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Minimum Horse power?

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bandkiller

Well-known member
This question is directed more to WATERTHUNDER, I was just curious what the minimum horse power was for running a 2.68 reduction on a 16-18 foot boat. I don't need to run the hill but would be nice to have the power if I need it. I have a 17x8 with a belt reduction now, just looking to build a new boat this spring and was thing about going to the gear reduction this time. Do I need to go to a big block or just keep the small block setup? Thanks for any info
 
If you go up in ratio you need to make sure you match the prop to it. 15in. super wide blade. I have run them both alot. It will make a man out of your boat be snappy and quieter! We have a new 255.1 and the 268.1 that i think you would like alot. There are other combo's you could run but this one works really good. The ratio will take some strain of of your motor as well. Good luck with your build.
 
I know of at least 30 people who have went from a 2to1 to a 2.68 everyone of them prefers the 2.68. To be honest the less HP a motor makes the less torque it makes and the less torque you make the more a 2.68 will help. Just look at your typical 2to1 set up and then look at the same exact motor with a 2.68 it will always swing more prop and pitch! I believe the weaker or less HP a motor makes the more a 2.68 will help it! I would just keep the small block and run a 2.68 with the new R blade I guarantee you your boat will do things it never could before and it will run the hill. I like to turn the superwides between 5,200RPM and 5,500RPM the new R blades or the old wide blade I would turn between 5,400 to 5,700 wide open. I know all the prop guy's will say this is not where the prop makes peak thrust at wide open throttle but your boat will make more thrust where you run it 90% of the time!P.S. oh a 17ft boat I would run an 82'' because your obliviously not worried about snap and torque roll and since the boat is so big I would set the pitch so it turns around 5,400 this will give you a nice cruise RPM! You are at the fine line of a big boat that doesn't respond to minor thrust improvements if you have a 18 and up or a huge heavy boat then I would recommend a BBC from Felber! Is you boat a medium or heavy 17ft?
 
take that from someone who's learning this the hard way- props are designed to have max push at a certain speed.

2.68 at 5,000 rpm = 1865 prop rpm
at 6,000 = prop is 2238 rpm

2.09 at 5,000 rpm = 2392 prop rpm

2.00 at 5,000 rpm = 2500 prop rpm


i ended up with a big prop and a 2.68 but not a superwide and when i put enough pitch in it to keep my engine at 5,000, the prop was no where near its targeted rpm.
and i had/have a dog, thankfully i'm getting the help from some very kind people and we'll see how she responds very soon.

thank you very much- sharon and dan the man.
 
78'' Sensenich R blade! You should run a 78'' on that small of a hull! On bigger boats I like the Super Wide turning 5,400RPM with a 2.68 insane push insainly low cruising RPM's!
 
My boat is a medium, but we load it down with alot of weight. I run just fine with the setup I have now but have the airboat addiction and want to start all over again and try something new :D So I was just looking at my options and want to go to a 2.68, just didn't want to get to deep into buying a motor and find out it was not enough motor to push a big gear box. Thanks for any more info.
 
You can slow down the superwides down a little! Still killer push !Just more pitch !I run a little less than Dave !But he s on the money!
 
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