hp and tq arent the 4bt's issue. its rpm. 2500 MAX (2800 in marine form) and it puts out A LOT of tq at 1000rpm.

 

You might want to go to www.boatdiesel.com and do some reading in the Cummins threads. There are some guys that use that forum that rare really sharp when it comes to Cummins and marine applications.
Would be worth your time. The Cummins forum moderator helped me a bunch when I did my repower.

Jay

 

QUOTE]Originally posted by mcinfantry
??? what?
they are MUCH heavier than a 350. 2 4bt's will weigh around 1500+ lbs. and 2 350's weigh around 1100. im not sure 400lbs is a big deal in a boat though.

a 4bt is 26"l x 32"h x 27"w
a 350 is 27"~29"l x 27"h x 19"w....... [/QUOTE]

A 350 chebie with exhaust for a car weighs 600#, a crusader or marine version weighs 750. They are heavier because they have a thicker block to hold up to the corrosion for the cooling.

Plus in a 42ft boat it wont matter.






Thanks Ill check there.


I also know about the rpm issure but with larger props and steeper pitch I can make up for the RPM's

Thats where the torque comes in. It will let me swing a lorger prop at slower rpm's and get better performance with better fuel milage.

Phil

 

Yes you will get better economy. My next door marina neighbor repowered a few years ago from twin Chevy based 350s (250 hp each) to twin 4 cyl Yanmar diesels( 170 hp each). He lost about 4 knots top end, and cruises about 2 knots less than before but at 1/3 the fuel consumption.
Good luck with the project.
Jay

 

Here are quite a few Frito Lay trucks for sale.

http://www.dovebid.com/browse.asp?UserName=TRAN0228

Hope this helps some out there.

Ryan

 

I know a guy, he has a few for sale!! Its here in Mexico though