Pic 3 really does show how high that X is.

at the end of the lower housing where the prop shaft comes out is about what 50 / 55 inches from the transom ?

what is the difference between the arneson and m8 as far as distance from transom to leading edge of propellor ?

did you build the extension boxes and set the x so the m8 propshaft was in the neighborhood of the arneson propshaft ? ,
so you could expect or hope for a similar base test ?

i think you spent more on green tape than i did on my whole boat

Yes I don't remember the exact number but I think it was around 54" back

I had a standoff/angle block on the arneson and about the same thickness of a standoff/angle block on the M8 So the distance is real close but the M8 is an inch or two farther back

We made the standoff mainly to get the prop back farther for handling, leverage, and for the tie bar to be back farther to clear the tunnel extension.

The X dimension of the arneson was technically 5 or 6" with the drive parallel to the bottom, I had the ball socket clearing the bottom of the boat by 3/4" but that is about 10" back from the transom. With the arneson ball socket to thrust tube straight the prop nut would be around 1" up.

It will not be a good base test because we have changed the engines too. But on the dyno I am going to find what fuel burn it is at when it is making 550 HP at 3300 rpm and the fuel burn at 750 hp so when I'm running it I can get to that fuel burn and rpm to see how comparable the drives are.

Somewhere back in the thread I listed how many rolls of green tape we use on a boat, I cannot remember but it was somewhere around 80-100 rolls.

I assume you'll have a full dive shop on board near the nuclear reactor room for equipment to go diving near Antarctic and change props correct?

I don't need a dive shop, that is what Chris is for. If we drop a prop in 120 feet of water he would just jump overboard and swim down and get it. Probably put it on the drive on the way up.

I checked with a few companies that do make small nuclear reactors, they would cost around $400 Million. I don't think the bouncing we will be experiencing would be very safe. You can truly buy a personal nuclear reactor if you had the money. It will not be long and someone will have one in a big yacht.

We don't plan on being by the Antarctic. We will probably never go much above or below the 40th latitude north and south. The northern passage is definitely one of the long distance records I will not try to beat. Those guys are crazy.

Tyson sounds like the project is taking a positive turn, certainly the M8s will help trim the boat and certainly look a neat package. What about long-term reliability? What do you think the rebuild intervals will be on these vs. the Arnesons considering your input torque is going to be high now that your overdrive is being done in the drive.

Was it not possible to go with an OD coaxial box to get your drive input speed up and reduce the torque in the drive?

4000rpm at the motor and .80 OD in the box would give you 5000rpm drive input closer to a high HP gas motor, and more drive gear ratios to play with.



Just a thought, I am sure you have already considered this.

are we on real time, or is thread still behind actual build, like on page 1

we are on real time. Sometimes I work on it for a few days and then post pics in the next few days when I get time but we are basically on real time.

Intercoolers:

I looked for a long time and could not find cupronickel core material for the intercoolers so we just had aluminum ones made by Bell Intercoolers. They are thicker walls on the outside and the core material is thicker to handle the high boost 80psi+ and to not corrode from the salt water as fast. They are also anodized so they would last for a little while but we do know they will eventually corrode through so I need to find cupronickel core material if anyone knows where I can get it from. Or eventually I will have a second set of these made for backups.

Did you try the Parvey's ? One goes by Coolerman on this board. They are the one's (Father Dennis and son Jason...if I remember that right) that have the famous Black Thunder that laid down 150+mph at Lotto.
Here is their website's contact us page: Contact Us

Here is one of the intercoolers they make: