Steel vs. Plastic fan : MGB & GT Forum : The MG Experience

Steel vs. Plastic fan #1 This topic is about my 1973 MG MGB
Tuscan1778 Dave Giovannini Aberdeen, SD, USA Sign in to contact 1973 MG MGB	Topic Creator (OP) Mar 24, 2017 09:22 AM Joined 8 years ago 166 Posts

Wondering if anyone has preference for either the Steel or Plastic fan? Anyone notice any performance differences? Or is it a foolish question?

Regards,

Tuscan Dave

Reply

Was this post helpful or interesting?

Yes No Thank

Re: Steel vs. Plastic fan #2
dickmoritz Dick Moritz Philly 'burbs, PA, USA Sign in to contact	Mar 24, 2017 09:24 AM Top Contributor Joined 14 years ago 26,273 Posts

The yellow plastic 7-blade fan is far more efficient and quieter than any of the metal fans, and does not have the tendency to throw blades through your bonnet... eye popping smiley

Dick

Errabundi Saepe, Semper Certi
(Often wrong, but always certain)

Reply

Was this post helpful or interesting?

Yes No Thank

Re: Steel vs. Plastic fan #3
dawvid David B Sharon, MA, USA Sign in to contact 1974 MG MGB GT	Mar 24, 2017 09:56 AM Top Contributor Joined 9 years ago 1,893 Posts

The 3 blade metal fan is the quietest of the lot but not as effective at cooling.

74 Damask Red BGT
Davesmg@outlook.com

Reply

Was this post helpful or interesting?

Yes No Thank

Re: Steel vs. Plastic fan #4
Engineered Doug W Hemel Hempstead, Hertfordshire, UK Sign in to contact	Mar 24, 2017 10:10 AM Joined 11 years ago 56 Posts

You can lose careless fingers in the metal three blader, whereas the plastic one will just give you a nasty - "don't do it again" - whack.

Plus, I understand the three blade fan has a propensity to shear and throw a blade, which at high speed could damage the bonnet/hood.

I've replaced mine with an electric fan which (apparently) liberates an extra bhp or two - not that I've noticed, but it is certainly quieter sans fan.

Dougie - Hertfordshire, England.
'67 Mk1 Tartan Red Roadster

Edited 1 time(s). Last edit at 2017-03-24 10:11 AM by Engineered.

Reply

Was this post helpful or interesting?

Yes No Thank

Re: Steel vs. Plastic fan #5
Donthuis Don van Riet Rijswijk, ZH, Netherlands Sign in to contact 1972 MG MGB MkIII	Mar 24, 2017 11:40 AM Top Contributor Joined 10 years ago 13,336 Posts

I never had any problems with my later type metal fanblade (not the early 3 blade) , after converting to electrical fan(s) no longer use it.
It sits under my spare wheel "just in case" all electrical fans fail. Maybe I am a bit paranoid on this issue grinning smiley

Reply

Was this post helpful or interesting?

Yes No Thank

Re: Steel vs. Plastic fan #6
Fogliner Mark Vanherd Port Clements, BC, Canada Sign in to contact 1974 MG MGB	Mar 24, 2017 12:48 PM Top Contributor Joined 13 years ago 2,298 Posts

I dont trust metal fans after my 63 ford econoline threw a blade and it came through the side of the center engine box under the passenger seat.
Imagine leaning over the engine reving it with the throttle cables and having it throw a blade.

Reply

Was this post helpful or interesting?

Yes No Thank

Re: Steel vs. Plastic fan #7
dohc281 Ira Eckstein Laurel Springs, NJ, USA Sign in to contact 1967 MG MGB 1973 MG Midget MkIII 1998 Ford Mustang	Mar 24, 2017 01:08 PM Top Contributor Joined 16 years ago 2,362 Posts

My list of things to do to my B include replacing the 3 blade metal fan on the car, Unfortunately this is not high on the list.

If you hit your pony over the nose at the outset of your acquaintance, he may not love you, but he will take a deep interest in your movements ever afterwards.

Rudyard Kipling

Tact is the ability to tell someone to go to hell in such a way that they look forward to the trip.

Winston Churchill

Reply

Was this post helpful or interesting?

Yes No Thank

Re: Steel vs. Plastic fan #8
64-MGB Ron S keller, TX, USA Sign in to contact 1964 MG MGB	Mar 24, 2017 01:37 PM Joined 9 years ago 39 Posts

The six blade steel on my 64 is happily churning away after 53 years. as for the metal being more dangerous... well...ummm... I don't put my fingers near it while running. Is it just me?

Reply

Was this post helpful or interesting?

Yes No Thank

Re: Steel vs. Plastic fan #9
RAY 67 TOURER Ray Marloff Fort Bragg, CA, USA Sign in to contact 1967 MG MGB "My Girl"	Mar 24, 2017 01:40 PM Top Contributor Joined 14 years ago 17,490 Posts

Same as Ron. RAY

Reply

Was this post helpful or interesting?

Yes No Thank

Re: Steel vs. Plastic fan #10
Steve S Abingdon, So Cal, USA Sign in to contact 1925 Ford Model T 1937 MG SA Saloon 1939 Ford V8 1946 Other Not Listed & more	Mar 24, 2017 01:51 PM Top Contributor Joined 19 years ago 22,379 Posts

I've personally found that the key with old metal fans is to inspect them regularly. Look for stretch marks near the base of each blade. Not only does this indicate a weak blade but probably points to an imbalance that is doing your water pump no favors. Plastic fans can break apart when old also, but with less disastrous results. I've thrown a metal blade once on a 60-year-old MGA fan and it was scary. Felt like a piston went sideways! Very luckily, no damage. Installed a new (metal) fan and the whole engine ran much smoother.

Reply

Was this post helpful or interesting?

Yes No Thank

Re: Steel vs. Plastic fan #11
ingoldsb Terry Ingoldsby Calgary, AB, Canada Sign in to contact 1971 MG MGB	Mar 24, 2017 02:04 PM Top Contributor Joined 20 years ago 20,146 Posts

The steel fan is fine right up 'til it throws a rivet and a blade goes through your bonnet! I ran my steel fan for decades - not a single problem. But when I thought how much it would cost fix my hood IF it went, I switched to the plastic fan.

The plastic fan is also supposed to draw more air. In theory, the lower mass should mean that the engine would spin up faster but I think that would be by an infinitesimal amount.

Terry Ingoldsby
terry.ingoldsby@DCExperts.com

Reply

Was this post helpful or interesting?

Yes No Thank

Re: Steel vs. Plastic fan #12
mvheim Mark Heim CA, USA Sign in to contact 1966 MG MGB "Uroboros"	Mar 24, 2017 06:20 PM Top Contributor Joined 18 years ago 1,927 Posts

The power "cost" of the fan is probably based on how much air it pushes, not its weight, I would say. So the 3-blade, which barely churns the air at all, is probably not costing much power. I find it adequate at engine speeds above idle, but I would like some extra margin of cooling in slow traffic, this being CA. So I have a plastic fan and shroud to install for summer.

Max Heim
'66 MGB "Uroboros"

Reply

Was this post helpful or interesting?

Yes No Thank

Re: Steel vs. Plastic fan #13
dickstag dickstag Stagnone Holbrook, MA, USA Sign in to contact 1966 MG MGB "Unknown MGB" 1973 MG MGB 1973 MG MGB "Mellow Yellow" 1974 MG MGB MkII "Ms Violet"	Mar 28, 2017 08:43 AM Joined 11 years ago 476 Posts

I agree, had personal experience with a blade breaking off a steel fan. Sad day...

Reply

Was this post helpful or interesting?

Yes No Thank

Re: Steel vs. Plastic fan #14
tkamd73 Tim Bradley Menomonee Falls, WI, USA Sign in to contact 1973 MG MGB MkIII 1974 Triumph TR6	Mar 28, 2017 01:41 PM Top Contributor Joined 13 years ago 1,237 Posts

There is a TSB concerning the metal fan on your 73, which directs the dealer to replace the metal fan with the plastic one, if needed. I also have a 73, and after a friends 72 threw a blade thru the bonnet, I figured it was cheap insurance and replaced mine. I have a printed copy of the TSB, but the exact same one is elsewhere on this site. I did like the look of the metal one, and is was quieter, but I like my original bonnet, with the original paint better. Tim

Edited 1 time(s). Last edit at 2017-03-28 01:57 PM by tkamd73.

Reply

Was this post helpful or interesting?

Yes No Thank

MGB & GT Forum

Steel vs. Plastic fan

To reply or ask your own question:Members Sign InorCreate an AccountRegistration is FREE and takes less than a minute

To reply or ask your own question:

or

Registration is FREE and takes less than a minute