Towers anyone ?

[will350]

While I'm pondering the boat thing..... I got to thinking about the ignition on my Rotax. Right now it has a "2 of everything" Bosche set up.2 coils,two triggers and an adjustable stator(so are the triggers) the interupter for the triggers is a round piece of 1/2" plate bolted to the flywheel.Needless to say,there is a bunch of reciprocating weight.
Now,right off I realize how archaic points systems are,but there is some rational behind this. My line of thought is that a points setup in a V8 fires 20,000 times @ 5,000 rpm and if I do the Polaris thing(both fire at once) then
my points are only going to have to carry a little more than half that.
With no advance or high rpm retard,it won't as "good" as it could and it might bite your arm off without some sort of retard(I can "do" something about that) I'll have to carry a battery but then I'll lose enough in the flywheel and trigger plate to offset the extra. So..... Am I way off on this
or does this sound promising?
Will

[Tim Chance]

Will,
With those intended speeds, you'll need around 90" - 92" afterplane. 60" sponsons and your overall lengtht will be around 12'6" With the light weight engines, 35" or 36" wide bottom would work fine.

Regards
Lee

I agree on the boat size. I have built several boats and driven many times where the boat was overpowered (or maybe the power was underboated). You're going to have to be over 12' to be ok in the 100 mph range. Plus the boat will need a proper ratio of the length of the sponson to the length of the boat. The worse boat I ever had, while its length was ok, had sponsons that were too short. It would drop a sponson, which would then act as a fulcrum and the tail of the boat would come up and around like a big lever. It put the previous driver in the hospital and out of racing. When it did it to me - fortunately I didn't get cut or hurt - I took the hardware off and used for firewood. So my advice is stay away from sponsons that are too short and pick a length that is suitable to the expected speed.

[JohnsonM50]

This is the "initial ( ?) rough lay out . It's kind of strange looking but the camera wouldn't pickup the scribed lines , hence the blue tape .
The pieces are slightly over finished size at 6"X19" for the 350 and .......
6"X25" for the 500 ( That's right, a 500 Polaris triple ) The L/U plates are
the same size at 4 3/4"X10". The side plates are roughly sized and will have
to be "custom " fitted and cut to final shape after the L/u plate is in it's proper place .
The first order of business is to cut out the rough pieces . That's the easy part . The hard part will the finished plate . I'm pretty finicky and if I had my "druthers " , I'd be hauling this stuff off to the machine shop and have them machine it to my specs but "Mr. bank account " is telling me to go buy a cheap saw and a decent blade and spend a few days filing and checking and filing and checking some more until I run out of patience or it's "good enough" to satisfy my critical eye . So.............................
I'm off to fight my way through the busiest shopping day of the year ......
Will

A carbide blade will cut Al. and barely go dull and for her curves Id suggest a Bosch jig saw w/ not too fine metal cutting blades.

[Roy Hodges]

Roy,
Yes I do offer one to fit the OMC 3 Cylinder, It looks very similar to the D mod in the pictures. The only difference is an adapter plate to attach the power head to the tower. Its the same swivel and clamp assembly.
Price $950.00

Question; will a Bass lower unit bolt on, without alterations ?

[Lee Tietze]

I can machine the tower to fit any gearcase. The bass case has the same bolt pattern as the Konig, Konny and Rossi gearcases. If you change your mind, you can always add a 1/2" thick adapter plate to fit anything else.

Regards
Lee Tietze

Machined Components
Aluminum, Try Racing Without it!

[will350]

After a fair amount of thinking about it,I've decided to copy the boat I have with some changes. Lengthen the after plane some(86" now)lengthen the sponsons to "match",change the nontrips to more of an inboard style and maybe the sponsons too(I will definately make them "round nosed).
I'm probably going to actually HAVE to draw this out as I don't think I can do the "cut and try"method that I use on my towers.
The boat runs pretty fair now and it's a temptation just to copy it as it stands but.....This may turn out looking like Holmbergs D stock Jones but I could live with that.
Will
'

Well,now I am in the indecisive mode... When I got the plans from Ed,I explained that I wanted it to be "good" to 100. I think I'm going to have to go and visit Ed again. The motors I run are anything but "lightweights".
They're about D stock weight( + or - a few pounds) so building something that "has" to have a light motor to perform is not going to work for me.
However,I may have enough material to build a boat and 3/4s(I'll have to study on this a bit) and if that's the case,building one to Ed's specs and "something else" may be how this is going to go. The D boat that I originally ran these on was a wonderful little thing,no surprises and very sensitive to position, but then the best I ever did was 73 with a bone stock 302 lower which is probably close to the limit of a stock case.I know that with the nose cone,there will a pretty fair jump in speed.
I may go to the drawing board myself on this,but will probably need more input. Don't want to blow my meager funding and time on something that will wind up being a warm glow for a beer drinking party.
Any thoughts,ideas are more than welcome.
Will

[will350]

I present,for your consideration,9 and 3/4 pounds of Rotax ignition....
The flywheel by itself weighs almost 7 pounds.I'll give you one guess as to where all this is going to go.I'm not going to use the "traditional"wet cell battery for this.Instead I'm probably going to run some sort of dry cell pack.
Maybe lithium ions.It won't have the best and finest of "advance curve technology",but the set up I'm thinking about should do the job.Simple,easy to time and maintain,and really inexpensive.Besides that,I get to shed 10+ lbs
by the time I get through chopping off some of the housing.
Stay tuned ,I'll keep you posted.
Will
(I guess I'll just have to post a picture when this thing will let me)

While I'm pondering the boat thing..... I got to thinking about the ignition on my Rotax. Right now it has a "2 of everything" Bosche set up.2 coils,two triggers and an adjustable stator(so are the triggers) the interupter for the triggers is a round piece of 1/2" plate bolted to the flywheel.Needless to say,there is a bunch of reciprocating weight.
Now,right off I realize how archaic points systems are,but there is some rational behind this. My line of thought is that a points setup in a V8 fires 20,000 times @ 5,000 rpm and if I do the Polaris thing(both fire at once) then
my points are only going to have to carry a little more than half that.
With no advance or high rpm retard,it won't as "good" as it could and it might bite your arm off without some sort of retard(I can "do" something about that) I'll have to carry a battery but then I'll lose enough in the flywheel and trigger plate to offset the extra. So..... Am I way off on this
or does this sound promising?
Will

[Roy Hodges]

you have a bunch of Rotating weight, not reciprocating -
the connecting rod reciprocates

[will350]

I stand corrected,but you got admit,that's a hefty amount.
Will

you have a bunch of Rotating weight, not reciprocating -
the connecting rod reciprocates

[Roy Hodges]

I stand corrected,but you got admit,that's a hefty amount.
Will

..............................O K , I will ADMIT its hefty , i mean ,that's a whole buncha unwanted weight -you're right !.............HMMmmmn ? I wonder what weight watchers or Jenny Craig could do for "your problem" ?