alj

I'm looking for all you guys who have already gone through what I'm in the middle of now! I'm looking for Kaamacat Katdrvr Fishead Fstboater perfectmix and all other KAAMA owners. For all the gory details see my thread on the Formula forum under "Expensive Weekend!" Short version... Just got my Formula F402 KAAMA in the water last weekend. Found out the hard way what happens to 20 year old three blade cleavers when you feed them 40 % more horsepower. Now need to figure out new props and am having some trouble. The boat is a monster. 40 feet, 10500lbs dry, 300 gallon fuel capacity, new 600 HP motors (originally 375 HP), Twin disc 502 trans w/ 1.54 gear ratio, KAAMA surface drive with ratio as indicated on plate "+8" which I now believe may indicate an 8% overdrive, Original props kiekaffer Short hub (4") three blade cleavers 17 x 24. Props turning in. With this set up the boat planes VERY easily. But can only reach about 4200 rpm and 50 to 52 mph. Oh... it also has a propensity for flinging prop blades off. Nice touch! There is clearly a metal failure here and you can view pics of the broken props on the "expensive weekend" thread. Props were probably fatigued and stress cracked previously. New horsepower made the F402 a labor day weekend prop stress tester and not much more! I tried a set of mercury four blade small shaft cleavers today. They are long hub (6"), 16 x 27. My thinking (flawed) was that I could use more pitch and the smaller diameter would get my rpm up and that four blades would help keep it planing well. Wrong on all counts. I could barely get it to plane., and with full plates and drives digging up turtles it took at least a third of a mile to plane off. The other noticable thing was that these four blades let the bow ride much higher. Although the boats bow up attitude was more desirable the other problem was that when I went to WOT I could only muster 3800 rpm or so and only was only getting about 40 mph. So back to the drawing board.
First thing is this drive ratio. I know most of the twin disc trannies are 1.54 but this overdrive thing in the drive ratio, how do I figure this? Some guys are telling me that their F357 which is as close in size and weight to me as I can imagine are using a 1:1 drive ratio. So when everyone else is saying "use a 27 pitch prop!" Is my ratio different and should I be using something else? What does the plate on a KAAMA drive say when it is a 1:1 ratio? Does it say "0" or something like that? Without considering all that, it seems I should be running a much smaller pitched prop, like a 24 or even a 22. That seems ridiculous, but if the drive is geared funny, is going to a wildly smaller pitch the right way to go? Also I believe I should be in the 16.5" or even 16" diameter category in order to help my rpm increase at top end. I need to get to about 5400 or 5500 rpm to really take advantage of the engines peak power but I'll be happy with 5200. After blowing two short hub props apart I know I want a long hub four blade for the increased strength. You KAAMA guys have been through some of this. Can I make a 27 pitch prop work with a drive gear change? Or do I need the elusive 22 pitch four blade cleavers? Any way, any help and advice is tremendously appreciated. Thanks....Al

fishead

I feel your pain.The +8 means an 8% overdrive.You are pushing a heavy boat.I am running 28 inch 4 blade long hub props.I changed the gear ratio to a 13% overdrive just recently but have not had the boat out to test.I do have a spare set of 3 Blade 29 pitch as a backup.I can send these to you if you want to try.It is all trial and error.I think Kaama cat was using 4 blade 26 pitch with an 8% overdrive and he had 450hp 454's.His boat was about 7k on the weight.That thing would cruise at 70mph at 3500 rpm.Give me a call in the evenings at 770-949-3746 after 8 in the evenings if you want to talk.
Mark
aka fishead

alj

Fishead, I'll try you monday night

alj

Ok, found out I have 8 % overdrive in the KAAMA's. Effective ratio is like 1.42 . Like a highway gear in a car so it's holding down RPM and motors aren't getting into the powerband probably. So now I need props that are something like a 16" diameter x 22 or 23 pitch which seems ridiculous but??..... other option is changing gearsets in drives to the 1:1 ratio. Does anyone know anything about a KAAMA 1:1 gearset or maybe have two sets of gears laying around? I'm thinking if I change to the 1:1 gearsets that I can use 24 or 25 pitch props that will be way easier to find for sale. Anybody have any info or ideas?

fishead

The gears are made by Cassale,the same people who make the v drive setups,I think they are in CA.You can get an idea of costs of gears from CP performance,they sell them.
Mark

watkinsco

Casale V-Drives

Casale Engineering
13030 Telegraph Rd,
Santa Fe Springs, CA 90670

(562) 906-4825

Does anyone have any info about Arena Surface Drives?

alj

Hey watkinsco,
Thanks for the address on casale. Do you mean Arneson Drives? If so, do a search in the forums on "Arneson". I think you will find anything you want to know and more. Welcome to the world of Offshore Only!
Al J.

watkinsco

glad i could help, from my old flat bottom days.

I found a Dan Arena original "Arena Surface Drive" in a boneyard in Costa Mesa, CA. From my understanding, Dan got the first patent on surface drives in the early '70s. Arneson's drive came afterwords. It is a stainless steel unit with no trim with the prop shaft as a #2. It hangs off the back of the transom about 5 feet with a standoff box. I talked to Dan once in the early '90s before he passed away as he was living in northern CA at the time. He went on and on about the thing until i mentioned that i might be interested in building them for him. I own a machine shop. He became real hesitant and we just kind of left it at that. I found out that he was pretty overly protective of his drive and never got into any big production.

On another note, I know of a couple of the engineers who helped develop the Kaama drive. They live in my area and we have worked on other projects before. If you have any questions, let me know.

Rik

Dan Arena, aka one of the first people to go 100 mph in a boat. Dan raced gold cup boats from the 30’s and on till??

Dan also made his own line of boats called “Arena Craft” from the 50’s onward to the mid 80’s I believe.

Dan built a boat for Howard Arneson in the early 70’s (39’?) and this is when we were still using fixed shafts and rudders. Later Howard developed his surface drive and after that Dan made his version of a fixed surface drive. Essentially it is an “I Beam” with a shaft coming out the bottom with a rudder on the back of it.

Look up the CA 1000 drive? Conner’s made this with $$$$$$’s money and it is very similar in design to Dan’s drive unit.

As far as gears for the KAAMA call Archer Marine in Costa Mesa, 949-646-9778

PatriYacht

I have an old pair of 17 x 21 3 blade cleavers. I'm not sure if they would fit but they do fit on a trs shaft. Would they be for a #2 speedmaster? Any way, you can try them if you want to pay for the shipping.