Current power is twin 415hp 502's with fixed surface drives. Gets me to about 50 @ WOT. I can cruise 35 with reasonable fuel burn, or cruise 40+ burning lots. I would like to cruise at least in the mid to high 40's, and increase my range significantly. this boat is deep V 42' long, and wieghs in at 14,000lbs dry. I know you can go with lower horse power with diesels, but I am looking for some informed opinions and maybe some personal experiance repowering to diesels from gas on larger sport boats.

Thanks,

Steve Hixson

what kind of boat is it?

harely sportfish??? i know some guys have posted question similar to you're abotu them in the passed. Search the archive for harley it might turn up some info for ya!

Yes it is a Harley. Most of these that are diesel are powered by old iron. I want to go with newer lighter engines. I am looking for comments from anyone who has diesel power in a sport boat of similiar size and weight. And what kind of fuel burn they are getting.

Thanks,

Steve Hixson

By light, are you talking iron or aluminum blocks? I'm interested in who is building these "light" diesels. The one thing that I've noticed is that the diesels are consistently slower. I don't know why, knowing that they produce significatly more torque than their gas rivals. Weight? Just to maintain your current speed, I'd suspect that you'd be looking for 500hp per engine. A built C series cummins could do it, but I think that you'd be looking for the better durability of a larger engine. A N14 will do it easily, but damn that's a big engine.

BTW-you'll be looking at a reprop too. Hope it's not too expensive with your drive.

Looked at Yanmar's site. They build high performance light weight diesels.
After seeing what they weigh I hope you know what you're getting into.
A 500 hp 6 cylinder Yanmar weighs in at 1815 lbs. and a 315 hp 6 cyl. is 899 lbs. And that's without transmissions.

I have looked at most manufacturers websites. What I am looking for is comments and performance from someone who has diesel power in a similiar size and weight boat. This boat was originally powered by triple Merlin diesels, then converted to twin gas. It is a little too light as is.

Steve H

I would also look at some of the Marinized Duramax setups that are coming onto the market.


Darrell.

i have done some repower's with yanmar's. they make a lot of power but at higher rpm than most diesels. honestly i don't care for them they seem to me like a entry level diesel when compared to others. they are light due to mostly aluminum block and heads. i think the cat to me is the best running diesels in boats along with detroits but you are going to pay. the cummins diesels which is part of mercruiser seem to be a cluster f**k when it comes to service. i have problem when i needed a tech rep and you call mercury and the blow you off and tell you call cummins and so on. if you plan on keeping the boat for any length of time go with a cat especially if it is a inboard. i know if you are outdrives your choices are slim. volkswagen has some diesels the dealer is located in florida they look nice but have yet to see one in person. i think they offer a really good warranty too. i would just be worried who was going to service it being there are not a lot of dealers out there.

No one is currently to market with a Duramax diesel marine power with more than 500HP in true current production. We are in R&D and working on one now but we are not there yet.
As for other manufacturers with current plants in use you might also look at some of Volvo-Pentas new D series motors, not real light but pretty good weight to horsepower ratios and they are on the shelf proven motors also.

Regards,
Ray @ Raylar

Steve H, I can tell you everything you need to know to go fast with diesel. You can call my office Monday 718-576-2131 I'll be glad to talk to you for hours!