Fixed fan conversion for IDI

[jwalterus]

Yes. It's a *******. You can find that tap in right hand thread but my casual browsing has yet to turn one up in left hand thread. I'm not personally enough of a machinist to turn my own threads.

http://www.gaugestools.com/1-1-4-16-un-tap-1-1-4-16-un-thread-tap-hss-bottom-lead-tap/


I deal with these guys on all my specialty taps, they take a while to get to you, and if you're expecting a cheapo...... guess again......
They are a supplier for major manufacturing operations, you'll be paying a serious premium if you're buying less than 10.......
Also, remember, you're talking about a $100+ tap in a cheapo at that size, that's why I use a lathe

 

[franklin2]

I have posted this before, this does work long term. A little noisy over 2000 rpm and I am sure it costs a little hp which is hard to give up on these engines, but it does work. Haven't overheated yet pulling loads up long hills.

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[CDX825]

All the big trucks use poly fans now it seems. The have many blades and are spaced closer together than our factory fan. I think if you could find something like that for our application it would move more air.

 

[MTKirk]

I have posted this before, this does work long term. A little noisy over 2000 rpm and I am sure it costs a little hp which is hard to give up on these engines, but it does work. Haven't overheated yet pulling loads up long hills.

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Yeah I saw that, and that will be my fall back plan. Good idea as the fan can't unscrew itself then. I suppose if you made all the metal pieces weigh the same you shouldn't hurt the balance to bad. Did you bolt on the angle tabs, install on the truck, then weld the angles together?

I think it would be advantageous to be able to run a lighter fan with slightly less output (maybe even a flex fan) if it's going to be on 100% of the time. With the stock fan you'll likely be constantly cycling your thermostat (perhaps wearing it out sooner), and spinning a lot of extra weight.

 

[franklin2]

Yeah I saw that, and that will be my fall back plan. Good idea as the fan can't unscrew itself then. I suppose if you made all the metal pieces weigh the same you shouldn't hurt the balance to bad. Did you bolt on the angle tabs, install on the truck, then weld the angles together?

I think it would be advantageous to be able to run a lighter fan with slightly less output (maybe even a flex fan) if it's going to be on 100% of the time. With the stock fan you'll likely be constantly cycling your thermostat (perhaps wearing it out sooner), and spinning a lot of extra weight.

I marked and drilled the holes, then mocked it up under the bolts and then marked it with a sharpie. I then took it off, lined up the sharpie marks and welded it. It is a heavy fan, and it doesn't do anything bad with the thermostat in the summer, but I do slip a piece of thin OSB in front of 1/3 of the radiator to help it warm up quicker in the winter.

 

[MTKirk]

So I ordered one of these https://www.flex-a-lite.com/accesso...spacers/thread-on-fan-spacer-and-adapter.html on Amazon.

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The plan is:

#1 find out for certain whether the thread fits or not.

#2 if thread doesn't fit, look into the feasibility of welding, or other wise attaching the big nut from a IDI fan clutch to the adapter.

#3 if #2 doesn't work, look into the feasibility of welding, or other wise attaching a four bolt flange to the nut side of the adapter, thus allowing the adapter to be bolted to the water pump pulley.

 

[laserjock]

It won't fit. The IDI water pump is standard not metric. 1.25 - 16 LH

 

[jwalterus]

It won't fit. The IDI water pump is standard not metric. 1.25 - 16 LH

unless you have the tap, then you could re-tap it to 31.75-1.588 metric

I'll save you some pain with your #2 idea....
both it and the nut are S2 tool steel, you'll HAVE to use H12-13 rods to weld it, otherwise it'll create a failure point in your weld, you could get away with E312+ rod, but it'd be a softer surface
and I should mention, if you've never welded tool steel, DON'T in this application, very specific pre-heat/post-heat requirements, you have to anneal first then re-harden it to be safe

take a junk set of large allen wrenches and practice if you're going to try it, same material

 

[jaluhn83]

Yes, I have an electric full lock up clutch. I love it. Mine is actually not a Horton, it's some German company. It actually works a 2 speed setup using a set of permanent magnets to provide a small amount of drag for a low speed and then a full lock up via an electromagnet. Basically the same setup as the AC compressor clutch but a touch bigger.

There is a Horton part number for an IH app idi that has the correct LH thread. I had to make an adapter insert on mine because it looks like it was mis boxed - the Horton part number very clearly specs a LH thread, with a different part number for the RH PSD clutch. The number on mine crosses to the idi LH one, but the thread was actually RH.

Making the adapter was fairly easy on the lathe. I did have to take the clutch completely apart which was fairly easy on mine. I have not laid eye on the Horton setup but I expect it would be about the same. Once you have it apart it's a fairly straight forward operation to machine it out, make an insert, weld in and then cut a new thread. I do not think it could be done without a lathe though. That thread has to be concentric and full depth - too hard to get it accurate without the lathe and a tap is going to be tapered (not full depth) unless you get a regular and a bottoming tap and use both.

Biggest problem with using the Horton clutch is the fan backspacing - the IH app puts the fan about 2" further forward, so the Horton clutch does the same - basically it mounts where the front of the stock clutch is vs the back of the clutch flange. On my clutch I was able to mount the fan in essentially the same way because of the clutch design but I don't think you can with the Horton. I do believe I had found a Horton fan that would fit though, IIRC it was something like $200.

I had also looked at adapting some other type of fan clutch probably to mount on the pulley flange but would need some custom fab work to do that as well. Biggest problem is likely to again be the fan back spacing - the truck is very tight here and most other apps have more room.

IMHO the best option for a fully locked up fan would just be to fill the clutch up with silicone fluid.

 

[jaluhn83]

Filling stock clutch

http://www.oilburners.net/forums/showthread.php?64852-The-4-fan-clutch-fix&highlight=fan+clutch

Horton thread

http://www.oilburners.net/forums/showthread.php?70947-Electic-Fan-Clutch&highlight=fan+clutch

 

[franklin2]

Did someone mention in this thread, or in another thread some time back, that these engines installed in a different application(school bus, u-haul, don't remember) used a straight bolt up fan, no weird thread on deal. The international dealer carry's that waterpump I believe?

 

[Dieselcrawler]

One major issue you guys keep forgetting. Everyone wants to put on a flexlite style fan. Well yes that would work if you don't tow heavy. At high rpm they flex to be flatter moving less air. Put a good load behind your truck an see how that works. I know with my old truck which had a healthy engine, towing 9000 lbs in the pa mountains my factory fan would come on often, running third gear at 3200 rpm.