TR4/4A TR4 Cooling Fans

[KVH]

Plastic was available in 1962. So, why did Triumph use a four blade steel fan?

Stated differently, if a plastic six or eight blade fan is so great, why wasn't that the spec?

 

[doughairfield]

That's a great question, one I've pondered myself, dying to know the answer too. Is there a plastic fan conversion for the TR4 that's worth a hoot?

 

[PeterK]

Use a TR6 yellow bladed plastic fan. Bolt on conversion for the TR4.

 

[TR4nut]

The higher pitch TR6 fan has worked very well for me in the Houston traffic. With the metal fan, I just didn't pull as much air into the radiator when idling and I overheated quickly. Now I overheat slowly!

But a possible theory on KVH's question - plastic may have been available, but they may not have had a good polymer system back then that wasn't too brittle so it didn't take off til the late 60's - or maybe the good stuff was too expensive early on so the metal fan was cheaper.

I think a separate question might be why didn't they put the higher pitch tropical fan in every car?

 

[TR3driver]

Stated differently, if a plastic six or eight blade fan is so great, why wasn't that the spec?

Because they suck more power; and Triumph/BL saw no reason to change. At the time, plastic was looked down on as 'cheap' (with some justification); and the stock cooling system was considered adequate.

BTW, my 95 Buick Roadmaster Estate with HD cooling & trailer towing package still uses a metal fan. There's nothing wrong with metal.

 

[Geo Hahn]

And of course that engine was around long before plastic fans were in use (around I think even before the TR2) so perhaps we simply inherited it. Anyway, a Ferguson tractor could hardly have looked right with a plastic fan.