Hi I have a 1996 Carver 37 AFT 21000 lbs LWL 32' 6" now i have twin 454 XLI 300 hp Borg Warner Transmission 10 18 000 010 2.57 to 1 and 22" X 23 pitch prop
I would like to cruise at about 7 to 8 Kts with twin small engine i think around 43 hp or 50 hp eacth will be enough power to cruise at around 1500to 1800 rpm at 8 kts
It is possible to adapt these engine to my transmission with adapter plate? Do i have enough power to cruise with good fuel consumption ? Do i Have to reduce the prop for a likr 18" X 20 pitch ? What you recomand to me ?
This will work quite well. We can provide our engines with the correct adaptors to mate with your Velvet Drives. This adaptor kit includes the oil cooler and hoses as well.
I have run some prop calcs for you and if you use the Beta 50 you should top out at over 10 knots using 22"x16" three blade propellers. The Beta 60 will add about 1/2 knot more boat speed using 22"x17"props. Either will give a comfortable 7 to 8 knot cruise with great economy. I would keep the 22"diameter as this will give you the best drive, especially in poor conditions.
Please note that these engines are not handed so any change for LH to RH prop must be made at the transmission.
Regards, Stanley
-- Edited by Stanley on Monday 20th of April 2009 04:59:51 PM
An educated guess says that 1800 to 2200 RPM will give between 7 and 7.5 knot cruise.
I actually have 2 different prop programs and they both gave the same answer. One is old and was written for DOS and the other uses Lotus. I have had good luck with these programs and a friend with a prop company has similar results with his program. I have found that the ones available on line dont seem to give reliable results for slower boats as they are all written for boats that are designed to get up on plane.
