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Lotus Europa Forums => Garage => Topic started by: europaspecial73 on Tuesday,April 22, 2025, 01:48:30 AM

Title: Radiator cooling fan motor RPM
Post by: europaspecial73 on Tuesday,April 22, 2025, 01:48:30 AM
Hello!
 
I'm planning on replacing the original (at least by the looks of it  ;D) radiator cooling fan motor for my -73 TCS, any idea what's the RPM for the stock motor?

The one I'm currently looking at has 4200 rpm  :o
Title: Re: Radiator cooling fan motor RPM
Post by: 4129R on Tuesday,April 22, 2025, 06:00:59 AM
I believe if you look hard enough, you can find direct replacements for the original motors.
Title: Re: Radiator cooling fan motor RPM
Post by: RonPNW on Tuesday,April 22, 2025, 06:01:06 PM
If originality is not important you might go with a more modern lighter 11" SPAL fan (30102040). It seems to push more air.

Ron
Title: Re: Radiator cooling fan motor RPM
Post by: 314159td on Tuesday,April 22, 2025, 10:39:23 PM
Just about 2000 rpm, running off a 12.5V battery. Don't have a wind speed meter here.
This is an original Ducellier 4-blade fan, same as used on the Renault 16 (https://live.staticflickr.com/105/305390085_396ba6bc68_b.jpg). Parts manual page for the Europa (http://www.lotus-europa.com/manuals/s2parts/k/index.htm).
Title: Re: Radiator cooling fan motor RPM
Post by: jbcollier on Thursday,April 24, 2025, 02:11:27 PM
I thought TCs used a different rad fan.  The S1/2s use the R16 unit which they run backwards as it originally was a puller.  The curvature of the blades are not designed to push so efficiency is way down.
Title: Re: Radiator cooling fan motor RPM
Post by: BDA on Thursday,April 24, 2025, 05:13:13 PM
You're right. I've seen S2 (and S1?) fans with a cast aluminum frame. The TC fans had a sheet metal frame with shroud. I would assume the motor was made by Smiths but I no longer have the one that came off my car so I can't be sure. I found some old pictures though.
Title: Re: Radiator cooling fan motor RPM
Post by: jbcollier on Thursday,April 24, 2025, 07:28:30 PM
Hmm, not sure on that.  If you look at the wiring diagram you’ll see that the motor is wired red to ground and black to positive to get it to be a pusher.  Do it must be an original French motor.

As an aside, this was a cause of high speed overheating.  People would wire up the fan the “right” way and it would run as a puller.  Works great when stopped or just trundling along.  Get it up to speed and not so great.  The force of the air from the vehicle speed would work against the fan and effectively stop air flow through the rad!
Title: Re: Radiator cooling fan motor RPM
Post by: Clifton on Friday,April 25, 2025, 12:24:15 AM
Spal makes a similar style/looking fan. I've run 3 different Spal's of the same diameter and this style moves an incredible amount of air compared to some of the other Spal's. Amp draw is high but so is the flow. Derale also makes high flowing fans.

Punch in your diameter
https://luefter-vertrieb.de/en/catalog/?durchmesser=280
Title: Re: Radiator cooling fan motor RPM
Post by: BDA on Friday,April 25, 2025, 06:53:16 AM
Well, you got me, JB. I thought that fan came from my car but I might have gotten from a third party. I can’t explain the wire colors but my memory is that this is the stock fan and shroud arrangement. But then we already know how good my memory is!  :-*