.12/.15 engine
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.12/.15 engine
Well guys I think I want to dig my boat designs back out. I really like this new "class" of .12/.15 sized boats. What are some of the engines that are being used in these boats? I will be running them in an outrigger. I see that there is a number of the .12's on eBay.
Thanks for the help,
Tim
Thanks for the help,
Tim
#2
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RE: .12/.15 engine
Right now the O.S.'s seem to be the hot ones. I'm still waiting for CMD Racing to come out with the new A/A .12. Think of it as a small MAC engine. I see that there is some work going on with a new tuned pipe, they're calling it a square wave pipe. It's a little hard to explain right now.
If you want to make it IMPBA legal, stay with the .12's unless you have no plans of racing it.
When shopping for a .12-.18 for a boat, try to find one with the long threaded shaft, no short cut ones like for Associated vehicles or SG shafts otherwise you'll run into hardware problems. A rotary carb is easier to set up than a slide carb.
The class, "A", hasn't been used yet at any race that I know of. The Hydro Masters meet in September is considering it and has had a lot of interest so far so it looks like it will be a go.
If you need some help along the way, I've had quite a bit of experience playing with the .12's the past few years and having a blast making mine scoot, both monos and 'riggers.
If you want to make it IMPBA legal, stay with the .12's unless you have no plans of racing it.
When shopping for a .12-.18 for a boat, try to find one with the long threaded shaft, no short cut ones like for Associated vehicles or SG shafts otherwise you'll run into hardware problems. A rotary carb is easier to set up than a slide carb.
The class, "A", hasn't been used yet at any race that I know of. The Hydro Masters meet in September is considering it and has had a lot of interest so far so it looks like it will be a go.
If you need some help along the way, I've had quite a bit of experience playing with the .12's the past few years and having a blast making mine scoot, both monos and 'riggers.
#3
My Feedback: (12)
RE: .12/.15 engine
Tim, listen to Ron's advice about staying within the IMPBA classes, you NEED to join some of our races when you're ready. It's a great group of guys. However, as Ron said, the .12 class doesn't have much activity yet. We have a couple guys with .21 size riggers, but no .12s.
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RE: .12/.15 engine
Ron, Chuck,
Thanks for the info guys. Looks like I'll go with a .12 sized boat now then. I was looking at the NovaRossi .12 RE and the HPI Nitro Star .12R for engines. I can make up a flywheel on my lathe and am drawing up some ideas for the rearend hardware that I would like to make on my milling machine.
I think before I get to far into a .12 size rigger I am going to build up a 1/2a sized rigger to run one of my Sniper DR .049's in. Something about 12" long 8"wide. Balsa over foam sponsons and balsa tub. Only hard thing will be digging up a small enough prop for it...hummm that might be hard to find[:@]
LAter,
Tim
Thanks for the info guys. Looks like I'll go with a .12 sized boat now then. I was looking at the NovaRossi .12 RE and the HPI Nitro Star .12R for engines. I can make up a flywheel on my lathe and am drawing up some ideas for the rearend hardware that I would like to make on my milling machine.
I think before I get to far into a .12 size rigger I am going to build up a 1/2a sized rigger to run one of my Sniper DR .049's in. Something about 12" long 8"wide. Balsa over foam sponsons and balsa tub. Only hard thing will be digging up a small enough prop for it...hummm that might be hard to find[:@]
LAter,
Tim
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RE: .12/.15 engine
ORIGINAL: Tim Wiltse-RCU
I think before I get to far into a .12 size rigger I am going to build up a 1/2a sized rigger to run one of my Sniper DR .049's in. Something about 12" long 8"wide. Balsa over foam sponsons and balsa tub. Only hard thing will be digging up a small enough prop for it...hummm that might be hard to find[:@]
I think before I get to far into a .12 size rigger I am going to build up a 1/2a sized rigger to run one of my Sniper DR .049's in. Something about 12" long 8"wide. Balsa over foam sponsons and balsa tub. Only hard thing will be digging up a small enough prop for it...hummm that might be hard to find[:@]
EDIT: I take the head off first and the back plate. Then use 2 or 3 snap ties and insert them through the exhaust when the piston is below the exhaust port. Then I rotate the crank to push the cylinder sleeve out. Once the sleeve is out I find positioning the piston at TDC and sliding the connecting rod off the crank to be the easiest. Then pull the piston out the top.
Ryan
#7
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RE: .12/.15 engine
We were thinking of downsizing the Hammerhead .12 just for the heck of it for 1/2-A power. There are props that can be used as Dumas and Octura both make them that small, X-427 and X-430.
www.microhydros.com has a lot of plans for boats this small.
www.microhydros.com has a lot of plans for boats this small.
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RE: .12/.15 engine
What speeds would be possible from such a small boat? Also how stable would it be at these speeds? 1/2A power has a cheap running cost compared to the larger engines. It would be great to have one of these in the fleet.
Thanks, Ryan
Thanks, Ryan
#10
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RE: .12/.15 engine
I wouldn't expect it to be a speed demon but maybe fast enough to be fun. Stability shouldn't be a problem except for water conditions as you'd need pretty much an almost glasslike surface to run a lt of them.
The Dumas Short Stuff and Lil Rascal were both built for .049's to .10's originally.
My .12 boats only have 4 oz. tanks and I have a blast plus a lot of run time with them.
The Dumas Short Stuff and Lil Rascal were both built for .049's to .10's originally.
My .12 boats only have 4 oz. tanks and I have a blast plus a lot of run time with them.
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RE: .12/.15 engine
Dumas Short Stuff, that sounds familiar. I believe it is a deep vee but I could be wrong. I have a .15 size engine with a 4oz tank and I achieve about 15-20 minutes of fun. What size fuel cell would the 049 use? Somewhere around 2oz - 75cc?
Ryan
Ryan
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RE: .12/.15 engine
Well it's been 15 years since I last made a hydro to run a .049. It was a Dumas Atlas Van Lines with a straight shaft. Big heavy standard size servo(only rudder) and a standard i.e. sized rx battery. With todays modern radios and gear and construction methods a guy could make a boat that would really move(for its size).
A good tank size is 1oz for a .049/.061 engine. The Norvel line of engines are around $50.00 and are very powerful. I know it's more or less apples to oranges but a Norvel .049/.061 can turn 23,000 rpm without breaking a sweet. I made a rear disk valve conversion for the old Cox reed valve engines and it will turn 23,000 also. Here is a picture of my engine conversion I make( and anodized) as well as my 1/2a sized carbon fiber tuned pipe I made.
LAter,Tim
A good tank size is 1oz for a .049/.061 engine. The Norvel line of engines are around $50.00 and are very powerful. I know it's more or less apples to oranges but a Norvel .049/.061 can turn 23,000 rpm without breaking a sweet. I made a rear disk valve conversion for the old Cox reed valve engines and it will turn 23,000 also. Here is a picture of my engine conversion I make( and anodized) as well as my 1/2a sized carbon fiber tuned pipe I made.
LAter,Tim
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RE: .12/.15 engine
They both look amazing! How would you set these engines up to fit standard running gear for a boat? Do they have a standard 5mm crank like the .15 or are they much smaller?
Ryan
Ryan