jjokrm

Hey everyone. I'm going to replace my mechanical fan blade on my 68' cutlass 350 and was looking at going with a Nylon Flex-a-lite blade. Does anyone on here have any experience running a nylon blade? Are they good to use for standard driving conditions (car only driven in spring & summer and not raced). Reason I was looking at the nylon blades is because they are light weight and good for 8,000 rpm as opposed to the standard steel hub/stainless flex blade replacements I've found that are 6+ pounds and good to 6,000 rpm. Can you guys weigh in and help me decide! Thanks!

oldcutlass

I use something along these lines:

http://www.summitracing.com/parts/mrg-1980/all

http://www.summitracing.com/parts/der-19818

M-14

This is really hard to beat, cools good & doesn't use much power.

joe_padavano

Flex fans suck (or more correctly, DON'T). Use the clutch fan shown above.

MDchanic

Why?

So you're saying that under "standard driving conditions" you rev your SBO close to 8,000 RPM?

Man, I wanna meet you.

Smoooooooth post of the year award.

- Eric

jjokrm

No, I'm not saying that. I actually have no idea what it revs since it has no tach
I just wanted something light weight......less rotating mass, less stress on the water pump bearing...etc.

MDchanic

You can install something lightweight that will work badly, or you can keep something heavier that a very large corporation with huge research and testing resources paid hundreds of engineers millions of dollars to develop.

Your choice.

- Eric

jjokrm

So flex fans don't cool well.....Why does the clutch fan cool better? Didn't these cars come standard with clutch fans? My 68' doesn't have the original Rocket 350 and somebody down the line put a 16" fan blade on it which is too small if you ask me.

Lady72nRob71

The clutch fan had a very deep pitch (like 2.5") designed to move huge volumes of air. The thermostatic clutch engaged it only when needed, like idling along on a summer day. They were installed mostly on A/C cars or those with heavy duty cooling systems.
If yours has a 16", it might be a bit small. Flex fans usually do not have a deep enough pitch to move enough air.

jjokrm

.....nice. Thanks for the words of wisdom. So would you recommend a clutch fan or something like this........

http://www.autozone.com/autozone/par...267104_9123_0_

jjokrm

Thanks Rob.

MDchanic

Either an original clutch fan, or a good quality electric fan, such as one from a late-model production car (others who have done the swap will know the best models), if you want to do a bit more work and have a bit less originality.

- Eric

krooser

I have used a flex-a-lite nylon fan on every one of my circle track cars in the 70's and 80's.... plus on some of my tow vehicles. They work great, are ez on the water pump bearings and my newest 330 powered dirt car will get one as well.

There's a circle track parts manufacturer here in WI that even makes thin spacers for these fans so they can be shimmed to get closer to the radiator. Evidently there are a lot of circle track guys using them on pavement cars.

Excellent product IMHO.

jjokrm

Thanks! Looks like I've got a decision to make........ Thanks again guys for all of your feedback. I really appreciate it.