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BJ8 Radiator Fan

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J

John_Progess

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The Moss Texas cooler fan on my BJ8 came apart. Is there something else better for sale?

I tried a flex fan but it was too noisy. Is the Denis Welch red plastic fan any good?

Thanks for the help and have a good day!

John
 
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Re: BJ8 radiator fan destroyed

John, How old is your Moss 'Texas Cooler?' I bought one from the Texas Healey club that sold them originally, and it's going strong after (approx.) 15 years and 80K+ miles. I heard there was a bad batch and that Moss refunded at least some owners--you might look into that--but that they had a new 'version' that supposedly was more robust.

Agree on the flex fan; they work best for keeping coolant temps down, but sound like a Cessna at idle. At least, it doesn't sound like your self-destructing fan damaged your radiator, which a flex fan can surely do (speaking from experience).


Bob
 
Re: BJ8 radiator fan destroyed

HI Guys:
Yeah that sounds like an after MKT fan that broke, The original Texas cooler was made by one of USA "s most experienced manufactures.

However , to keep fan noise down make sure the fan uses an unequal number fan blades.
 
I replaced the original fan with one from British Car Specialist about 2007 or so ..six blades,metal..car has stayed normal temp in traffic ever since . not sure what to say about fan noise since Healeys are loud anyway .
 
I still use the original 4 blade fan. I am curious if the total surface area of the replacement fans blades is greater than the original. It seems to me that the more surface area would be the factor that determines how much air is pushed rather than the number of blades. (I don't generally have a problem with over heating). And the noise level is not a factor with the original. I do check the rivets often as I have heard some horror stories of them coming apart.
 
I think it's more complicated than surface area and number of blades. I say that because wind turbines have few thin blades. One reason for the original fans not being that noisy is that the blades are not evenly spaced. I have an original Texas Kooler and a Spal electric fan. The Spal has evenly spaced blades and is quite noisy. Of course, being in front of the condenser makes it louder.
 
I think blade pitch has the most effect. This is why flex fans have higher-curved blades at slower (engine) speeds, to pull more air through the radiator, then flatten out at higher speeds to put less load on the engine and allow more airflow through the radiator. More blades are better, up to a point, but each blade disturbs the airflow of the blade following it*, reducing efficiency. Many (most) fans have non-uniform spacing between the blades to mitigate harmonic noise and vibration.

* In theory, at least, a single-bladed propeller, is more efficient than one with two or more blades (but never caught on for some reason):

http://www.rexresearch.com/unibladeprop/onebladeprop.htm
 
John Turney said:
...being in front of the condenser makes it louder.
Click to expand...

John,
That's interesting - wonder why that is.

I converted my TR6 to electric-fan-only with a puller straight-blade Spal fan. I can hear it at idle, but not when driving. Straight blades are supposed to be more efficient than curved but noisier. Yours may be a higher-amperage than mine - more power, more noise.
 
Being in front of the condenser (on my car) means that the sound is not deadened by the radiator and condenser. Our modern cars have the electric fans behind the radiator and are much quieter. My Spal is a curved blade with ~22-amp draw.
 
I don't think I have read anything here about the utility of a fan shroud of the type offered by British Car Specialists ($69.95) in helping control engine temperature. I have a Texas "cooler" type fan on a BN7 and fabricated a 3 or 4-" deep sheet aluminum shroud around the top and sides of my rebuilt radiator but still get concerning temperatures in slow traffic during north Florida's hot weather. I also have an air scoop of the type Steve G. has described and attempted to make the barriers he has designed for either side of the radiator to reduce hot air from the high-pressure engine bay from exiting on the sides and then going back through the radiator, reducing efficiency. That was too challenging for me. The fan shroud--it has a circular cut out in the center for the fan blades--was suggested to me by a fellow AHCA club member who has a great deal of experience with Healeys. I've already ordered a higher temperature thermostat (currently a 160 degree one) in anticipation that the new shroud will work. Earlier I purchased a Chinese-made aluminum radiator from a U.S. source but eventually decided it was no better than my original rebuilt radiator. The Chinese product was very susceptible to damage. It seemed well made and included the fitments, including the short shroud at the top, but it was a bit high. With the radiator at is lowest position, the outlet hose at the bottom touching the frame, the radiator cap on that unit rubbed the brace on the underside of the hoot. I wasn't comfortable with that. If and when my shroud arrives, I will report back on whether it works once the really hot weather returns. By the way, the blades on my fan appear to be fiberglass riveted to a metal center section. I have no idea of the fan's origin as it came with the car.
 
When I restored my BJ8s I bought a used original four blade metal fan , separated the blades and added a third section to my originals to create six blade fans .
However the best way I improved engine cooling was to recore the radiator with an extra pass in the core for more cooling surface area .
 
On my BJ8, I have:

- 4-row 'excel' re-cored radiator
- freshly rebuilt, hot-tanked block and head
- correct mixture and timing
- BCS fan shroud
- original Texas cooler fan
- rebuilt, calibrated 'safety' (OP/temp) gauge

The one, and only, thing that made a significant change in engines temps, esp. at idle, was a 7-bladed SS flex fan I installed along with the shroud. I took it out because it made too much noise and blew dust out from under the car at idle (at speed, the blades flatten out and you can't hear it). I may put it back in someday. Curiously enough, my BN2 with re-cored radiator but stock fan behaves exactly the same as the BJ8 WRT engine temps.
 
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