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> Jensen Healey & Jensen GT Tech > Cooling > Is a radiator fan shroud needed?

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brendansriley@gmail.com
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I have a newly acquired 1973 JH MkI. It does have an electric fan that is hard wired and running when the key is turned to accessories position. There is no fan shroud. Is the removing the shroud typical of a non thermostatically controlled electric fan? Shouldn't the electric fan be thermostatically operated or at least time cycled initially to allow the engine to get up to temp fairly quickly?

redracer
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Don't know how many amps your electric fan uses, but hopefully there is a relay for it. You could just run a switch inside that you turn on & off as you watch the temp. gauge?

Tom Bradley
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If the thermostat controlling the coolant flow is working correctly then having the fan operating continuously should not make any significant difference in how fast the engine warms up. After all, the original fan connected to the crank shaft was always running whether there was a shroud installed or not. If the fan is mounted directly to the radiator, I do not think a shroud makes that much difference. The main reason a shroud was needed on the original fan was because there was too much space between it and the radiator for it to pull air through very efficiently.

noomg
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Brendan,

Is your J/H overheating or even running hot? I'd think that would determine what course of action to take, shroud, no shroud, fan on, fan off, etc.

I don't have a shroud on mine, It doesn't look like it's ever had one. Also I don't have an add on electric fan, which I know is a popular addition, and my J/H never overheats or runs hot for that matter, and that includes when daily temps are running above 90 degrees.

I attribute this more than anything else to the J/H uprated 3-row radiator. I had considered adding an electric fan early on when I first had the car but with the 3-row I just never needed it.

discogodfather
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Got to say where I live in San Francisco, CA, this thing runs so cold blooded already....

Had to run a thermostat on the oil cooler.

I always liked the factory setup with the fan and the shroud. The shroud isn't too difficult to find, or expensive. If you are not racing or in a hot area, then maybe try the stock setup again?

They also sell a fail open thermostat for $25 bucks, which always appealed to me.

Art DeKneef
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The reason there is no fan shroud is probably because the fan shroud wouldn't fit with the electric fan was installed. Rather than try to modify it the fan shroud was completely discarded.

My guess is that when the electric fan was installed, for whatever reason, the thermostatic switch wouldn't fit anywhere. All of the kits I have seen include a switch or adapter that fit an American engine. Since the Jensen Healey has just the one water temp location on the intake manifold for the temperature sending unit, they decided to wire it so the fan was always on. Maybe they couldn't find a thermostatic switch with a probe.

Your account doesn't show a location so we can't guess at the weather you will be experiencing.

Best advice is to determine what shape the cooling system is with the car now and then determine if anything needs to be done.

Here in Mesa, Arizona, my car has the 3 row radiator, electric fan, shroud and is fine. But then I don't go out when the temp is 110 degrees or higher. Not having AC in those temps puts a damper on driving the car in those temps.

brendansriley@gmail.com
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Thank you all for your replies/comments. Greatly appreciated.

B

noomg
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Brendan,

I'm not getting the main thrust of your post. Are you concerned that you have an electric fan that runs constantly? Are you concerned about no fan shroud? Or are you concerned about overheating?

If it's the fan, the only way to tell if it's needed, short of talking to the PO who installed it, is to disconnect it and see if the car starts to run hot.

mgreaves
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Brendan,
I had overheating problems with 55032, There was no fan shroud.
This was probably the easiest thing I have done to my car.
I Installed a electric fan to the outside of the radiator and left the existing fan in place. I installed switch to a thermostatically controlled switch to a relay. Set the dial for the fan to come on when the engine is getting on the hot side, and haven't had overheating problems since, even in a hot Melbourne summer.

redracer
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The cars never came with a fan shroud; they were add-ons for mostly the engines after the '73s, which had about 2 extra quarts of oil to help with the cooling. As noomg stated, the
3 row radiators with STAGGERED tubes(i/e., not in line with one another) work well.
Many have gone to a CHAMPION aluminum radiator(about $220 on AMAZON) which will take care.
BUT--BE VERY CAREFUL; THE '75 AND LATER ENGINES WITH THE WIDE CLUTCH FAN WILL TOUCH THE BOTTOM OF THE CHAMPION ONES(they're a bit wider) AND RUIN ITUNDER HIGH RPMs. THE BOTTOM BLADES WILL FLEX OUT.
found this out the hard way and ordered another CHAMPION but put the smaller yellow fan on.
I've got a bunch of fan shrouds; we were, up until the early 2000s, able to get them 4 rowed, but no longer.



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