SV 26cc please help
10-22-2012, 02:06 PM
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SV 26cc please help
I bought this piper super cub on floats and need some help getting familiar with this engine. I decided to make the leap from 40 size glow planes to a gas 1/4 scale. Prior to buying this plane Saturday I've only flown 40 size glow engines. The way the prop attaches to the hub is not what I'm used to seeing. On my glow engines it has one nut to tighten if you're not running a spinner. This engine, on the other hand, has four bolt holes. Two of which were not utilized. Upon getting the plane home and testing the engine in my backyard, the prop flew off. The two bolts that were holding the prop on are now bent and I believe the holes are stripped too but won't know unless I get a couple new bolts to try out. My question is, does anybody know if they sell an adapter for this engine that would have the single bolt I'm used to or will I have to replace the hub with the same kind and drill holes in a new prop? Also, is this configuration common for 26cc gas motors or is this only because it is a Chinese brand? Any help would be greatly appreciated.
Thanks,
Ryan
Thanks,
Ryan
10-22-2012, 02:15 PM
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RE: SV 26cc please help
The gas engines have more torque than the glow engines, hence the 4 bolts to take the torque load. I think that's something that you will have to get used to. Other than the small bother when fitting a new prop, it's not really that bad. Is it? Sort of like going from an automatic to a stick shift. It just takes getting used to.
Just my $.02 worth.
Just my $.02 worth.
10-22-2012, 03:20 PM
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RE: SV 26cc please help
I would replace the prop hub for sure. Drill a new prop and use all four bolts. After every flwing day, ensure those bolts are tight. The wood can crush down over time causing the holes to open & vibrate the prop loose. Just as you've seen how much torque gassers have. The reason behind changing the prop hub to a new one: vibration. That's the last thing you need is that motor coming loose at speed or a ground run-up.
Jack
Jack
10-22-2012, 03:27 PM
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RE: SV 26cc please help
Okay, if I have to replace the hub, is there a special socket for it because my standard deep well socket from my tool kit isn't long enough. I think I'll watch a youtube video on prop balancing before trying to install a new prop. Is there a jig for drilling so I get the holes perfect? Also, I bet it's going to be close to impossible to find a new prop hub for this sv 26.
10-22-2012, 03:40 PM
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RE: SV 26cc please help
ORIGINAL: rsdonomoore
I bought this piper super cub on floats and need some help getting familiar with this engine. I decided to make the leap from 40 size glow planes to a gas 1/4 scale. Prior to buying this plane Saturday I've only flown 40 size glow engines. The way the prop attaches to the hub is not what I'm used to seeing. On my glow engines it has one nut to tighten if you're not running a spinner. This engine, on the other hand, has four bolt holes. Two of which were not utilized. Upon getting the plane home and testing the engine in my backyard, the prop flew off. The two bolts that were holding the prop on are now bent and I believe the holes are stripped too but won't know unless I get a couple new bolts to try out. My question is, does anybody know if they sell an adapter for this engine that would have the single bolt I'm used to or will I have to replace the hub with the same kind and drill holes in a new prop? Also, is this configuration common for 26cc gas motors or is this only because it is a Chinese brand? Any help would be greatly appreciated.
Thanks,
Ryan
I bought this piper super cub on floats and need some help getting familiar with this engine. I decided to make the leap from 40 size glow planes to a gas 1/4 scale. Prior to buying this plane Saturday I've only flown 40 size glow engines. The way the prop attaches to the hub is not what I'm used to seeing. On my glow engines it has one nut to tighten if you're not running a spinner. This engine, on the other hand, has four bolt holes. Two of which were not utilized. Upon getting the plane home and testing the engine in my backyard, the prop flew off. The two bolts that were holding the prop on are now bent and I believe the holes are stripped too but won't know unless I get a couple new bolts to try out. My question is, does anybody know if they sell an adapter for this engine that would have the single bolt I'm used to or will I have to replace the hub with the same kind and drill holes in a new prop? Also, is this configuration common for 26cc gas motors or is this only because it is a Chinese brand? Any help would be greatly appreciated.
Thanks,
Ryan
I would get a die and put threads on the shaft that you have. I use one bolt or nut on everything up to and including 62cc engines. The shaft is probably 8mm so you could either do 8mm or 1/4x28. I'd do threads to about 3/8" of the prop drive, you'll find that the props for this size engine have 8mm holes unless the prop is made in USA, Zingers at TopFlight are really good for mixing paint.[
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10-22-2012, 03:44 PM
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RE: SV 26cc please help
Rich,
That sounds like a good idea and would be a quick fix. A nut seems better than those cheesy little bolts, in my opinion. Where's a good place to get a die kit or do you have a recommendation on a brand that you've used in the past?
Thanks
That sounds like a good idea and would be a quick fix. A nut seems better than those cheesy little bolts, in my opinion. Where's a good place to get a die kit or do you have a recommendation on a brand that you've used in the past?
Thanks
10-22-2012, 03:52 PM
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RE: SV 26cc please help
If you want metric, Harbor Freight sells cheap tools, how good do you need for one thread? Though if you buy just the 8mm die you might be able to get a good one cheaper at a auto-parts store than the set you would have to buy at HF.
10-22-2012, 03:55 PM
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RE: SV 26cc please help
I see your point. I'll check harbor freight tomorrow. Thanks for the info. I was just looking at the zenoah 26cc and it looks like they use the prop nut and washer as well instead of the four bolts that the sv was designed with so I think it will work.
10-22-2012, 04:14 PM
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RE: SV 26cc please help
Oh cool! Did your SV come with the nut or was it like mine? I bought the plane used so I'm not sure if he's modified it in any way.
