1/2A OPC?? :^)

[Darin Jordan]

So, now that NAMBA has officially recognized 1/2A as an official Engine Class... Perhaps it's time to dust off those older, 24"-ish sized 3.5 hulls...

Ducking under my chair now...

1/2A Mod! A nice Novarossi .12 on an older K&B Lower... SWEET!

 

[Marty Davis]

WOW, that is a good thing. ANOTHER new class? I guess we should stop at 100 or so.

 

[RonShaw]

Darin,

Do you know anyone that makes a reverse crank for a NR 12?

 

[Darin Jordan]

Darin,

Do you know anyone that makes a reverse crank for a NR 12?

Hahaha... Ron... you could have just stopped at "Do you know anyone..."...

I don't. I could ask Glenn at the next D8 club meet.

I was just kind of joshin around, guys. I know we need another class like we need holes in our heads.

It just dawned on me that the class is technically allowed now, so I figured I'd wake the forum up a bit.

 

[Darin Jordan]

That being said, however... it would be fun to SAW or TT something like that...

 

[RonShaw]

Lol. Yes, mention it to Glenn. Maybe he has some ideas. Rod did it with a special gear drive unit so he could swing larger props. His used a traditional engine retrofitted to a lower as no reverse crank or PTO is available. There are some pics of his setup floating around.

 

[Darin Jordan]

Lol. Yes, mention it to Glenn. Maybe he has some ideas. Rod did it with a special gear drive unit so he could swing larger props. His used a traditional engine retrofitted to a lower as no reverse crank or PTO is available. There are some pics of his setup floating around.

I suppose one could rig a geardrive setup to reverse the propshaft rotation... It would sound cool leaned out and on the pipe flying through the timing lights...

(notice I'm testing out my Nitro lingo... Racing with D8, I think it's time to expand my fleet beyond FE, perhaps with an A-Stock OPC for starters, and maybe a .12 Hydro)

 

[lohring]

With the long ago death of K&B we really only have one stock outboard class, the 3.5. There are only two lower units in production, the OS and the Thundertiger. Sure you can look on ebay or in your junk pile if you've been around a while and put together something, but production units are the future. Both of the above lower units are a little big for the .12 (2 cc) engines. The Thundertiger has the advantage of not needing a reverse rotation, but the gear drag might be too much for a .12. I would consider an Irwin style adapter like the one pictured below for a CMB 7.5. That way you can run a cable drive with an OS or lawless lower and an RC car engine. If you wanted to get really serious you could run Mike Bontoft's style outboard. (see below)

Lohring Miller

PS: I see gas outboards as well as 2 and 3 cc mod (maybe 3.5 stock) as the future of outboard racing.

 

[Grimracer]

As confusing as the lettering scheme can be to some I have never understood why NAMBA jumped ship and one upped each letter displacement..lol..





I would have liked to have sat in on that meeting..lol.. Even the two rocket organizations follow “like” letter sizing.


Grim

 

[TomMoorehouse]

I did read the title and thought, wow an .049 cox powered tunnel!

 

[RonShaw]

Lol.

 

[Tim_Duggan]

Lohring's TT lower idea has merits (if it goes on a diet). The 1.28:1 gear reduction set in particular would allow the use of 3.5 sized props (keeping in mind the available 3/16" bore 1.4 pitch ratio props only goes down to 37mm). Most 12's are available with pull start cranks so have the extended pin. Would just need to fab up a PTO. A 12 spinning at 36KRPM (possible with the right combo!) would translate to about 28KRPM at the prop. Pretty good.....

 

[RaceMechaniX]

I dug up some pics for inspiration. Darin you could do something like Chris Fine.

 

[Geraghty]

Lol. Yes, mention it to Glenn. Maybe he has some ideas. Rod did it with a special gear drive unit so he could swing larger props. His used a traditional engine retrofitted to a lower as no reverse crank or PTO is available. There are some pics of his setup floating around.

Actually David Hall is the boater that built the gearbox for the .12 Novarossi to change the rotation of the motor for outboard use....This setup holds the IMPBA .12 SAW record....

The record was set in 2006 and there is still a ton left in that boat/motor combo.....Just waiting to have it challenged and it will come off the shelf.. I will try to post some photos of the boat,motor & gearbox....

 

[Geraghty]

Here are the photos of the .12 tunnel/motor/gearbox combo that currently holds the IMPBA SAW record....

We have a new boat that this motor will go on to eventually assault the .12 tunnel 2-lap record....

 

[Darin Jordan]

Rod... you guys are amazing! Guess that shouldn't come as a surprise!

Thanks for sharing. No plans to try to challenge any SAW records, but it fun to see that this can and has been done by others. Makes me not look quite so NUTS to the guys here in our district.

 

[Bob Kensill]

Graupner f1 Sirio .12 outboard

 

[Jerry Dunlap]

Rod... you guys are amazing! Guess that shouldn't come as a surprise!

Thanks for sharing. No plans to try to challenge any SAW records, but it fun to see that this can and has been done by others. Makes me not look quite so NUTS to the guys here in our district.

Well, I wouldn't go that far.

Jerry

 

[Darin Jordan]

Rod... you guys are amazing! Guess that shouldn't come as a surprise!

Thanks for sharing. No plans to try to challenge any SAW records, but it fun to see that this can and has been done by others. Makes me not look quite so NUTS to the guys here in our district.

Well, I wouldn't go that far.

Jerry

UMPH!

 

[lohring]

As usual, Rod has a great setup. I still think the gearing loss may be a problem, but it would be very small in a well designed spir gear setup like Rod's. I am in the process of installing a new (to me) lathe. After the workshop revamp, the adapter would be a fun project.

Lohring Miller