MX5 -NA6 radiator thermofans

TOPCAT · Postby **TOPCAT** » Sun Mar 17, 2013 8:39 pm

Does anyone know how many CFM (cubic feet per minute ) airflow the two fans produce when operating .Specified CFM not a guess !
My MGTC radiator finned area will only accept one single fan which needs to be the equivalent CFM airflow of the two on an MX5 .
This is part of my mod to fit anMX5 engine into my 1948 MGTC
TOPCAT

Postby **NitroDann** » Sun Mar 17, 2013 9:03 pm

Mx5s only have one cooling fan, so just use one stock cooling fan

Easy.

Dann

emily_mx5 · Postby **emily_mx5** » Mon Mar 18, 2013 2:28 pm

Some mx5's have 2 fans.
The 2nd one is for aircon

Postby **NitroDann** » Mon Mar 18, 2013 2:41 pm

To be fair they have 3.

Cooling fan on radiator

Air con condenser fan next to it, which turns on when the air con is turned on.

Cabin fan for blower use.

So in the end 1 cooling fan.

Dann

TOPCAT · Postby **TOPCAT** » Mon Mar 18, 2013 10:48 pm

Thanks Emily & Nitrodann
Still don't have the answer to my question re specification CFM airflow for the 2 thermofans which are fitted as standard to an MX5 radiator for cooling the engine depending on what amount of cooling is required .ie (with or without the aircon operating ) My question still relates to the radiator cooling fans & not how many fans are fitted to an MX5 in total .
My problem is that the MGTC has a radiator finned area only a third as wide as the MX5 radiator & I have some serious space restrictions in trying to fit in a single thermofan with sufficient CFM to cool the engine from a smaller finned area than the MX5 radiator . It is physically not possible to fit 2 smaller fans and 2 fans are also not as efficient as one larger diameter unit . Therefore I still want to know the specification CFM figures for the 2 fans before I buy a larger CFM capacity single fan .
Incidentally the aircon system in my TC is the hood down for more airflow over you regardless of whether its summer or winter !
Thanks again
TOPCAT

Postby **NitroDann** » Mon Mar 18, 2013 10:57 pm

Ah ok, I thought you were using the stock radiator.

Dann

TOPCAT · Postby **TOPCAT** » Wed Mar 20, 2013 10:08 pm

emily-mx5 and nitrodann
An ex MGTC owner and longterm MX5 NA6 owner from 1989 sent me this info on stock /standard cooling fans today .Thought you both may be interested .
Stock radiator cooling fan: 1400CFM.
Air conditioning radiator cooling fan: 1320 CFM.
Total cooling :2720CFM airflow produced with both fans running . Apparently even this isn't enough for serious competition or high speed highway work with the standard radiator and fan setup in hot weather from the info that I have been sent.
Regards
TOPCAT

manga_blue · Postby **manga_blue** » Wed Mar 20, 2013 10:15 pm

I ran my MX5 1.8 for years in serious competition with no fans at all and a stock radiator. Airflow through the radiator at any speed over about 20kmh far exceeds the airflow from a fan. The fans are only needed to provide airflow when the car is stationery or stuck in slow traffic. All I ever had to do was watch the temp gauge when waiting on the grid.