Father Son 75 CB200T Rise From the Ruins
- Thread starter Texasstar
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Texasstar said:Matt we got something that looks top secret in the mail today! Is it a flux capacitor?
That is a 22,000µF capacitor. Since you're running without lights on lucky, you can also probably get away without running a battery. The capacitor stores voltage between cycles of the alternator so that everything can stay running. Your bike will be running solely from the alternator, so no electric start, and possibly no bump start, either.
Whether or not it works will depend a lot on the health of your charging system, which is why I included the R/R as well. The Sparck Moto R/R has lower internal resistance than most R/Rs on the market, and so your bike will be producing usable wattage lower in the RPM range than many other models of R/R will provide.
Some wiring changes will likely need to be made to accommodate the cap, but I'm optimistic. The red wire to the the ignition and the rectifier will be the ones to plug into the cap (same wires that would have gone to the battery) and the black wire from the cap can be bolted to some bare metal to act as the negative terminal.
Capacitors (especially big ones like this) can store enough power to kill someone and they can take quite a while to bleed down after use, so be careful. If you need to work in and around the cap after the bike has been run, discharge it by touching the positive and negative terminals together. You can also wire in a discharge circuit to make that task easier.
To test it out, wire it into place where the battery used to go and give the bike a couple of kicks with the ignition switch off. Then turn the key on (with the kill switch set to 'run') and kick it over. Hopefully Lucky will start right up and rev freely.
Texasstar said:
See, there is method in my madness. Or was it just madness in my methods. Squish is the fast moving gas from the outer edges of the annulus into the space around the plug and that is measured as MSV Mean Squish velocity and there is an established range for MSV at least on 2 smokes, so I use a 2 smoke head design package to work out theoretical squish. I tend to run squish so that if I miss a gear the piston just kisses the head on the exhaust stroke which is where it stretches its legs.
I still use 2 compression rings because a single ring loses power below about 8k and sometimes that's useful power coming out of a tight corner.
You have choices with ignition: Battery without charging, charging without battery or a full system. We use total loss battery system to reduce flywheel effect an that's Ok for about one full day of racing ie a few runs.
Starter and related parts are best filed in the recycling bin. You just do not need the weight, and with a battery, if the bike can't be paddle started or bumped at worst, then something needs to be changed. Spin the alternator up on a test rig and see where it starts to spark. 500 rpm (fast walk) is good, over 800 rpm - brisk trot is not so good.
For swirl, I like tangential ports like an old Triumph twin. Honda tends to use ports that are straight into the center of the cylinder with zero swirl.
I like to weld on new intake stubs offset to the side to generate a slight swirl effect but that isn't always easy to achieve. Do not insert anything into the port to encourage swirl because the resistance will typically cost more flow that the improvement in swirl is worth.
When thinking about squish, think angled head surface like a 2 stroke and forget Quench and flat surface on a 4 stroke. Try to get the streams to collide near the plug for slightly less turbulence but better placed flame kernel in the middle of that tumbling storm of small gas droplets.
I like to weld on new intake stubs offset to the side to generate a slight swirl effect but that isn't always easy to achieve. Do not insert anything into the port to encourage swirl because the resistance will typically cost more flow that the improvement in swirl is worth.
When thinking about squish, think angled head surface like a 2 stroke and forget Quench and flat surface on a 4 stroke. Try to get the streams to collide near the plug for slightly less turbulence but better placed flame kernel in the middle of that tumbling storm of small gas droplets.
Texasstar
Can't is a four letter dirty word
These are Michael Moore's molds.teazer said:
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Texasstar
Can't is a four letter dirty word
Have you found that a short skirt will get you in more trouble than a long skirt? That is the advice I am giving my son and that the last thing you want to do is throw a rod because a short skirt got you in a jam. 
so after reading Stealing Speed and how the riders we killed at the TT over seized engines and Zeke and I seeing how temperature impacted the honda pistons with the 175 pin being stuck because of the cold it didn't give me a warm fuzzy about the short skirt Tbolt piston. So I called Tbolt and they said if you aren't tearing the engine down and measuring the piston on a regular basis they have been know to throw a rod and a rider. So we are going with a longer skirt and a proven manufacturer. However Serendipitously started talking to me about intake swirl and how he used an aluminum wire mounted in the intake to promote swirl...so I started doing research and the first document that came up was the Defense Department Study.
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so after reading Stealing Speed and how the riders we killed at the TT over seized engines and Zeke and I seeing how temperature impacted the honda pistons with the 175 pin being stuck because of the cold it didn't give me a warm fuzzy about the short skirt Tbolt piston. So I called Tbolt and they said if you aren't tearing the engine down and measuring the piston on a regular basis they have been know to throw a rod and a rider. So we are going with a longer skirt and a proven manufacturer. However Serendipitously started talking to me about intake swirl and how he used an aluminum wire mounted in the intake to promote swirl...so I started doing research and the first document that came up was the Defense Department Study. Sent from my iPhone using Tapatalk
Re: Re: Father Son 75 CB200T Rise From the Ruins
Just thought I'd tell you that I have successfully run a cb200 on an Accel capacitor and nighthawk 250 reg/rec. it was also running a dyna twin tower coil. You had to blip it with the headlight on occasionally (35/35w), but it will purr all day long with no lighting at idle and beyond. The reason I mention this is that I have no doubts you'll be just fine running a capacitor on your stripped down racing machine and that charging system.
Texasstar said:
Just thought I'd tell you that I have successfully run a cb200 on an Accel capacitor and nighthawk 250 reg/rec. it was also running a dyna twin tower coil. You had to blip it with the headlight on occasionally (35/35w), but it will purr all day long with no lighting at idle and beyond. The reason I mention this is that I have no doubts you'll be just fine running a capacitor on your stripped down racing machine and that charging system.
Short skirts are always a problem but not in an engine. Long skirts help to stabilize the piston and reduce rocking but just for comparison check out any modern 600 piston. It's shorter than a CB200 and roughly twice the diameter (touch of hyperbole there but you see what I'm getting at) and no issues with rock (and roll).
I like them short to reduce viscous drag. The friction between the piston and bore is the single largest loss of power in an engine. Short skirts and excessive camming help a little, as do thin rings.
Swirl helps a little but squish helps more.
As long as your valves are partially shrouded by the bore, they will naturally generate some swirl.
The thing to notice about those port shapes is how low the roof is on the 175 and 200. That's where there's room for improvement, but the carb end of the port is already large enough relative to the valve seat and critical port diameter. Check the dimensions up and down the port to work out where metal has to be removed and where it should be added. I'm generally a fan of small carbs but those ports can use larger than "ideal" carbs to better match the other dimensions.
That's good info from Kiley about the alternator output.
I like them short to reduce viscous drag. The friction between the piston and bore is the single largest loss of power in an engine. Short skirts and excessive camming help a little, as do thin rings.
Swirl helps a little but squish helps more.
As long as your valves are partially shrouded by the bore, they will naturally generate some swirl.
The thing to notice about those port shapes is how low the roof is on the 175 and 200. That's where there's room for improvement, but the carb end of the port is already large enough relative to the valve seat and critical port diameter. Check the dimensions up and down the port to work out where metal has to be removed and where it should be added. I'm generally a fan of small carbs but those ports can use larger than "ideal" carbs to better match the other dimensions.
That's good info from Kiley about the alternator output.
Texasstar
Can't is a four letter dirty word
the pw26 superhawk carbs are HUGE compared to the intakes of the 175 and 200. When you said that the superhawk carbs would form the perfect intake shape I am assuming that using a 175 manifold cutting it in half, grinding smooth the ridges and then using radiator hose and then use another manifold that better port matches the manifold to the carb???? Thus creating the high speed area of the port...then on the intake raise the floor with devcon and port the ceiling. Is there a better manifold to work with on the pw26 side since the superhawk carbs were bolted to the head separated with a spacer?teazer said:
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We had a pair of manifolds machined up. Carb side they bolt to the carbs with a short 1 - 1.3" length to slip inside some radiator hose. The other part can be a bolt on or weld on, so it's a tube or a tube and flange.
That will provide a short parallel section prior to the long tapered port, of get the head side of the manifolds machined small that the carbs and port them as an extension of the port to lengthen the tapered section.
We use CB77 carbs on our 181cc motor with a mild cam and it's perfect. And that's with stock sized valves on a poor old sloper 175 head. So we know they work OK. I can't remember what taper I machined into the needles to get mid range fueling cleaner. Lucky will love them.
Especially if you buy her some short skirt..................................... pistons.
That will provide a short parallel section prior to the long tapered port, of get the head side of the manifolds machined small that the carbs and port them as an extension of the port to lengthen the tapered section.
We use CB77 carbs on our 181cc motor with a mild cam and it's perfect. And that's with stock sized valves on a poor old sloper 175 head. So we know they work OK. I can't remember what taper I machined into the needles to get mid range fueling cleaner. Lucky will love them.
Especially if you buy her some short skirt..................................... pistons.
