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Radiator Shroud


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Hi Everyone,

Looking for some more help please.

My car has the radiator shroud from the grill to the front of the radiator. The usual cardboard one.

My question is, should there be another shroud on the inside of the radiator, between the engine, enclosing the fan it self.

Would this not pull more of the cold air through the radiator, to help with cooling.

Does anyone have the inside fan shroud fitted to their car. ??

If so could you advise where you purchased it from please & how much you paid for it.

I attach a photo of my engine bay, which shows where it should go. If there is such a shroud

Thanks

David

IMG_2607.jpg

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53 minutes ago, David.B said:

My question is, should there be another shroud on the inside of the radiator, between the engine, enclosing the fan it self.

No

David, do you have a heating problem?

I know this can be controversial but I do not have any shrouds.

 

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Yes and no.

Triumph never fitted a shroud/cowling as Stuat says, but yes one would theoretically make it more efficient if there was one.

However in reasonable condition there is ample cooling capacity on the 6 so you wouldn't benefit from a shroud or cowling anyway!

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David - as everyone has pointed out already, you don't need an inner one - I see you said you had an original cardboard front shroud - these can get tatty fairly easily - If you fancy a nice black powder coated ally front shroud at a good price, I have one left out of my old stock - PM if you are interested.

Cheers Rich

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3 hours ago, JochemsTR said:

No

David, do you have a heating problem?

I know this can be controversial but I do not have any shrouds.

 

No I don't have a heating problem. Just wanted to know if I was missing one. Thanks

 

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Hi David,

compared with other cars there is indeed a shroud missing, the TR builders saved this money and effort.

I made myself this shroud and the benefit is enormous, probably the best you can do for the cooling system.

Apart from the fact I never had any cooling problem!

It looks a bit like one of my wifes cake pans :lol:

zgT5QQ9qJBkTuMXIsCAF3wNOBCWR6q-HGow0DwQd

Ciao, Marco

 

Edited by Z320
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30 minutes ago, Z320 said:

Hi David,

compared with other cars there is indeed a shroud missing, the TR builders saved this money and effort.

I made myself this shroud and the benefit is enormous, probably the best you can do for the cooling system.

Apart from the fact I never had any cooling problem!

It looks a bit like one of my wifes cake pans :lol:

zgT5QQ9qJBkTuMXIsCAF3wNOBCWR6q-HGow0DwQd

Ciao, Marco

 

Hi Marco

I like your shroud design. The shroud in front only works when the car is moving forwards - better as the speed increases up to a point. The fan only comes into its own when sitting in traffic. On my 4A I have the multi bladed plastic fan as in Davids original posting above. The standard on the 4A is the metal 4 bladed fan that is not very good. Your shroud will help pull air through the radiator better when the car is stopped in traffic. In the case of David's car the hole in the front shroud will make no difference when the car is stationary but will reduce the airflow through the radiator quite significantly when the car is travelling along. The air takes the line of least resistance through the hole that has been made for the air intake filter. If David's car does not overheat then leave it as it is would be my option. If it overheats when travelling along then I would close the hole in the front shroud and see if I could fit an air intake tube pointing forwards and down towards the road

Marco I notice your horns are mounted vertically. Was this originally? Mine fit in the horizontal position

Keith

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please show me an original TR :lol:

the horns have ever been this way since I own the car

edit:

my fan is from a BMW 1602, I wanted to swop back to the original one - but installed at once the BMW fan again

 

Edited by Z320
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15 hours ago, JochemsTR said:

No

David, do you have a heating problem?

I know this can be controversial but I do not have any shrouds.

 

I've got what you've got and never had overheating problems even on 40 deg C days. If I had a shroud around the fan it would probably be gone by now as I use the fan to turn the engine over for timing etc.

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20 minutes ago, Mike C said:

I've got what you've got and never had overheating problems even on 40 deg C days. If I had a shroud around the fan it would probably be gone by now as I use the fan to turn the engine over for timing etc.

I also do - with shroud!

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15 hours ago, keith1948 said:

Marco I notice your horns are mounted vertically. Was this originally? Mine fit in the horizontal position

Keith

Originally they were horizontal.

Stuart.

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The inner shrouds around the fan are actually stopping the (an) open fan from creating turbauence in the air stream so you will notice the effect because of it. That is, you want a smooth air flow through the radiator and gets rid of hot air quicker away from the rad. Without a shroud, the air is being chopped all over the place and tending to stop new air from coming through the rad. Electric fans have a shroud so are more efficient than a standar open TR6 fan but fitting a shroud may negate buying an electric fan if you are having problems (and obviously in traffic queue situations).

Strictly speaking the TR6 front funnel shroud is wrong. To enable more cooling via heat transfer you want to slow the air speed down through the rad - small cross-sectional surface area at front of shroud will reduce flow automatically with a larger cross-sectional area at rear / radiator - simple maths as air slows when volume expands. However this is probabl academic in a TR6.

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55 minutes ago, Richard Pope said:

The inner shrouds around the fan are actually stopping the (an) open fan from creating turbauence in the air stream so you will notice the effect because of it. That is, you want a smooth air flow through the radiator and gets rid of hot air quicker away from the rad. Without a shroud, the air is being chopped all over the place and tending to stop new air from coming through the rad. Electric fans have a shroud so are more efficient than a standar open TR6 fan but fitting a shroud may negate buying an electric fan if you are having problems (and obviously in traffic queue situations).

Strictly speaking the TR6 front funnel shroud is wrong. To enable more cooling via heat transfer you want to slow the air speed down through the rad - small cross-sectional surface area at front of shroud will reduce flow automatically with a larger cross-sectional area at rear / radiator - simple maths as air slows when volume expands. However this is probabl academic in a TR6.

Hello Richard

Heat transfer from rad to air depends on the temperature difference between the hot water inside the rad and the cooling air flowing through the rad fins. With slow moving air there is a risk of a boundary layer of warm air building up on the surface of the rad. This will actually reduce the heat transfer. A faster flow of air will help reduce the tendency to form this boundary layer and so help heat transfer. I did a lot of work on heat exchangers and elimination of the boundary layer was important in increasing the efficiency. So I would have to disagree with your view of the shape of the front funnel. Fast flowing cold air is better than slower moving warmer air when it comes to heat transfer.

The classic mini had a shroud around the inside of the radiator because it was mounted at the side of the engine bay. The shroud improved the air flow otherwise it is doubtful the radiator would have worked at all. The shroud had a small indentation so you could feed a new fan belt on without removing the shroud.

Marco's shroud around the fan will improve air flow through the section of the radiator within the shroud area thus slightly improving the effectiveness of the fan. I have often thought that the fan wasn't that effective because it is simply stirring the air behind the radiator with lots of turbulence as you have said. If you are thinking of fitting a fan shroud then I would have thought that the plastic multi bladed fans would work better than the original 4 bladed paddles. A complete inner shroud as on the early minis would have the problem of 'dead' areas around the edge of the rad where air flow could in fact be lower than if a partial shroud (Marco's) was used.

Maybe Marco could use smoke tracer to look at air flow through his rad with his modification?

Keith

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A slight hijack of the thread but it is about radiators and cooling.

My car had an original radiator that externally looked to be very old. On hot days (I'm talking over 40 degC and up to mid 40s) in very heavy traffic my engine would get very warm. After half an hour it would be in the top of the gauge but not boiling. Using a infra red heat sensor it was running about 215 degF.

I bought an ebay aluminium radiator. The engine temperature still rose with long periods at idle. On closer inspection the old radiator is in excellent condition so the new radiator wasn't needed.

The ebay radiator was actually a pretty good product so I bought a fan from the same people. Fitted it yesterday and while it is very cool here in Sydney for late spring when I turn this fan on it makes an almost immediate difference.

So my answer to any cooling problems that aren't due to a poorly maintained car is to fit a 14" electric fan to the front of the radiator.

I am now tempted to remove the engine driven fan. One of my TR2s has a manually operated electric fan so I am ok at keeping an instrument scan (a pilot in a previous life) and operating a manual fan.

My question is, will there be a noticeable lift in performance without the engine driven fan.

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You are talking of a 3-4 hp difference...no, only in your mind. Oh...it will be slightly quieter.

Mick Richards

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Hi, 

I run my more effective BMW fan with 4,000  revs on my lathe, the lathes max power is only 1.5 kW.

Not included is the benefit from the fast driving car: the air pressed faster through the rad by the driven speed and shroud in front of the rad.

So the fan needs less power on high speeds, possibly no power at all?

I guess the „rule“ was made by looking on a electric fan data sheet pressing air in a ventilation system.

Because it is told since ages - when nobody had the tools check this.

And because of the need of car owners to „improve“ their cars.

But this is all my own opinion, I can’t proof that (btw as others can’t proof the more engine power with electric fan).

Ciao, Marco

Edited by Z320
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I also removed my engine driven fan and now only use an electric fan mounted in front of the radiator. One of the nice side-effects (other than a cool engine when in traffic) is that there is plenty of room in front of the engine, so no problem manually turning the crankshaft and no chance of removing my knuckles when using a strobe for timing.

Cheers, Robert

Edited by rwest
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Hi All

Many thanks for all your comments

I seem to have opened up a can of worms on this one.

I do not have a cooling problem on my car, even during the summer here in the UK

My take, from all your responses are

It seems our cars do not need the internal cowling to maintain a good engine temperature.

If one was fitted, as like the old mini, it would help maintain better cooling whilst in traffic jams.

I know my intake filter is not original, but it does work well.

I am thinking about adding a length of tubing and putting the filter closer to where the original intake filter was placed, so as to maintain cool air to the intake manifold.

If I then add a cowling to the back of the radiator, as in the old mini, it should improve airflow through the radiator, keeping the engine cooler.

Hope this makes sense

David

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34 minutes ago, David.B said:

f I then add a cowling to the back of the radiator, as in the old mini, it should improve airflow through the radiator, keeping the engine cooler.

 

Hello David

Personally I wouldn't bother trying to make a mini style cowling for the inside. You have the multi bladed fan same as I have fitted to my 4A. I have driven in France and Spain in temperatures in the 40's in traffic and no problem with overheating. Mine is ex California and came with the multi bladed fan so I guess they fitted it there because of the hot weather. The older 4 bladed fans are another matter. They don't work well at all. Marco's design of cowl might be worth considering. Maybe get a cake tin with a loose base of the right diameter and make one out of that?

If it ain't broke don't fix it is my motto

Keith

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I've been through a number of iterations of cooling on my 6. Only one, the first one was because if cooling issues. 

When I got the car there was no shroud and an engine driven fan. It did not cool well in hot weather. Fitting a new shroud solved the issue completely and I suspect the issue was warm air from behind the fan recirculating to the front of the Rad. All this happening only when stationary. 

The final itteration I have has a 14 inch spal puller fan (because I can't have engine driven with the supercharger) this works exceptionally well with a < 20% duty required even at >30oC ambient. 

Cheers

Tim

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