Dremel VS bolt ons

[INTP_ty]

Porting works.

Well it’s working so far.

Are you guys opening up the holes (intake/exhaust) OR simply “whaling” the mouths? I opened the mouths up but as far as the actual holes near where the piston goes up and down, I only removed the burrs.

You guys make those bigger too? I like the increase in power off the start, but do not want to decrease top speed

 

[butre]

I make everything as big as I can get away with. for the transfer ports, I cut out the transfer walls and clean up any casting defects. as for port timing, don't touch it until you get a degree wheel.

 

[INTP_ty]

Well I’m def not porting my next jug to the same degree. PITA to start now.

And vibrates like mad. Power is def there though. Guess I know how much to take off on my next one

 

[6blueoval9]

You can widen both the intake and exhaust port on the cylinder side without any timing changes to improve volume of air...widen around 1mm then blend back into the port...This is a common mod.

Around the transfer port skirt area at the bottom you want to round off the inside edge to help improve incoming flow.

Many do what they call knife edging and grind away at the bottom till it has a sharp knife like edge to it.


I prefer just a nice radius to the edge maintaining the skirts strength and allowing improved flow.

There's alot of little things you can do that can make as much if not more of a difference than just bolt ons.

This is mainly what my first build is all about...no real bolt ons but doing the little things to the stock parts that should make a nice difference in performance...No fancy porting or timing changes...no intakes or heads or exhausts....All stock parts reworked in some manner with a Dremel.

I suppose time will tell how it all works out but I'm confident in what I'm doing so far will give me reliability and improved performance and hopefully 40 plus mph...lol

 

[INTP_ty]

You can widen both the intake and exhaust port on the cylinder side without any timing changes to improve volume of air...widen around 1mm then blend back into the port...This is a common mod.

Around the transfer port skirt area at the bottom you want to round off the inside edge to help improve incoming flow.

Many do what they call knife edging and grind away at the bottom till it has a sharp knife like edge to it.


I prefer just a nice radius to the edge maintaining the skirts strength and allowing improved flow.
View attachment 79932

There's alot of little things you can do that can make as much if not more of a difference than just bolt ons.

This is mainly what my first build is all about...no real bolt ons but doing the little things to the stock parts that should make a nice difference in performance...No fancy porting or timing changes...no intakes or heads or exhausts....All stock parts reworked in some manner with a Dremel.

I suppose time will tell how it all works out but I'm confident in what I'm doing so far will give me reliability and improved performance and hopefully 40 plus mph...lol

Holy^^^
Post of the year


Yeah I def raised lowered the hole/s near where the piston goes up and down cuz the RPM’s tend to float.ill be cruising at like 20-25, let off gas, and the motor does not wanna come down



I didn’t know that these kits were sold with different intake manifolds. My last one was whale mouthed. This one is just a coicle. And that last one broke lol

 

[Frankenstein]

Uhh... Why would you leave it not knifed, the piston doesn't go down far enough on those cut outs on the piston skirt to worry about and certainly doesn't exert enough force to even consider it as a problem. At the very least this is something anyone can do with a simple file and improve the performance of an engine.. These things get replaced every 6 months if you replace top ends, it's not going to be there long enough to worry about it getting weak, especially because that area receives almost no wear so you have a decentish layer of chrome to help keep it integral. If you want to put faith into stock design buy a vespa.

 

[6blueoval9]

Uhh... Why would you leave it not knifed, the piston doesn't go down far enough on those cut outs on the piston skirt to worry about and certainly doesn't exert enough force to even consider it as a problem. At the very least this is something anyone can do with a simple file and improve the performance of an engine.. These things get replaced every 6 months if you replace top ends, it's not going to be there long enough to worry about it getting weak, especially because that area receives almost no wear so you have a decentish layer of chrome to help keep it integral. If you want to put faith into stock design buy a vespa.

The thickness of the skirt may just be me being over cautious, however.....

Just a simple rounding of the edge does as much to improve flow without increased turbulence and loss of port velocity/case pressure....At least that's what current leading 2 stroke development has led me to understand.

Alot of good 2 stroke books out there but alot of it is outdated in several areas compared to what's been learned with today's technology.

Not saying you can't find an improvement with knife edging but its not really needed to obtain a solid improvement yet gives a lesser degree of negatives than with knife edging.

 

[butre]

knife edging has no negatives so long as you're smart enough to not leave a burr. my tactic of removing the transfer walls entirely comes with only one downside, that the flow is a hell of a lot more turbulent, but the power increases with my porting are easily worth the somewhat choppy torque curve.

 

[Street Ryderz]

Holy^^^
Post of the year


Yeah I def raised lowered the hole/s near where the piston goes up and down cuz the RPM’s tend to float.ill be cruising at like 20-25, let off gas, and the motor does not wanna come down



I didn’t know that these kits were sold with different intake manifolds. My last one was whale mouthed. This one is just a coicle. And that last one broke lol

That's not your port timming causing the rpm to float as you say there is a vacume leak somewhere that causes that to happen.