Hevi Kevi wrote:
[I'll only be doing what I can do myself so I won't be sinking much money in engines, just time. The cost of a new prop is going to hurt a little. Just out of curiosity, are these dyno readings for the SST motors crankshaft hp or propshaft? I've always heard they were around 100hp but never knew where they were rating that
They are measured at the crank. I believe the last special SST 60 powerhead Blair Kants got from this builder cost him $5000.00. Most good SST60's dyno 90 to 95 hp in this range 5900 to 7500. The top ones run 95 to 102. The powerheads last 10 hours on an SST60 tunnel.
REMEMBER it is not horsepower that you feel when you accelerate. IT IS TORQUE! The fishing motors have more torque.
That is why there is little performance difference in the motors on a T boat. On the SST60 these motors turn 7700 to 8400 rpm. The top motors turn 8000 to 8500 and still make power thru the complete range. That is what costs the money in the build. The top costly ones pull off the dock thru every RPM range. On a T boat because of the difference in prop load being much greater, a lower ported motor with more torque in the 5900 to 7200 range works better. Listen to Todd's motor is a good example.
JUST TO ADD. We took a full race SST60 and ran it on Dave Whittington's 411 Critchfield. In testing the boat GPS 72 to 73 mph on a race course. We never raced the motor in that form in T Class. In 2011 that motor with a fishing head GPS 61.8 mph at Waterford. That was the same race that Ryley GPS 69 mph on the same course. Dave WON Sundays race! At Dunnville the same year we had a 152 compression head on the boat. It was a great race between Scott with the fishing motor at 160 compression and Dave with the 152 compression motor. The difference in the motor was very clear. Scott would pull Dave out of every corner. Dave would catch him at the end of every straight. On the last turn Dave tried to go around Scott on the outside only to hook the boat.POINT IS: An SST 60 at 160 compression will have no advantage. Check the compression at the race and they are equal.