Bad Ass 23 CC inboard! 454??

[Captppan]

Hi

I've come across a great deal on an new 454 with a velvet drive transmission. I'm just wondering if it would fit? I have the small Seacraft console but I would be willing to upgrade the console also if this beast would fit.

I'm running a 350 Captians Choice now aprox 260 HP

Thanks

[kmoose]

Had a friend with a 502 IO in a scepter on a duo prop Volvo penta with straight thru hulls. One of the best power plants I ever rode in.

[Captppan]

I'm thinking Arneson AS6 Drop box with a Jack shaft to the 454 under the console.

I'd have to glass in the tunnel and find a new way to route the exhaust.

Shallow draft is one of the goals but I'll take the increase top end also.

[kmoose]

If you went without the drop you could leave the tunnel. Surface drives ride at the surface and it would pull water right from the tunnel. I would love to see Daves Seavette with a surface drive and if I win the lottery I will fully sponsor the refit.

[Fr. Frank]

Moose is right: leave the tunnel if you're going to run a surface-piercing drive. You'll be able to run a flatter/straighter angle of thrust and still surface your propeller, thus more fully utilizing your power.

But it won't back up for squat. No surface piercing drive does.

Propeller slip while reversing on a surface piercing drive averages between 65-80% if I remember correctly. Although, it's theoretically possible to reduce that somewhat, but at the cost of forward thrust efficiency while surfaced.
In other words, you could have better reverse capability if you changed to a non-surfacing propeller, and actually ran the propeller close to the surface without ventilating.

It would be interesting to watch a 23' running about 500hp in front of an ASD6, though...

[Captppan]

Ric at Arneson said that because the tunnel only starts around 4 feet from the transom the water wouldn't be clean enough to maximize a surface drives efficiency. Also I'm not to concerned with going backwards LOL

Does anyone know if the 454 will fit between my stringers and in my the existing space under my console?

[Captppan]

It would be interesting to watch a 23' running about 500hp in front of an ASD6, though..

Yes I think It would!!

[deepsushi]

I have a 454 crusader in my inboard and it fits no problem. Its an old crusader with lots of hours on it that is pretty tired. I have the large console on my boat; I don't know if the footprint of the smaller console is the same or not.

Honestly, I don't think its worth putting the big block in the inboard. My boat is no faster than the other inboards (avg 20 -22 knot cruise) that have 350's in them. The 454 is a very fuel inefficient motor designed back in times when gas was cheap. When I go to repower I will most likely use a new vortec 5.7.

The inboards are limited to at most a 17" prop and just are not that fast. If you want to go fast you need to go yanmar as the diesel torque can push the boat up to the 30 knot cruise range.

I would not go messing around modifiyng the inboard tunnel to work with a surface drive. Inboard seacrafts are in high demand. The last inboard listed here at CSC sold in a day or two. You could easily sell the hull for a nice price and purchase a boat originally setup for an I/O.

[Bushwacker]

Originally Posted by deepsushi

. . . The 454 is a very fuel inefficient motor designed back in times when gas was cheap. . .

Amen to that! One boat which made a trip to the Abaco's with me and the Moesly 21 "Unohu" in the late '70's was a 23' Sceptre with a 454/Mercruiser No. 2 outdrive. It really guzzled gas! He had a 105 gallon tank and he couldn't even make it from Palm Beach to Green Turtle (167 nm). He actually ran out of gas at Coopers Town, which was about 155 nm, so he averaged roughly 1.5 nmpg! My old carb'd 115 Evinrude burned just a little under 70 gallons on that same trip, and I thought IT was a gas guzzler! The Unohu, which had a 265 hp/350 Mercruiser burned about 75 gallons on that same trip!

[Captppan]

The 454 that I'm considering is a fuel injected model so maybe a little better on MPG put I would also have to replace my New fuel tanks to make room for exhaust.

I'd hate to part with my 23Potter but I need the shallow draft.