My post said 'for anyone who wants to dyno their engine'... (not just you).
20hp? BTR build
- Thread starter AdamJankowski51
- Start date
Pirelli MT66 is what I was thinking. I’ve seen them on Pats bikes at the bike show. They come in a 80/90-21 which is only a 1/8” wider than your beach bums and probably smaller on the OD. There is also Shinko 230. You’ll still have to run tubes if you have spoke wheels but they won’t leave the rim if they pop like bicycle tires will
Pirelli MT66-Route Tire - Dennis Kirk
With over 160,000 unique items ready to ship today, Dennis Kirk carries the largest selection of motorcycle, ATV, and snowmobile helmets, apparel, parts, and accessories.
Yeah Norm been planning a build for my new design 2-speed with a Tilly block maybe the 263cc although small block builders I know say the smaller 236cc can make more power because it is a stronger block capable of higher compression. When I have the money to start I’ll make a build thread then. Before last year I would have built it and rode it out there, but now I must have a cage around me on public roads. Been wanting to go to that event for years now.
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Motorcycle tires won't happen. The front fork has maybe. 3/16 of an inch clearance. Again a new fork is required as well as rims and spokes.Pirelli MT66 is what I was thinking. I’ve seen them on Pats bikes at the bike show. They come in a 80/90-21 which is only a 1/8” wider than your beach bums and probably smaller on the OD. There is also Shinko 230. You’ll still have to run tubes if you have spoke wheels but they won’t leave the rim if they pop like bicycle tires will
Pirelli MT66-Route Tire - Dennis Kirk
With over 160,000 unique items ready to ship today, Dennis Kirk carries the largest selection of motorcycle, ATV, and snowmobile helmets, apparel, parts, and accessories.www.denniskirk.com
Yeah Norm been planning a build for my new design 2-speed with a Tilly block maybe the 263cc although small block builders I know say the smaller 236cc can make more power because it is a stronger block capable of higher compression. When I have the money to start I’ll make a build thread then. Before last year I would have built it and rode it out there, but now I must have a cage around me on public roads. Been wanting to go to that event for years now.
Dang. 19s would look good and they have far more tire size options. A couple panic stops and you’ll be looking to replace that moped front brake… I’ll be here for ya when you’re ready
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So been working to try and get the electric up and running.
Here is what I have found out. I also found this information is near net impossible to find out easily.
Honda engineered a charging system (2 magnet flywheel) with LIGHTING COILS (not to be confused with charging coils) and a diode. This system with 2 magnet flywheels is only capable of charging at 3600 RPM... Not good for a battery above that, it will produce far too much voltage since there was no voltage regulator. Works fine with lights apparently though. So trying to hook a rectifier up to this half wave signal was not getting the voltage necessary to charge the battery. I did get some 8-10v DC after rectification at 5k or something like that.
Honda also engineered a system with a 3 pole flywheel and charging coils that uses a 3a rectifier but that wont work for my application due to the unbalanced flywheel. I also cant run a cast flywheel, you see the issue there. This system however produces a full wave signal which can be rectified and charge batteries.
So in the end I am needing to develop my own electric system with a billet 4 pole flywheel.
Here is my stator that I made, its a single phase 4 pole using 18AWG magnet wire with 27 wraps per pole. Resistance measured out at 3.4 ohms. This is my second attempt, my first ended up too thick with 3X something wraps per pole and 9 laminates of the core, it hit the flywheel and governor boss. I am going to likely need to modify the engine block where the governor pin goes even with this one but I will just weld it flat. I will also be using a different flywheel configuration. 4 N43EH heat rated Neodymium magnets with opposing poles. These will be placed in milled pockets in the back of the flywheel (new one on the way) similar to the 2 magnet configuration but much smaller and in 4 spots.
My goal is to have at least 5 amps of usable power for lights, speedo cluster, battery charging, electric start ect.
The journey for electric power continues.
Here is what I have found out. I also found this information is near net impossible to find out easily.
Honda engineered a charging system (2 magnet flywheel) with LIGHTING COILS (not to be confused with charging coils) and a diode. This system with 2 magnet flywheels is only capable of charging at 3600 RPM... Not good for a battery above that, it will produce far too much voltage since there was no voltage regulator. Works fine with lights apparently though. So trying to hook a rectifier up to this half wave signal was not getting the voltage necessary to charge the battery. I did get some 8-10v DC after rectification at 5k or something like that.
Honda also engineered a system with a 3 pole flywheel and charging coils that uses a 3a rectifier but that wont work for my application due to the unbalanced flywheel. I also cant run a cast flywheel, you see the issue there. This system however produces a full wave signal which can be rectified and charge batteries.
So in the end I am needing to develop my own electric system with a billet 4 pole flywheel.
Here is my stator that I made, its a single phase 4 pole using 18AWG magnet wire with 27 wraps per pole. Resistance measured out at 3.4 ohms. This is my second attempt, my first ended up too thick with 3X something wraps per pole and 9 laminates of the core, it hit the flywheel and governor boss. I am going to likely need to modify the engine block where the governor pin goes even with this one but I will just weld it flat. I will also be using a different flywheel configuration. 4 N43EH heat rated Neodymium magnets with opposing poles. These will be placed in milled pockets in the back of the flywheel (new one on the way) similar to the 2 magnet configuration but much smaller and in 4 spots.
My goal is to have at least 5 amps of usable power for lights, speedo cluster, battery charging, electric start ect.
The journey for electric power continues.
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I have put many electric starters on bikes with battery and never really had any problems overcharging. If you buy an electric start engine it comes with the full wiring harness with regulator, starter solenoid, key switch, etc.
I prefer using the true Honda electric start as my starting point. The components just seem better, including the flywheel. Think I saw some discussion once on cast flywheels with people saying they will come apart. There was a thread somewhere trying to locate anyone who had exploded a Honda cast flywheel and no one stepped up to say they had. Always a friend of a friend knew someone kind of thing. Now, I am in no way saying any cast flywheel is safe on a 20 hp engine. Do your own research on flywheels.
I thought someone started making billet two magnet flywheels recently.
Also, you can find the electric start wiring diagram on line and Honda even makes an electric starter kit.
I prefer using the true Honda electric start as my starting point. The components just seem better, including the flywheel. Think I saw some discussion once on cast flywheels with people saying they will come apart. There was a thread somewhere trying to locate anyone who had exploded a Honda cast flywheel and no one stepped up to say they had. Always a friend of a friend knew someone kind of thing. Now, I am in no way saying any cast flywheel is safe on a 20 hp engine. Do your own research on flywheels.
I thought someone started making billet two magnet flywheels recently.
Also, you can find the electric start wiring diagram on line and Honda even makes an electric starter kit.
Yeah, honda stuff is better. I still don't trust a cast flywheel spinning 9k or more right next to the boys.
From everything I could find the honda ignition box only has a silicon diode in it no voltage regulator. What regulator are you using?
This guy here also posted a good amount of content and what's required for everything.
Predator 212, GX200 Charging Electronics
:welcome2: This is an electronics continuation / summary of the thread started by bob58o named Predator Lighting coil. It is a story as one struggles through the challenges of figuring out most of the mechanics and electrical of this topic. Pics, Charts, Graphs! Great questions and...
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I know about over charging batteries on motorcycles. My BSA needs the lights on or battery charging can hit 15 volts. My flat track motorcycle went through a few batteries before I figured out I had a cheap regulator.
I have never popped a battery with a GX200 using the standard components. Also, 9K on a 200 is pretty optimistic. My 100cc beast which is a sleeved down GX200 for racing at Bonneville can reach 9k. My 200's never get that high. Just my experience. Your results may vary....
I have never popped a battery with a GX200 using the standard components. Also, 9K on a 200 is pretty optimistic. My 100cc beast which is a sleeved down GX200 for racing at Bonneville can reach 9k. My 200's never get that high. Just my experience. Your results may vary....
Yep batteries are getting expensive. I'm running a ebl 200 ca lithium.
I have built internals with dual valve springs stainless valves, 308 cam, arc rod, flywheel, 1.3 ratio rockers, and a shred head (not yet installed). Also I'm not anticipating 9k, I have already hit it. I prefer not to go above 8k personally.
That's cool you have a speedo and rpm gauge. What speed did you hit at 9k?
Yes, added a speedo. Ran 75mph for a split second just to say I did it. I did calibrate the speed using a GPS so it may be off by a mph or two. Although with my gearing 9k correlates to 75
Also with a keen eye you may notice the little panel added to one of your gas tanks. That's my fuel level sender.
Also with a keen eye you may notice the little panel added to one of your gas tanks. That's my fuel level sender.
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(RPM × TIRE DIAMETER × π)
÷(1056 × TOTAL REDUCTION) = MPH
So to do 75 mph on 26" tires with 9000 rpm your total reduction is around 9.28\1.
This would be based on a 100% efficiency on level ground with no wind. Which is impossible. So it would be more likely at 9000 rmp on 26" tires with a 9.28 total reduction you'd be doing around 73 mph. Some of the loss would come from possible head winds, rolling resistance, aerodynamic design, wheel hubs etc. In the event you're going faster than 75 it means there's contributing forces at play gravity, tail wind.
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Yeah, I was likely off a little on the RPM reading as I was watching the speedo which is GPS calibrated.