Possible mechanical fan option...

[Hans]

In my excessive digging, found an interesting part

Flex-a-lite #851 and #852. They are adapters to convert clutch-fan systems to a direct drive mechanical fan (I.E. No clutch) They are both the same part in 30mm x 1.5 threads, one is standard threading, the other is reverse. They are priced at $43 at Summit, plus you would need a fan and most likely a spacer too. But it might be a good option for uprating the airflow through the radiator.

Now, anybody know the threading on the nose of the water pump? Or do I have to take a chance?

-Hans

[Bowtracer]

I'll check tomorrow!

[Hans]

Cool, thanks. If I can get a solid "yes/no" on the threading, I will be more than willing to give this option a go and report back. If the adapter fits, then I'll order it and start trying different fan options and such.

-Hans

[JBurt]

I was gonna volunteer if Peter can't get it to you (but I'm out of town right now). I just happen to have a water pump on my front porch...I'm sure I can fix it, ha ha ha, but at least I'm gonna try.

[Bowtracer]

The threads are 1.5 mm I am not sure of the 30mm measurement.

[Buckon37s]

I would not do this if this is what I think it is. No fan clutch robs HP and puts serious stress on both the engine and the fan. Really not a good idea.

[Hans]

Well, if the adapter fits, you don't necessarily need to run a non-clutched fan. If it's really M30x1.5 threads (which is looking more to be the case if it's definitely x1.5) then it's a standard pilot. I'm also planning on trying to source some direct-fit clutches as well for those who want them. Hayden has a really comprehensive listing in their catalog, there's GOT to be a cheaper way to do it. It might mean replacing both the clutch AND the fan, but the goal is cheaper and better even in that case.

That being said, the Buick/Rover V8's were run for 20 something years with direct fans until the mid 1980's. As long as you use a fan rated for a high enough RPM range, you'll be fine. I honestly wouldn't mind the 2-3hp loss in this case, since it means one less part to fail which can be almost impossible to diagnose. Plus, it won't be running at a reduced speed like a fan-clutch, and will have a lot bigger blade area. It's a compromise, but which one you choose depends on what you use the truck for.

It's all about having options. But what I would REALLY like to find is a spec sheet for the factory fan-clutch that shows all the critical measurements. That would make things a lot easier.

-Hans

[Hans]

Ok, got the deal on this one. Bad for me and other V-belt guys, good for the serpentine belt folks I think.

The V-belt V8's appear to have an M24x1.5 theading on the water pump nose. The only other cars with that threading are BMW's, which are even pricier. Well, damn... that sucks. But flex-a-lite does do some custom work, so I might ask them about doing an M24x1.5 adapter. Either that, or a couple machinists I know might be into it. If anybody wants in, let me know.

BUT. For the serpentine belt crowd, it appears you guys ARE the M30x1.5 threads (reversed rotation). There are piles of viscous and thermal clutches out there for you guys, as well as upgraded fans... etc... etc... etc... Seems it was the standard threading for Ford and Mopar.

-Hans

[Cmikefly]

Hi,

I was just reading over this old post and was wondering if anyone has confirmed that that the 30 x 1.5 fits on a 97 and what the result was.
thanks

[Hans]

Unfortunately I never dug further into this one, and ended up going with an electrical flexi-lite 210 setup in mine. Since I don't have access to a '97 truck to do the measurements on, there isn't much I can do to push any further.

-Hans