Why not use an motorcycle engine?

[s.strömbäck]

Originally posted by BluFin
I agree a motorcyle motor in a cat , purrrrrrrfect.
But at the end of the day it's cost effectiveness. the shear expense of having a transmission built is scary. I'd plum for the Suziki or the Kawasaki, aint even touched on getting it into reverse yet, that presents another set of problems if the original box is retained.
I'm know there are several firms in the US that can build to suit but $$$$$$$$$$$$

What does theese cats look like? Cant say I recognize them from Swedish waters.
The whole idea is to keep the expenses down as mouch as possible. Im studying mechanical Engineering here in Sweden, so the way I see it, its going to be a fun challenge to manufacture the parts needed. At school, I have access to 3D-CAD and a lot of CNC machines and so on.

Originally posted by Jon Fuller
Anyone know what ratio the lower unit on a F1 motah has?


trouble with going for lower prop speed is, you wind up with bags of pitch and it's subsequent troubles, if you intend going fast.

Im not really sure of what you mean by that (hehe, I told you my english sux) Can you explain it with other words?

Originally posted by Lars T
What about a 2 cylinder "ducati"-style engine?
Lots of Torque and HP at low revs???

Nah, I've decided to use an inline 4-cylinder engine. The suz. 1100r engine is a budget alternative. The best would be if I could get an Hayabusa or Kwak ZX12-R engine to fit into my budget.

They produce just beneath 140Nm somewhere around 7500rpm.
I think the busa keep its torque-peak at 6700rpm. And THAT would be more than welcome into my boat

[Matt]

The more pitch you have, the more the prop tries to paddle wheel sideways. So you need to compromise between lots of pitch to keep the prop speed down, and not enough pitch, so the tip speed is high. Also you need to factor in prop diameter into tip speed calculations.

Having thought about it, I reckon Jon's thought's on using 4000rpm as the max shaft speed is gonna be a good starting point.

[s.strömbäck]

Thank you Matt, it's great to have a good startingpoint.


[QUOTE]Originally posted by s.strömbäck
[B]What does theese cats look like? Cant say I recognize them from Swedish waters.

Uh, forget it, I assume you mean cat = catamaran. =)

[Jon Fuller]

Originally posted by Matt
Having thought about it, I reckon Jon's thought's on using 4000rpm as the max shaft speed is gonna be a good starting point.

Thank you