• Hi Guest!
    If you appreciate British Car Forum and our 25 years of supporting British car enthusiasts with technical and anicdotal information, collected from our thousands of great members, please support us with a low-cost subscription. You can become a supporting member for less than the dues of most car clubs.
    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

TR4/4A TR4 Fan [Yellow Plastic] on a TR3?

Share this page

D

dspeed

Freshman Member
Offline
Sorry to be such a bother, but I seem to be rushing through a series of decision points right now as I put the pieces I've assembled and preped over a few years back together for a final assembly effort.

Having a 1955 'smallmouth' TR3 with the later high port head (engine otherwise unmodified) and an original radiator (with crank hole) seems to put me near the edge for around town driving in the 105+ heat of Carlsbad, NM.

I've seen recommendations to exchange out the original TR3 fan (4 blade steel/Al) for the later yellow plastic TR4 fan.

After a couple of abortive attempts to change out the fan hub, I saw where the TRF catalog noted that you could just turn it over and install it backwards.

I did this and was uncomfortable with the lack of clearance I had. After some careful shimming, I now have a good 1/4" clearance with the shock tower support member. Is this enough? What is the collective experience with this mod?

The new fan does look like it would pull a lot more air through he radiator.

Should I go back to the original fan, or will this be OK? Would like to hear from somebody who has done this mod.

Dave in Carlsbad
 
I have not done this mod though 1/4" sounds very close given the amount of rocking the engine can do.

I use a TR4 fan (square tip paddle) on my TR3 which gives a little bit more air (also stock w/ a crank hole). Also use an electric auxiliary fan and a few other tricks and drive in 105+ heat. I get too hot but the engine's okay.

I've told the story before of driving past one of those time/temperature signs and thinking it seemed later than a quarter past one... then the sign changed to read 2:30 and I realized that 115 wasn't the time.
 
Hi Dave I did this mod on a small mouth. However, what I used was a metal 6 blade fan. I got the fan off a 58 tr3, but it must have either come off a tr4 or tr6 or perhaps a Volvo. I guess early Volvo uses the same bolt pattern and center hole size. Anyway, the fan is very close to the bottom of the radiator when I get home I will measure it. What I did was slot the radiator mounting bolts holes on the frame, so I could slide the radiator to the front as much as possible. Now that I think about it, the distance between the fan and the radiator is about 5/8 of and inch because putting a fan belt on is even a bigger pain, it just barely gets between. I mean, I have to work at it and be careful. But the fan has been a great improvement for cooling. For example, I can sit idling at a stop in hot Northwest Washington for maybe 20 to 30 minutes whereas with the original fan, maybe 5 to10. I do not have an auxiliary fan or oil cooler and I am sure they would help a great deal more. Back to your question about space, I have been driving my car just with this narrow space for years. I think with good motors mounts and moving it forward and say 5/8 of an inch clearance you should be ok.

Regards George
 
I live in Florida now but lived in Hobbs for a couple of years so I understand about the heat. Here is how I cured my TR3 so I could drive in the Florida summers. First of all I took the metal fan off and replaced it with two electric fans, one puller one pusher. It's always hot here so I wired one direct and put one on a thermostat. In Florida I run pure water with 'Water Wetter'and some water pump lube. Remember that anti-freese/water mix of 50/50 only has 80% of the thermal transfer ability of pure water.
This would work for you in the summer but not winter.

I think one of the best sports car drives in the world is between Carlsbad and the cavern entrance. Desert mountains and clear blue skies make for the perfect spring or fall drive. I'll pass on summer or winter.

Good luck
 
Hmm - I've been out on business for a week and no 'yellow plastic fan' responses. Guess I'll give her a try.

I wanted to keep something out there to act as a harmonic damper, hence my decision not to go to electric.

As a chemist in a former life, I would not run pure water w/o a corrosion resistance package. Yes, you get less transfer w glycol.water, but you get a higher boiling point - not a trivial matter at 3100 feet.

You said:

"I think one of the best sports car drives in the world is between Carlsbad and the cavern entrance. Desert mountains and clear blue skies make for the perfect spring or fall drive. I'll pass on summer or winter."

Winter here is hardly a problem <g> except on a *very* few days.

I'll assume you mean the ride from White City to The Caverns HQ. Yes that is pretty. I am thinking of taking it up to Cloudcroft to do the Mayhill / Weed / Sunspot run. Also thinking of doing fall colors on the circle from Taos to Eagle's Nest Lake.
 
dspeed -

I'll be putting one on my '57 at some point. Bought one from TRF, along with the installation kit. Like you, I want to retain the balancing function of the blade. I'll probably put in a new radiator at the same time, as mine has run hot no matter what I've tried.

Let me know how yours comes out, particularly the clearance issue.

Mickey
 
Mickey -

Its been deades (literally) since I was running her on the street in the western Pennsylvania summer, but I don't ever recall a cooling problem with a 50/50 antifreeze mix. Most of my driving was 2 lane roads at moderate speeds during the day. Probably 90 degrees tops. Not much stopping in traffic etc.

I've flexed the fan by hand and think it will be ok - really, the worst I think it will do is skuff a little paint off the support arm. (Well, I *hope*....).

Will learn the answer soon enough; heading out to the garage now after 10 days on the road...
 
Hey, Dave, I read your post w/ interest, as I just put on my Yellow plastic fan on my TR3 last night. Without shimming, I have 1/4 inch clearance, with my tired old motor mounts.

I feel like that's enoungh clearance... we'll see, though, When I get my radiator back from being rebuilt!

Best, Kevin Browne '59TR3A #58370
 
Kevin -

Too danged hot to work outside much today so I didn;t get a startup.

I put in new motor mounts and shimmed 3 washers worth IIRC. I'd say I have 5/16 - 3/8 (eyeball estimate).

d
 
Back
Top