The idea of the full circle crank is not to improve balance, it is done simply to decrease the volume of the crank case, ie; more metal on the crank shaft means less free volume inside the case. The way this benefits performance is that as the piston moves down on the power stroke, the fuel/air charge under the piston and in the crankcase will be at a higher pressure when the tansfer ports open because there is less space in the crankcase due to the higher displacement of the circle crank. A higher case pressure when transfer ports open will result in more fuel/air in the combustion chamber, and in most cases better cylinder scavenging. Based on this theory, your grinding of the counterbalance lobes on the stock shaft= adding volume to case= decrease in case pressure during blowdown, will likely result in a drop in performance.
@@jaguars004 I disagree you want less volume in the crankcase you don't want more volume because that's just more , the more metal in crankcase = more Aire / gas flow to get immediately in transfer ports. I've worked on these things for many years and I've been designed many engines and still do, and this is just simply wrong
When you remove material (or add) from a rotating assembly it will affect balance.Keep an eye out for any vibration that was not there before.I know two strokes and just about any single cylinder engine vibrates anyways.
Changing from the original crank to a full-circle crank is the same. These vibrations are second order and to be honest with these little shitty engine, reliability isn't a concern.
the amount of vibration produced from the crank like this and circle crank is night and day. the stock "turbo" crank i see mainly in home use land use machinery. i have some of them and rebuilt some and use them still to this day (1990). it vibrates a lot more really. your hands will feel it. how can i tell? the same engine with circle crank is on a moped. and i ride it.
Nice video dude and I like your enthusiasm. But you're well off the mark here. What you were trying to do is called 'knife-edging' and you've done even that wrong. I'll do a video 'reply' soon. All also send you the link - cheers matt.
im pretty sure knife edging would be for 4 stroke engines. it keeps the crank from slapping the oil as much. but i guess i can see what you mean in a way.
@@xtrah8ed4life in this style of 2 strokes the crankcase is used as a supercharger. the piston going down pressurises the fuel and air mixture in the crankcase witch rushes into the cylinder as soon as the intake port opens due to pressure difference. this extreme change of pressure in the crankcase draws in a fresh air fuel mix through the reeds
@@xtrah8ed4life to tell you the fuel absolutely goes to the bottom and how do you think it gets to the top? I don't agree with what he's doing to the crankshaft but you need to understand the way a two-stroke works
Can't wait to see this rip! I think you should do all the porting you can. Also do you have a dyno? If not you should make on or something so we can see the horsepower! The crank mod should definitely give you some power.
I did it on my 50cc Evo engine and I left one side lighter than the other side and it vibrated a lot eventually got it fixed and now it's all good runs very good
Full circle crank increases primary compression, giving more power in mid to higher rpm. The half crank gives better low end torque. half crank i find to be smoother running if well balanced. Great for everyday use.
I know you do pit bike engines but I would love to see the 50cc amazon gearbox engine I believe they are for mopeds on this channel and do similar mods to it and see how the acceleration changes between the two
pps can you do a mini quad 50cc 2 stroke fit and test video please installing bigbores/exhausts/air filters/carbs/ etc etc really appreciate it cheers :)
dont really know why exactly this mod would improve performace, the crank you put in is not the best shape. the one you took out was better, the circles cause to maximize pressure in crankcase because there is lower amount of space in crankcase and they are easier to balance. ideally the crank should suppress as much space as possible (even bigger circles) in crankcase to maximixe pressure. you should portmatch the ports on cilinder to the ports on the crankcase, you can polish only exhaust port, it would be also interesting to see what port timing the cilinder has originally and then you can play with it.. you should look into different reed valve or reed valve modifications...thats for start.
Idk if you watched the whole vid but The turbo crank is considered better because it will cut through the air and fuel faster and for the full circle, what you mentioned I cover in the video when comparing the two cranks, thanks for the Info here!
i dont understand what you mean with cut through the air and fuel. the function of it. only the gasoline to the air ratio matters. design of circle crank produces lot less vibrations. the crank should be smooth and round and as tight to the crankcase as it can be. it should also be heavy so engine can sustain momentum easier.. it should be balanced by weight between piston and crank itself frequently the piston is lighter for higher revs but you take off momentum and force. it should also be balanced by length so it is not bent. a bent crank can snap at high revs. the stock crank because of its shape creates internal currents that distort the fastest flow possible. the smaller the space in the crank case faster the fuel gets to cilinder. also i recommend that you port match the Cilinder ports to the crank case. i said it wrong before. after that if the stock crank ports still have some angles that cilinder ports did not cover then you match the crankcase. i say this because the ports on bigger cilinders are frequently larger and different shape. you can also change the springs in the clutch so it goes at higher rpms. i talk from experience and only want to help you.
i personally think the crank cut like that is actually a pretty good idea. sure, the circle crank displaces more, but it doesnt atomize the fuel as well as that angle cut crank. makes sense to me. im curious to see if that tiny amount of weight even affects balance. i kinda doubt it.
i watch ya vids all time but rarely see you do any FIT AND TEST IN THE SAME VIDEO WHICH ISNT HELPFULL SO.. can you please do more FIT AND TEST videos? thanks :)
hey man i’m 19, it’s my first engine i ever took apart trying to learn the basics for cheap. there is no key for the clutch right? i just want to make sure i don’t loose it. i punched it out last from the inside out and it kinda flew off, didn’t see a key, no one mentions it, but there is a space for one…. idk
Full circle is so much smoother . The half moon crank is garbage a throw back from the old non center spark plug . also they love a decent reed valve a rocket key and a massive expansion chamber.
The full circle crank is way out of balance (90perc out ) ! I gave up with that and ended up lightening the standard crank then adding tungsten slugs to get the balance weight right,t sure the 'turbo ' mod puts it more out of balance ? at 6.18 there's the bit on the crank :th-cam.com/video/EHFyIM1_iv0/w-d-xo.html , check out 2 stroke stuffing shows the easy way to check the balance with simple tools : th-cam.com/video/0hoE_MuFpPI/w-d-xo.html
I have a Amstar Nostalgia 49. I've put on it a racing spark plug performance racing carb and a performance CDI could i put this turbo crank on it? Its a 4 stroke. Semi automatic bike.
Turbos will not or should not work on a 2-stroke because their self supercharging you put a supercharger on a 2-stroke you're going to blow out more seals . again they are not made for supercharging they are self supercharging when the Piston goes down it's a positive force that charges the transfer ports The only two stroke that needs and has to have a supercharger is a two-stroke Detroit Diesel and it has nothing to do with one of these two strokes I've worked on both all my life and I know both turbo supercharging does not work on a 2 cycle get it out of your head right now
NEVER... E V E R take a grinder to a crank shaft. What you have done is a COB JOB. You need education on engine theory. There is no "slicing the air" LEAVE THE CRANKSHAFT alone. If you Must modify it, send it out to be balanced
I ended up running the engine with a FULL CIRCLE not this crank.
full circle gives a bit more torque aswell you should try using multi stage reeds and a walbro wt603 carb
So did turbo crank mod work
@@meyou8716 Ive never tried it yet for fear that mine isn't balanced
I did that mod it works but perfectly on my pocket bike
Where is that video??? I’m really depending on you here to get my bike running bud.
The idea of the full circle crank is not to improve balance, it is done simply to decrease the volume of the crank case, ie; more metal on the crank shaft means less free volume inside the case. The way this benefits performance is that as the piston moves down on the power stroke, the fuel/air charge under the piston and in the crankcase will be at a higher pressure when the tansfer ports open because there is less space in the crankcase due to the higher displacement of the circle crank. A higher case pressure when transfer ports open will result in more fuel/air in the combustion chamber, and in most cases better cylinder scavenging. Based on this theory, your grinding of the counterbalance lobes on the stock shaft= adding volume to case= decrease in case pressure during blowdown, will likely result in a drop in performance.
The practice of adding material to the case to decrease volume is referred to as "stuffing".
Good stuff thanks, glad I never used the 'turbo crank'
And that's what we used to call stuffing and that's what it still is stuffing not taking metal away..
@@jaguars004 I disagree you want less volume in the crankcase you don't want more volume because that's just more , the more metal in crankcase = more Aire / gas flow to get immediately in transfer ports. I've worked on these things for many years and I've been designed many engines and still do, and this is just simply wrong
@@ronziebell337 exactly thanks..
When you remove material (or add) from a rotating assembly it will affect balance.Keep an eye out for any vibration that was not there before.I know two strokes and just about any single cylinder engine vibrates anyways.
Fang Of Truth I was gunna say that. 1000 percent true
Changing from the original crank to a full-circle crank is the same. These vibrations are second order and to be honest with these little shitty engine, reliability isn't a concern.
the amount of vibration produced from the crank like this and circle crank is night and day. the stock "turbo" crank i see mainly in home use land use machinery. i have some of them and rebuilt some and use them still to this day (1990). it vibrates a lot more really. your hands will feel it. how can i tell? the same engine with circle crank is on a moped. and i ride it.
That filleted crank counterweight looks great. It should work awesome. Nice work dude.
Nice video dude and I like your enthusiasm. But you're well off the mark here. What you were trying to do is called 'knife-edging' and you've done even that wrong.
I'll do a video 'reply' soon. All also send you the link - cheers matt.
The Workshop Thanks I’m assuming your just going to bash the balancing of this?
You cut on the wrong edge of the crank. You want to take the material from the inside not the outside.
The Workshop didn't know you watched this.
im pretty sure knife edging would be for 4 stroke engines. it keeps the crank from slapping the oil as much. but i guess i can see what you mean in a way.
I hate how a decent, informative, and understanding reasonable review of the rocket key is no where to be found -.-
I really hope nobody tries to do this to their engines.
This started in the RC hobby world and a lot of people claim it adds power!
You say ots gonna cut through the fuel. But no fuel is in that part of the engine. Fuel is only in the top end.
@@xtrah8ed4life in this style of 2 strokes the crankcase is used as a supercharger. the piston going down pressurises the fuel and air mixture in the crankcase witch rushes into the cylinder as soon as the intake port opens due to pressure difference. this extreme change of pressure in the crankcase draws in a fresh air fuel mix through the reeds
Agreed stuffing would work better.
@@xtrah8ed4life to tell you the fuel absolutely goes to the bottom and how do you think it gets to the top? I don't agree with what he's doing to the crankshaft but you need to understand the way a two-stroke works
If you want to increase performance, get a windowed piston, make the ports in the head bigger, get the wavy S shape exhaust, and upgrade the carb.
Can't wait to see this rip! I think you should do all the porting you can. Also do you have a dyno? If not you should make on or something so we can see the horsepower! The crank mod should definitely give you some power.
Looking really good
Cool buddy.. The only concern I would have is throwing the balance out... Would have to try it man
I did it on my 50cc Evo engine and I left one side lighter than the other side and it vibrated a lot eventually got it fixed and now it's all good runs very good
Basing off my video, would you say mine is off? Or is it impossible to tell
Trust me you'll be able to tell when you start it and it vibrates you'll notice it
Oh and another thing don't put that stock exhaust you're losing a lot of power I made a homemade exhaust for mine it breathe better more power
All this will do is produce 1) an unbalance crankshaft 2) Reduce crank case compression. This is little more than a COB JOB
Very good content !
Full circle crank increases primary compression, giving more power in mid to higher rpm. The half crank gives better low end torque. half crank i find to be smoother running if well balanced. Great for everyday use.
Nice job on the modification!!!
I am just wondering how this will effect how balanced the crank is
I have a question for you is your big bore a 44mm piston
I know you do pit bike engines but I would love to see the 50cc amazon gearbox engine I believe they are for mopeds on this channel and do similar mods to it and see how the acceleration changes between the two
The syx Moto 50 dirtbike ones?
I have first hand knowledge of experimenting with turbo cranks in a Yamaha and a Kawasaki on flat track and Motocross
What is the size of the oil seals in the crankcase that covers the crankshaft bearings?
Can you send a link to all the upgrades you've done so I can order it exactly or a series on the upgrades and they held ip
pps can you do a mini quad 50cc 2 stroke fit and test video please installing bigbores/exhausts/air filters/carbs/ etc etc really appreciate it cheers :)
dont really know why exactly this mod would improve performace, the crank you put in is not the best shape. the one you took out was better, the circles cause to maximize pressure in crankcase because there is lower amount of space in crankcase and they are easier to balance. ideally the crank should suppress as much space as possible (even bigger circles) in crankcase to maximixe pressure. you should portmatch the ports on cilinder to the ports on the crankcase, you can polish only exhaust port, it would be also interesting to see what port timing the cilinder has originally and then you can play with it.. you should look into different reed valve or reed valve modifications...thats for start.
Idk if you watched the whole vid but The turbo crank is considered better because it will cut through the air and fuel faster and for the full circle, what you mentioned I cover in the video when comparing the two cranks, thanks for the Info here!
i dont understand what you mean with cut through the air and fuel. the function of it. only the gasoline to the air ratio matters. design of circle crank produces lot less vibrations. the crank should be smooth and round and as tight to the crankcase as it can be. it should also be heavy so engine can sustain momentum easier.. it should be balanced by weight between piston and crank itself frequently the piston is lighter for higher revs but you take off momentum and force. it should also be balanced by length so it is not bent. a bent crank can snap at high revs. the stock crank because of its shape creates internal currents that distort the fastest flow possible. the smaller the space in the crank case faster the fuel gets to cilinder. also i recommend that you port match the Cilinder ports to the crank case. i said it wrong before. after that if the stock crank ports still have some angles that cilinder ports did not cover then you match the crankcase. i say this because the ports on bigger cilinders are frequently larger and different shape. you can also change the springs in the clutch so it goes at higher rpms. i talk from experience and only want to help you.
Dylon Desbiens There is a youtube channel called 2strokestuffing. He makes great videos about balancing and truing your crank and other stuff too.
Dylon Desbiens I think even the most unbalanced full circle crank is more balanced than the one you made yourself.
i personally think the crank cut like that is actually a pretty good idea. sure, the circle crank displaces more, but it doesnt atomize the fuel as well as that angle cut crank. makes sense to me. im curious to see if that tiny amount of weight even affects balance. i kinda doubt it.
i watch ya vids all time but rarely see you do any FIT AND TEST IN THE SAME VIDEO WHICH ISNT HELPFULL SO.. can you please do more FIT AND TEST videos? thanks :)
One question Dylon could I ask how old you are and where you're from?
Isn't that 2 questions?
Nice
What size is the clutch on this engine ? I hope it’s 76mm
With crank... wont it be unballanced?
hey man i’m 19, it’s my first engine i ever took apart trying to learn the basics for cheap. there is no key for the clutch right? i just want to make sure i don’t loose it. i punched it out last from the inside out and it kinda flew off, didn’t see a key, no one mentions it, but there is a space for one…. idk
Some of them have a key and some don’t, if you lost it it’ll be fine you can just put the clutch on.
What is the advantage of doing this?
Remove the plastic in the carb that switch is plastic and the gas eats it over time. Weld it shut Copper gasket allow for extra squish
Give this video a LIKE for ME!!
Should we do more porting? What do you think?
Dylon Desbiens I think you should port then engine and the intake between the carb and reed valves
Keep the crank stuffing once that area is clear, then do the ports
Dylon Desbiens do the performance ignition coil
Full circle is so much smoother . The half moon crank is garbage a throw back from the old non center spark plug . also they love a decent reed valve a rocket key and a massive expansion chamber.
just so 1
Well,
Just help myself,
With a thanks thoses words,
I get how experienced are some .
Have nice feed too !
💓🌹 from Malaysia
How about your crankcase compression? It will become too low
There you go agreed
jeaaa!!
What is the official name of that tool you use to pull the cluch out?
3 jaw puller
The full circle crank is way out of balance (90perc out ) ! I gave up with that and ended up lightening the standard crank then adding tungsten slugs to get the balance weight right,t sure the 'turbo ' mod puts it more out of balance ? at 6.18 there's the bit on the crank :th-cam.com/video/EHFyIM1_iv0/w-d-xo.html , check out 2 stroke stuffing shows the easy way to check the balance with simple tools : th-cam.com/video/0hoE_MuFpPI/w-d-xo.html
What did u torque the crank case and head at?
No really need to torque these engines
I have a Amstar Nostalgia 49. I've put on it a racing spark plug performance racing carb and a performance CDI could i put this turbo crank on it? Its a 4 stroke. Semi automatic bike.
No I wouldn’t do this mod
@@jaguars004 is there something similar i could do?
I did the full circle crank in this. Seems to help Performance some
@@jaguars004 thanks bud ill try that
What does a full circle help with?
Decreased case volume/increased pressure. If run in conjunction with a CORRECTLY reeded engine it produces a lot more power.
How much power these things have tuned?
I honestly don’t know yet, they’re all different but I hope to go over the advertised 30mph or so they yield stock
speed detection result
Trye a bigger carb on it this one looks a bit smal.😉
biger carb and remove the air filter u no need it if u want more power
The only performance gained from that is less weight on the crank
Less balanced crank too 😂
and if tyou had a standard fitted with 44-6 HEAD you're a major plantpot as the piston will be smashing the sparkplug to bits :/
Please say if minipocketrockets.com ships to europe or not
I would be careful on that one, I just got a comment today saying someone ordered and they didn’t ship it. Idk if they ship there tho. Ask
Bro the bigger baring they gave u is still to small it should not wiggle at all. It will defiantly fail
Who the hell dose that in the garbage can
An unbalanced crankshaft can also cause a multitude of problems. Grinding material of nilly willy is not good.
Bro, please modify a 49cc cvt.. x2
Is it possible too put a turbo on a scooter engine?
If it’s a 2 stroke, I wouldn’t try it
Dylon Desbiens ok, for what reason? Is it possible with a 4 stroke
Yes it’s possible for both
4 stroke is very possible, there’s a lot to say about turbos and 2 stroke tho. I would just do your own research, lots of opinions out there
Dylon Desbiens Yeah, ok I was just curius. I would never do that to my scooter cus it runs like thrash. Thanks doe
What does sharpening it do
I have an equal amount of cases that use philips head on the case bolts instead of allen bolts.
Its a $50 engine, you really think they balance the crank from the factory?
where's the turbocharger?
Rattle gun?? You mean impact... I hope
Lol. 😂😂😂💯
Just add a real turbo, jeez 😂
Turbos will not or should not work on a 2-stroke because their self supercharging you put a supercharger on a 2-stroke you're going to blow out more seals . again they are not made for supercharging they are self supercharging when the Piston goes down it's a positive force that charges the transfer ports
The only two stroke that needs and has to have a supercharger is a two-stroke Detroit Diesel and it has nothing to do with one of these two strokes I've worked on both all my life and I know both turbo supercharging does not work on a 2 cycle get it out of your head right now
How about you put dirt bike tire and go off road
Who convinced you this mod is beneficial? If there is any advantage, it will be negligible.
NEVER... E V E R take a grinder to a crank shaft. What you have done is a COB JOB. You need education on engine theory. There is no "slicing the air" LEAVE THE CRANKSHAFT alone. If you Must modify it, send it out to be balanced
ps stop uploading fit vids and do more fit and test vids ffs lol :)
Second
1
Way Not.
I can’t even get one like😢