Hi Kiwi.

I take all advices I get. Yours too. (Thanks).
I also beleive that Scott has experience like no other. This I really respect.
Trouble is that I really don't understand his terms.
A simple "what-to-do-advice" is what a danish hillbilly like me needs.

By now MHZUSA has not answered my question.
Maybe I should go to Jim's...

Cheers!

Woodie.

A lot of guys on this forum running twins...maybe you can get some other opinions there: www.xtremercboats.com/phpBB/

I think with what you have now, you are looking at counter-wound flex cables and counter rotating props...unless you change gearboxes. As for MHZ-USA, it seems they are no longer affiliated with MHZ Germany, so I would suggest going to MHZ Germany.

Woodie,

MHZ USA no longer sells MHZ products - taken off them by MHZ Germany.
Contact MHZ Germany, you must be near their time zone.
Sounds like the lady there speaks really good english or maybe you speak German? Deal with the manufacturer and get the correct info.
Also try their website - I believe it's English or German.
I think what Scott was trying to get you to understand, was do your proposed drives do the counter rotating within them. i.e. one is RH turn and one is LH hand turn, or are they built the same and can be turned whatever way you want depending on what gearbox you use. Some gearboxes can be turned any way.

I guess if you already have a gearbox with both LH & RH rotation, you have to use that.
As Marc said - a lot of the USA guys use non counter rotation gearboxes/drives as they can get a better selection of props. Torque steer is minimal when the boat is big enough.

So
1 Look up MHZ's website and see what you've got and what it can do.
2 Ring MHZ and speak to them I find that phone calls are so much better than e-mails.

Let us know what you actually have and how it will work.

David

Woodie.

Been looking at ALL your posts re the boat.
Why not the surface drives. Cheap, easy to adjust, and the boat will go fast.
They can be turned either way, just need the right 1/4 in cables.
You obviously need speed, you have to beat 2 other boats!! After all are you not a 'Cat Killer' ?
Stern legs etc look really nice and are nearly true to scale, but I don't believe will give you the best performance.

I see that you've already been advised about surface drives, and you seem to have a problem with the rooster tails, and losing performance. You don't lose performance because you spin bigger props, and the rooster tails look really great!!
Only my opinions, and I;m sure that others would disagree.
David

Hey Kiwi!

Regarding this boat I am kind of stubborn. It will never be a scale model, but it should look like one if possible.
I am a konservative old boatbuilder, and I try to build in the way a boat should be build.
So when it comes to the drives, I will accept nothing else but submerged props on twin drives (on this boat, that is), as I am convinced this will do best on rough salt waters.
On calm water I don't think speeding will be an issue, when running a 56" boat with twin drives on a 13,6 hp Blata engine.
Only real issue is to get the right design on the bottom strakes, which is not done yet. (Still looking for inspiration or advices).
About "stern legs": I don't understand that term. (Remember I'm danish).

Anyway thanks for trying to help a stubborn old guy. I really appreciate it.

Cheers!

Woodie.

Woodie wrote:
Woodie,
You can no longer buy from MHZ USA. MHZ Germany has cut off ties with the US dealer.

I have the same gearbox as you but I use the regular jocheung drives. In your case you will need counter rotating flex shafts and just because you have chosen to use an S6 drive then I suggest that you get 1 Counter Rotating (Clockwise or CW) S6 and the other a"Regular S6 (Counter Clockwise or CCW). I will assume that the CR S6 will have CCW thread on the prop shaft so the prop nut will keep the propeller in place. and not back off.

Having said that, MHZ Germany is also telling you that it is OK to use two Regular S6's on your m1570-T, you just need to double up on the prop nut on one of the S6 that is turning CW to secure the prop from backing off.

Now for setting up the two S6 drives, you need to decide whether you will run the props INWARD (for speed) or OUTWARD (for manueverability). I run mine INWARD because almost all offshore boats be it mono or cats runs INWARD and wins the races.

I hope this information has helped you.

Viper.

THANK YOU soo much!

You told me just what I wanted to know, and in a simple way too.
I will absolutely go for the MHZ S6 - one normal rotating and one counter rotating.
About the flexcables, I allready have ordered the right ones as you recommend.

Again: THANKS! This was absolutely helpfull!

Cheers!

Woodie.

The video you see is a 64" Bonzi Fountain powered by a V3 M6 Twinline (52 CC) from WHH, its top speed is 40 MPH on calm water. It currently has an untested Dominator (58 CC) Twinline engine from Perfomannce Unlimited Products. I hope to see 50 MPH on calm water this summer with its current powerplant.

With your combined set up of 54% (as per the MHZ Germany) overdrive you will need a torquey engine to overcome the overdrive from both your gearbox and drives. Hence, the reason why I went up to two 29 CC Dominator engines coupled inline. You will need the bare minimum of 14000 RPM underload for your boat to plane to a reasonable speed.

What hull and engine will you be using?

Woodie
I had a friend down there playing with some thing similar ,, email Mick a note on utube and he may answer



second




Randy

Woodie, sounds like that you've worked it all out.
Don't worry too much about the strakes. Strakes are good for lifting deep V's, and do aid low speed planing. A lot of our full size deep V's are now taking the strakes away from the stern area, because at speed and with the boat trimmed correctly, you probably only have the last 500 - 900mm in the water. My 7 metre boat has a ski plank and gets virtually right out of the water at 60 mph. Just the prop in the water. Some are taking most strakes off just leaving small bow ones to aid lift.
Strakes can have a downside. Too much vertical area on them creates extra drag.
David