Marine 12 valve

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Marine 12 valve

Postby Remps » Sun Jan 07, 2018 1:55 am

A friend of mine has a 40 ft boat with 2 351 windsors in it, and wants to put diesel power in it. Could on road engines be converted to work in a marine application? What would need to be changed? Is that too much of a weight increase for a 40 ft boat? Would a ve pump or p-pump motor be more ideal, or different motors altogether? It would see salt water for the most part.
'90 D250 R/C,727,IC,6x.009's,1/8" bump,fuel psi,straight pipe w/5" stack.
'90 W250 R/C,47rh,K@N,HX35,1/8" bump,2nd gen IC,boost,egt,trans temp.3.07's.
'96 2500 S/C L/B,2wd,NV5600,3.54 L/S,cai,egt,pacbrake,mbrp exhaust,10 plate.
Bring back the Bank of Canada, PRE- 1974.
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Re: Marine 12 valve

Postby Richie O » Sun Jan 07, 2018 10:48 am

There are tons of b's in boats. You could use a truck engine, but would need a water cooled exhaust manifold, A water to air intercooler ( after cooler ) if your over 210 hp and either a heat exchanger or keel coolers. I run a common rail 24 valve 355 horsepower in my boat. A 40 foot boat would not mind the extra 1000 pounds. If you buy a 6b now the 210's are rotary ( cav ) the 260's are p pumped in mechanical engines. You can go as high as 435's in mechanical but the duty cycle at that power is very small. Even my 355 is only rated at 20% duty cycle at full song. A constant full power rated 6b is around low 200 horses.
1989 W250 727, 3.07 L/S, S300, P/S Intercooler, Stans exaust, Pump adjustments, 127k miles,297 hp
1993 W250 extended cab, rag, 4.10 l/s, 6x16's, HTT 62/71/14 piston l/p, Isspro EV series tach, fuel pressure, boost, oil pres, water temp, volt, pryo, 132k/ 301 hp
1992 W250 with NV4500, 3.54's, 16cm 60mm GDS H1C, ground stock cone, Isspro tach, pryo, boost, fuel pressure, slow, rusty, dented,180k
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Re: Marine 12 valve

Postby Remps » Tue Jan 09, 2018 4:28 pm

Good to know info Richie, thanks. Would one use larger more aggressive props to compensate for the lower rpm diesels, or would the V drive have to be re-geared somehow?
'90 D250 R/C,727,IC,6x.009's,1/8" bump,fuel psi,straight pipe w/5" stack.
'90 W250 R/C,47rh,K@N,HX35,1/8" bump,2nd gen IC,boost,egt,trans temp.3.07's.
'96 2500 S/C L/B,2wd,NV5600,3.54 L/S,cai,egt,pacbrake,mbrp exhaust,10 plate.
Bring back the Bank of Canada, PRE- 1974.
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Remps
14mm rotor
 
Posts: 1099
Joined: Sun May 03, 2009 12:57 am
Location: Saskatchewan
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Re: Marine 12 valve

Postby Richie O » Tue Jan 09, 2018 5:37 pm

The reverse gears have different ratios. I had a 160 horse mitsubishi with a borge warner 2.57 input to 1 output rpm. When I stepped up the power I had to update to a heavier duty twin disk reverse gear. Over 210 hp the borge warners get eaten up. I went with a 2 input to 1 output ratio so I gained some shaft speed from that. I also had to have the wheel reshaped. It was a 22 inch, by 23 inches of pitch and they added ( bent ) 4 inches of pitch. Pitch is the length of travel the propeller would move forward with one rotation. So with one rotation I gained 4 forward inches of movement. Between the 2 changes it put the wheel where it needed to be to use the power I have. I have no experience with v drives, but the actual transmission ( reverse gear ) may be separate from the actual v drive. One other thought too is the turbo most likely will have to be updated to a different foot and or water cooled turbo. My turbo is a hx40 water cooled unit. Not all boat turbos have a water cooled hot side. Your looking at a pretty heavy priced change over of hard parts. I think the water cooled exhaust manifold is a cool grand. My water cooled aftercooler is 4k if I need to replace it. OUCH. Marine is MONEY.
1989 W250 727, 3.07 L/S, S300, P/S Intercooler, Stans exaust, Pump adjustments, 127k miles,297 hp
1993 W250 extended cab, rag, 4.10 l/s, 6x16's, HTT 62/71/14 piston l/p, Isspro EV series tach, fuel pressure, boost, oil pres, water temp, volt, pryo, 132k/ 301 hp
1992 W250 with NV4500, 3.54's, 16cm 60mm GDS H1C, ground stock cone, Isspro tach, pryo, boost, fuel pressure, slow, rusty, dented,180k
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