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[ksd]

Gentlemen:
I've read about people installing  a TR6 fan on a TR4. In some cases there is a clearance problem between the fan and radiator and some folks have gotten around this by installing the TR6 fan backwards! I'm wondering if anyone here has done that and how it's working for them. I'm wanting to install the eight blade TR6 fan on my TR4 but  suspect I'm going to have a clearance problem. Another question I have for the forum is what is the differance between the TR2-3B and the TR4 fan extension hubs sold by Moss and other dealers? If the fan extension hub for the TR2-3B is shorter  than the one for the TR4, and that is the only differance,I'm thinking I need a TR2-3B fan hub extention to mount up the TR6 eight blade fan on my TR4. I would appreciate any words of wisdome from anyone who has fitted a TR6 fan on the TR4. Thanks KSD       

[charley fitch]

Are you thinking of the "yellow" fan that was ( key point --was) available until recently?  I believe that it might still be available on eBay or in England.  I can tell you about using this fan.  I put one on my TR4 and it really moves the air!!!  I did move the radiator forward slightly to accommodate what looked like a very close fit.  There is some room in the bracket to allow moving the radiator a little bit.  I however made up a plate for each lower mounting site and moved the radiator another 1/3 inch or so. This was easy enough to do as I was building up the car.  I imagine that with the grille in and everything closed up it would be very tight but should be doable.
I will be using one of these yellow fans on my current TR4 project.  Although my mechanic and TR4 owner friend feels that I would be better off dumping the fans and putting in an electric pusher fan.
Charley Fitch 

[ksd]

Charley:
 Thanks for your input. I did find my eight blade yellow TR6 fan on ebay.
 I've also considered relocating the radiator as you have done to provide some additional clearance. However if just installing the fan backwards will eliminate having to relocate the radiator I may try that. No doubt that the efficiency of the fan will be somewhat effected if mounted backeards but I think it's worth a try. Others seem to have done it with good results. Hoping to hear from someone with a TR6 fan installed backwards on the TR4. Thanks KSD       
 

[charley fitch]

KSD,
I just checked on the fan that I have and you do save about an inch by reversing the fan.  However that seems to me to be counter productive as you are then pushing air forward while the car movement is pushing air backwards.  I have a friend that was able to mount his yellow fan on a TR4 without any major hassle.  You might try mounting the fan and see what clearance you do have. There is a little room for adjustment within the lower bracket on the radiator mount.  I also note that the reversed fan did not fit over the nose piece without removing some material from one or the other piece.
My friend is thinking of removing his fan completely in place of a electric pusher fan.  You gain a few horsepower in the process and can get better cooling at low speed or while stopped in traffic.  I am not convinced of this as the Morgan+4 that uses the TR3/4 motor has no fan on the engine and uses an electric fan in the front.  But the Morgan locally is having overheating problems.  I also know from personal experience that overheating can be caused by a lot more than just a fan or radiator.
Charley Fitch 

[ksd]

Charley:
 If you mount a fan backwards it will still move the air in the same direction. In the case of the TR6 fan where the blades are airfoil shaped it won't be the same as it would be with a perfectly flat blade but the fan will still be pulling air through the radiator. Years ago when studing for an aircraft mechanic's license that was a trick question on the test. What would happen if you mounted a prop backwards on an aircraft? The answer, the engine would still develop thrust but not as much!
 I talked to moss motors today and they say that the fan hub extension for the TR3 is 5/8 shorter than the TR4 extension so I ordered one thinking that might be the easy way to go. I'm making a sincere effort to "do no harm" and keep my TR as original as possible, or at least be able to return it it's original state if and when the time comes to sell. If your interested I'll let you know how the TR3 extension works out. KSD                         

[charley fitch]

Yes please let me know of your success.  I assume that you will also have to get a new bolt along with the shortened extension.
Charley 

[Bob Muzio]

When I mounted the TR 6 yellow fan on my TR4 I used a TR3 extension pice and it fit and has worked just fine.
Bob

[ksd]

Charley:
 Mounted the fan  the other day with the TR3 extension. Shortened the extension  bolt by about 1 3/8.  Cut an additional 1 3/8  of thread on the bolt and things are looking good. Haven't had a chance to run her in hot weather yet but she's cooling  a lot better pulling the local hills.