Roddie-Rigger.. a 2005 original design

Looks great, Roddie, precise down to the smallest detail!!

Looking forward to the mer-maiden run! Any water surface near you where you will try her? Hopefully weather permitting..

Where is the water intake point for the engine jacket cooling circuit, is it pointing forward somewhere below the waterline, or behind and facing the prop, like on an outboard Mercury?

BTW Mercury, my first encounter with American engine technology dates back to the early '70-s when on lake Balaton in Hungary some folks had motor boats powered by beautiful American black Mercuries, white Evinrudes and white Johnsons..my father was a well-to-do doctor and fan of motorboating, towing my sister and me on waterskis behind his boat powered by a 50 HP outboard  Mercury and later,  a brand new Johnson 50 that I have no idea how he could get hold of behind the Iron Curtain where American engines - including COX - were absolute rarities..( he also got me a COX Super Sport Trainer in '75 and how, remains a mistery to me...) no IC engines are permitted on the lake anymore, but my memories of those summers still make me smile...

Yes, Bob, I do not miss the jetskis and powerboats, this lake is about 600 square kilometers with an average depth of 3meters, so it would not easily heal itself if the powerboats of nowadays were allowed..it has enough challenges due to droughts and hot summers already...and despite the motorboats banned it still gets overloaded in the tourist season by local and foreign visitors..

She looks really Good Roddie ! hope ur parts get there soon ready for a test ride

Turned out very nice Roddie!!….. I think a balloon tank would serve well for your boat…. You can make one up and practice filling an evacuating the air on the test bench…. They give clean runs for 1/2A engines….

I seal up everything possible and bag the RX. Way too many holes in your project water weight will bog the
engine down. You will learn more by water runs if that ever happens. Too many things to point out best you
walk the path and learn what last / what works.

Best wishes rare to see anyone attempt 1/2A boats.

Behold the fastest 2 ch .8cc 1/2A rigger on Youtube aka my design with ply const.

.05

19,336 views Oct 9, 2016
1st Run - Picco P-Zero Outrigger Hydro Profi Tuned Pipe!
.85cc / .050 cu. in. / 1/2A car engine converted for boats.
Very stable, design with unique sponsons for it's time.
Will do another vid after the setup is tweaked out.
True 3 point Hydro riding on the prop hub- no assistance / rear ramp.
Stock Octura X427 / 20% castor 30% Nitro. Per Doppler analysis.
Best pass read thus far hit 62.25 Kph or 38.7 mph. / 27,290 rpm
The cooling head car type makes it look like a .12 engine.

Empty weight of the plywood hull & carbon tubes 180g
196g fuel proofed less all gear / hardware. Ply sheet covered balsa
core sponsons. All up weight will check: 534.9g / 18.86oz dry weight and
555.6g or 19.59 oz with 2oz fuel.
Water cooled head. 165 deg. timing Profi .8cc tuned pipe / .062 wire drive.

Tub: 20.5" L x 2.5"W / Inside Sponson Width: 16.5in
Total Length Transom to Sponson Tip 26.25" / Sponson Ride pad width .98" each



2,813 views Nov 22, 2016
Picco P-Zero .05 / .85cc engine 2nd Vid
Profi 1cc Tuned Pipe - Cut Octura to 1426 de-tongued 1.8" total pitch.
Static rpm on the field bench hit tad over 50,000 rpm.
RPM higher than the stock X427 prop, best pass 36,902 rpm
Med lift prop. 30% nitro / 20% castor. Best note pass 43 mph.
Suspect the drive shaft was slipping. Good size running area,
water buoy race layout for the big gas boats. Rare flat water.

.07



1,353 views Mar 16, 2017
SH-.07 / 1.14cc converted car engine. 38,680 rpm static / 30% nitro / 20% oil.
With only a few mins. at a rich idle I leaned it up just enough to stage the engine on the pipe for a brief rpm check should do about 44k + Needle valve set about 3/4th to 1 turn rich per this vid. Belt started with the plug a bit loose the smoke was from the fuel still burning off around the plug. Low end needle setting from the factory was good for a great idle, can go much lower need to adjust the carb barrel to close down more. Update- finished rigger with sponsons ready to run: 457g / 16.12oz less fuel.

Great 1/2A boat engine can recommend!
7CXP Side Exhaust Nitro Engine Factory Specs:
Brand: HSP
Item No.: PT0701A1
Capacity: 1.14CC
Bore: 11.50mm
Stroke: 11.0mm
R.P.M: 31000
Power: 0.65HP
Weight: 125g