MAX 4 MODS PART 1 radiator relocation

[oztrax]

I am in the process of some fairly extensive modifications to my MAX 4

I have the kawasaki FD750 liquid cooled engine .

I have relocated radiator from the top of engine to be inline with the crankshaft
With the cooling fan directly connected to a stub shaft mounted to the flywheel

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The stubshaft is a 2nd hand unit from a john Deere 550, or Toro,made for the kawasaki
Air cooled versions to run a cooling fan

I punctured my radiator backing into a tree branch a year ago, so having the radiator
Mounted lower will protect it.
The other plus is if the air cleaner is shifted lower, you now have a decent size
Cargo storage compartment about 6 inches deep.

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But the primary purpose for release acting radiator is to provide space for a belt driven alternator, a small AMR300 supercharger and a PTO drive.

To be continued.......

OZ

[oztrax]

Just completed close to 10 hours running time, to see how the cooling mod performed

Initially I had a problem with the overtemp light coming on. Laser temp gun had the inlet manifold adjacent to the overtemp sensor at 95 C , when light came on. But after shutting down engine I could put my finger in the radiator fluid, eg it was barely warm.

Below the manufacturer setup for the radiator
The fan is geared slightly faster to a 1.16 ratio.
But more importantly, the fan blows air past cylinder heads and inlet, being a V engine, some cooling air flow reaches the exhaust.

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So when overtemp light came on, looked like my design was flawed
Researched radiator cooling design and changed a few things.

First I insulated the overtemp sensor from exhaust radiated heat with Kevlar exhaust
Tape and high temp silastic and made a heat shield for exhaust out of 16 gauge stainless steel (very challenging to weld with my TIG )
this improved things greatly.

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Next I discovered my fan was mounted too far from radiator core, so moved it closer
To 1 inch from radiator core. This is considered the most efficient spacing for fan

These Changes were enough to sort out the cooling system, after a 2 hour run yesterday,
With a fast run on the beach, my temp gage stays between 70 and 75 degrees C.
Laser temp gun shows 61 C out of engine to radiator and 30 C pipe temp after radiator
Cyl head temps 87 to 97 C

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Am adding an electric fan which primarily,will provide airflow to cylinder heads, inlet manifold and exhaust like the original installation did.

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So far so good

OZ