Piston Window Porting for 2T Boost Ports

[@Avantone]

Nice mod, and should also help small end lubrication. You're braver than me; I would have gone for two windows and retained a little more skirt strength. Thanks for the videos 👍

[@brandoncox7474]

Dude. Awesome. Not many ppl want to share secrets

[@Corn-ped]

Yeah haha people are stingy

[@TumTuhm]

I always window just because that’s how the original metrakit design was… I also cut the bridge out of the skirt. Seat dyno’d, no idea on impact. Most of the fresh charge is through the side transfers so 🤷‍♂️ Thanks for the hard work bud, I owe ya a coffee.

[@Corn-ped]

Thank you! I believe the boost port pushes the mix that is already there from the transfered to the head. I feel like it makes a difference. Thank you for the coffees!

[@TumTuhm]

@@Corn-ped yeah, and I think it was in Bell that the boost port should open first, pointing directly at the head, so that it will force expended mix out the exhaust port and improve fresh mix retention.

[@HoarderErik]

great tech info!

[@Corn-ped]

Wooooo

[@tyleraugustine2436]

Ive seen the argument that by increasing flow through the boost ports while the ex port is open that the only real thing happening there is that you are losing more unburnt fuel through the exhaust at the scavenging stage. Personally I think you want a smaller amount of fuel to do the job without reducing efficiency. I have tried both ways and have had the best performance without a windowed piston but thats just me measuring by the seat of pants dyno. However I am just a common moron, and this is mainly just for the al gore rhythm. ❤ya 💋

[@Corn-ped]

yeah I can see that. On this cylinder the boost ports are aimed aggressively towards the head so it should help with scavenging and the ex/transfer duration over lap is pretty minimal. Without a dyno and fuel measurement I don't know how you would tell if it worth it? If it feels faster I dont care too much about lower mpg. My black derbi has the window cut and this one didnt, the black derbi feels a lot better, but yeah my butt also is not the best dyno.

[@zacharygillette7810]

Get a dragy and document your engine changes to performance changes, you can get refurbished dragys with 2 year warranty for about $130.

[@maxpionier5241]

If you ever get access to a dyno, I would love to see you try your piston vs a normal one. I don't think you can see a big difference. Many garage tuners have their tricks, and maybe you are on to something here but I doubt it.

[@Corn-ped]

I really wish I had a dyno so I could do testing. I m just going for it and testing it out.

[@laneadams8998]

Weird question but do you know where to get transfer decals for puchs?

[@Corn-ped]

Stickers? Treats sell them. as well as a bunch of random people on Mopedarmy who have vinyl cutters

[@laneadams8998]

@@Corn-ped as always ur the man 👊🏽

[@splak_5624]

looks rad, but there is a 100% chance that I would ruin my piston lol

[@Corn-ped]

Go slow!

[@buttcheeksbuzzard8765]

Pistons are cheaper than buying a cylinder. Take chances!

[@meskalin64]

Is a piston with windows always better than one without?

[@hamzahmushtaq877]

Not always, and only with a reed valve

[@meskalin64]

@@hamzahmushtaq877 But people talk about piston window on chainsaws and they dont have reeds. So im abit confused.

[@hamzahmushtaq877]

@@meskalin64 if it has a window there is always a reed maybe the chainsaw looks like it doesnt but it might have a case reed?

[@meskalin64]

@@hamzahmushtaq877 They do have different carbs though. The windows are much higher up on the piston (from the top down to the piston rod/bearing) and not on the intake side but on the fuel channel sides. 2 windows on each side.

[@hamzahmushtaq877]

@@meskalin64 dude what you just said made no sense