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Discussion Starter #1 (Edited)
Hello,

I have fitted a 6BT into my 1940s Diamond T 969 and have problems with fan-to-shroud alignment.
The fan is [SUP]3[/SUP]/[SUB]8[/SUB]" too low and 1 [SUP]1[/SUP]/[SUB]4[/SUB]" too far to the right.
I have a mount/hub that bolts to the front of the head and one that bolts to the block, beside the timing cover.

It is not an option to move the engine or the radiator and, as the fan (560mm dia.) is already on the far right edge of the radiator, it is not just a shroud problem, the fan needs to be moved.

My current idea is to cut the mount (that bolts to the block) parallel to and a bit above the two top holes, weld a [SUP]3[/SUP]/[SUB]8"[/SUB] plate to it and weld the top part of the mount onto the top of the plate, but 1 [SUP]1[/SUP]/[SUB]4[/SUB]" to the left. And add a web or two.
I have test welded the mount to check that it is cast steel, not cast iron.

But, before I go to that trouble, is there a stock mount out there that will do the job for me in a cost/time efficient way?
As I am in Australia, o/s shipping is a major issue.

Also, there is about a 2+" gap between the fan and shroud. Do I extend the fan with a spacer, or weld an extension onto the steel shroud? Will extending the fan with a spacer place too much load on the hub bearings/mount?

If you are interested, here is a link to my rebuild thread.
http://g503.com/forums/viewtopic.php?f=26&t=157023&sid=7a040cbb965a7affd3ad0f767b0227c2&start=570

Expert/experienced comment appreciated.

Have a nice day.
Sam.
 

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There were at least 5 different fan mounts for the 6bt. If you're facing the front of the engine, one mounts it off center to the right and slightly downward, one mounts it centered on the block, one mount is centered in a medium height, one mounts it centered at a higher position, and the fifth mounts it centered on the head. Sounds like the one centered on the block would be what you need. That was used on the '91-93 Dodge inter cooled engines only and not the easiest to find even here in the US. Here's photos of each one. Yes, being in the land down under really sucks when it comes to shipping. Which style fan do you have? Is it a clutch type or permanent mount? If its a 4 bolt mount, then a spacer would do fine. Cummins offers a variety of different lengths or you can just make one. You want the fan in the shroud for best performance. There a guy named Trevor from Melbourne that goes by SloSpeed. He has a friend who imports a lot and might be able to get you a better shipping cost. Might drop him a PM. Can you post some photos of what you have?
 

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Discussion Starter #3
Hi Char,
First of all, thanks for taking the time to reply.
I was almost ready to go ahead without a response from here.

I have had several attempts to upload/attach images to this reply, but I can't manage it.
I tried direct from my computer, but that 'exceeds' my quota ?!?
I tried to link from my usual photo host site using both the image icon and the attach icon, but it is an 'invalid URL', despite multiple types of reference tried. I also tried 'quick reply' and 'go advanced'.
I dunno what else to try. Annoyingly, I think that I have posted pictures here before, can't remember how.
I will keep a photo record of this and gladly post the pictures if I can work out how.

Anyway, I have one each of the 4th and 5th pictures you posted, and the fans I have fit the 4th one.
The one centered on the block would be too low, the center of the fan needs to be 3/4" higher than the top of the timing housing.

However, you have kindly answered my question about other fan mounts available. It seems that I would have to modify or manufacture one regardless of which types I had on hand.

I have decided to go with extending the shroud as is is easy, simple compared to finding/making a hub extension.

Have a nice day.
Sam.
 

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Sam,
Sorry to hear the hub did not work.
If you have a 2" in gap between the fan to shroud you could just offset the shroud opening to suit. That is enough clearance for good air flow.
Fan should be 1/3 into shroud, 2/3's outside.
Cheers Steve
 

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Discussion Starter #6
Hi Dougal,

yes, that is an option. I'll have another look with that in mind. That could be a good way to 'trim' the fan-to-shroud position. The fan needs to go 2" forward to clear the top hose, but then the fan clutch housing will be 2" from the radiator, a nice mid-ground, methinks. So, I am going to have to extend the shroud either way.

Hi Steve,
how goes it?
The fan and hub are still needed, I'm thinking to cut your hub in the next hour or two, tack it in the new position and test fit.
I've had a closer look at it and don't think I need to raise the fan from the position of the mount shown in the 4th pic above, but still move toward the left side (of the vehicle) by 30mm. Blades 1/3 into the shroud, got it. Thanks.

Can someone suggest a simple way to make a 2" spacer for the fan? I might go for a walk around the local auto wreckers yard.

Also, how can I post pictures here?

Sam.
 

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Those spacers aren't mega expensive. The Cummins pilot is 1.00". There are 2 different bolt patterns on the hubs. The ones you have should be 4 x M10 bolts in a 60mm bolt circle. That is common for all the commercial hubs. Did you reverse the head mount hub to the low position? That would be really close to where you need it.The Cummins part # for the 2" fan spacer for the 60mm circle is 3910130. Here's what it looks like. They are around $30 here in the US. Of course you'll need bolts that are 50mm longer.
 

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Discussion Starter #8
Cool, thanks Char.
I'll chase that number and see what happens.

To get the left-ward movement of the fan, I could only see two options, 1) to modify the mount, or 2) to fabricate up a new one.

I went with the first. After a good look and measure, I mounted the hub in a metal bandsaw and cut it off about 1/2" above the top two bolt holes, tacked in together 1 1/4" to the left and test fitted. All good so far. Then had trouble with welding, only to find that it is a cast iron mount, not cast steel as I first thought. It fell apart with a decent hit from my hammer. Hmmm. . . .

So, now I either braze it together (as I have done when repairing cast iron vices and manifolds), or throw it and go with option two.
I'll probably braze it up and see how happy I am with it.

Onward and upward!
Sam.
 

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Yes, all those mounts are cast iron. Apparently your radiator is not centered to the engine. The head mount is centered on the crankshaft. Another possible method of modifying the hub could be to machine away part of the back. Those head mounts are extremely thick. Shave off 1/2" and make a new mounting plate from 1/2" stock. Mount that to the head with counter sunk cap screws and locate the hub where you need it and bore and tap new holes. I have one of those hubs and I believe the bearing assembly is recessed into the back far enough to allow that. Of course this is an after thought.
 

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Discussion Starter #11
Thanks for the replies gentlemen.

char, yes, I could have gone down the road of thinning the bracket and putting an adapter plate between the bracket and head/block. Unfortunately, I have now cut the bracket.
I locally priced that spacer, that you suggested, . . US$105. gasp!

Ed, sorry, I haven't explained here (this is being posted on two sites, I get mixed up if not paying close attention).
The fan is hard up against the right side of the engine compartment, would probably hit the hood in normal operation.
Yes, the engine is off centre, it is in the position of the original engine, and needs to be so as everything else is being kept close to original. I found a surprising number of things are affected by the engine position, which is off centre probably to get around the front axle differential.
So, it needs to go about 1 1/4" to the left side of the vehicle and be extended by about 2" and the shroud extended by about 2".
This Cummins is about 5" shorter than the original petrol lump.
So, my next attempt will be to braze the cut bracket in its' new shape and add several webs. I also think I'll make a mesh guard to go between the fan and radiator in case of the bracket failing.

Have a nice day.
Sam.
 

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Discussion Starter #12
Update:
I have managed to get a hold of some cast iron welding rods at much less that retail price, which is about AU$10 each (3.2mmx300mm).
So, off to my welding-works mate when I can to weld the fan hub in its' new position.
 

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Hi Char,
First of all, thanks for taking the time to reply.
I was almost ready to go ahead without a response from here.

I have had several attempts to upload/attach images to this reply, but I can't manage it.
I tried direct from my computer, but that 'exceeds' my quota ?!?
I tried to link from my usual photo host site using both the image icon and the attach icon, but it is an 'invalid URL', despite multiple types of reference tried. I also tried 'quick reply' and 'go advanced'.
I dunno what else to try. Annoyingly, I think that I have posted pictures here before, can't remember how.
I will keep a photo record of this and gladly post the pictures if I can work out how.

Anyway, I have one each of the 4th and 5th pictures you posted, and the fans I have fit the 4th one.
The one centered on the block would be too low, the center of the fan needs to be 3/4" higher than the top of the timing housing.

However, you have kindly answered my question about other fan mounts available. It seems that I would have to modify or manufacture one regardless of which types I had on hand.

I have decided to go with extending the shroud as is is easy, simple compared to finding/making a hub extension.

Have a nice day.
Sam.
Hi Sam

I'll tell you what I have learned about posting pictures on this site. You are only allowed 390.6 KB's and if you exceed that your next the picture will not be displayed. You said you think you have posted before. To check, click on reply then click Go Advanced then click the paper clip which is attachments and it will show you the current attachment total. If you are close to the total 390.6 you will have to delete those pictures or replace them with a smaller version of the picture. I reduce mine to 20-30 KB. char1355's pictures of the 5 fan mounts range from 25 to 42 KB. Put your pointer on each and it'll show the KB's.

To delete your previous pictures click on your username at the top of the page and bring up your profile. Click on send private message and on the bottom left of that page click on attachments. This will show the pictures that you have posted along with the size of the picture as KB's. You are only allowed 390.6 KB's worth of pictures and if you try to post a picture and it puts you over 390.6 it will not be accepted so you will have to delete some older pictures in order to add more. You will see how to delete old pictures on the right. It's best if you can reduce the size of the picture before downloading it. If you can get it down to about 20 - 30 KB you can post a lot.
I hope this helps.
Dana
 

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Don't boot me off but why not an electric fan? I'm not a fan of electronic but they are cheap and reliable. I used to carry a spare.
 
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