Custom fan pulley

[324darrin]

You folks might find this story a bit interesting even if the subject matter is not original Darrin equipment.

My wife's uncle bought our Darrin in 1963 after it had been modified to a V8. The entire job was pretty cobbled together and I am dealing with that aftermath now. One of the things that Uncle Ray thought needed changing was the distance from the fan to the radiator. He felt that it was too far away, and his thinking was not faulty but his solution was rather unusual. At the time he was working in the Aerospace Industry as a machine tool programmer. He decided to write a program whereby one of his machinist buddies would make a new fan pully that was about 2 3/4" longer than the stock pulley.  So far so good. He "found" a cylindrical piece of Inconel 718 with which to create this new part. For those that are not familiar with this material, it is a austenitic nickel-chromium-based superalloy. This translates to EXPENSIVE and very heavy! He almost lost his job over that piece of "government work". Here is the million dollar question for you gearheads. The stock pulley weighs a little less that 2 pounds but the new improved part weighs 7 pounds 12 ounces. Although I would love to retain the custom pulley because of the back story, my fear is that the water pump bearing would take a beating in short order. If I don't use the custom pulley, I will have to figure out how to move the radiator a bit closer to the fan. What are your thoughts about fan to radiator clearance? Thanks, Steve,  Darrin number 3

[MarkH]

Go with it, the story is too good. Reminds me of a very similar story an old finisher told me about a co-worker
"acquisitioning" a slab of unusual black material for a hand float during the build of an "atomic plant" in the '50's.

I'm guessing it was machined well, so it should be balanced and not exerting any dynamic load on the bearing. Barring any imbalance issues it's just the weight hanging on the bearing. You could have one made of aluminum like ones I've seen on GM engines.

 I have heard that a bicycle wheel mounted on a scale exerts less downforce (weight) while spinning, compared to when it's at rest, but I can't confirm that's true. It's possible your spacer doesn't bear against the bearing at speed as much as you might think.

[324darrin]

Two take-a-ways from the responses so far. First, thank you MarkH for you great reply. I was leaning toward using the custom pulley so I am going to go with it. The second take away is a question. what in the hell does an extra hood have to do with anything that is being discussed. Jake or Chris or whoever, do you just have to throw in a comment for every post? Use some restraint. Steve

[joefrazer]

I would use the pulley. It has a story all its own and will only enhance the unique qualities of your Darrin. The extra hood, however, would not!

[njpatera]

Nothing to do with this thread! Put it in parts for sale🤔

[Gordie]

Jake has wisely pulled his offer of a hood for sale so don't wonder what the hood comments are about.

[Terry T]

Jake has wisely pulled his offer of a hood for sale so don't wonder what the hood comments are about.

an often used trick to confuse

[jake]

Jake has wisely pulled his offer of a hood for sale so don't wonder what the hood comments are about.

an often used trick to confuse

You must be confuse. I sold stuff to 5 different  state last month..  I never post some of the stuff..They just called me.

[Thomasso]

Why wouldn't the uncle or you just use a fan spacer?

[MarkH]

…………………….. At the time he was working in the Aerospace Industry as a machine tool programmer. He decided to write a program whereby one of his machinist buddies would make a new fan pully that was about 2 3/4" longer than the stock pulley.  So far so good. He "found" a cylindrical piece of Inconel 718 with which to create this new part. For those that are not familiar with this material, it is a austenitic nickel-chromium-based superalloy. This translates to EXPENSIVE and very heavy! He almost lost his job over that piece of "government work"...…………….

Next time you're in the shop, snap us a photo of what might be the most expensive Darrin pulley on the planet!

[324darrin]

Here’s the Olds 324. Yes, that shiny fan pulley was machined from a solid cylinder of Inconel 718.

[MarkH]

That's just a cool story, and part. Apparently it's been working well but if the weight keeps you up at night a good machinist could likely drill or mill quite a bit of mass off. Either way I'd definitely keep it.