A little bit of credit? No bro, this is way cool. A little different then Tinman's. A little better explanation for me then his. But his is very good too. But I really like this. Thanks!
Thanks man... there are definitely way more in depth videos and I would be terrible at doing a really involved technical explanation... people gotta give those guys credit its not easy to explain when there are multiple things happening and for long periods of time throughout the cycle... my brain wants to get ahead of myself lol
This definitely helps a caveman like myself better understand. I learned about the "suck bang blow" concept with gas turbines (GE LM2500's)... crosscut items make grasping the actual workings much easier on many levels. Good stuff man. Now let's do this race saw. Lol
"You raise the exhaust roof BUT this is why I stress you gotta machine it as well"(paraphrasing your point at 9:00) That is probably the best, most-succinct way I've heard to properly dispel the "myth of '2-schools/methods' of porting" that so many seem to hold, IE that you EITHER: - machine, and make power via torque, or: - raise exhaust roof, making power via RPM increase... This "dichotomy"/choice puzzled me the moment I started learning Re porting last year, especially w/ creating my own timing#'s/layout BEFORE having a jug in-hand, realized very very quickly that the "2 schools/approaches" mindset was a "false dichotomy", and the optima would necessarily include BOTH....I would explain/phrase it as "the dichotomy breaks-down if you are in a hypothetical situation wherein a manufacturer offers to cast you a jug with ANY specs you tell them", forcing you to choose exhaust height, volume swept gas & comp.ratio & squish clearance, you'd be choosing optimal #'s not "aiming for 1 approach at the expense of the other", you'd "harmonize" them/approach it holistically and take both into consideration......ERGO, that should be the approach to porting any jug, as you say "raise the exhaust roof" to increase RPM but this must be done on a stronger-compression (decked) cylinder or you *are* trading your torque for RPM's, if you do both you're *not*....cannot understand the "other side" logic of machining-only, guys who want super high compression and exhausts at 105+... Thanks for these "basics" videos, I suspect we'd all like to think we have a better grasp on these mini-miracles than we do, I know it's all relative and at your level it's probably about the swirls/eddying/loop-efficacy whereas for me it's "I bumped power 15%, gnarly", but would imagine you could *never* stop learning/improving 2-strokes (or even a specific platform, I bet you'd improve your 44*/46* builds over time, w/ lessening gains but *never* a cessation of gains)
I learn more from watching your channel than any other amd i really appreciate it. Ive messed witb saws for years but you are on another level and its really cool you show us your work and theory on this stuff. Thanks for real
Hey John first things first thanks for all you do to help us newbies! Your content is some of the best on TH-cam and your work is amazing. Could you recommend a chain grinder that works well without breaking the bank. I had an Oregon and it was stolen unfortunately I can’t afford a new Oregon right now so any advise would be greatly appreciated. Have a great night.
people are going to freak when i say this but i used the harbor freight 30 dollar grinder for over a year and it works just fine... i have had people tell me theirs broke in 2 days but mine has sharpened hundreds of chains... i am NOT a chain guru tho and in fact far from it!!! i get them done by someone with a square grinder... i just haven't tried any other grinders... i had the same expensive oregon grinder and the brake broke and i waited 4 months for the warranty replacement to arrive and i finally told them to forget it and i bought that 30 dollar HF grinder and its been great
BD is tough... it can change performance DRASTICALLY and it doesnt take much... i have tossed quite a few cylinders in my day trying to test different BD numbers... i truly dont even have a good handle on it and i bet thats why guys are afraid to talk about it... i just dont have anything to prove so i will admit i dont fully understand it... i have found that the higher the exhaust I run I get better performance with a wider BD... for example if i run a 96 exhaust i would want a 28 BD and with a 100 exhaust i would want a 22 BD... now that is just what has worked for me... not saying thats what you should do... it is all relative to intake timing and case compression angle... all that fun stuff... i have gotten as tight as 16 on a BD and the saw ran like total shit... but i know saws that are built with a BD of 15 and they run like crazy... but they are running higher compression than me and map their cylinder different... so there is my honest but super unhelpful answer lol
I will say this and have always stuck by it... for a good strong build you can just about always go with: Intake 80 Exhaust 98 Uppers 122 Squish .020 ... that will be a runner no doubt 100%
@@johnscustomsaws good stuff. Guess the only way to find is expect to loose a few jugs in trying. Interesting to know how drastic it can be, i figger its a good number to have an idea of, but not specifically a set number to shoot for
When you talk about trying to sound SMART, that is about 90% of the people on here. At least you are smart enough to know that most people KNOW what they are doing. THAT makes you smarter than them! A very GOOD simple explanation of a 2 stroke engine....and NO BULL S...T!
I've noticed with all your videos that the transfers ports and carburetor port are huge compared to my Ms 441 . Im thinking of just opening up the transfer ports on the very bottom of the cylinder and doing a gasket delete and that's all like think I can handle at this point . thanks for the videos
the 441 is a whole different animal and i know that saw like no other lol... you can definitely open up the lowers/uppers/intake... dont widen or raise the exhaust unless you are machining... and you can tunnel the strato ports a bit so you are getting fuel/air in the strato ports as well... you can also find coils that aren't limited if you have the adjustable carb... the mtronic coils are all limited as far as i know
@@doyletech623 absolutely my man... did you get my emails? Lotta people haven't been getting my messages but I just wanted to run something by you so I can finish the NOS cookie... it turned out really good
Re-watching your explanation of RPM//exhaust height//torque (~6:00-->10:00, which everyone should rewatch if they're not getting it as you explain it better here than I've found elsewhere), in rewatching it I'm finding it harder & harder to respect the chainsaw-performance-norm of not "dialing-in" compression, heck maybe it's your "secret sauce" for your professional builds & you just don't share it? "It" being, of course, a truly optimized compression ratio of the unit, not just "strong" like most go for....I'd honestly wondered this before, since you're such a tinkerer/experimenter *and* have such a specific focus on new/high-displacement Stihl models, I mean at the end of the day we're getting super-precise in our measurements & preferences for: - operating RPM, and - exhaust port opening-time, and you help a lot of people by acknowledging/clarifying that it's not "machine OR raise exhaust" but, of course, is both, however this NECESSARILY means that for true optimization, we have 1 more step: Determine true optima for compression, not just "oh it's 19thou squish and a hard-pull start, that'll do", but actually just do a build, drop the cylinder like 2 or 3thou more than usual and, w/ a dyno, figure out PRECISELY where power starts dropping-off. You'd then have your ideal / perfect optimal efficiency (for power) of said cylinder, which for your purposes is awesome (the more I think of it the harder I find imagining you *haven't* done this already...but you've never spoken an iota of it on your vids...but if it's your secret sauce then I get that & feel bad even suggesting it on your channel-space but am only thinking aloud / caring about the saws/building!!) Thanks again for the great vids, just finished a 6-day project am gonna be watching youtubes while building/cleaning/sharpening/etc saws all day :D
PS- would be neat for you to finish your already-the-best demo saw by cutting that muffler in half, I'm still newer to Stihl layouts but the 2-part muffs are one of my favorite things Re "stihl differences", sadly chainsaws - all OPE, really - are of course not getting the push&pull of an expansion-chamber type muffler, so almost all chainsaw builders effectively "throw the baby out with the bathwater" and strictly worry / concern themselves w/ "opening up the muff" with little thought to its function (or size of exit hole/holes, or their placement, or Grunt Gasket header-pipes etc) The 880 muffler is, funnily enough, the most-similar OEM design I'd ever seen that embodied what I'm trying to do on my 660 mufflers, I'd genuinely put $$ that the 880 muff design would beat a 660's (or 440's) and most other saws' muffs (provided you open-up the final exit in the muff, obviously that is a choke-point on basically every saw in existence so far as I've seen...though even here, people just blindly "make bigger exit holes" they don't bother, say, putting a steel plate atop the hole so they can gradually increase size until cut-speed stops increasing, *then* they'd have their precise optima for muffler-exit-area, and so far as Jennings'&Blair's books on 2-strokes paint it this is a very very important part of the exhaust system, there's zero reason to suspect this doesn't apply to can/box mufflers (as the final exit affects the entire engine's throughput-resistance, independently of sonic/acoustic activity from the piping) I WILL get my "Grunt Gasket" built & posted today, wish I had a dyno as I only suspect a few % power from it, probably not enough to show up on my cut-time measurements :/ I've already made the raw/base Grunt Gasket by ripping the exhaust port from a spare cylinder, it will have at least 3 increasing angles of divergence before entering the muffler also it will extend the saw's exhaust port from 0.8" to nearly 2", that's awesome for 'the symphony' as you put it, but the increased diverging-angles of the tube create 'suck'/pull, not as good as the divergence cone of a true pipe of course but a non-zero for sure!![EDIT-- "Grunt Gasket" is the IP/idea of Dominant Saws, I saw it on their Facebook a couple weeks ago but they'd just milled a straight-tube type "header gasket", I expect using the diverging-angles effect will cause a significant increase over just the lengthening of the exhaust-tract....also let's not forget this moves the muffler from millimeters, to >1", from the cylinder, or "the cylinder's hot side" I should say, actually given the disproportionate heating of exhaust-side of cylinder(and piston), you'd think there'd be greater efforts physically-distancing the muff from the jug from OEM's!]
ding ding ding!!! you are the first person to figure out the sauce... in fact once i know you have read this i may delete your comment even tho i love ya my man lol... or i will just delete this response thats more appropriate... this is key tho... if you have noticed and i am sure you have... i do not build super high compression saws and obviously i could but dynjo results show (and yes i do have access to a dyno just not "the dyno guy" hereon youtube) wow quotes inside parentheses thats a first for me lol... but i have said many times the domed piston build behaves so different and my numbers especially squish will NOT work in a standard build... thats why i stay away from giving out my specific build numbers and people take offence to it and i do it bacause running my numbers probably isnt the best... i still do a few saws flat top but i machine the squish quite a bit and its a pain in the ass!!! you are definitely no dummy my man... and i really dont care what the other saw builders think of me... i NEVER start anything with them but i think people think i am trying to single out some by the comments i make but its just me speaking about a general topic... i will never understand the thinking when guys dont machine but raise the exhaust but i guess everyone has a different purpose for building a saw... if you dont need torque i guess its acceptable but still i have a hard time thinking its truly benificial...
Would the manufacturer not have spent years of research making it as efficient and powerful as possible in the first place? I don't understand why a lot of people have to porting and modding and this and that. I liked your explanation of how the engine works , it that 461 a strato engine?
I know nothing about timing a chainsaw port. The transfer ports a just that. As the piston is going down it causes the upper ports to become a vacuum of the air and fuel in the crank case. The suction of the down stroke sucks the available air and fuel up the transfer ports. I would suspect that there's next to no pressure in the crankcase. This theory could be checked by tapping a hole a putting a guage on the crankcase. Good experiment for a saw guy. But molding a saws ports might change crankcase pressure I would suspect.
How does a guy even make a crosscut like that without screwing it all up? Nice job on the vidya man.
LOL... a sawzall and a lot of swear words
A little bit of credit? No bro, this is way cool. A little different then Tinman's. A little better explanation for me then his. But his is very good too. But I really like this. Thanks!
Thanks man... there are definitely way more in depth videos and I would be terrible at doing a really involved technical explanation... people gotta give those guys credit its not easy to explain when there are multiple things happening and for long periods of time throughout the cycle... my brain wants to get ahead of myself lol
This definitely helps a caveman like myself better understand. I learned about the "suck bang blow" concept with gas turbines (GE LM2500's)... crosscut items make grasping the actual workings much easier on many levels. Good stuff man. Now let's do this race saw. Lol
I am SOOOOOOO ready to have you do this 084 head brother... I got the squish and chamber straightened out i just need to test run it now
Very nice explanation john,keep up the great work buddy..ALOHA! 🤔🤗👌🤙🏾
Good demonstration like the cut out demo of saws.
Suck bang blow! Sounds like chainsaw porn.🤣🤣
thank you Johnny nitrous!!!
Thanks Teacher.
Good work 🍻
Thanks for being real very smart man
Very good 👍👍
"You raise the exhaust roof BUT this is why I stress you gotta machine it as well"(paraphrasing your point at 9:00) That is probably the best, most-succinct way I've heard to properly dispel the "myth of '2-schools/methods' of porting" that so many seem to hold, IE that you EITHER:
- machine, and make power via torque, or:
- raise exhaust roof, making power via RPM increase...
This "dichotomy"/choice puzzled me the moment I started learning Re porting last year, especially w/ creating my own timing#'s/layout BEFORE having a jug in-hand, realized very very quickly that the "2 schools/approaches" mindset was a "false dichotomy", and the optima would necessarily include BOTH....I would explain/phrase it as "the dichotomy breaks-down if you are in a hypothetical situation wherein a manufacturer offers to cast you a jug with ANY specs you tell them", forcing you to choose exhaust height, volume swept gas & comp.ratio & squish clearance, you'd be choosing optimal #'s not "aiming for 1 approach at the expense of the other", you'd "harmonize" them/approach it holistically and take both into consideration......ERGO, that should be the approach to porting any jug, as you say "raise the exhaust roof" to increase RPM but this must be done on a stronger-compression (decked) cylinder or you *are* trading your torque for RPM's, if you do both you're *not*....cannot understand the "other side" logic of machining-only, guys who want super high compression and exhausts at 105+...
Thanks for these "basics" videos, I suspect we'd all like to think we have a better grasp on these mini-miracles than we do, I know it's all relative and at your level it's probably about the swirls/eddying/loop-efficacy whereas for me it's "I bumped power 15%, gnarly", but would imagine you could *never* stop learning/improving 2-strokes (or even a specific platform, I bet you'd improve your 44*/46* builds over time, w/ lessening gains but *never* a cessation of gains)
Bottom end air movement is probably better described as displacement. The piston displaces it more than compresses it.
that is a good way to explain it... i have a hard time trying to explain it in words thats for sure
I learn more from watching your channel than any other amd i really appreciate it. Ive messed witb saws for years but you are on another level and its really cool you show us your work and theory on this stuff. Thanks for real
"Suck-breathe-bang-blow" now that is stuck in my head.....
outstanding
Hey John first things first thanks for all you do to help us newbies! Your content is some of the best on TH-cam and your work is amazing. Could you recommend a chain grinder that works well without breaking the bank. I had an Oregon and it was stolen unfortunately I can’t afford a new Oregon right now so any advise would be greatly appreciated. Have a great night.
people are going to freak when i say this but i used the harbor freight 30 dollar grinder for over a year and it works just fine... i have had people tell me theirs broke in 2 days but mine has sharpened hundreds of chains... i am NOT a chain guru tho and in fact far from it!!! i get them done by someone with a square grinder... i just haven't tried any other grinders... i had the same expensive oregon grinder and the brake broke and i waited 4 months for the warranty replacement to arrive and i finally told them to forget it and i bought that 30 dollar HF grinder and its been great
@@johnscustomsaws Perfect thanks for the help! Have a great day buddy.
Great video !
Hey, this is a really good illustration of what the transfers are doing. Thank you for making this video.
How do you find the best numbers for blowdown? This is the number that seems to always be up in the air, to an extent.
BD is tough... it can change performance DRASTICALLY and it doesnt take much... i have tossed quite a few cylinders in my day trying to test different BD numbers... i truly dont even have a good handle on it and i bet thats why guys are afraid to talk about it... i just dont have anything to prove so i will admit i dont fully understand it... i have found that the higher the exhaust I run I get better performance with a wider BD... for example if i run a 96 exhaust i would want a 28 BD and with a 100 exhaust i would want a 22 BD... now that is just what has worked for me... not saying thats what you should do... it is all relative to intake timing and case compression angle... all that fun stuff... i have gotten as tight as 16 on a BD and the saw ran like total shit... but i know saws that are built with a BD of 15 and they run like crazy... but they are running higher compression than me and map their cylinder different... so there is my honest but super unhelpful answer lol
I will say this and have always stuck by it... for a good strong build you can just about always go with:
Intake 80
Exhaust 98
Uppers 122
Squish .020
... that will be a runner no doubt 100%
@@johnscustomsaws good stuff. Guess the only way to find is expect to loose a few jugs in trying. Interesting to know how drastic it can be, i figger its a good number to have an idea of, but not specifically a set number to shoot for
@@johnscustomsaws i just checked bd on this stock 056 and got 13 degrees... thats eyeballed thru the plug hole. Intake duration is 160
Thanks for this great explanation!!
I don't know a guy that has a red pointer. And played with his markers. Sounds like he know a little. Lol
Thanks for the help, it really helped and I love your the outro response 13:45 lol 😂
Great vid. Would of like to touch on rist pin in transfer port and the side ports of piston and why they line up with upper transfers.
i purposely avoided that so i didnt make an even bigger fool out of myself lol
Very good video but you sound like your going through something bro it's aight bro just talk it's going to be ok
When you talk about trying to sound SMART, that is about 90% of the people on here. At least you are smart enough to know that most people KNOW what they are doing. THAT makes you smarter than them! A very GOOD simple explanation of a 2 stroke engine....and NO BULL S...T!
Cool, great teaching tool!
I've noticed with all your videos that the transfers ports and carburetor port are huge compared to my Ms 441 . Im thinking of just opening up the transfer ports on the very bottom of the cylinder and doing a gasket delete and that's all like think I can handle at this point . thanks for the videos
the 441 is a whole different animal and i know that saw like no other lol... you can definitely open up the lowers/uppers/intake... dont widen or raise the exhaust unless you are machining... and you can tunnel the strato ports a bit so you are getting fuel/air in the strato ports as well... you can also find coils that aren't limited if you have the adjustable carb... the mtronic coils are all limited as far as i know
@@johnscustomsaws thanks for the info ill look into it
@@doyletech623 absolutely my man... did you get my emails? Lotta people haven't been getting my messages but I just wanted to run something by you so I can finish the NOS cookie... it turned out really good
@@johnscustomsaws the last email I got from you I replied to that's all I've revived.
Whats weird is i didnt know the air fuel mixture was on the bottom of the piston
Lower end is displacement pressure. Not compression
Luv it 👍
Now cut a turbo in half and explain it in simple terms! 😂
hahaha... not a chance my man!!!
Re-watching your explanation of RPM//exhaust height//torque (~6:00-->10:00, which everyone should rewatch if they're not getting it as you explain it better here than I've found elsewhere), in rewatching it I'm finding it harder & harder to respect the chainsaw-performance-norm of not "dialing-in" compression, heck maybe it's your "secret sauce" for your professional builds & you just don't share it? "It" being, of course, a truly optimized compression ratio of the unit, not just "strong" like most go for....I'd honestly wondered this before, since you're such a tinkerer/experimenter *and* have such a specific focus on new/high-displacement Stihl models, I mean at the end of the day we're getting super-precise in our measurements & preferences for:
- operating RPM, and
- exhaust port opening-time,
and you help a lot of people by acknowledging/clarifying that it's not "machine OR raise exhaust" but, of course, is both, however this NECESSARILY means that for true optimization, we have 1 more step: Determine true optima for compression, not just "oh it's 19thou squish and a hard-pull start, that'll do", but actually just do a build, drop the cylinder like 2 or 3thou more than usual and, w/ a dyno, figure out PRECISELY where power starts dropping-off. You'd then have your ideal / perfect optimal efficiency (for power) of said cylinder, which for your purposes is awesome (the more I think of it the harder I find imagining you *haven't* done this already...but you've never spoken an iota of it on your vids...but if it's your secret sauce then I get that & feel bad even suggesting it on your channel-space but am only thinking aloud / caring about the saws/building!!)
Thanks again for the great vids, just finished a 6-day project am gonna be watching youtubes while building/cleaning/sharpening/etc saws all day :D
PS- would be neat for you to finish your already-the-best demo saw by cutting that muffler in half, I'm still newer to Stihl layouts but the 2-part muffs are one of my favorite things Re "stihl differences", sadly chainsaws - all OPE, really - are of course not getting the push&pull of an expansion-chamber type muffler, so almost all chainsaw builders effectively "throw the baby out with the bathwater" and strictly worry / concern themselves w/ "opening up the muff" with little thought to its function (or size of exit hole/holes, or their placement, or Grunt Gasket header-pipes etc) The 880 muffler is, funnily enough, the most-similar OEM design I'd ever seen that embodied what I'm trying to do on my 660 mufflers, I'd genuinely put $$ that the 880 muff design would beat a 660's (or 440's) and most other saws' muffs (provided you open-up the final exit in the muff, obviously that is a choke-point on basically every saw in existence so far as I've seen...though even here, people just blindly "make bigger exit holes" they don't bother, say, putting a steel plate atop the hole so they can gradually increase size until cut-speed stops increasing, *then* they'd have their precise optima for muffler-exit-area, and so far as Jennings'&Blair's books on 2-strokes paint it this is a very very important part of the exhaust system, there's zero reason to suspect this doesn't apply to can/box mufflers (as the final exit affects the entire engine's throughput-resistance, independently of sonic/acoustic activity from the piping)
I WILL get my "Grunt Gasket" built & posted today, wish I had a dyno as I only suspect a few % power from it, probably not enough to show up on my cut-time measurements :/ I've already made the raw/base Grunt Gasket by ripping the exhaust port from a spare cylinder, it will have at least 3 increasing angles of divergence before entering the muffler also it will extend the saw's exhaust port from 0.8" to nearly 2", that's awesome for 'the symphony' as you put it, but the increased diverging-angles of the tube create 'suck'/pull, not as good as the divergence cone of a true pipe of course but a non-zero for sure!![EDIT-- "Grunt Gasket" is the IP/idea of Dominant Saws, I saw it on their Facebook a couple weeks ago but they'd just milled a straight-tube type "header gasket", I expect using the diverging-angles effect will cause a significant increase over just the lengthening of the exhaust-tract....also let's not forget this moves the muffler from millimeters, to >1", from the cylinder, or "the cylinder's hot side" I should say, actually given the disproportionate heating of exhaust-side of cylinder(and piston), you'd think there'd be greater efforts physically-distancing the muff from the jug from OEM's!]
ding ding ding!!! you are the first person to figure out the sauce... in fact once i know you have read this i may delete your comment even tho i love ya my man lol... or i will just delete this response thats more appropriate... this is key tho... if you have noticed and i am sure you have... i do not build super high compression saws and obviously i could but dynjo results show (and yes i do have access to a dyno just not "the dyno guy" hereon youtube) wow quotes inside parentheses thats a first for me lol... but i have said many times the domed piston build behaves so different and my numbers especially squish will NOT work in a standard build... thats why i stay away from giving out my specific build numbers and people take offence to it and i do it bacause running my numbers probably isnt the best... i still do a few saws flat top but i machine the squish quite a bit and its a pain in the ass!!! you are definitely no dummy my man... and i really dont care what the other saw builders think of me... i NEVER start anything with them but i think people think i am trying to single out some by the comments i make but its just me speaking about a general topic... i will never understand the thinking when guys dont machine but raise the exhaust but i guess everyone has a different purpose for building a saw... if you dont need torque i guess its acceptable but still i have a hard time thinking its truly benificial...
Fun Fun Fun great video!
Would the manufacturer not have spent years of research making it as efficient and powerful as possible in the first place? I don't understand why a lot of people have to porting and modding and this and that. I liked your explanation of how the engine works , it that 461 a strato engine?
Excellent Smithers! Very clear explanation. Also Kudos on the color coding.
I know nothing about timing a chainsaw port. The transfer ports a just that. As the piston is going down it causes the upper ports to become a vacuum of the air and fuel in the crank case. The suction of the down stroke sucks the available air and fuel up the transfer ports. I would suspect that there's next to no pressure in the crankcase. This theory could be checked by tapping a hole a putting a guage on the crankcase. Good experiment for a saw guy. But molding a saws ports might change crankcase pressure I would suspect.
Awesome video baby. Thanks for the explanation. Sent it to a few people.
💯💯👍👍👍🤝🤝🤝
So putting a turbo on a saw wouldn't work, because you blow the seals out.
Just learned me some stuff. Thanks again bud
Great explanation John 👍
It doesn't "compress" the lower end. It pressurizes it.
Appreciate this Brother. Thank you👍🏻