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Post by 190mech on Jun 17, 2024 19:08:10 GMT -5
Billwill, High octane (100) can be had at any local small airport. They are not supposed to sell it to road vehicles, but some will sell for race cars,etc.. The squish band is designed to chase all the mixture into the combustion chamber bowl so detonation is suppressed as there is none to burn at the outer edges of the cylinder. If you increase the squish gap, then some mixture will stay in the larger gap and allow combustion to occur at the edges..Keeping the squish as tight as possible and adjusting your bowl volume is the safest way..Yeah I know it's a lot more work, but a smoked piston is not fun either.. Your pipe cracking is not from excess heat, it's from mounting stresses as others have said..Mount the pipe at the spigot and all the mount brackets should align perfectly, if not slot the holes and add shim washers till it does..  |
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Post by billwill on Jun 17, 2024 20:43:03 GMT -5
Billwill, High octane (100) can be had at any local small airport. They are not supposed to sell it to road vehicles, but some will sell for race cars,etc.. The squish band is designed to chase all the mixture into the combustion chamber bowl so detonation is suppressed as there is none to burn at the outer edges of the cylinder. If you increase the squish gap, then some mixture will stay in the larger gap and allow combustion to occur at the edges..Keeping the squish as tight as possible and adjusting your bowl volume is the safest way..Yeah I know it's a lot more work, but a smoked piston is not fun either.. Your pipe cracking is not from excess heat, it's from mounting stresses as others have said..Mount the pipe at the spigot and all the mount brackets should align perfectly, if not slot the holes and add shim washers till it does.. This makes a lot of sense. So squish keeps the burn away from the outer edges of the piston and focuses it in the larger area toward the center. And I guess what your saying is removing material from the bowl would be best. I didn't even know that was a thing. Sorry to have hijacked your thread Brent, I'm done talking about my own scoot for now LOL. |
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Post by 90GTVert on Jun 17, 2024 23:01:55 GMT -5
I went out and looked over my new and old cylinder with base gaskets. They're simply cut to match the base gaskets supplied by Malossi. The cases were cut a lot to match the gaskets. The cylinder wasn't. It's really not much material removal. This is another place where I'd think everyone that gasket/port matched this engine should be having trouble. I know some people take it out of the box and assemble, but I'm sure a large percentage of RC-One owners gasket match.     No plans to change squish or cut the combustion chamber right now. I've cut multiple heads on the lathe and with them chucked in a drill before that, but I don't see those as likely cures without losing power. Again, that stuff is stock for the RC-One and basically to spec. My compression lowered when the ring ends broke off and it was still over 1200F at 60MPH. Didn't climb as much at the end of the run, but it also was at a point where it didn't even like to idle by then and was outside of the powerband. I don't really want to go hunting down race fuel because this is a street scoot and I don't see it as something that's very likely to tell me for sure what's up. I could change ignition timing to whatever I want for free. That would seem like a better move to me, because it's working toward solving how it runs as it will actually be used. Malossi tried to process my order and emailed me to tell me they don't have 2 AA pistons that I ordered. They have one and are trying to offer me A or BB. I'm trying to get the one AA with free shipping still so I offered to buy some other Malossi stuff that I was going to get (replacement parts... gasket sets, o-rings...) to help keep the order in the threshold for free shipping. Still waiting on a reply. I know that a lot of people don't go through pistons, but it sure would be nice if one of the biggest scooter performance manufacturers could keep a few pistons around... especially since they put out kits that are AA from the factory. |
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Post by xtremrox on Jun 18, 2024 3:44:02 GMT -5
I went out and looked over my new and old cylinder with base gaskets. They're simply cut to match the base gaskets supplied by Malossi. The cases were cut a lot to match the gaskets. The cylinder wasn't. It's really not much material removal. This is another place where I'd think everyone that gasket/port matched this engine should be having trouble. I know some people take it out of the box and assemble, but I'm sure a large percentage of RC-One owners gasket match. No plans to change squish or cut the combustion chamber right now. I've cut multiple heads on the lathe and with them chucked in a drill before that, but I don't see those as likely cures without losing power. Again, that stuff is stock for the RC-One and basically to spec. My compression lowered when the ring ends broke off and it was still over 1200F at 60MPH. Didn't climb as much at the end of the run, but it also was at a point where it didn't even like to idle by then and was outside of the powerband. I don't really want to go hunting down race fuel because this is a street scoot and I don't see it as something that's very likely to tell me for sure what's up. I could change ignition timing to whatever I want for free. That would seem like a better move to me, because it's working toward solving how it runs as it will actually be used. Malossi tried to process my order and emailed me to tell me they don't have 2 AA pistons that I ordered. They have one and are trying to offer me A or BB. I'm trying to get the one AA with free shipping still so I offered to buy some other Malossi stuff that I was going to get (replacement parts... gasket sets, o-rings...) to help keep the order in the threshold for free shipping. Still waiting on a reply. I know that a lot of people don't go through pistons, but it sure would be nice if one of the biggest scooter performance manufacturers could keep a few pistons around... especially since they put out kits that are AA from the factory. Okay now the transfer theory is ruled out that ammount of grinding wont cause issues(atleast big ones) Now i just think your carb is way too big and that your combustion event is somehow flawed |
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Post by 90GTVert on Jun 18, 2024 19:17:21 GMT -5
The detonation gauge arrived yesterday. Here it is along with the Bosch knock sensor and EV1 pigtail.   I worked on an adapter to allow me to use it on the head. The original design was modified after I got the sensor and realized that it's too big to fit up against the outer head. There's not enough material that I felt safe grinding the head for it to fit, so the sensor needed to sit higher. I used 1" brass round bar.  The very bottom section fits in the recess in the head for a cap screw. I will still use the copper washers that Malossi supplies for all head bolts with their gasket kits. The two different diameters above that are to clear the head's rounded profile. It was faster to just cut 2 diameters than to try to match the curvature. Next section is a base for the sensor and above that is a collar to adapt the 8mm knock sensor to a 6mm bolt. Snug fit. I've tried to keep slop out to help it transfer engine vibes the best I can. That's why I used brass instead of aluminum as well. Not sure if it's the right move, but the sensor appears to be brass.   I used an 8Ah battery, freshly charged, on some test ride trips when the scoot was last running. I put it on the charger and it flashed red and green, a battery error. It was at 13.4V. I figured it would be safe down to 12V or so anyway. Maybe not. I found a method of using jumper wires to get another battery to boost voltage and got it to take a charge. I used it for test rides again and it was at 11.4V on the second one, and these are just roughly 7 mile trips to do 1/8 passes. This battery sits on the charger most of the time and seems to have low capacity anyway for not being used a lot. Sitting on the charger all of the time isn't good, so I got a little battery rack to encourage me to store them somewhere other than the charger.  I got a generic battery on amazon to try. About $50 for a 9Ah. It, and many generics, claim to have low voltage protection. Not sure if that's the same as the genuine batteries and only works in conjunction with a tool. Figured it was worth a try. Reviews are often negative for generic batteries, but then a friend got one of the cheapest ones he could find and said he's used it a long time and can't see a difference. amzn.to/4c93k4M |
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Post by xtremrox on Jun 19, 2024 12:35:04 GMT -5
The detonation gauge arrived yesterday. Here it is along with the Bosch knock sensor and EV1 pigtail. I worked on an adapter to allow me to use it on the head. The original design was modified after I got the sensor and realized that it's too big to fit up against the outer head. There's not enough material that I felt safe grinding the head for it to fit, so the sensor needed to sit higher. I used 1" brass round bar. The very bottom section fits in the recess in the head for a cap screw. I will still use the copper washers that Malossi supplies for all head bolts with their gasket kits. The two different diameters above that are to clear the head's rounded profile. It was faster to just cut 2 diameters than to try to match the curvature. Next section is a base for the sensor and above that is a collar to adapt the 8mm knock sensor to a 6mm bolt. Snug fit. I've tried to keep slop out to help it transfer engine vibes the best I can. That's why I used brass instead of aluminum as well. Not sure if it's the right move, but the sensor appears to be brass. I used an 8Ah battery, freshly charged, on some test ride trips when the scoot was last running. I put it on the charger and it flashed red and green, a battery error. It was at 13.4V. I figured it would be safe down to 12V or so anyway. Maybe not. I found a method of using jumper wires to get another battery to boost voltage and got it to take a charge. I used it for test rides again and it was at 11.4V on the second one, and these are just roughly 7 mile trips to do 1/8 passes. This battery sits on the charger most of the time and seems to have low capacity anyway for not being used a lot. Sitting on the charger all of the time isn't good, so I got a little battery rack to encourage me to store them somewhere other than the charger. I got a generic battery on amazon to try. About $50 for a 9Ah. It, and many generics, claim to have low voltage protection. Not sure if that's the same as the genuine batteries and only works in conjunction with a tool. Figured it was worth a try. Reviews are often negative for generic batteries, but then a friend got one of the cheapest ones he could find and said he's used it a long time and can't see a difference. amzn.to/4c93k4MI suggest you turn the sensor connector far as you can from the spark plug and use one of those pc charger magnet thingies so it won't pickup any emp Btw i think you should do these things to your intake system to try help the flow speed. 1.grind the carb intake bellmouth edges round its bad if they end sharply 2.rough up the whole intake side of your carb until the needle, i mean ROUGH like 300-400 grit paper 3.make the engine side surfaces of carb after needle also a bit rougher than the stock polished like 500-600 grit 4.chek the crosssectional area changes, for example the carb engine side id is usually much smaller than the intakes id, so match them by grinding the carb with dremmel ect. Then chek the manifold/reed interface i suggest using reed stuffer or filling the reedblock with epoxy to make the Reedblock hole same Area and size(this may seem like a bad thing to make the reedblock crosssectional area smaller but it helps a lot, by keeping the crosssectional area of the intake stable as possible and removing any sudden steps reduces intake turbulance and energy losses a lot) |
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Post by 90GTVert on Jun 20, 2024 11:31:33 GMT -5
I looked at the knock indicator and noticed that the wiring appears to come through holes with no sealing. I opened it up and saw that nothing is sealed, so I put electronics grade silicone all around the inside of the LEDs and wires. The sensitivity dial on the side isn’t sealed either, but I’m afraid it may not want to move if surrounded in silicone, so I’m thinking that I’ll wait till it’s working, then just put some silicone on the outside of it.   A little extra on the outside for the wires.  My rear tire is flattened from uneven wear and well beyond wear indicators so I swapped it out. The NoMar tire changer worked very well for it. Much easier than the tough tires on the TMAX. I even made a quick video.  youtube.com/shorts/c70tA8ddsYw?feature=share |
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Post by oldgeek on Jun 20, 2024 14:39:21 GMT -5
I will have me one of those before I change another tire!
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Post by oldgeek on Jun 20, 2024 18:09:32 GMT -5
I will have me one of those before I change another tire! Maybe not, those things are $$$!  |
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Post by 90GTVert on Jun 20, 2024 22:50:38 GMT -5
I will have me one of those before I change another tire! Maybe not, those things are $$$! They are, but I didn't see much affordable. I got mine on Black Friday so it knocked off about $75-80 in shipping costs and came out to about $500. I said the same as you after a prior set of tires for the TMAX. I fought those things and wasn't so sure the back tire was ever gonna go all the way on for a bit. You can get much cheaper changers. Pretty much everything that I was interested in had a shaft mounted in the center of the stand and the wheel had to go over it. Not gonna work for scoot wheels unless you want to take out the wheel bearings each time up front and won't even fit in the splined holes of some rear wheels. I thought about trying to make my own rod to work with it, but the NoMar design looked better to me with the shaft coming from the top and can go into the base or it has a small tip to go into about any wheel. I thought about trying to build my own NoMar, but steel ain't cheap either and it made way more sense to me to get the powder coated unit with special plastic parts to prevent scratches and not spend forever trying to fabricate something. I haven't had a tire mounted for me in many years now, but I used to pay $10-$20 if I took the wheel and tire only to a shop. That was basically 20 years ago though. I thought I may just take the wheels off of the TMAX and go into a shop to save the fight. I was shocked when a guy that I ride with said a local shop told him $80 install fee. I said, well it does take time to get the wheel off. He said that was just bringing the tire and wheel to them. Maybe you can get a better price buying tires from the shop, but based on what I saw locally the tire markup could be pretty bad vs online price. |
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Post by 90GTVert on Jun 21, 2024 12:58:41 GMT -5
It was obvious that the compensator ring was wearing too much when I took the wheel off and checked out my homemade torsen. The two aluminum spacers were wearing against each other a little. The bearing was harder to move than it should be. I cut a tiny bit off of the OD of the section of the adapter nut where the ring sits. Replaced the ring and the bearing and put an 0.5mm thick shim between the two spacers. It feels better now. Doesn’t feel like it’s crushing the compensator ring and everything moves freely. 🤞  |
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Post by 90GTVert on Jun 24, 2024 9:34:28 GMT -5
I suggest you turn the sensor connector far as you can from the spark plug and use one of those pc charger magnet thingies so it won't pickup any emp I believe you are referring to a ferrite core. I wasn't sure so I asked a friend that is a phone/network tech... and uses them on his guitar cables. He said yes and as long as it's a shielded cable and grounds are good, I shouldn't need it, but it won't hurt. They're cheap on amazon so I'll add one. He said it doesn't really matter where I put it (nearer sensor or gauge). It should cover the run. Btw i think you should do these things to your intake system to try help the flow speed. 1.grind the carb intake bellmouth edges round its bad if they end sharply 2.rough up the whole intake side of your carb until the needle, i mean ROUGH like 300-400 grit paper 3.make the engine side surfaces of carb after needle also a bit rougher than the stock polished like 500-600 grit 4.chek the crosssectional area changes, for example the carb engine side id is usually much smaller than the intakes id, so match them by grinding the carb with dremmel ect. Then chek the manifold/reed interface i suggest using reed stuffer or filling the reedblock with epoxy to make the Reedblock hole same Area and size(this may seem like a bad thing to make the reedblock crosssectional area smaller but it helps a lot, by keeping the crosssectional area of the intake stable as possible and removing any sudden steps reduces intake turbulance and energy losses a lot) I'm gonna pull the carb and intake off soon. Most of this makes perfect sense to me. I have a question about numbers 2 and 3 though. I've read a considerable amount of stuff related to porting... largely 4T heads because that's what so many publish info about... and I haven't seen info about making the pre-fuel area rough. Generally, dry flow (without fuel droplets that we want to keep suspended) can be polished if you wish. Wet flow areas are better off with a more textured finish. You seem to be saying the inlet of the carburetor should be even more rough than the outlet where fuel is intended to be. None of this is nearly as rough as some suggest for intake ports, but I'm still surprised at the idea of roughing it at the entry. Is the idea that the 2T is pushing fuel everywhere, whether we like it or not, or something else? If it's the former, then bellmouths should be roughed up too. |
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Post by 90GTVert on Jun 26, 2024 19:28:45 GMT -5
I checked the carb to intake match and it wasn't good. Can't believe I went over the intake to reed block area when I got the intake and never even looked at this. Roughly 2mm mismatch.
 Marked with a paint marker and then I used a Dremel drum sander and Scotch Brite pads to finish.  I moved on to the air filter adapter/mini-bell-mouth. The outer edge is flat and abrupt. There is a ledge in the air filter that it would probably work well with, but the carb can't go that far in to meet up with it.  I need the filter to have room to mount, so I can't cut it way back. I did stick it in the lathe and cut it back and chamfer it slightly. I used 120, 220, 320 and then a sort of worn Scotch Brite green pad to round the chamfers. I also smoothed out the adapter a bit. I could feel a sort of ramp in the angle so I just tried to make it more constant. The finish is pretty smooth. Easy enough to change surface finish from here if desired.   The engine side is quite smooth. Didn't touch it yet. 
No reply about the finish from xtremrox, so I tried searching. Didn't find much. Just what I've always seen where many polish the air filter side. I decided to try to ask known pros and posted in the ESE Works thread on KiwiBiker. First post, so I don't know if they'll even approve it there. Worth a try. |
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sinfull
Scoot Enthusiast
Posts: 413
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Post by sinfull on Jun 27, 2024 4:04:59 GMT -5
Polished speeds up the air flow around the Polished surface faster than the middle where the fuel is, so faster air on the edges is not pulling the fuel with it, rougher creates more turbulence and pulls fuel with it. Is basically the science. Air goes path of least resistance.
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Post by 90GTVert on Jun 27, 2024 6:30:37 GMT -5
Polished speeds up the air flow around the Polished surface faster than the middle where the fuel is, so faster air on the edges is not pulling the fuel with it, rougher creates more turbulence and pulls fuel with it. Is basically the science. Air goes path of least resistance. Right, which is the explanation to the wet vs dry surface difference. Doesn't tell me why I'd want the filter side rough, but maybe I'm missing something or maybe I'm just giving 1 person from the internet more merit than I should. His points seemed valid to me, aside from that one, so I'm trying to explore the idea. Maybe I'll learn something or maybe I already knew what I needed? Also seems to go against the idea of adding roughness if you believe in the air straighteners and such that some install, though those have the function of dividers as well. I did find this along the way when I was searching yesterday. The whole page may be interesting. From : groupk.com/index.php/high-performance-pwc-carburetion/"A Note About Fuel Atomization – Many of the aftermarket carb makers go to great lengths to promote the exceptional fuel atomization abilities of their carbs. The “real” priority here is the need to deliver well-atomized and well vaporized mixture “into the combustion chamber”, not the crankcase. In truth, the mixture being admitted into the crankcases (no matter how well atomized it is) goes through a separation process before making it’s trip to the combustion chamber. High-speed internal photography of engines in operation has revealed that the spinning crankshaft tends to throw the heavier fuel to the outside of the crankcase, while the lighter weight air remains within the center area of the crank case. The fuel in the crankcase is in a constant state of being atomized by being thrown off the outside of the flywheels (in the same way that water spirally sprays off a road tire). This process, which represents the biggest percentage of fuel atomization and vaporization, is performed in the crankcase and transfer port passageways…not in the carburetor.
The inside of the crankcase of a high output two stroke is best described as a miniature hurricane of biblical intensity. The intense turbulence of this hurricane does a great deal to atomize the fuel being delivered for the next cycle. The walls of the transfer passages can further enhance atomization if their surface finish is rough enough to disperse any “un-atomized” fuel droplets that “make contact” on their high-speed trip to the combustion chamber. This is why Group K porting includes a mild “rough-finish” on the walls of the transfer passages…(instead of polishing). This helps to insure that all fuels induced into the crankcase, by the carb, will experience significant atomization during it’s millisecond whirlwind journey to the combustion chamber.
For sure, it helps matters slightly if the fuel metering apparatus of a carburetor can assist in atomization, however (on a 2 stroke pwc engine) the impact of that help has more to do with fuel economy/efficiency than sheer power output. The best example of this point, is the MRD mechanical fuel injection system. These systems perform virtually no atomization at all, yet still yield very good single-point full-throttle power. The lack of atomization of the mechanical fuel injection systems does contribute to a very significant wasting of fuel. But the MRD’s, nearly non-existent, atomization does not have a measurable cost in the area of lost power." |
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