

 

Where abouts in West London

 

Roger

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If you don't go for originality it's good to fit a second fuse box to the 6 for the additional items. I had quite some problems with my electric fan. did blow the fuse at start up.

I replaced it by a SPAL fan connected via 2 independent circuits. one for thermo switch and one for override both via relays, never had a problem afterwards.

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Electrical extra fan is certainly something interesting based on the current road and traffic condition. Nevertheless do not underestimate the Triumph engineers, in case of overheating it is important to cure the problem at the source. So do not forget to go back to the basics by checking the engine set up and consider the global system (Fuel system: Carb/Inj. mixt, system linkage tuning, Air filter… , Ignition system: Points gap, Timing/Advance, Spark Plugs…., Engine condition: Valves seat & clearance…., Cooling system: Thermostat, radiator, air look… Air duct..).

 

With a Stag since 97 and TR6 since 86 (both in original configuration no extra fan, no larger radiator....) this is something I reconsider on regular basis and up to now overheating is not a concern(cross my fingers…)

 

Regards

Edited by Marc R
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Electrical extra fan is certainly something interesting based on the current road and traffic condition. Nevertheless do not underestimate the Triumph engineers, in case of overheating it is important to cure the problem at the source. So do not forget to go back to the basics by checking the engine set up and consider the global system (Fuel system: Carb/Inj. mixt, system linkage tuning, Air filter… , Ignition system: Points gap, Timing/Advance, Spark Plugs…., Engine condition: Valves seat & clearance…., Cooling system: Thermostat, radiator, air look… Air duct..).

 

With a Stag since 97 and TR6 since 86 (both in original configuration no extra fan, no larger radiator....) this is something I reconsider on regular basis and up to know overheating is not a concern (cross my fingers…)

 

Regards

Edited by Marc R
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Agree with Marc.

 

My 6 has std set up, no electric fan. I got stuck in a traffic jam for 1/2 hour on the A3 the other week, sweltering conditions. Thought here we go, will she heat up ? No not at all, perfect temperature and the engine idled without change.

 

So what are we subsidising by adding a fan.......surpressing a developing problem ?

 

 

Peter

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The standard fan does take a bit of power to run, and on the move its not really needed.

The other drawback is that the blades will bend forward in a deep puddle and take out the bottom gills on the radiator.. Have had that happen twice.

But for cooling the standard fan works fine - I never had over heating in 10 years/150k miles of daily driving.

Its is however b8888y dangerous be around when checking the timing with a strobe lamp in a darkened garage and running up to 3500rpm.

Peter

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Hi Farly6 (have you got a name),

 

what ever the problem is with the temp I'm sure somebody here will put you on the right TRack.

However in the mean time put a relay on your fan with a 30amp fused supply direct from the battery. The relay coil can then be run from the normal fuse box.

 

Where abouts in West London

 

Roger

 

Roger I live in Fulham, Best wishes Charlie

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  • 1 month later...

Thanks everyone for the help and advice on this thread today, unfortunately I've still not got to the bottom of the increasing idling speed when the engine gets hotter in traffic. The idle speed is still slowly increasing when the electric fan runs. The next plan is to check the vacuum from the manifold to the servo.

 

I have so far extensively rewired, and added a relay for the Kenlowe Fan, checked all the inlet manifold for fitting. Its so all very frustrating, but not in surmountable I suspect.

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Charlie,

Is it standard PI with the standard plenum and intake hose. ie its not sucking in hot underbonnet air blown back by the fan? I could see that speeding up the tickover gradually.

 

I'm with TimD on an airlock.

And I would try a new thermostat, summer grade.

 

Peter

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Buy two or three thermostats and chuck 'em in a pan with a thermometer. Bring slowly to the boil and observe them opening. Add a bay leaf if desired.

You will notice variations in the temp that they open and the amount that they open.

I bet your rebuilt engine was fitted with a new 'stat that opens slightly late. It doesn't take much to make a difference to the running temp.

Why it would start to rev is more difficult.

Throttle return spring getting less springy with heat? Try a new spring.

Manifold leak only noticeable as it expands? Try a new gasket and check for spindle wear.

Jerry

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Is it possible that the increase temp makes the inlet manifold expand widening the gap between the manifold bore and the butteflies?

Cheers

Tim

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Is it possible that the increase temp makes the inlet manifold expand widening the gap between the manifold bore and the butteflies?

Cheers

Tim

It is possible if its just minimally sealed at cold.

Stuart.

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Thankyou Peter, Jerry, Tim and Stuart

 

So it look s like the next thing I should do is "burp" the system, can anyone give me a Duffers guide to "burping" please?

 

The car has a standard PI with the standard plenum and intake hose. it is not sucking in hot underbonnet air blown back by the fan, as the air intake via the standard air filter is in front of the radiator. I think I also need to check the gap between the fan and the radiator.

 

 

I think I need to check the manifold when hot, or perhaps cold as well.

 

 

Best wishes all!

Edited by Farly6
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