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Skoontz
03-09-2009, 10:55 AM
Ok, got a question about the engines for this class. I found a 31 cube motor, good shape, but, it has the old style bolt in half sheer pin lower unit. Its stuck, the genius who took it in trade is on the bay and left it sit with no hood on for a few months, and, the salt did it's thing.

He started at $200 and will take $25.00....If the lower was changed t9o a through hub, is this motor a legal Mini GT motor?

brichter
03-09-2009, 06:08 PM
Skoontz, in order to switch the lowers you would have to switch the exhaust housing, in that case you might as soon look for a different motor....
However if you can get it for only $25, I am sure there is something useable on the motor to make it worth it even if it is not rebuildable.

I don't think there are any restrictions in the mini GT Rules that disallow the
split gearcase(???), but the props that were made for it were not as good and the water pickup location would force you to run it deeper, increasing the drag.

JohnsonM50
03-10-2009, 03:43 AM
Skoontz, in order to switch the lowers you would have to switch the exhaust housing, in that case you might as soon look for a different motor....
However if you can get it for only $25, I am sure there is something useable on the motor to make it worth it even if it is not rebuildable.

I don't think there are any restrictions in the mini GT Rules that disallow the
split gearcase(???), but the props that were made for it were not as good and the water pickup location would force you to run it deeper, increasing the drag.
Bill, you do need to change the mid to bolt the thru hub up but the powerhead will bolt on & the exhaust tuner tho different from some 25s/35s will work in either mid. [it sends water to the block in a different place but is the same externally.
Altho I hear the thru hub is geared lower, exhaust flows better, is more hydrodynamic & has better prop availability.. It has a HUGE clamp bracket so overall a somewhat heavier motor.
If you remember,couple years ago I was messin with the split foot? I ended up at 52mph on a hydro with that. Its on a HK Wetback now & does 48 with a 12:21 ratio @ about 6800rpm

JohnsonM50
03-10-2009, 04:36 AM
Bill, you do need to change the mid to bolt the thru hub up but the powerhead will bolt on & the exhaust tuner tho different from some 25s/35s will work in either mid. [it sends water to the block in a different place but is the same externally.
Altho I hear the thru hub is geared lower, exhaust flows better, is more hydrodynamic & has better prop availability.. It has a HUGE clamp bracket so overall a somewhat heavier motor.
If you remember,couple years ago I was messin with the split foot? I ended up at 52mph on a hydro with that. Its on a HK Wetback now & does 48 with a 12:21 ratio @ about 6800rpm
As far as running deeper to be fair I never used a thru hub but have one & it has pretty hi pickups too. I do know for sure you can run the prop thrust pickups pretty hi, [ant-icav plate 1 1/2" above the waterline], depending on boat & -watchful- testing. Running an extension hose forward from the indicator so you can see is an idea I borrowed that works.