What is the best thing to do to the transfer ports remove the divider or just clean them up. Also what about drilling holes in the side of the piston ?
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The best thing to do is remove the divider or you can enlarge both channels and add a 3rd boost port along with matching windowed piston...What is the best thing to do to the transfer ports remove the divider or just clean them up. Also what about drilling holes in the side of the piston ?
Fantastic. I bought a stock 49cc engine today im going to strip this one and blueprint , port it. My cylinder has a 1 boost port but no window on that side of the piston.The best thing to do is remove the divider or you can enlarge both channels and add a 3rd boost port along with matching windowed piston...
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Just know that windowing the piston in relation to the boost port will enhance bottomend torque....The more boost ports you grind the more torque you can make..
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Taking the tool based engine totally apart and blueprinting the crankcase aswell as the cylinder to crankcase youll enhance velocity and reduce turbulence...
In 2 stroke you want velocity and you do not want Turbulence...…..Velocity makes power...Turbulence robs power...…..
Sharp edges inside the crankcase causes turbulence...……..Sharp edges need to be rounded and polished..
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I think I have someone that can balance the crank for me. Where would I add pathes to the bearings in the bottom end? I might just run the standard crank if the FC crank is problematic.one wide boost port keep the window small and away from the ring gap so you dont get blow by when you pump up the compershon if your going to a full circle crank your going to need to balance it to a somewhat reasonable balance factor and add some pathes so the bearings dont get oil starvation are you going to run VP 105 or Juice
I use a carbide barrelcutter on a Dremel and drill my holes in the piston by hand in my hand with a glove literally holding it..……….I chamfer and debur with a deburring tool aswell as 2000/4000 grit sandpaper and jewelers files.Fantastic. I bought a stock 49cc engine today im going to strip this one and blueprint , port it. My cylinder has a 1 boost port but no window on that side of the piston.
So for my application a few more ports would be better?
What cutter do you use to cut these boost ports in the cylinder?
I will be using my Bridgeport. Also what is the best cutter to cut the window in the piston I was just going to use my Endmills for Aluminum?
How High in the piston do I cut the window?
And if I add 2 more boost ports in the cylinder do I cut 2 more ports in the piston or just cut a long horizontal window in the piston to match it ?
Do you use better crank bearings and crank seals?
Thanks again Mike
Crank balancing is easy if the stock engine is matched right when built by the Chinese kids in China...I think I have someone that can balance the crank for me. Where would I add pathes to the bearings in the bottom end? I might just run the standard crank if the FC crank is problematic.
I run VP94 ETHANOL Free mixed with Castor 927 now in my RC's but if I have to run VP105 that's not a problem I will definitely get some.
I want to set my squish around .030" - .035" will I need the VP105 if so do you have a part number for the fuel? I don't see any VP105 on there website.
You need off the line power and revs,,,,Modifying the clutch can do that just fine if you want to maintain the higher revs....The more boost ports you add the more the revs reduce but the torque goes up....Fantastic. I bought a stock 49cc engine today im going to strip this one and blueprint , port it. My cylinder has a 1 boost port but no window on that side of the piston.
So for my application a few more ports would be better?
And if I add 2 more boost ports in the cylinder do I cut 2 more ports in the piston or just cut a long horizontal window in the piston to match it ?
Do you use better crank bearings and crank seals?
Thanks again Mike
I have build many 2 stroke Dirt Bikes but never had to do many mods on them Built many SBC back when I used to drag race the 1/4 mile but this engine is a different animal as you say so all this info is much appreciated. Do you have part numbers on the wrist pin bearing and Pistons from Husky/Stihl that fit a 44mm bore? Again Thank you very much for all the info.Crank balancing is easy if the stock engine is matched right when built by the Chinese kids in China...
40mm cylinders with 40mm 10mm piston pin require an IE-40 crank to start with...…...
44mm cylinders with 10mm piston pin needs a IE-44 crank...……
44mm cylinders that have a 12mm pin needs a IE-44 HD crank
You match the parts right youll be matched for bone stock and pretty ready to run then you use a balance bar rail type setup and then you have the option of using a digital scale to prove it out to make sure it falls within proper %age after you modify the piston with windows which ultimately lightens it too but if engine is matched good when the Chinese kid initially built it then it isn't overly critical...
Its not rocket science and another way to keep costs down too in this cheap hobby...
One thing you'll want to steer away from is any form of FCC as the FCC reduces volume inside the crankcase and it also reduces the amount of fuel that reaches the transferports too....
These engines are a way different type of animal compared to a 2 stroke MX engine as the atomized mix must be fed through two crankweights with a mixing stick in the center creating a bottleneck..
If you had a crankcase like this....A FCC will become very beneficial....
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Good Luck
I completely understand about shaving the top of the cylinder but With this cylinder if I just took .060” off the top it would not allow the head to sit any lower because it hits where I circled in my pic. I was wondering if that was normal or was this cylinder not machined correctly ? Either way I will machine it offYou need to remove about .060" ( 1.5mm ) off the top of the cyld where the compression cap sits with the round copper head gasket, which brings the piston to the top of the cyld. Then you need to raise and shape your exhaust port to the right height. My favorite cyld has hogged out transfer ports and one .600" to .700" wide upper port.
Because this is going in my RC Monster Truck I want more torque than high revs so I’m going to do what CAM2 has suggested.The anti parachute mod combined with the turbo crank mod and no boost ports clutch mods for a higher revving engine
What is the anti parachute mod and the turbo crank mod do you do this while balancing or do the crank mod and then balance ? Thanks again Mikei agree your going to want to maximize the tourqe and throttle response in the way Cam2 is saying for those on demand wheelies 🙂