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 mph at 9000 rpm, 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.
So haven't posted in awhile due to winter rolling in and some issues. I have finalized my build finally and added all the nick knacks any enthusiast would desire.
First the bad.
I found the limit of when a piston starts to get weak due to over temp. Cruising along at around 45-50mph for 5 min or so I ended up cracking a ring land on my first motor. This was likely due to over temp as I had no cooling shroud and extremely high compression pushing 15:1 + on 93 pump gas (yes i know. ) I decided to completely rebuild the motor with a new block and start over due to modifications of the flywheel (removal of the cooling fins), I had cracked a mount which was welded, and the bore was showing some wear as I had about 800 miles on it. I also discovered that the piston was likely tapping the head at high RPM. I only had about .02 of squish and the heads carbon buildup showed some marks from the top of the piston.
Fast forward.
Motor is rebuild with 14:1 compression and I'm now running E85, fan shroud, and new pvl flywheel. So the bike is now an alcoholic as well. Internals are the same except I'm running a dished piston instead of a flat top and a .04 head gasket. So Arc rod, 1.3 ratio rockers, 308 cam, Honda crankshaft, shred head, stainless valves, dual valve springs. I upgraded the carb to a Nibbi PWK 28 as the round slide would sometimes vibrate so much it caused the RPM to stay elevated. With the PWK I can have hose mount to dampen the vibration and stop that. Still in the process of dialing in the jetting which is helped with the aid of a wideband O2 sensor. I also added a cylinder head temp gauge. Currently its mounted on the side of the cylinder so I'm looking at getting a sparkplug mounted sensor for better accuracy and normalcy with what the karting world knows.
Upgraded the flywheel magnets to neodymium for charging at lower RPM. Beautiful thing is the new flywheel is a ARC racing PVL and it sticks out further allowing for more clearance behind in the coil area. The PVL coil also retards the timing to 10 deg before TDC allowing for easy starting and zero kickback issues while cranking. With the new magnets and stock coils I'm getting 10vac at 2k and over 30vac at 5k. My current rectifier does not have voltage control as it was designed to be a constant RPM rectifier, so I'm looking at a Honda xr400 motorcycle rectifier which fits the bill. Based on research this should do the trick.
Battery is bigger as the previous one barely had enough to get the motor to turn properly and overall needed a size increase. Redid the wiring harness due to me just not liking the overall look. I found some really cool woven cloth heat shrink tubing which looks fantastic when you do it right. I also added another tail light to provide lighting to the license plate area.
Braking in the front was also something to be desired with the C6 Worksman drum brake. I found a Honda CB350 brake drum with dual lever design looked really neat so that made it into the build. Braking is now on par with where it needs to be. The rear is a 100mm Motobecane drum which has reasonable braking as it is.
I redid the exhaust due to a weld fracturing, yes I back purged while welding. As you can see I added a flex pipe to the design helping reduce the amount of stress the pipe has to deal with. This is also upgraded to 1.5" pipe. Its louder now so I'm looking at installing a muffler to help tame it down some.
The fork also gave me something to be desired. The bicycle fork just felt flimsy and the design was not meant for 50mph+ so after doing some research and opting not to build my own I found a Kicker 5150 mini motorcycle fork was the ticket. It is a true triple tree design which greatly increases the stiffness and feel of the front end. I also added some oil lite bushings and shoulder bolts for the pivot locations as I didn't like the original Kicker design and needed new pivot mounts anyway.
I added a oil catch tank as without it I constantly got oil dripping out the breather tube. Used 6an fittings and braded hose for the install. Looks quite slick.
There were a few other things I didn't like, kickstand, turn signal and starter controls, no key for ignition, those all got redone.
Overall the build is about done and ready to be torn down so the frame can get stripped and powder coated. I have learned a lot, developed some new territory things and and had a lot of fun doing it.
First the bad.
I found the limit of when a piston starts to get weak due to over temp. Cruising along at around 45-50mph for 5 min or so I ended up cracking a ring land on my first motor. This was likely due to over temp as I had no cooling shroud and extremely high compression pushing 15:1 + on 93 pump gas (yes i know
. ) I decided to completely rebuild the motor with a new block and start over due to modifications of the flywheel (removal of the cooling fins), I had cracked a mount which was welded, and the bore was showing some wear as I had about 800 miles on it. I also discovered that the piston was likely tapping the head at high RPM. I only had about .02 of squish and the heads carbon buildup showed some marks from the top of the piston. Fast forward.
Motor is rebuild with 14:1 compression and I'm now running E85, fan shroud, and new pvl flywheel. So the bike is now an alcoholic as well. Internals are the same except I'm running a dished piston instead of a flat top and a .04 head gasket. So Arc rod, 1.3 ratio rockers, 308 cam, Honda crankshaft, shred head, stainless valves, dual valve springs. I upgraded the carb to a Nibbi PWK 28 as the round slide would sometimes vibrate so much it caused the RPM to stay elevated. With the PWK I can have hose mount to dampen the vibration and stop that. Still in the process of dialing in the jetting which is helped with the aid of a wideband O2 sensor. I also added a cylinder head temp gauge. Currently its mounted on the side of the cylinder so I'm looking at getting a sparkplug mounted sensor for better accuracy and normalcy with what the karting world knows.
Upgraded the flywheel magnets to neodymium for charging at lower RPM. Beautiful thing is the new flywheel is a ARC racing PVL and it sticks out further allowing for more clearance behind in the coil area. The PVL coil also retards the timing to 10 deg before TDC allowing for easy starting and zero kickback issues while cranking. With the new magnets and stock coils I'm getting 10vac at 2k and over 30vac at 5k. My current rectifier does not have voltage control as it was designed to be a constant RPM rectifier, so I'm looking at a Honda xr400 motorcycle rectifier which fits the bill. Based on research this should do the trick.
Battery is bigger as the previous one barely had enough to get the motor to turn properly and overall needed a size increase. Redid the wiring harness due to me just not liking the overall look. I found some really cool woven cloth heat shrink tubing which looks fantastic when you do it right. I also added another tail light to provide lighting to the license plate area.
Braking in the front was also something to be desired with the C6 Worksman drum brake. I found a Honda CB350 brake drum with dual lever design looked really neat so that made it into the build. Braking is now on par with where it needs to be. The rear is a 100mm Motobecane drum which has reasonable braking as it is.
I redid the exhaust due to a weld fracturing, yes I back purged while welding. As you can see I added a flex pipe to the design helping reduce the amount of stress the pipe has to deal with. This is also upgraded to 1.5" pipe. Its louder now so I'm looking at installing a muffler to help tame it down some.
The fork also gave me something to be desired. The bicycle fork just felt flimsy and the design was not meant for 50mph+ so after doing some research and opting not to build my own I found a Kicker 5150 mini motorcycle fork was the ticket. It is a true triple tree design which greatly increases the stiffness and feel of the front end. I also added some oil lite bushings and shoulder bolts for the pivot locations as I didn't like the original Kicker design and needed new pivot mounts anyway.
I added a oil catch tank as without it I constantly got oil dripping out the breather tube. Used 6an fittings and braded hose for the install. Looks quite slick.
There were a few other things I didn't like, kickstand, turn signal and starter controls, no key for ignition, those all got redone.
Overall the build is about done and ready to be torn down so the frame can get stripped and powder coated. I have learned a lot, developed some new territory things and and had a lot of fun doing it.
Attachments
Hi Adam,
Looks like you have sorted out the bike well. Nicely done. One last upgrade would be 21" motorcycle rims and tires. At that point there is confidence at speed. As far as piston contact that has happen to me as well. Blew up an expensive engine. We actually lost two engines that way.
Looks like you have sorted out the bike well. Nicely done. One last upgrade would be 21" motorcycle rims and tires. At that point there is confidence at speed. As far as piston contact that has happen to me as well. Blew up an expensive engine. We actually lost two engines that way.
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