Datsun Roadster Forum-311s.org

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.

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!

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

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

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.

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.

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.

I think jt68 has a 4 blade fan.

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.

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:
Which version is correct, the ford or the chevy? (2.12" or 2.5")

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

It has 5 blades.



Been on there since at least 2006.

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.