Part 7 - Gasket Matching Porting 2 Stroke Piston Ported Engines for High Performance and Efficiency

[@joescissorhands141]

Dude this is just A+++ content I think your muffler-theory may be some of the best I've seen (LOL maybe I should phrase it "it's some of the closest to how I understand mufflers-in-chainsaws to operate at-optimum"), we KNOW that a no-muffler powersaw is NOT the performance-optima, but most fall prey to the dual notions of: #1 - If you're not using a long pipe, you're not able to 'tune' a muffler for performance, and: #2 - "Flow" is the primary, oftentimes the *only*, thing to be concerned with. But a 2-stroke engine, when piston is leaving BDC on its upward/compression stroke, there's a moment where pressure is higher in the muffler than in the cylinder and the cylinder(via exhaust port) re-uptakes some of the good charge that it 'held' in the muffler for a quick moment, this happens every revolution of the engine hundreds of times per second, guys who go putting big holes in the rear-portions of their mufflers, or the front-walls where the exhaust-pulse is aimed, are inherently "pushing-out" fresh charge (which automatically causes the muff to draw-in atmosphere, which is then mixed-in for re-uptake into the cylinder as piston's beginning its upward stroke) Because of this it seems you want your rear-half of the muffler to have ZERO exits-to-atmosphere, only after exiting the rear half and entering another cvhamber (or taking a long or sharp turn, if using short pipe mufflers like some saws a la Tinman, Iron Horse et al), obviously you must bore-out the baffle/portage between the two halves of the muffler to prevent sub-70% choke-points, and the final exit must be ~65-75% of exh.flange, depending, but this is how you do a muffler properly, I feel awful seeing guys do such extensive port-work, timing advances and all kinds of stuff but then they go and put a 1/2" hole in the rear of their muffler like 2" away from the exhaust flange, I'm left banging my head-on-desk wondering what % of fresh-charge they are trading for atmosphere by the improper hole-placement!! Grade-A content man, have downloaded the whole series so I can watch on my media player but am still letting y.tube run the videos so I can thumbs-up/give the views/Comment ;) I haven't dared to check my luck yet to see if you have any 2511t content, I was right that there was a TON out there but, sadly, SO much of it is bad/improper/contradictory, for instance every muff-mod video I found seemed "normal-ish", for chainsaw-tuners at least, but the moment I remove the muffler I see the muffler's entry-port has a ~1mm bottom lip that's not just choking-off the exhaust-flange by 1mm across its entire bottom, restricting total throughput/flow, but also just killing aerodynamics/flow which is even more critical in that area because this saw's exhaust-port, and mating-to-muffler, is very funky, the gas has an odd, uneven path to travel it's not a straight-shot exhaust port like most saws, it's a sideways port that angles-out and takes a hard 90deg turn into the muffler, will have video on it by today or the weekend (am doing the 2511t, the 2nd 660 clone and a 355t "overhaul" today so they can be tip-top through the weekend for a job!!)

[@JRA79]

hey Joe! Thanks for your support! I am reading through your comments now. You are well on your way to being a heck of a tuner. Sorry for not getting back sooner... New job has me super busy. Ill try to answer your questions as i go. Thanks again and good luck!

[@IndianaDoug]

I can’t believe nobody has commented on this porting series! That was great! I sub’d for sure man. You should put it in a playlist.

[@joescissorhands141]

Seriously!! This guy *really* understands his stuff, it's weird because guys this advanced usually "gloat" a bit more, try peppering-in more lingo/jargon, he's certainly a high-end mechanic (am guessing it's more-than just chainsaws, if it's just chainsaws then I guarantee he works-with them professionally, not like me ie cutting with them but like literally building/repairing/selling them) Guys this sharp are usually not sharing chainsaw-specific info, totally stoked to have found his channel & like you am surprised others haven't, am gonna be linking his vids wherever appropriate on the forums (gotta love OPE, AS and the like!)

[@JRA79]

thanks bud! its a numbers game for sure.... flashy and a host on cocaine seem to get the views LOL

[@IndianaDoug]

@@JRA79 pretty much🤣