Flex fan

Tech tips and how to's

Moderators: notoptoy, S Allen, Solex68

Post Reply
User avatar
scotty
Roadster Fanatic
Posts: 156
Joined: Sat Feb 07, 2004 3:45 pm
Location: Los Angeles

Flex fan

Post by scotty »

I've heard that the 4 blade fan is critical to avoid overheating problems even with a 3 core radiator. I was wondering if anyone has had any problems running a flex fan, and if not which one have you been using? Thanks.
User avatar
Bungle
Roadster Fanatic
Posts: 86
Joined: Sun Apr 24, 2005 5:01 am
Location: Brisbane, Australia

Post by Bungle »

Scotty, there's a bit of discussion about temp with mention of successful use of a flex fan on this link:

http://www.311s.org/phpBB2/viewtopic.ph ... sc&start=0

hope this helps!
John
'66 1600
User avatar
nismou20
Roadsteraholic
Posts: 1488
Joined: Thu Jul 07, 2005 2:16 pm
Location: Pasadena, Ca

Flex fan

Post by nismou20 »

Hi,

The only problem that I had with a flex fan was one of the blades flying off under the hood @ about 5,000 rpms ricochetting around and slicing my upper radiator hose. Other than that no prblem.

Tom
User avatar
spyder
Roadster Fanatic-Site Supporter
Posts: 2206
Joined: Tue Apr 12, 2005 1:43 am
Location: Live Oak, TX.
Model: 2000
Year: High Windshield-68-70

Post by spyder »

I think this is the one I used along with 1½ inch individual spacers. The water pump flange is pressed close to the housing and I cut off the excess pump shaft for appearance reasons.

http://store.summitracing.com/default.a ... search.asp

Part # FLX-1314
User avatar
dbrick
Roadster Fanatic-Site Supporter
Posts: 10084
Joined: Thu Sep 09, 2004 11:05 pm
Location: Kenilworth, New Jersey

Post by dbrick »

I had a spacer made for 20.00, very well done. I went with a 16" electric fan in front of the radiator, but may add a low pitch flex on the water pump. The good flex fans are rated at up to 10,000 rpm.

Dave Brisco

Take my advice, I'm not using it"

66 2000 The Bobster
64 1500 in pieces for sale
1980 Fiat X1/9
2009 Volvo C-70
08 Expedition EL, STUPID huge but comfy
1962 Thompson Sea Lancer, possible money pit
twinight
Roadster Fanatic
Posts: 85
Joined: Fri May 07, 2004 9:57 am
Location: Ladera Ranch, Ca

Re: Flex fan

Post by twinight »

I've been using one for over 2 years. picked up a 14" one from summit racing and pep boys has the 1-1/2" spacer for about $20.

best part is you can actually use a wrench on the crankshaft pulley to turn the engine over instead of having to roll the car when adjusting valves.
Geistfahrar
Roadster Nut
Posts: 60
Joined: Tue Sep 11, 2018 1:50 pm
Location: S G Valley, So Cal

Re: Flex fan

Post by Geistfahrar »

This is a very old thread, so I may not get a response. If not I will re-start the subject. So far I have found one positive reponse (spyder) and one negative (nismou20). The link to summit racing offered by spyder no longer exists, and a search of summit racing's flex fan offerings show only 6-blade models ( spyder's pix show a 4-blade ). So again I am searching for up-to-date info on recent ( since 2015 ) experience with flex fans. I am replacing the busted water pump on my 69' 2L, and I don't want to continue using my OEM 7-blade ( with spacer ) howler. In winter I have to put cardboard in front of the radiator, to get it up to temperature ( 180d thermostat ).

Thanks for any help,

Garry S.
Location Southern Cal
69' 2000 Roadster, being repaired by O/O
2001 Mercedes ML430; Was Wife's ride, now Grocery-hauler
2005 Jeep Wrangler X; Was Motor-home Toad, now local shopper
2005 33' Dolphin motor-home; Was vacation home, now guest house
User avatar
mraitch
Roadsteraholic
Posts: 3629
Joined: Mon Oct 02, 2006 7:03 pm
Location: Lake Balboa (SFV) - CA
Model: 1500/1600
Year: High Windshield-68-70
Contact:

Re: Flex fan

Post by mraitch »

I think jt68 has a 4 blade fan.
Peter Harrison
1970 1600 (Stroker) - TOAD SAN (Eliza)
1970 1600 (Stock) - As Yet Unnamed
Lake Balboa (SFV) , California
User avatar
Gregs672000
Roadster Fanatic-Site Supporter
Posts: 8983
Joined: Fri Aug 07, 2009 11:47 pm
Location: Tacoma, WA

Re: Flex fan

Post by Gregs672000 »

Consider going electric. Mine is off a Datsun 310, but there are many off the shelf options. Someone here will post something I'm sure. The electrics just work better IMHO, especially in hot, slow traffic. More room in front of the engine too.
Greg Burrows
'67 2000 #588
Tacoma, WA
User avatar
dbrick
Roadster Fanatic-Site Supporter
Posts: 10084
Joined: Thu Sep 09, 2004 11:05 pm
Location: Kenilworth, New Jersey

Re: Flex fan

Post by dbrick »

Unless the looks bother you, the electric fan works very well, as do the aluminum radiators. I put mine in front of the radiator by making a custom top bracket, 16" S blade pusher. You do need to check the amp draw.
Generally, if you can't get up to temperature in winter, your thermostat may not be fully closing. May as well change it if yours doing the water pump etc. I used this one balanced valve thermostat
Carl put a small digital temp gauge in, way more accurate than the dash gauge.

Dave Brisco

Take my advice, I'm not using it"

66 2000 The Bobster
64 1500 in pieces for sale
1980 Fiat X1/9
2009 Volvo C-70
08 Expedition EL, STUPID huge but comfy
1962 Thompson Sea Lancer, possible money pit
User avatar
notoptoy
Vendor-Site Supporter
Posts: 9677
Joined: Fri Oct 02, 2009 2:55 pm
Location: Winston-Salem, NC and Ocala, FL
Contact:

Re: Flex fan

Post by notoptoy »

Dave:
Which version is correct, the ford or the chevy? (2.12" or 2.5")
"When all else fails, force prevails!" Ummm, we're gonna need a bigger hammer here.

67.5 SPL311 H20 w/5 speed
65 Impala Convertible
2017 C43 AMG
User avatar
dbrick
Roadster Fanatic-Site Supporter
Posts: 10084
Joined: Thu Sep 09, 2004 11:05 pm
Location: Kenilworth, New Jersey

Re: Flex fan

Post by dbrick »

I think the 2.12, but it was 14 years ago :) I can measure a housing

Dave Brisco

Take my advice, I'm not using it"

66 2000 The Bobster
64 1500 in pieces for sale
1980 Fiat X1/9
2009 Volvo C-70
08 Expedition EL, STUPID huge but comfy
1962 Thompson Sea Lancer, possible money pit
User avatar
spyder
Roadster Fanatic-Site Supporter
Posts: 2206
Joined: Tue Apr 12, 2005 1:43 am
Location: Live Oak, TX.
Model: 2000
Year: High Windshield-68-70

Re: Flex fan

Post by spyder »

It has 5 blades.

Image

Been on there since at least 2006.

Image
User avatar
dbrick
Roadster Fanatic-Site Supporter
Posts: 10084
Joined: Thu Sep 09, 2004 11:05 pm
Location: Kenilworth, New Jersey

Re: Flex fan

Post by dbrick »

Only big thing with flex fans is to follow the instructions, they tell you it will need "X" amount of clearance to the radiator, plus a little bit for safety, as the blades get pulled forward, as well as flattening out at high rpm.

Dave Brisco

Take my advice, I'm not using it"

66 2000 The Bobster
64 1500 in pieces for sale
1980 Fiat X1/9
2009 Volvo C-70
08 Expedition EL, STUPID huge but comfy
1962 Thompson Sea Lancer, possible money pit
Post Reply