Fan Type?
 

Should i run a high rpm flex fan or go with a clutch fan? I still have the factory 4 blade steel fan on and with the cam change it now runs a bit hot for my likin. Just wanted some opinions.

Re: Fan Type?
 

I switched to a flex fan from a clutch fan on my vette and it dropped 10-15 in traffic. I don't know what the difference would be on a truck but I plan on putting one on my 68.

Re: Fan Type?
 

Flex fans are a bad idea, fins can fly off at normal highway speeds, the plade wil slice right through the sheet metal, and if your head is there (tuning and reving) it'll cut through it just as fast.
GM used to use flex fans, but there was a huge recall on itfor these same reasons.

If your eng temp dropped after putting on a flex fan, then your fan clutch was out to lunch. As far as engine driven fans go, a thermostaticly controlled clutch will conserve more power, and control the temp better than a flex, a fixed fan, or a non thermostaticly controlled unit.

Re: Fan Type?
 

:agree:
I wouldnt use a flex fan. had one on my 3/4 ton it broke & went right through a 400.00 cowl ind hood. I went & bought a clutch & put the clutch fan back on the next day.

Re: Fan Type?
 

Definitely avoid flex fan, go with clutch fan. Check this thread http://67-72chevytrucks.com/vboard/s...ht=flex+clutch

Re: Fan Type?
 

Link

Here's a link I posted on another thread about flex fans.

Mike

Re: Fan Type?
 

How about going with an electric fan out of a Volvo? Friend has a Bronco with a 460 and could not keep it cool enough. Put this fan on and it will literally suck a sheet of paper out of your hand and stick to the grille.

Re: Fan Type?
 

for pure cooling power, it is hard to beat a mechanical fan. For run of the mill stuff, a generic electric fan will do the job, but personally I've replaced too many blown head gaskets from failed fans, not just 80's stuff either, plenty of fairly modern vehicles too.

Re: Fan Type?
 

I now know first hand, the thermal fan clutch is much better than the flex fan. I had a flex fan on before, and at speed, it was noisy, like a jet about to take off. With the thermal clutch, you don't hear the fan, I have not had any overheating on these 102 degree days (and I'm even using a smaller radiator than I had before), and my highway milage has gone up 1-2 mpg.

Keep in mind, though, that if you don't have a fan shroud, the thermo clutch fan might not work as well as it should. But I'd much rather have the shroud and a clutch fan over the flex fan again.