The C's are too long to stagger you need a side by side boat, the Arneson drives with chain/gear boxes will allow you to offset the prop shafts inward toward each other.

I'm no boat designer but staggered engines were not for "weight forward" otherwise why would they mount fuel tanks in the engine comparment alongside the staggered engines??? Staggers were so you could place the outdrive closer to each other and keep the props lower in the water and hide the drives behind the boat transom to cut down on drag. As the boat goes faster the hull rides higher - correct? If the drives were not low enough the boat would rise above the drives and the speed would no longer increase. If you set side by sides too deep the drag from the drives themselves would hold the boat back.

That is what makes Arnesons so dam good, put the engines side by side and use the drop boxes angled in to get the props really low in the hull and keep all the weight in the boat toward the stern with just the engines. Fuel can be now be carried anywhere throughout the boat to achieve balance or change balance as needed - just how I thought it worked?

Apache 41 speed, you need to ask the Apache guys what does it take to run 75/80 mph in the heaviest Apache they have ever seen. Then add 1,500 lbs to that and how much more Hp would it take to do the same 75/80 mph - when you know that then you'll know how much Hp you need to make and can make an engine choice from that?

If it existed for cheap money there would many other people doing what you want to

Here is a pic of my adventure into using a Cummins. This is a fit trial before the marine changeover.



Here is what it looked like after.



LT

http://www.goldcoastpower.com/

plenty of sense there, too.

but is does exist for (reasonably) cheap money - engines anyhow up to ±500hp - but rigging is also in the plans, and it can be a lot easier to stay with gas on a re-power.

converting to diesel is a pretty narrow NEED.

it is a LOT easier, and more cost effective to go diesel, new, esp with Yamaha, Volvo packages; going shafts adds another dimension.

A 6B is 370-ish hp and dims: 41x33x35, bobtail @ 1.000# more-or-less

A 6C is 400-450hp and dims: 46x33x39. & ±1.200#

Goldcoast sells Cummins-kissed re-man 6C for USD15.000 (world 2yr warranty w/startup)

A NEW QSB.6.7-550hp is USD30.000, 1.450-ish#

The QSC.8.3, 600(+)hp is USD34.000 and weighs just shy of a Ton.

I have no idea what the new Ilmor or Volvo LS (or Merc 525) cost or weigh, but I can't see how they would be MUCH cheaper than NEW Cummins, but 450hp for $15k and a serious and genuine warranty is not trivial.


I don't think RM can get the speed he wants out of a pure-vee Apache, with 900-1000hp, but the Apache people can tell him.

that makes a lot of sense, thx, rm

which model cummins is that? what hp? what did you have for power before and what is the speed diff with the diesel? thx, rm

what transmission are you running? is it a single or two speed...thx, rm