fan distance from Rad?

[robertglines1]

Ready to set fan blade distance from Rad on my Prevost. How far away. This is a custom fit so I have no history/past guideline to go by.  I bought coach without drive line and no fan or rad.  Looks like 3 inches would be about where it would have been??? to much ?   Bob

[chessie4905]

my 4905 is a lot closer than that; probably an inch without looking. If you have a close fitting shroud, 3 inches will probably be ok.

[robertglines1]

Building shroud also!  Plastic fan(10 blade 30 inch) so was wondering about fan blade flex. I slotted mount so I can move near if you think that would be better?  Bob

[luvrbus]

The shroud dictates the distance if you are using the Prevost angle drive and parts there is not much one can do about the distance,but I am thinking it is more than 3 inches by the time you add the clutch 

My tunnel on the shroud is deep it looks to me like the fan is at least 5 or 6 inches from the radiator,it is a plastic fan 32 inches 12 blades

[robertglines1]

It is the prevost fan and to be honest don't know whether it is 10 or 12  was thinking 10 but it is out of sight now.  I don't have shroud.  But did come up with gear box from a different year that I had to modify to fit my mounts. Have air to air charger worked out and shroud will be easy. All in the suction thru the rad in the end.   Thanks

[Boomer]

Shroud is about in the middle of the blades.  Blade tips as close as possible without touching.

[robertglines1]

No problem rolling a 3/8 rod into perfect circle with uniform clearance all the way around. From there the rest is easy. Was thinking about 3/8 inch clearance for flex. and possible blade growth. Could always be snugged up with plastic overlay.  Bob

[Hard Headed Ken]

I agree with Boomer. Half of the fan blade outside the shroud. Don't forget to move your fan through the range of motion when checking for clearance in case you break the belts / belt. It travels in an arc. I used my stock fan and shroud. That allowed about 3/4" clearance between the fan and shroud when centered up. I'll try to measure the distance tomorrow, I'm guessing about 6" between the fan and radiator. If you need any of those little air bags let me know, got 2 new ones I didn't use.

Ken  

[robertglines1]

Added a mechanical travel stop in case of a belt failure.  I try to add safety X 3 for things like that.  Cheaper than Rad...   Do you think I will ever get it done??  Still not rushing it!   Bob

[paul102a3]

On my 2000 XL II the leading edge of the fan blade is 4.5 inches from the radiator. The shroud is 6.5 inches from the radiator which leaves the trailing edge of the fan blade slightly exposed.

Paul

[bobofthenorth]

My LeMirage is a jurassic model c/w yours Bob but bone stock AFAIK so FWIW:

4" from the blade tips to the fins and the trailing edge of the blades just barely protrudes from the shroud.  There's also a double guard ring between the fan and the rad.  Looks to be 3/4 x 1/4 flat bar rolled into rings.  

[robertglines1]

Thanks : to all:: now working it all out.  I like the extra ring guard to protect rad from fan failure.  They are high dollar and a bus stopper!.  Simple things now save major $$$ later. Not reinventing light bulb here. Just doing the best Job possible with what i have. Would have been nice to have stock set up with coach. That did not happen-I did come up with one out of a 91 XL less fan shroud. Looks very good and workable. Ya'll guidance is always reassuring.    Bob

[Skykingrob]

Bob
The front edge of the fan hub is 4.5" from the radiator, the fan blades are .75" from shroud and the shroud in 6" total depth from the radiator on my 91 Prevost XL 40. If you need more measurements, let me know.
HTH

Rob
91 Prevost XL40
Missouri

[robertglines1]

It's built. Not  as bad as I thought it would be. Thanks to all.  Just a few more pipe details to work out on air to air charger and rad pipes and major hook up work will be history.  Thanks to all!!  Would been allot easier to buy a coach finished---not as much fun!....BUSNUTS     Bob