Torque roll

Does a jet pump drive reduce or elimanate torque roll in a narrow - 4' X 21' constant 24 degree deep V hull powered by 400 ft lbs of torque from 1000 to 3600 rpm? Thanks for all advice, Rich. The reason I write this is because of a Powerboat test of a 2002 Donzi 22' Classic with a 470 hp Merc. Bless them for the honesty of the report. Big torque problems. In January I will start a 21' X 4' 8" constant 24 degree deep V bottom for 13', then fold the bottom skins up into a cleaver ( vertical ) bow. Yes, the boat will want to be a rolly polly at rest and side ways to a wave. I was planing to use a Nissan Titan V 8 engine which has a flat torque curve from 1000 to 3600 rpm, at 389 ft lbs of torque. I am now concerned I may be building myself a real problem.Please read the Powerboat test And let me know. Thanks, Rich.

 

Sorry Richard...but that would be way outside my ability to help you there. Don't know much about jetdrives.
Am I reading that right 4' x 21' 24 degree deadrise? Tell me that is the center hull on a tri !!

 

No error. It is 4 feet 8 inches wide. I can send you a scan of the plans. Looks great if you like mahogany speed- gentleman's runabout- Charles D. Mower plans. I am taking a few tiny liberties with the design. It has a 24 degree at the widest foward frame. I want to continue that 24 degree to the transom, it has a cleaver (vertical ) bow to improve the rough water abilities. I have the design for a 25% to 90 % adjustable max. speed floor pedal. Why is it so easy for me to try to help other people be safe in their boats but not do the same for myself in MY BOAT! I am NOT perfect!!! I e mailed 2 old woody designer's and builders for their input to save me if I get to nutty. 1939 plans call for a 15 hp or a 25 hp for a speed of 15 mph. Pretty good with the L to w ratio of 4.5 : 1. I give better information than I do. ( 305 hp ) instead of 25. Thanks Mr. Greenwood. Rich

 

Richard... it occured to me today that one possibility for you would be the Duo-prop or single output counter-rotating props like the Bravo 3 or Volvo setup. I understand Volvo also has a new Tractor drive, that is, of the same duo-prop type only forward facing and on a leg sticking out the bottom of the boat. I really don't have a clue if either of these would cure a torque issue but it seems like it would??

 

Bless you, Mr. Greenwood. I rode in a 2002 Sea Ray that had it. Dealer said there was a hp & torque rating limit around 300 or 400 hp or ft lbs. Bought a Chaparall. Fantastic boat- wife reads mystery novel at anchor. I need a 16' ,wood, 2 seat speeder with a 5.6 L V8 5 blade prop - might even give whiplash. YES, YES, THANK YOU, Thank you so much!!!! Rich 67 and loving it.

 

I called American Turbine jet pump people. Great staff. NO torque on the boat from the engine. But what killed the deal was where I dock. During droughts it can get very shallow. It also has a silty bottom. Both are death to jets. Rebuild at least every year. A " Woody " jet drive ? Not me, Thanks again, my best to you. Rich