gear ratio differences on the mid 90's 60 degree loopers

[bob johnson]

ok so I have a few of these motors, and I swap parts as I need them, since a bunch have blown cylinders. I had a Extra Long shaft V4 115...that I figured I could use, but was told the gear ratio is an odd ball.... so I didn't use it...now thinking about my parts supply..im wondering if I could ever even use this LU! the Extra Long shaft of the V4's were actually V6 cases....but they had 2.25:1 gear ratio. All the V6 motors came with the same heavy duty V6 cases but used 1.85:1 gear ratios. the standard shaft V4's came with the smaller "v4" cases and used 2:1 gear ratios...... so im figuring the longer drive shaft of the 25" v4 is why they changed the gear ratio....less chance of twisting the drive shaft I am guessing. so if I need a long shaft V4 I have the midsection and the LU ... for any 60 degree v4 power head I aquire. BUT.. I also have two good running V6's in the 60 degree looper motors . One being a extra long shaft and one being a 20" shaft.... if I got desperate and needed to use the extra long V4 LU on the extra long V6..... what are the ramifications? Ill be turning the 2.25 gears instead of 1.85 gears.... am I JUST playing with props...or will the higher HP try to damage the LU because of the gears????......

 

[jimmbo]

I will assume the larger case and lower gearing of the extra long shaft motor is because the expected use of that engine would be on large heavy boats.
If the driveshaft splines are the same, the gearcase could be used on the V6s. However the props would need to be higher pitch, which might not be as readily available