On 08/10/2007, Gary Crandall <email@example.com> wrote:
> The easiest way to get more room for the fan is to use a shallower pulley
> and press the water pump hub further down on the shaft, thus maintaining the
> alignment of the water pump pulley groove with the crankshaft and
> generator/alternator pulley grooves.
> Measure how much distance there is from the back of the present fan blades
> to the fan belt and subtract half the difference in width between the old
> fan and the new fan. This distance is how far you can relocate the pulley
> and determine how deep the pulley should be; add a little for
> tolerance/clearance. If you can move the mounting face of the water pump
> pulley more than half the difference in width between the 2 fans, then the
> new fan will at least fit behind the radiator.
> I notice you do not have a fan shroud. A shroud is critical in order for
> the fan to pull the air through the radiator, otherwise it bypasses the
> radiator and just comes in around the sides of the radiator. Air and fluid
> (like teenagers) always follows the path of least resistance. For the most
> efficient air flow, the center plane of the fan should be in line with the
> trailing edge of the shroud. Base on the picture on your website, it appears
> your fan might be too far farward, had you a shroud.
> Clearance to the rack is another story. The Tigers orginally came with
> exhaust heat shields and spacer/washers between the motor mounts and engine
> block. If these pieces are missing and/or your motor mounts are old or
> sagging with age (aren't we all), the motor may be lower than it should be.
> You may also install additional spacer/washers. A set of 1/8" washers will
> raise the front of the engine about 1/4". I also run the fan mentioned in
> TBON, but trimmed it about 1/4". It really moves a lot of air.
> Hope this helps.
Had not thought about the heat sheilds, should check to see whats going on
down there, im sure the mounts will be in good condition but will keep an
eye open. As for the pulley, i believe the stock ones are hens teeth? Is
there an aftermarket one that is short? Also i want to try and avoid
trimming my nice new fan (i think compliments to you?) but will see how i go
once i have sorted this.. maybe i can make/modify a pulley that will be
short enough to resolve the rack interface issue? I am thinknig the fact its
only had a 12" fan might have been the overheating at idle issue.
As for shrouds, i thought the stock one was not much good given they are not
a sealed unit. As i also dont have one i was thinking of making one that
went round the whole fan and would be much more efficent.. but all in good
time i guess.