How would cold shrinking the head change the dimension of the cylinder? They're 2 different parts. Even if you're thinking is conduction, the mass of the head is maybe 1/3 that of the cylinder.
@@papapetad Wrong. There are some two smokers where the head and cylinder are combined in one piece and cannot be separated, for those it would be most appropriate to call the whole thing a cylinder, not a head. You take the cylinder off from the crankcase and there is no separate head. But most of them have separate head and cylinder just as on a four smoke engine of similar design. The engine in the film is of the latter design.
@@mwilliamshs Even if it was a joke, the joke would have been better with the relevant engine part as you point out. To put the cylinder in the freezer would have made more sense, at least for a short while.
For future endeavours Tony, A leak down test is arguably more important than a compression test with two stroke engines. Basically you plug the intake on the carb, and the exhaust on the head, and pump it up through the spark plug hole to around 7 psi or so. It should hold for a few minutes. If pressure drops some over a few minutes, or bleeds off entirely, you can use soapy water to find the leak. This checks for seals on the crank, reeds hanging open, case damage, reed block gaskets etc. I havent seen the reveal yet so i dont know if you were right or not, but its a good test to keep in mind. Especially if you find its running lean and cant fifure out why. Also, as im sure you know, every bike has a service life for the top end, X amount of hours.
... and a vacuum test - critical for two strokes. Leak down testing is way more repeatable then compression tests and it tells you where the issue is immediately. Test hot at TDC
I feel like such an idiot. My minivan has been down on power for about six months now, and it never occurred to me to look at the rotors! I'm so ashamed. Here I was sure it was the wiper blades.
After watching my European heroes contest an Inter-Am motocross meet, I went out and bought a 1970 CZ 250 MX. I had never ridden a dirt bike but assumed I would be an instant Joel Robert on such a mount. The owner's manual did not expand on the terms of the factory warranty (Both Halves Are Yours), but rather gave instruction on how to win races. Before each contest, it suggested, I should fit a new piston and ride the bike hard to see if it seized, repeating the process until satisfied that the piston would last the race. It also recommended a new chain for each race. CZ chains had individual bronze sleeves between each roller and pin, and were priced accordingly. Being used to torquey street bikes, I stalled the CZ several times before getting it moving for my first ride. Broke my collarbone twice the first year I had it, and never had so much fun in my life. Every once in a while I watch a VHS copy of On Any Sunday to relive the thrills.
So, just to mess with you Tony. Pistons are not machined perfectly round when cold. They are machined to grow to circular when at operating temperature. Even el cheapo pistons. Forged race pistons have full 3d machining for growth at temp. The piston bore is also not checked or bored just sitting free air. It should be torqued down with torque plates to simulate the stresses of the head and block in place, which changes the bore shape due to the elastic deformation of the clamping loads. On your trials bike, you found it's a thousandth or less. Hard core race engines are bored at operating temp with torque plates installed to simulate the head, accessory, trans and block deformation and are effectively seized when not clamped together to create the clearances.
I was wondering if anyone would mention this. The reasons they change from oval to round at operating temp is that there's more meat where the wrist pin goes so more expansion in that direction than the thinner front and back. Also with a 2-stroke there's more heat at the exhaust port so more expansion at the front of the piston.
I wasn't believing my compression tester one day, it was saying my perfectly running car had 0 psi of compression. Turns out the adapter side had a wasp nest in it and the schrader valve on the other side was rusted. Cleaned those out and it worked perfectly. Even with little use, just checking and spraying with WD40 every so often works wonders.
I'm starting to get that twitch that I get when I'm coming down off of TOT, pretty soon I'll be breaking into my grandmother's house, rifling through her VCR collection to see if there's any TOT on there, hanging out on street corners, offering favors for just a little fresh TOT. I get chills every time I walk past my local machine shop, they won't let me in anymore... I got so excited yesterday when a guy sold me a USB stick for $20, he told me there was some fresh TOT on there, but it was just some Abom79. But in all seriousness, I hope you and your family are safe and well and I hope you're back with a video soon.
I got all the TOT you need man, great price and its high quality stuff too. Lol. I know the feeling though man, i just started TOToholics anonymous, great program.
@@kilrahvp yeah I don't know why he didn't mention it! for somebody that doesn't know anything about engines and all the numbers he talked about, that kinda worried me.
@@OhShitSeriously You jest... I knew a guy at high school that turned a wooden piston to repair his dirt bike. He checked it ran (very well apparently) and promptly sold it. 60 minutes after sale the dude turned up saying "WTF it doesn't go at all now" only to hear "tough shit, your bike". Yeah, the guy I knew wasn't a friend of mine and that is exactly the behaviour I'd have expected from him and his family.
809k subscribers 15 years from now: "There's no way I'm paying someone else to do what I'm fully qualified to do myself since I watched that video fifteen years ago."
I tried once to make one for a 50cc but failed so I made the skirt and used the middle of the old piston to fix the axe. It did about 3 km. I came home using the pedals and passed in front of policeman who lough at me. A part of their job was to catch young going more than 30km/h. He didn't know that before I was at 70...
Open Minded Air Head my baby is napping so time to sit and relax got 45 minute left but neighbor just started revving up his demolition derby car with open exhaust that will last until dark tonight like every day since his job was not essential....
@@TheHungrySlug My Uncle Vernon was a professional mechanic and a bit of a philosopher. His take was, "If you can't take a piss in your own back yard without the neighbors getting an eyeful, it's time to move further out of town."
Quite enjoy your mechanic videos! On a sidenote: pistons and cylinders aren't necessarily meant to be cylindrical when they're cold, they're often manufactured to account for different heat expansion due to their geometry, so a measurement of roundness might not always be super meaningful.
Old Smokey Yunick discovered that way back when after designing a fixture to hone cylinders perfectly round, and the engines not making power until they wore to a certain pattern. Then special plates, and preheating of the block was done to get close to as round as possible while running.
Cylinders are always round. For very high perf engines (think Nascar and NHRA) honing plates are bolted to the block to mimic the distortion caused by bolting the head to the block. The block is then honed round. The honing plate removed. The bores egg shape a tiny bit. The heads are installed and torqued, they are round again! Pistons will have a circular section profile on the piston skirts and contract a bit near the wrist pin.
The cylinders are bored straight. But the pistons have a "barrel" shape: do to heat/expansion. The skirts are thin and flare out a lot during operation. On an extremely worn cylinders,: you can sometimes hear the piston skirts slap, when cold, during the first few revolutions.... There are also machined cuts across the pistons at certain areas to limit the conduction/travel of heat (from the blazingly hot crown to the thin skirts). Some pistons have steel inserts cast into them...to control expansion as well. Cast pistons expand and contract less than forged pistons...but both have pluses and minuses. Just saying.
This Old Tony, it's always worth watching to the end. As always, great content! I'm a land surveyor & woodworker and just from watching your videos, i now know i need to stick to those things. HA. Kidding! Thanks for the awesome videos, I always get excited when i see the new ones pop up in me feed...I don't use the bell icon, i like to be... Thanks for reading.
The amount of comedy material he manages to put together in these timeframes and with everything else he's having to do for these is just unbelievable, honestly.
Another great video. (As always!) 🤙 As a lifetime dirtbike rider/racer and a hobby machinist, I really enjoy when you bring the two subjects together. Ps. To really get the most performance increase out of doing a top end you might want to throw in new clutch plates and clutch springs (or in a pinch stack an extra washer on the clutch springs) to ensure that the horse power increase is making it all the way to the ground. You’d be surprised how a slightly worn clutch can keep you from feeling the full performance increase.
Just an aside, thank you for properly calling this an ENGINE!!! The entire world can't seem to get this right (motor),,, I've been screaming (it's not a motor) about forever and here you go out of the gate and call an apple and Engine! Seriously, I couldn't be more proud of humanity then I am of you right now!!!
When the "Emergency Alert" went off, my cat, who was sleeping next me. Woke up freaking out, looking all around. Was pretty funny. Thanks for reading!!!
Yeah me too, I only became familiar with that sound a few weeks back. I can't remember the last time I had a big frighten cut so hard and fast to a stupid chuckle.
I've rebuilt many 2-smoke bikes in my time and you did everything right. You are exactly on the money with the Nikisil coating, the only thing I ever do is light clean it with a Scotch-Brite pad. The new rings will take time to bed in. I first rebuilt a 1977 Honda MR175 Elsinore 2-smoke, I borrowed a book on rebuilding 2-smokes from the library and did it in my dad's garage. Great video!
Thank you! Yes! I stuck around till the end, and I thought it was most definately worth it! Yes, ofcourse I would have liked to see you hone (also own?) it! But, I stand by your decision, and I would have done the same. Again, you are truly a fountain of wisdom and good humor. Thank you so much. Alicia from Sweden.
Mr T, 90 is a bit low for a 150psi cylinder - with new rings. I normally see closer to 135psi on a new rebuild of that size, and it'll quickly tighten up and make its way to 150psi over a little bit of running time. Also, check out a leak down tester for the cylinder vs a standard compression tester. You to put the piston at TDC (or crank in the case of a 1cyl), and put compressed air into the cylinder to your desired pressure. You then wait. The leak down tester has a gauge on it, and you watch it with exuberant anticipation... and it slowly leaks down, crushing your soul, or not. Anyway, they're great for getting a better idea of cylinder and ring wear on a 2 stroke. The leak down will show wear that a compression test will not.
Man, Tony, I knew nothing about combustion motors but I do now (and I am just half way in your vid!) You are explaining things like every teacher and howto-vid should. Love your vids, keep it up, keep the fun it makes your videos worth to watch. Even if the thematic isnt even close to interest. I learned so much about stuff I never had interest in. You rock!
this is the struggle of building engines at home. You make it seem hilarious and fun. I miss the honing machine I used to run along with all the other machine tools that made it look easy. Good job!
As a retired m/c mechanic of 40yrs in the business, I have enjoyed laughing at the escapade while having coffee !! Comments are something else, also !! Ya got it right, even using the tools ya did. Would suggest cleaning the s/a, silencer after every top end job !!
Doing the exact same thing with my bike except it is a 4 stroke 250cc inline 4. Learning a lot of lessons (the hard way) and this video taught me even more.
As I logged on to RUclips I thought to myself “ I could really do with a ToT video now” - and would you guess what...an half hour video. I love this channel 😫
I raced RDs and TZs and still have a KX500 so I know the smell of two strokes well. When I was racing some were still using castor oil - to be honest I don't know if this was a belts or braces left over or they knew something but it will produce gum that will need to periodically cleaned. What I found was running a good synthetic as lean as possible produced the most power and actually the longest piston/cylinder life. Back then new pistons/jugs used to be cheap as chips and I had access to factory spares so I could experiment but I never seized an engine - I think I went as lean as 70 to one.. What I think is happening and what the engineers told me is that increasing the oil/fuel ratio actually causes detonation which then leads to overheating which then causes scoring/seizure. Of course the human tendency is to add a little more just for safety. I totally agree with you yes you can hone with a diamond flex hone but don't. Nothing is better for oil retention then raw Nicasil and matching the piston to the jug is best done by the plater when you get to that point. Love your videos and your sense of humour. Awesome stuff
actually those tips you pointed out @9:12 was very important. its details like that(+ snarky sarcasm comedy) that keep me coming back and watching(re-watching) your videos.
The thanking us for watching at the end is 100% unnecessary. Loosely speaking for everyone here when I say, we absolutely love your videos and knowledge and we should be thanking you for the time and effort on your end, and personally speaking id love it if the videos were even longer! Can’t get enough
Speaking as a mechanic I was taught and have found that most engines won't run under 100 psi (at least not well) and wont run great under 120 psi. That is kinda a good reference to go with I have found
I had a cylinder down at 110 psi and my truck ran its fastest 1/4 mile time like that. Almost a second quicker than stock and all I had was cold air intake and exhaust done. Surprised doesn't describe how I felt when I saw the time slip.
True, most modern engines anyways. An old VW or straight six will chug along alright at 90psi, maybe with a cylinder or two at 80psi. No, it's not ideal, but older stuff will be ok.
Be careful, 2 strokes normally run a lower compression because of the way the Piston compresses the air fuel mixture on the bottom of the stroke. I have seen my old 1969 Yamaha dt1 run at 70 Psi. Was a pain to start but it ran.
And it's also hard to get a true compression reading on a 2 stroke as the ports are exposed on some of the stroke. Unlike a 4 stroke compression stroke when you have a full sweep with the valves shut. Did that make sense? Haha
@@NickyP500 There are 2 stroke compression test kits. They come with block off's for the intake and the exhaust ports. The lowest I've seen with the motor still running is 60 psi. It was a bitch to get started and didn't idle very well.
I had a side-gig in a motor shop for a Motocross race team for a little under a decade. I'm not going to go into any "advice" as well, as you said a dozen mechanics, a dozen answers. To answer your question on compression to draw fuel. We found that smaller motors usually around 80 on the gauge and it was only starting when hooked to a tow vehicle. Considering you went to spec on everything, your compression is more than adequate. The only other thing to say is when you checked the piston crown height at the top of the bore, you can get different thickness of base gasket to adjust your "squish" to make the most of the explosive forces in the cylinder. "Squish" is exactly as it sounds. Take a couple of pieces of the softest solder available, put it in through the spark plug hole and allow TDC to squish it flat. do both intake and exhaust side. measure the squished solder and boom bobs yer... [jump cut]
Hi Tony, hope you are fine. Just want to say, that we miss you. In case you ran out of topics, you can just upload an "i'm fine" video. Starting to get worried in these times...
Наука
Compression issues? Maybe it's finally time to buy that WinRAR license...
😬
yall know 7zip exists, right?
never
Tar -xf
30 years later, Goonies never say buy a WinRAR license!
Apparently regular maintenance on a trials bike is every 25 miles.
Maintenance on these bikes is expressed usually in hours
@Jim Alley what?
Many many years ago I had a Yamaha TY250, that required maintenance pretty much every 25 inches :-)
I had no idea a trials bike was even a thing until Tony started talking about them.
You must mean minutes.
Just chuck the cylinder head in the freezer for a bit and that bore measurement will be proper good :)
How would cold shrinking the head change the dimension of the cylinder? They're 2 different parts. Even if you're thinking is conduction, the mass of the head is maybe 1/3 that of the cylinder.
@@mwilliamshs Being a 2 stroke engine, designations change. Intead of block/head, you get head/crankcase.
@@papapetad Wrong. There are some two smokers where the head and cylinder are combined in one piece and cannot be separated, for those it would be most appropriate to call the whole thing a cylinder, not a head. You take the cylinder off from the crankcase and there is no separate head.
But most of them have separate head and cylinder just as on a four smoke engine of similar design. The engine in the film is of the latter design.
@@mwilliamshs Even if it was a joke, the joke would have been better with the relevant engine part as you point out. To put the cylinder in the freezer would have made more sense, at least for a short while.
Hahaha hold my
Beer
0:05 As a wise man from the north once said “Tappy Tap Tap...”
Since i found that guy all the other reviews and stuff seems boring and lame.
Happy Gilmore?
Ave🤣
Blondihacks? Not a man.
"First, I love you"
You don't even know how much a lot of us needed that...
Heard that and missed his next sentence entirely laughing.
Lol it felt so genuine
Absolutely couldn’t agree more. Even the love part !! 🤣🤣 hahaha. Jokes TOT ! Or is it... Crreeeeppppy maaaan stalking yooou !! Hahahah
So fucking true
@@mJlReplicanT001 I like to think a little of both. A smidge.
“...kick this thing like it owes me money...”’ I always suspected ToT was a loan shark for the mob.
I think it's ToT the mob goes for loans...
Imagine an italian guy saying This Old Tony
That was the funniest line out of a video that had so many... I LOL'd at loads of points on this one. Bravo!
Pretty obvious considering his latest mill ...
"all over my bullets, and everything. "
22:13
Watching this totally qualifies me to fix someone else's bike now.
Not your own?
@@jasonvossbrink2296 Fixing someone else's bike and making all the mistakes there then qualifies me to work on my own.
Never ever start on your own bike should be the motto for everyone. Besides what are good friends for - for having their bikes fixed :-).
@@wojciech_migda
If mates aren't happy with the professional job you do then they should bite the bullet and learn how to wreck their own bike. . .
Sure dous
For future endeavours Tony,
A leak down test is arguably more important than a compression test with two stroke engines.
Basically you plug the intake on the carb, and the exhaust on the head, and pump it up through the spark plug hole to around 7 psi or so.
It should hold for a few minutes. If pressure drops some over a few minutes, or bleeds off entirely, you can use soapy water to find the leak.
This checks for seals on the crank, reeds hanging open, case damage, reed block gaskets etc.
I havent seen the reveal yet so i dont know if you were right or not, but its a good test to keep in mind. Especially if you find its running lean and cant fifure out why.
Also, as im sure you know, every bike has a service life for the top end, X amount of hours.
yep and a wrist pin bearing always accompanies a top end rebuild
... and a vacuum test - critical for two strokes. Leak down testing is way more repeatable then compression tests and it tells you where the issue is immediately. Test hot at TDC
“Just to be sure, I changed both brake rotors.” Classic!
Rather like how 90% of all carburetor problems are ignition related.
I feel like such an idiot. My minivan has been down on power for about six months now, and it never occurred to me to look at the rotors! I'm so ashamed. Here I was sure it was the wiper blades.
@@tcmtech7515 I think thats only because ignition is really only 100% or 0% it doesn't have a value like clogged filters slowly decreasing flow
@@TomHaroldArt I mean the only logical place to look for an engine problem is the brake rotors
@@hollodollo4771 EXACTLY! It's always where you least expect it!
For the curious: the reverse audio part was, "The only thing I'm changing are the piston and the rings."
Wow thanks for going thru the trouble of doing that!
Reverse? I thought it was polish.
@@FPanka loool
I was sure it will say 'Subscibe'
how did u reverse it? to find out
Excuse me TOT, there are at least 3 of us who wanted to see the inside of that cylinder bore.....thanks for sharing.
After watching my European heroes contest an Inter-Am motocross meet, I went out and bought a 1970 CZ 250 MX. I had never ridden a dirt bike but assumed I would be an instant Joel Robert on such a mount. The owner's manual did not expand on the terms of the factory warranty (Both Halves Are Yours), but rather gave instruction on how to win races. Before each contest, it suggested, I should fit a new piston and ride the bike hard to see if it seized, repeating the process until satisfied that the piston would last the race. It also recommended a new chain for each race. CZ chains had individual bronze sleeves between each roller and pin, and were priced accordingly. Being used to torquey street bikes, I stalled the CZ several times before getting it moving for my first ride. Broke my collarbone twice the first year I had it, and never had so much fun in my life. Every once in a while I watch a VHS copy of On Any Sunday to relive the thrills.
So, just to mess with you Tony. Pistons are not machined perfectly round when cold. They are machined to grow to circular when at operating temperature. Even el cheapo pistons. Forged race pistons have full 3d machining for growth at temp.
The piston bore is also not checked or bored just sitting free air. It should be torqued down with torque plates to simulate the stresses of the head and block in place, which changes the bore shape due to the elastic deformation of the clamping loads.
On your trials bike, you found it's a thousandth or less. Hard core race engines are bored at operating temp with torque plates installed to simulate the head, accessory, trans and block deformation and are effectively seized when not clamped together to create the clearances.
In most cases they are tapered or diameter below rings is slightly bigger than the diameter above the ring.
Thats how we do ours, tapered ever so slightly, especially on CI sleeves because of the growth rate of the different metals.
Awesome insight!
Wow, just wow. That’s interesting to know for sure!
I was wondering if anyone would mention this. The reasons they change from oval to round at operating temp is that there's more meat where the wrist pin goes so more expansion in that direction than the thinner front and back. Also with a 2-stroke there's more heat at the exhaust port so more expansion at the front of the piston.
3:35 “and the kill switch is on” don’t forget that, don’t want it starting with that compression tester in the spark plug hole
Or getting the snot knocked out of you by being the best conductor around for that great coil......
So he had the *killswitch engaged*
lml
How would it start without a spark plug? Can a 2-stroke ignite on compression alone? I thought that was a diesel thing
@@magicoddeffect are you being serious?
@@lynspyre i see what you did there
I wasn't believing my compression tester one day, it was saying my perfectly running car had 0 psi of compression. Turns out the adapter side had a wasp nest in it and the schrader valve on the other side was rusted. Cleaned those out and it worked perfectly. Even with little use, just checking and spraying with WD40 every so often works wonders.
I'm starting to get that twitch that I get when I'm coming down off of TOT, pretty soon I'll be breaking into my grandmother's house, rifling through her VCR collection to see if there's any TOT on there, hanging out on street corners, offering favors for just a little fresh TOT. I get chills every time I walk past my local machine shop, they won't let me in anymore... I got so excited yesterday when a guy sold me a USB stick for $20, he told me there was some fresh TOT on there, but it was just some Abom79.
But in all seriousness, I hope you and your family are safe and well and I hope you're back with a video soon.
I got all the TOT you need man, great price and its high quality stuff too. Lol. I know the feeling though man, i just started TOToholics anonymous, great program.
This Old Tony existentially essential in these here difficult times.
Nothing's out of spec here, you just happen to have a B cylinder now.
And if you notice he got a B piston too!
@@kilrahvp yeah I don't know why he didn't mention it! for somebody that doesn't know anything about engines and all the numbers he talked about, that kinda worried me.
@@svampebob007 he's illiterate, that's why he missed the B ..he would have caught the 8
@@liebherr11602 and went with 9 anyway, because that's close enough.
Saw that to. TOT you scrup
I've heard that if you use a green marker instead of blue, and go arround the edge of the piston, you get better sound.
Has to be the right green marker. Wood piston rings help more anyway.
Remember, apply the green marker in a clockwise direction if the engine is north of the equator.
That’s to defeat the DRM license also.
@@OhShitSeriously You jest... I knew a guy at high school that turned a wooden piston to repair his dirt bike. He checked it ran (very well apparently) and promptly sold it. 60 minutes after sale the dude turned up saying "WTF it doesn't go at all now" only to hear "tough shit, your bike". Yeah, the guy I knew wasn't a friend of mine and that is exactly the behaviour I'd have expected from him and his family.
If ToT is an amateur, I’d be terrified to know him in his professional capacity. 😍
chris kaprys he’s a professional amateur.
809k subscribers 15 years from now: "There's no way I'm paying someone else to do what I'm fully qualified to do myself since I watched that video fifteen years ago."
fingers crossed in 15 years we'll still have 2-strokes to rebuild!
Fingers crossed, in 15 years ... we ...
You do realise that we now think we're qualified because we watched you on _this_ video?
I feel like the old this old Tony was hardcore enough to have made that piston.
I don't remember a time when he would make anything that would interact with explosions you sit on lmao
I tried once to make one for a 50cc but failed so I made the skirt and used the middle of the old piston to fix the axe. It did about 3 km. I came home using the pedals and passed in front of policeman who lough at me. A part of their job was to catch young going more than 30km/h. He didn't know that before I was at 70...
You mean The Older Tony
Yeah, hey! Who are you, and what did you do with That real Old Tony?
Abom would have made one
What's a magazine article?
OK Millennial.
Disclaimer: I'm 50 and officially already an old fart. My descent into "GET OFF MY LAWN YOU DAMN KIDS!" is going to be an easy one.
It's like if someone printed out a blog post. like the Amish do.
Tony, I’m baked and this feels like high school shop class. That was 25yrs ago, lol. Thanks so much for the memories. Keep it up.
AWWWW This Old Tony, I love you too 🥰
Tony says "hone the bore"
I heard the h and b get swapped, but then again, I've been in lockdown for too long.
Aye...
Nice
Ahahaha... took me a few to decipher what you were getting at.. Good one!
well I heard it as "hone the bone"
Yep, that is a top quality comment. 😎
Tony, do you ever think, "A quarter of a million people watched this in a day?" You deserve it and more. Baby, you're gorgeous!
20:28 dying looking at that B on the piston head
4:16 AM wife sleeping
Me: watching This Old Tony
Life is good.
For now!
Open Minded Air Head my baby is napping so time to sit and relax got 45 minute left but neighbor just started revving up his demolition derby car with open exhaust that will last until dark tonight like every day since his job was not essential....
@@fryreartechnology7611 That's the sort of thing that makes me happy I live just outside of town. It's harder to annoy neighbors ;)
@@TheHungrySlug My Uncle Vernon was a professional mechanic and a bit of a philosopher. His take was, "If you can't take a piss in your own back yard without the neighbors getting an eyeful, it's time to move further out of town."
@@DavidKutzler That's some sentiment I can get behind!
"Turn around, Turn around she's behind you"
Quite enjoy your mechanic videos!
On a sidenote: pistons and cylinders aren't necessarily meant to be cylindrical when they're cold, they're often manufactured to account for different heat expansion due to their geometry, so a measurement of roundness might not always be super meaningful.
Good point, I've seen many a tapered piston, assume it's to account for slightly different rates of expansion between top and bottom
Old Smokey Yunick discovered that way back when after designing a fixture to hone cylinders perfectly round, and the engines not making power until they wore to a certain pattern. Then special plates, and preheating of the block was done to get close to as round as possible while running.
Cylinders are always round. For very high perf engines (think Nascar and NHRA) honing plates are bolted to the block to mimic the distortion caused by bolting the head to the block. The block is then honed round. The honing plate removed. The bores egg shape a tiny bit. The heads are installed and torqued, they are round again!
Pistons will have a circular section profile on the piston skirts and contract a bit near the wrist pin.
@@padraicmcguire108 I didn't know I was building high performance engines, but I always use stressplates when boring and honing
The cylinders are bored straight. But the pistons have a "barrel" shape: do to heat/expansion. The skirts are thin and flare out a lot during operation. On an extremely worn cylinders,: you can sometimes hear the piston skirts slap, when cold, during the first few revolutions.... There are also machined cuts across the pistons at certain areas to limit the conduction/travel of heat (from the blazingly hot crown to the thin skirts). Some pistons have steel inserts cast into them...to control expansion as well. Cast pistons expand and contract less than forged pistons...but both have pluses and minuses. Just saying.
I’ve been waiting for a decent LONG upload for so long now. Aghh , nothing on Netflix compares to your educational antics 🤣
If ToT can feel ridges is the piston with his finger nails, that scoring must be deep. Just kidding TotT :)
LOL
That's funnier than people think
Well, atleast 30 minutes of my day was enjoyable. Thanks Tony.
AvE Aaaand This old tony on the same day. What a treat!
It's a good day, Tater...
Did you see that "weld job" AvE did , hell Stevie Wonder could have done better...lol 🤣🤣🤣🤣🤣
@@generaldisarray swiss chess welding (full of holes) 😎😎😎😎😎
Ya, a double tech-comedy act day :D
Both appear to be competent in their own ways and have unique senses of humor :D
My exact thought. Ave an this old Tony. How great in these apocalyptic Corona days lol
Those markings you made on the piston, pure art baby!
This was just a random RUclips recommendation but i have never been so entertained by a RUclips mechanic lol amazing content
One of us! One of us!
This is a truly memorable moment, I don't think you've ever told us you love us before 👊
@Shambles1980TRealOne changed
Shambles1980TRealOne ‘rememorable’ because its not the first time 😆
@@SWhite-hp5xq wait I'm jealous, you mean to tell me he's told you he loves you before!!!
HE SAID HE LOVES US!!! Ughm, i mean... we love you aswell, Mr Tony
Always my favorite RUclips channel TOT. Haven’t seen a TOT video that hasn’t put a smile on my face or a laugh yet. TOT for president 2020. GW
This Old Tony, it's always worth watching to the end. As always, great content! I'm a land surveyor & woodworker and just from watching your videos, i now know i need to stick to those things. HA. Kidding! Thanks for the awesome videos, I always get excited when i see the new ones pop up in me feed...I don't use the bell icon, i like to be... Thanks for reading.
*shows the old ring gap
Me: DEAR GOD
Yeah if you can measure the ring gap with a ruler in mm, there's your problem.
My guess is the compression reading was similar, but once it's actually running, there was a ton of blow by due to that ring wear.
HOW DID IT EVEN RUN!!!
You can make anything look or seem interesting, ty for the content
Everything motorcycle related is interesting
I guess the old spinsters who have alot of cats and hate everything and everyone to include persons walking on their lawn and persons who are young.
The amount of comedy material he manages to put together in these timeframes and with everything else he's having to do for these is just unbelievable, honestly.
@@orijimi I've been thinking the same thing.
Thoroughly enjoyed that, like the humour and the technical content. Amazing how watching someone else work can create so many experts!
Another great video. (As always!) 🤙 As a lifetime dirtbike rider/racer and a hobby machinist, I really enjoy when you bring the two subjects together.
Ps. To really get the most performance increase out of doing a top end you might want to throw in new clutch plates and clutch springs (or in a pinch stack an extra washer on the clutch springs) to ensure that the horse power increase is making it all the way to the ground. You’d be surprised how a slightly worn clutch can keep you from feeling the full performance increase.
9:18 As you can see, the piston is pregnant and wearing a tank top.
Yeah, I was thinking I need to get out more, too. Mind you, these days we all do!
0:50 thank you for also displaying the cup size for the imperial folks.
Just an aside, thank you for properly calling this an ENGINE!!! The entire world can't seem to get this right (motor),,, I've been screaming (it's not a motor) about forever and here you go out of the gate and call an apple and Engine! Seriously, I couldn't be more proud of humanity then I am of you right now!!!
Awesome as always Tony! brought back memories of machining window ports in Hodaka pistons for reed valve setups.
ATB, Robin
When the "Emergency Alert" went off, my cat, who was sleeping next me. Woke up freaking out, looking all around. Was pretty funny. Thanks for reading!!!
That’s funny, my dog did the same thing. Knuckle head.
So did my cat!
Oh jeez, mine too
Yeah me too, I only became familiar with that sound a few weeks back. I can't remember the last time I had a big frighten cut so hard and fast to a stupid chuckle.
So did my cat 😂
Your wit is indubitably the best on RUclips that I've found so far.
Try AvE
I've rebuilt many 2-smoke bikes in my time and you did everything right.
You are exactly on the money with the Nikisil coating, the only thing I ever do is light clean it with a Scotch-Brite pad.
The new rings will take time to bed in.
I first rebuilt a 1977 Honda MR175 Elsinore 2-smoke, I borrowed a book on rebuilding 2-smokes from the library and did it in my dad's garage.
Great video!
"That was long" -- please more ~30min videos, i enjoy them
1:07 Haha hiding going the wrong way by changing the battery :D Good one!
Well spotted.
Dude, that made me spill my drink. 😂
(3:35) - "Now I'm gonna kick this thing like it owes me money..."
I had to crawl back up off the floor to just type that.
>
My biggest take away.
I may need to watch it again... 😊
I hope you feel better now.
Need medical assistance?
Kick it to pieces and sell it for scrap - it's probably worth more that way anyhow.
Thank you! Yes! I stuck around till the end, and I thought it was most definately worth it! Yes, ofcourse I would have liked to see you hone (also own?) it! But, I stand by your decision, and I would have done the same. Again, you are truly a fountain of wisdom and good humor.
Thank you so much.
Alicia from Sweden.
Learning lots and having fun.
I really love your channel, Tony. Cheers.
Learning lots of things I'll never use and having fun.
I really love your channel, too, Tony.
TOT:
"for the two curious people out there..."
Me:
"I'm A Wild PIiiig!"
Tony's Modern Life!
Mr T, 90 is a bit low for a 150psi cylinder - with new rings. I normally see closer to 135psi on a new rebuild of that size, and it'll quickly tighten up and make its way to 150psi over a little bit of running time.
Also, check out a leak down tester for the cylinder vs a standard compression tester. You to put the piston at TDC (or crank in the case of a 1cyl), and put compressed air into the cylinder to your desired pressure. You then wait. The leak down tester has a gauge on it, and you watch it with exuberant anticipation... and it slowly leaks down, crushing your soul, or not. Anyway, they're great for getting a better idea of cylinder and ring wear on a 2 stroke. The leak down will show wear that a compression test will not.
Man, Tony, I knew nothing about combustion motors but I do now (and I am just half way in your vid!) You are explaining things like every teacher and howto-vid should. Love your vids, keep it up, keep the fun it makes your videos worth to watch. Even if the thematic isnt even close to interest. I learned so much about stuff I never had interest in. You rock!
this is the struggle of building engines at home. You make it seem hilarious and fun. I miss the honing machine I used to run along with all the other machine tools that made it look easy. Good job!
7:28 Confirmed. This Old Tony and ProjectFarm are neighbours.
"Great, now I've got the hiccups". That line caused me to spit beer out my nose. Thank you so much for another wicked smart and funny video.
This channel is just ridiculously good. The quality of production and information do not deserve to be free. Much appreciated Mr. Tony.
I want to say thank you. Your channel is great, The special effects and the humor are the best!
You can make your video's an hour long if you want. Always enjoy them so much!
I honestly didn't notice that it was a "long" video.
Huntracony I seriously thought it was just another 10/15 min video, oh damn!
As a retired m/c mechanic of 40yrs in the business, I have enjoyed laughing at the escapade while having coffee !! Comments are something else, also !! Ya got it right, even using the tools ya did. Would suggest cleaning the s/a, silencer after every top end job !!
Doing the exact same thing with my bike except it is a 4 stroke 250cc inline 4. Learning a lot of lessons (the hard way) and this video taught me even more.
As I logged on to RUclips I thought to myself “ I could really do with a ToT video now” - and would you guess what...an half hour video. I love this channel 😫
I'm not an engineer, and In know little of engines. So i can definitely tell you that an engine like that does indeed require PSI to start. Good luck!
dude i love your videos, your humor is too good. keep making these, love them so much.
I raced RDs and TZs and still have a KX500 so I know the smell of two strokes well. When I was racing some were still using castor oil - to be honest I don't know if this was a belts or braces left over or they knew something but it will produce gum that will need to periodically cleaned. What I found was running a good synthetic as lean as possible produced the most power and actually the longest piston/cylinder life. Back then new pistons/jugs used to be cheap as chips and I had access to factory spares so I could experiment but I never seized an engine - I think I went as lean as 70 to one.. What I think is happening and what the engineers told me is that increasing the oil/fuel ratio actually causes detonation which then leads to overheating which then causes scoring/seizure. Of course the human tendency is to add a little more just for safety. I totally agree with you yes you can hone with a diamond flex hone but don't. Nothing is better for oil retention then raw Nicasil and matching the piston to the jug is best done by the plater when you get to that point. Love your videos and your sense of humour. Awesome stuff
Dyslexia got the better of me with "hone the bore" read backwards.
BPollard86 nice spoonerism :)
@Alan Jackson i think he may have meant, bone the hore
I'm glad I'm not the only one who thought it said 'bone the hore'😂😂
Yep, I was also getting ready to bone the hore... been too long inside...
@@frotobaggins7169 that wooda even made AVe laugh ..🤣👍
Well it is a dirt bike, it’s supposed to run on dirt, right?
Actually its a trials bike. Iirc they run on time itself.
Ella Banana how much does a gallon of time cost?
@@ahumanbeing7554 i think its 16 cups of hot air for a gallon of time...last i checked
actually those tips you pointed out @9:12 was very important. its details like that(+ snarky sarcasm comedy) that keep me coming back and watching(re-watching) your videos.
The thanking us for watching at the end is 100% unnecessary. Loosely speaking for everyone here when I say, we absolutely love your videos and knowledge and we should be thanking you for the time and effort on your end, and personally speaking id love it if the videos were even longer! Can’t get enough
I did not just "stick around". I thoroughly enjoyed every joke and reference. Especially the tootsie roll one!
Speaking as a mechanic I was taught and have found that most engines won't run under 100 psi (at least not well) and wont run great under 120 psi. That is kinda a good reference to go with I have found
I had a cylinder down at 110 psi and my truck ran its fastest 1/4 mile time like that. Almost a second quicker than stock and all I had was cold air intake and exhaust done. Surprised doesn't describe how I felt when I saw the time slip.
True, most modern engines anyways. An old VW or straight six will chug along alright at 90psi, maybe with a cylinder or two at 80psi. No, it's not ideal, but older stuff will be ok.
Be careful, 2 strokes normally run a lower compression because of the way the Piston compresses the air fuel mixture on the bottom of the stroke. I have seen my old 1969 Yamaha dt1 run at 70 Psi. Was a pain to start but it ran.
And it's also hard to get a true compression reading on a 2 stroke as the ports are exposed on some of the stroke. Unlike a 4 stroke compression stroke when you have a full sweep with the valves shut.
Did that make sense? Haha
@@NickyP500 There are 2 stroke compression test kits. They come with block off's for the intake and the exhaust ports. The lowest I've seen with the motor still running is 60 psi. It was a bitch to get started and didn't idle very well.
Thank you for making it! Although I do only basic maintenance on my bikes and would never attempt such a repair, it was an entertaining video. Thanks!
I had a side-gig in a motor shop for a Motocross race team for a little under a decade. I'm not going to go into any "advice" as well, as you said a dozen mechanics, a dozen answers. To answer your question on compression to draw fuel. We found that smaller motors usually around 80 on the gauge and it was only starting when hooked to a tow vehicle. Considering you went to spec on everything, your compression is more than adequate.
The only other thing to say is when you checked the piston crown height at the top of the bore, you can get different thickness of base gasket to adjust your "squish" to make the most of the explosive forces in the cylinder. "Squish" is exactly as it sounds. Take a couple of pieces of the softest solder available, put it in through the spark plug hole and allow TDC to squish it flat. do both intake and exhaust side. measure the squished solder and boom bobs yer... [jump cut]
Oh this is a blessing. Two stroke Tony!!!
A male Police Officer of my acquaintance had the nickname of, "two stroke" and it wasn't because he needed oil in his petrol :-)
@@loydsa We call them a 2 pump chump lol
Hi Tony, hope you are fine. Just want to say, that we miss you. In case you ran out of topics, you can just upload an "i'm fine" video. Starting to get worried in these times...
I’ve rebuilt hundreds of two strokes over the years, you didn’t make a single mistake I wouldn’t have. Great work.
This Old Tony has kinda become the dad I never had. I love you too, Tony.
Best channel on RUclips, period.
Sounds like you need to compression test the compression tester.
Hope all is well with you and yours, as we haven't heard from you for a while. Great content. All the very best from Scotland.
As always, most entertaining, & informative. A nice digression.
Starting to wonder if ChrisFix is the love child of ToT and AvE - would explain why non of them dare show th face around here.
@@Wolf78033 yeah so has this bloke ruclips.net/video/vJIzkIc_wIU/видео.html
we just need to compare how they say "water"
"All over my bullets and everything!" Hahahahahaha!!!! I think I need some tacos now.
Love your vids! Been binge watching. You’re like Ave but your jokes and humor are actually funny!
man, ToT, you never miss a beat. All them jokes are superb. Don't mind waiting months for your videos. Even years, you'd just a finer aged wine!
Tony: Pistons, the tarot cards of the engine world
Mazda doritos: 🙄
Was kinda shell shocked, after an unfamiliar sentence, so I had to rewind a few times. What's next? A hug?
I really like your videos Tony. They are funny, good looking and i every time even learn something :D
I stuck around. Your welcome bro.
I get entranced watching your teaching tutorials bud. Keep em comin
The easiest way to fix the problems with your bike is to buy a new house that comes with a new bike in the garage.
Still waiting on that surface gauge build ;)
Love your videos Tony. Easily my favorite channel on youtube.
ComputersandJava I second everything.
ToT is what led me to watch ANY youtube videos. Then I found Clickspring, Abom, Howarth, etc.
Çà Lem beat him to it. He has kind off the same humor.
Really enjoy these longer vids. I learned a lot from that, thank you.
I enjoy your sense of humor. I look forward to it in every video.