The heater reminds me of the old intros, Only the music missing. Good tip if u are drilling a hole for a thread in the press, after you drilled the hole, put the tap in the press and thread just a couple turns to start the thread, that way you know it is straight when you go to thread it by hand later. Maybe not optimal with these small dimension threads, because of the risk that the force upwards from the return spring will mess up the outer threads when threading it out.
take a one part piston and -insert a bolt for the pistonring from the Top in a little bore hole where you can hammer it out (down in the piston or so) Hope that helps
Soon after filming this vid I realized I can probably just stone the lower ring land on all the piston skirts and maybe they'll all work. We'll see. Thanks for watching!
When you are honing try to keep the tool as straight as possible because it will hone more material to what ever side it is pulling to. Resulting in the boar not being straight. Also do about six strokes from the top and then flip the cylinder to the bottom. This will reduce the tapering in the boar. It's a learning process and you get the hang of it. Good luck
Thought about it. Have a feeling the set screws will work loose if the two parts aren't locked together without them - might solve the problem, but not for long I think.
Stone? You mean to put in a lathe and do a small cut on the bottom ring land so tighten the piston and have the right ring play at the same time? Don't mix up the pistons mark the parts.
The cylinder warping reminds me of an issue I had with the left cylinder on my Canadian import Suzuki GT550 B, back in the late 1980's. I'd tuned it for drag racing (well they don't go around corners and are nose heavy, handling like a drunk cart horse on roller blades!!) and started to have issues with piston skirts cracking on the left hand cylinder. I suspected something wrong with the cylinder and took it to a tuning shop where they measured it and informed me that it was "twisted & warped". Suzuki GT550 M/A/B cylinders are alloy with nickaseal plating. They contacted Suzuki about it and I was informed that apparently Suzuki made a whole batch of GT550 cylinder castings where the pouring was done in two parts, because they had to top up the pouring vessel, so the casting partially cooled before the moulding was completed. This caused this twisting and warping fault. Nearly all were fixed under a Canadian dealership recall, in the late 1970's, but mine must have slipped the net most likely as it had been exported to the UK at sometime in the late 1970's. I fixed the fault by simply buying another engine for £50 down a breakers yard and transferring a cylinder from that engine.
Something to consider when you're measuring ring end gap. You want to ensure the ring is perfectly parallel with the cylinder block deck, otherwise your measurements may be slightly off. Easy way to do this is install the ring in the cylinder by hand like what you're already doing, then take one of your pistons and gently press the ring a little further down the cylinder using the piston crown - your piston will be facing upside down while doing this. The result is a perfectly parallel ring for you to measure end gap with less chance for human error. If you're already doing it this way and not showing it in the video, then ignore this comment. Keep up the excellent work.
It amazes me that you are finding problems while in the building/design phase. Tons of shops only find problems by blowing stuff up over and over. Well done, keep up the excellent work
David Vizard demonstrated the difference made by boring cylinders with and without boring plates in a cast iron block. This was back in the late 70's or early 80's.
Great video. What you really need is a finer thread in piston top with a good 3 more row of thread. And when threads being made. Must sneak up on them slowly. Also the finer the thread the less canter of the opposing piece. Corse thread. Say a bolt and nut. Coarse thread will make the nut whobble (canter) as it’s screwed on an fine thread will allow nut to not canter as it’s screwed on. Nut in this case is the piston dome(top of piston)
I once had an idea for a two stroke piston with transfer through piston top that is a valve, thus deleting transfer ports..I did make a prototype piston but after many thought experiments I could see all the pitfalls that lay a head and never proceeded. Seeing what you have achieved over time is remarkable, and Im kicking myself for not continuing my 'Portless 2- Stroke'.
You can try to mushroom (or cross gash) the threads to create a type of jam nut style threading to tight it all up to avoid having to use Loctite... we do this on some of our Snowmobile bolts to avoid them backing off when loc-tite and ny-lock nuts are not an option. Works well. So in other words, smudge the thread in 2 or three spots, perpendicular to the direction of the threads and that will cause a slight binding to lock the threads once they sleeve is bottomed out on the ring land ridge. Hope this helps!
Maybe the piston expand at the upper section on the lower part when you tighten it together and it is getting hot. And thread the inner part instead for the lockscrew so the outer doesnt expand. And use a taper thread tap (förtapp på svenska) so the screw dont shake loose. Have a nice day.
It’s a very interesting challenge that you are doing. Being an old chap, it was in my time that 50 CC 2 stroke were very popular. The most powerful racing machine was the German Kreidler developing 20 hp, followed by the Japanese and Italian with little less power 18/19 hp. This is a very huge power of 400 hp/L engineers extracted 60 years ago. So, I wish you can do at least the same or maybe better ! All the best to your project.
Heat treating aluminum, especially castings, can be somewhat of a black art . If there is a sleeve, make sure it cannot move while in the oven . However I don't think it's anymore esoteric than the plating process(s) you have already accomplished .
You should think of the stress in the upper part that is pressed in one direction by the screw even you make the upper part not wabble that screw remains a stress point, maybe 2 opposite or even 3 in a triagular shape would be better. Its also a solution for the wabble: drill and tap 3 or 4 holes in the skirt like the one that you made and calibrate the upper part ajusting the screws. maybe the screws should be more near the bottom so they have more lever and precision. Its not that good but it could work.
I believe the reason it is warping to the extent it is, is because the deck and base surfaces are just printed to finish, not properly machined flat and parallel.
Design a squished shim system to fit inside your ring groove. Precision wire might serve as gap stock... possibly arranged like hour markers on an analog clock face. Just thinking and my thumb started typing.
Loctite 266 is made for extreme heat, I use it on the ford 5.4l v8's sparkplug time sert repairs. You may look into that. Just a thought. Great work I'm really impressed! Brings me back to my old days of tinkering.
That's great the step will eliminate the play. What about the hole on the ring changed to a slotted hole so the ring,at that point it will slide back and forth which may increase the sealing.
You can anodize the thread area of the piston to make it grow and create an interference fit (Anodizing thickness is Half below the surface half above the surface). You can also hard anodize the cylinder to make that a little harder to reduce distortion from the honing plates...
Heat treatment does not change the stiffness of the metal, if the bolts are overtightened in a soft material there will be plastic deformation, given you use an O ring and a lot of bolts they do not need to be that tight. A quick test would be to lightly hone the cylinder to ensure a round bore, measure it then install the torque plates and measure it again. Remove the torque plates and measure again, if the last measurement is the same as the first then no plastic deformation has take place and heat treatment will not help. Take 2 measurements turning the micrometers 60 degrees between measurements just in case the bore has 3 lobe distortion. Putting a bit of mark out blue on the piston and sliding up an down the bore a few times will give a good idea of the skirt contact. With those new rings it should be possible to use a normal piston and machine a pocket to clear the pin in the back of the ring groove. A sinker EDM would do it easy failing that a reground woodruff key cutter would work.
Love the project and can't wait to see the end results! I just wanted to mention that when filing the ring gap you should always file towards the inside of the ring. That way you don't leave a burr on the outside edge of the ring that can scratch the cylinder walls.
You could put some marking paint in the inside of the pistonhead and screw it toghether to see where it touches the other side and why it has play/ movement.
Hi! I allready wrote to you once. Why dont you try to use a ringless steel piston in a cast iron sleeve? This combination is proved in small model engines. It would be much easy to design your ports and also design the piston in such manner to create a labirinth seal, so the blowby gases will be in small quantity, especially at high revs.
I admire your passion and work. 👍 I'm wondering, aren't those pistons too heavy for the rpm which you are planning to push this engine to? Maybe the stress on the con rod will be too high...
Indeed heat treating will not change the stiffness of the material, that is related to the chemical composition of the cast aluminium and geometric design of your cilinder.. Heat treating has an effect on the yield limit of the material, this means that the material can be loaded / stressed to a higher value MPa until it starts to yield or in other words permanently deform. When appling the top plat withe bolts to the cylinder its all elastic deformation and so heat treatment will not effect the current deformation of 0.01-0.02mm as founding during your measurements.
I was thinking the exact same thing. The warping in the skirt may still occur becaus of the pressure point but maybe that's fixable on a lathe after installing the skirt to the piston.
I was thinking that too. 3 or 4 keeper screws should do the trick. AND you get oriented piston top just line with skirt. now there is small chance, that it not be alignment.
Watch you bore micrometer. I think at 2:50 it went in slightly angled. We used to wobble them and get a nice scrape. And check your adjustment on how tight you make it. It looks tight. I could be wrong. That happens.
Could you make thin shim washers so that the inner and outer pistons lock up at the right point to give the correct ring clearance? OR. Lock the two piston halves together and put the assembly in the lathe and machine out the grouve to the correct clearance. Rusty from downunder
Correct me if 2 strokes are different but honing with torque plates on water cooled racing blocks is done with hot water to get thermal stability in the bore.
Be careful when using a grub screw like this as it may jack your piston skirt off to one side making it oval, we use a similar technique at work but would have a through hole in the skirt then a blind tapped hole in the part housing the little end bearing, the other option would be to use a dog point screw which doesn't pass fully through the skirt.
Alex, a couple thoughts. First, awesome coffee mug, is that from Pikes Peak? I have the same one! Second, you've got some good ideas already for solving your ring clearance issues, remember KISS will probably always be the best solution for a part exposed to such an extreme environment. I'll jump on the ESE Works thread to share some more detailed design thoughts for future pistons, but they can probably be summarized as: (1) selectable shims for ring-to-ringland clearance and (2) don't rely on the threads to keep concentricity between the piston pieces, use a tighter radial fit on cylindrical sections of each piece. So basically *one and only one* controlling feature in each of the axial and radial directions.
I'd consider honing the cylinder while its bolted to the crankcase. Maybe use a spare cylinder head with a hole in the top or just the top honing plate. Use gaskets. Then warm the whole thing up in the oven to normal operating temperature. Then hone to clearance you want. Keep up the great work
I would highly recommend the use of flat, hardened washers under the nuts (or heads of bolts) when installing torque plates (and when assembling the engine as well). Cylinder bore deflection is caused more by the “tipping” movement that is possible on a bolt or stud due to them “digging into” the aluminum and applying a slight sideways force... than by the pure tension the bolt or stud should be applying. That force is also unpredictable (and inconsistent) if flat/hard washers are nut used under the head or nut.
I really admire your dedication to this project you like to do my kind of brainstorming a little alchohol and a whole lot of thinking with some machining and you have churned out a whole new engine design I Bet that is how Harley and the Davidsons came up with there first motorcycle. Someday they may make a movie about your journey. Thanks for sharing 👍
Hi, Well done again with all the work, it is great to see how it is coming along. I thought about the shoulder or ring, and I think that despite needing a hard stop I keep thinking if it is sufficient. If the grab screw move the top eccentric, maybe it is worth considering having the internal piston sliding with interference in the skirt. I mean the cylindrical part of the internal piston be tight to the internal diameter of the skirt. This will give you concentricity, and then the shoulder will give you the height. Personally I am not a fan of the side grab screw either, I would put it underneath, but that is purely a personal preference. Keep it up, the engine looks faster and faster at every step! Andrea
As I said earlier, the piston ring may ultimately end up taking on the appearance of an internal circlip, with the 'plier holes' in a ramp form engaging with pins mounted in ring groove on the opposite side to exhaust port center.
u can tap holes in your drill press, thats what the pros do. it saves time, and u are sure the tap is straight to the hole, wich can bedifficult, specially if u tap
Your cylinder with several inlaid vertical ring guide pins of Trinium alloy would allow a regular piston and rings to be used for testing. A suitably tough material could be thin enough to perhaps not affect your flow too much. I forgot that the Trinium mine planet buried their stargate. The planet I recognize out our front window has plenty of Naquadah. Maybe a trade?
Just an idea: I don't like the grub screw screwed into the sleeve. It could push the piston's top-end ever so slightly out of allignment with the piston sleeve. I'd tap the threads into the top end of the piston and either make a grub screw out of a m3 or m2,5 screw by grinding the head into the diameter of the thread, or make the hole in the sleeve as big as the screw's head.
Before you go making any new pistons, I thought of a way to retain your skirt with a circlip. I described it in a comment on your last video. It might be a worthwhile concept or just get you thinking about different solutions.
Can you drill through the set screw hole to make a mark on the inner part then the tip of the screw doesn't press against the inner piston but enters a little cavity so the screw tip keeps it from rotating relative to outer part. Like the drive pin in a collet.
Some advice on heat treating: don't do any machining before the treating, you will warp the block and every machined surface Once the heat treating is done, machine the parts
Hey mate the ring land doesn’t need to be right at the join. Or dose it?? Have a standard type ringland below/above the piston join, the ring locator peg can be trapped in a hole when the 2 piston parts are screwed together. It will save the extra comlecations! Those ultra thin rings will be harsh on the bore and ports. Keep up the good work 👍👌✌️🤘cheers 🍻
Surely you don't need to make a little spacer ring to sit behind the piston ring, can't you just put either part of the piston back in the lathe and make the step in the ally part? The step you machine will become the gap for the piston plus clearance and mark's original faces will now clamp together tightly as long as there is enough extra thread length. Putting the step in the skirt side won't affect the squish. Also, I'm not sure a 2 piece piston is needed any more since you don't have that T-shaped land like before. A normal piston would work but with an extra pocket for the lump on the ring and then a pin inserted from under the skirt to fix the hole in the ring?
Good idea Kai. I am going to eliminate the problem but making a separate spacer as the bottom ring land. I showed this idea in one of my videos last year but haven't implemented it. The nice thing about the two piece is it still gets rid of the wrist-pin hole and the round skirt I think is much better than the cammed skirt.
I can see future issue of the combustion compressing the piston crown over time slowly squeezing the ring. Put it together and check. Then smack the crown with small dead blow. See if it compresses.
Awesome channel,I enjoy watching Your progress.When I get a Block honed with deck plates they use a head gasket to duplicate a running engine.if You are running a base gasket I would use one when honing also.Just my opinion.Keep up the Great content.👍
Maybe outher shell piston (crown, ring seats and skirt) with screwed in part with wrist pin? Should solve clearing issues, altought locking the ring and skirt is still a must.
You probably already know this but I've seen Pistons with a pin in the ring Groove to keep the ring from rotating, of course you would have to file the end of the ring to fit the pen
try a soft coating on your pistons wearing away while running. i think the perfect geometrical match at operation temperature is most important. Than you can run without piston rings like a RC engine. Also a much oil helps sealing the combustion. maybe 1:15 oil ratio.
Just an idea. To get more Patreons so you can do this part time or full time. Try showing the Patreon logo and maybe the names of your Patreons, like you have done in some videos. It can be real quick just a cople of seconds scrolling the names four or five names per row. You can do a voice over so it dont get boring for non patreons. It rubs peoples egos to see their own name and will probably get you more people donating. And also it reminds people that you have a patreon.
Could you make it in one piece and just press the pin in that holds the ring from underneath maybe above the wrist pin so it can't come out. Just requires machining the ring Grove the right size.
I wonder if you could modify a standard 40mm racing piston to accept your new ring design. Drill a vertical hole down through ring groove & press in pin & peen over? Will need to machine back of groove at that location for clearance.
I haven't watched all your videos so forgive me if I'm missing something, but have you considered other ways to split the piston in two? Wouldn't it be better for the crown and the skirt to be made as one piece with ring grooves and all, and have the pin assembly attached internally, from the bottom? for example, with bearing caps and bolts, similar to the crankshaft end of the connecting rod. Or, with a large diameter threaded locking ring, securing the pin assembly, again, from the bottom side (edit: snap ring maybe?) Now there's just so many things to go wrong at the same area: the ring grove, the set screw, threaded aluminium-to-aluminium connection...
i think pistons should be forever assembles using an interference fit that extends the entire length of the skirt. after assembly with small end bearings, rod and pin already installed turn the outside on a lathe. or use a close fit with many tiny groves on both pieces that youl fill with epoxy to secure the parts together. also permanent assmebly but would not require turning after
I'm not sure heat treating is the answer, you actually want a little elasticity and you already have a nice hard cylinder coating. If you were to remake the block I would suggest working on the geometry a little - a thicker cylinder wall and try to keep the radial supports/cavities as consistent as possible. There is a reason two stroke engines are usually cast iron or sleeved. My 2 cents, but if you harden it then find it doesn't hold it's shape throughout temperature changes don't' say I didn't warn you.
if its possible or economically feasible you should try and get the cylinder CRYO Treated. the increased hardening and reduced coefficient of friction could assist in preventing the piston seizing to the bore or at the least elongate the time you have to shut it down or come to a stop before total destruction. in theory. from what i understand about the most effective way to cryo treat parts. the process also involves heat treatment processes. its a combination of both that makes a significant gain in internal strength , reduced internal stresses , and decreased coefficient of friction.
Some people dip their cylinders in liquid nitrogen, I don't know what it does, but it happens. Isn't a screw thread always going to give you variable 'squish' on your piston ring?
I dont know about aluminum cylinders, but I know they cryogenically treat steel gears and shafts. It takes the stress out of the metal increasing wear and fracture resistance. Liberty gear does it to transmissions
So many dynamic forces in a complex part like this during heat treating... Not sure if there's enough material movement on a part this small to be a concern, but I imagine that the quench could cause stress fractures in any weaker areas, voids, or thin spots. Not that it's practical, but would pouring the casting and throwing it into a vacuum and cooling as slow as possible help if heat treating proves destructive?
![АЛАУДИНОВ у Скабеевой: эти их ВСУ нас НЕ ДОГОНЯТ 😁 [Пародия]](http://i.ytimg.com/vi/an0anqU4WGQ/mqdefault.jpg)
Lots of good suggestions and advice here, thanks guys! I'll reply as soon as I can!
The heater reminds me of the old intros, Only the music missing. Good tip if u are drilling a hole for a thread in the press, after you drilled the hole, put the tap in the press and thread just a couple turns to start the thread, that way you know it is straight when you go to thread it by hand later. Maybe not optimal with these small dimension threads, because of the risk that the force upwards from the return spring will mess up the outer threads when threading it out.
take a one part piston and -insert a bolt for the pistonring from the Top in a little bore hole where you can hammer it out (down in the piston or so)
Hope that helps
Soon after filming this vid I realized I can probably just stone the lower ring land on all the piston skirts and maybe they'll all work. We'll see. Thanks for watching!
When you are honing try to keep the tool as straight as possible because it will hone more material to what ever side it is pulling to. Resulting in the boar not being straight. Also do about six strokes from the top and then flip the cylinder to the bottom. This will reduce the tapering in the boar. It's a learning process and you get the hang of it. Good luck
could you put 4 set screws in?
Thought about it. Have a feeling the set screws will work loose if the two parts aren't locked together without them - might solve the problem, but not for long I think.
Stone? You mean to put in a lathe and do a small cut on the bottom ring land so tighten the piston and have the right ring play at the same time? Don't mix up the pistons mark the parts.
Can you hone using the drill press for accuracy?
The cylinder warping reminds me of an issue I had with the left cylinder on my Canadian import Suzuki GT550 B, back in the late 1980's. I'd tuned it for drag racing (well they don't go around corners and are nose heavy, handling like a drunk cart horse on roller blades!!) and started to have issues with piston skirts cracking on the left hand cylinder. I suspected something wrong with the cylinder and took it to a tuning shop where they measured it and informed me that it was "twisted & warped". Suzuki GT550 M/A/B cylinders are alloy with nickaseal plating.
They contacted Suzuki about it and I was informed that apparently Suzuki made a whole batch of GT550 cylinder castings where the pouring was done in two parts, because they had to top up the pouring vessel, so the casting partially cooled before the moulding was completed. This caused this twisting and warping fault. Nearly all were fixed under a Canadian dealership recall, in the late 1970's, but mine must have slipped the net most likely as it had been exported to the UK at sometime in the late 1970's. I fixed the fault by simply buying another engine for £50 down a breakers yard and transferring a cylinder from that engine.
Something to consider when you're measuring ring end gap. You want to ensure the ring is perfectly parallel with the cylinder block deck, otherwise your measurements may be slightly off. Easy way to do this is install the ring in the cylinder by hand like what you're already doing, then take one of your pistons and gently press the ring a little further down the cylinder using the piston crown - your piston will be facing upside down while doing this. The result is a perfectly parallel ring for you to measure end gap with less chance for human error.
If you're already doing it this way and not showing it in the video, then ignore this comment. Keep up the excellent work.
👍 How I do it😁
@@2STROKESTUFFING Good to hear my friend. Keep at it.
It amazes me that you are finding problems while in the building/design phase. Tons of shops only find problems by blowing stuff up over and over. Well done, keep up the excellent work
David Vizard demonstrated the difference made by boring cylinders with and without boring plates in a cast iron block. This was back in the late 70's or early 80's.
Great video. What you really need is a finer thread in piston top with a good 3 more row of thread. And when threads being made. Must sneak up on them slowly. Also the finer the thread the less canter of the opposing piece. Corse thread. Say a bolt and nut. Coarse thread will make the nut whobble (canter) as it’s screwed on an fine thread will allow nut to not canter as it’s screwed on. Nut in this case is the piston dome(top of piston)
I've never seen a piston made up of two separable parts before, really interesting 🤔
Diesel engine pistons are often made in 3 parts, a skirt, a ring carrier, a heat shield top
I see it very many times in this channel😉
I once had an idea for a two stroke piston with transfer through piston top that is a valve, thus deleting transfer ports..I did make a prototype piston but after many thought experiments I could see all the pitfalls that lay a head and never proceeded.
Seeing what you have achieved over time is remarkable, and Im kicking myself for not continuing my 'Portless 2- Stroke'.
You can try to mushroom (or cross gash) the threads to create a type of jam nut style threading to tight it all up to avoid having to use Loctite... we do this on some of our Snowmobile bolts to avoid them backing off when loc-tite and ny-lock nuts are not an option. Works well. So in other words, smudge the thread in 2 or three spots, perpendicular to the direction of the threads and that will cause a slight binding to lock the threads once they sleeve is bottomed out on the ring land ridge.
Hope this helps!
Maybe the piston expand at the upper section on the lower part when you tighten it together and it is getting hot.
And thread the inner part instead for the lockscrew so the outer doesnt expand. And use a taper thread tap (förtapp på svenska) so the screw dont shake loose.
Have a nice day.
It’s a very interesting challenge that you are doing. Being an old chap, it was in my time that 50 CC 2 stroke were very popular. The most powerful racing machine was the German Kreidler developing 20 hp, followed by the Japanese and Italian with little less power 18/19 hp. This is a very huge power of 400 hp/L engineers extracted 60 years ago. So, I wish you can do at least the same or maybe better ! All the best to your project.
Heat treating aluminum, especially castings, can be somewhat of a black art . If there is a sleeve, make sure it cannot move while in the oven . However I don't think it's anymore esoteric than the plating process(s) you have already accomplished .
Ceracoat the top of the piston ...top fuel guys have been doing it for years to help mitigate some of the thermal expansion from the piston itself
You should think of the stress in the upper part that is pressed in one direction by the screw even you make the upper part not wabble that screw remains a stress point, maybe 2 opposite or even 3 in a triagular shape would be better.
Its also a solution for the wabble: drill and tap 3 or 4 holes in the skirt like the one that you made and calibrate the upper part ajusting the screws. maybe the screws should be more near the bottom so they have more lever and precision. Its not that good but it could work.
I believe the reason it is warping to the extent it is, is because the deck and base surfaces are just printed to finish, not properly machined flat and parallel.
This is my (machined) home-cast cylinder, not the printed one. Should've specified in the video, sorry.
Easy is not worth anything then that engine must be worth 12 million dollars. Absolutely love your channel
Design a squished shim system to fit inside your ring groove. Precision wire might serve as gap stock... possibly arranged like hour markers on an analog clock face. Just thinking and my thumb started typing.
I had a similar thought.
I love that you never have given up on your dream . It is always nice to see what you are doing with this build
Loctite 266 is made for extreme heat, I use it on the ford 5.4l v8's sparkplug time sert repairs. You may look into that. Just a thought. Great work I'm really impressed! Brings me back to my old days of tinkering.
Thanks for the tip!
@@2STROKESTUFFING your welcome
That's great the step will eliminate the play. What about the hole on the ring changed to a slotted hole so the ring,at that point it will slide back and forth which may increase the sealing.
You can anodize the thread area of the piston to make it grow and create an interference fit (Anodizing thickness is Half below the surface half above the surface). You can also hard anodize the cylinder to make that a little harder to reduce distortion from the honing plates...
First like, then watch
Unlike other UA-camrs we know his quality of work. It speaks for itself.
Correct. Every single time
Just like i do on tinder
Watching first is not worth anything
Yes
Heat treatment does not change the stiffness of the metal, if the bolts are overtightened in a soft material there will be plastic deformation, given you use an O ring and a lot of bolts they do not need to be that tight. A quick test would be to lightly hone the cylinder to ensure a round bore, measure it then install the torque plates and measure it again. Remove the torque plates and measure again, if the last measurement is the same as the first then no plastic deformation has take place and heat treatment will not help. Take 2 measurements turning the micrometers 60 degrees between measurements just in case the bore has 3 lobe distortion. Putting a bit of mark out blue on the piston and sliding up an down the bore a few times will give a good idea of the skirt contact. With those new rings it should be possible to use a normal piston and machine a pocket to clear the pin in the back of the ring groove. A sinker EDM would do it easy failing that a reground woodruff key cutter would work.
Love the project and can't wait to see the end results! I just wanted to mention that when filing the ring gap you should always file towards the inside of the ring. That way you don't leave a burr on the outside edge of the ring that can scratch the cylinder walls.
You could put some marking paint in the inside of the pistonhead and screw it toghether to see where it touches the other side and why it has play/ movement.
Hi! I allready wrote to you once. Why dont you try to use a ringless steel piston in a cast iron sleeve? This combination is proved in small model engines. It would be much easy to design your ports and also design the piston in such manner to create a labirinth seal, so the blowby gases will be in small quantity, especially at high revs.
I admire your passion and work. 👍 I'm wondering, aren't those pistons too heavy for the rpm which you are planning to push this engine to? Maybe the stress on the con rod will be too high...
Thanks! They're almost exactly the same weight as "normal" 40mm racing pistons.
Heat treating the cylinder (or any aluminum part) will not change the "stiffness" of it within the elastic limit.
Indeed heat treating will not change the stiffness of the material, that is related to the chemical composition of the cast aluminium and geometric design of your cilinder..
Heat treating has an effect on the yield limit of the material, this means that the material can be loaded / stressed to a higher value MPa until it starts to yield or in other words permanently deform.
When appling the top plat withe bolts to the cylinder its all elastic deformation and so heat treatment will not effect the current deformation of 0.01-0.02mm as founding during your measurements.
conical conections are good for acurate and secure locating, if tighter manuf. tolerances or limited interchangability are aceptable
Could you add three more grub screws in a cross pattern + to stop the movement have just one causes wobble adding three more should stabilise
3 in a triangle pattern would be enough I think.
I was thinking the exact same thing. The warping in the skirt may still occur becaus of the pressure point but maybe that's fixable on a lathe after installing the skirt to the piston.
I was thinking that too. 3 or 4 keeper screws should do the trick. AND you get oriented piston top just line with skirt. now there is small chance, that it not be alignment.
Watch you bore micrometer. I think at 2:50 it went in slightly angled. We used to wobble them and get a nice scrape. And check your adjustment on how tight you make it. It looks tight. I could be wrong. That happens.
Maybe run four set screws to stabilize the two piece piston. At 12-3-6-9.
Could you make thin shim washers so that the inner and outer pistons lock up at the right point to give the correct ring clearance?
OR.
Lock the two piston halves together and put the assembly in the lathe and machine out the grouve to the correct clearance.
Rusty from downunder
Top answer mate!
Sounds like a perfect job for This Old Tony! He'll knock you up some new pistons, he loves a 2stroke too. Maybe get in contact with him.
Correct me if 2 strokes are different but honing with torque plates on water cooled racing blocks is done with hot water to get thermal stability in the bore.
Harden @ 520-530°C for 3-6 hours.
Cool water quench only, as polymer quench won't give the same hardness. Age at 150-175°C for 6-10 hours.
This thing when finished would look killer with old school engraving. Badazz man!
Be careful when using a grub screw like this as it may jack your piston skirt off to one side making it oval, we use a similar technique at work but would have a through hole in the skirt then a blind tapped hole in the part housing the little end bearing, the other option would be to use a dog point screw which doesn't pass fully through the skirt.
Alex, a couple thoughts. First, awesome coffee mug, is that from Pikes Peak? I have the same one! Second, you've got some good ideas already for solving your ring clearance issues, remember KISS will probably always be the best solution for a part exposed to such an extreme environment. I'll jump on the ESE Works thread to share some more detailed design thoughts for future pistons, but they can probably be summarized as: (1) selectable shims for ring-to-ringland clearance and (2) don't rely on the threads to keep concentricity between the piston pieces, use a tighter radial fit on cylindrical sections of each piece. So basically *one and only one* controlling feature in each of the axial and radial directions.
on the piston that doesnt have a step on it you could put 4 set screws intead of one. one every 90 degrees that way it stays aligned. just a thought
I'd consider honing the cylinder while its bolted to the crankcase. Maybe use a spare cylinder head with a hole in the top or just the top honing plate. Use gaskets.
Then warm the whole thing up in the oven to normal operating temperature.
Then hone to clearance you want.
Keep up the great work
I would highly recommend the use of flat, hardened washers under the nuts (or heads of bolts) when installing torque plates (and when assembling the engine as well).
Cylinder bore deflection is caused more by the “tipping” movement that is possible on a bolt or stud due to them “digging into” the aluminum and applying a slight sideways force... than by the pure tension the bolt or stud should be applying. That force is also unpredictable (and inconsistent) if flat/hard washers are nut used under the head or nut.
The noise is the part of a mekanik/kemi place ;)
I really admire your dedication to this project you like to do my kind of brainstorming a little alchohol and a whole lot of thinking with some machining and you have churned out a whole new engine design I Bet that is how Harley and the Davidsons came up with there first motorcycle. Someday they may make a movie about your journey. Thanks for sharing 👍
very interresting Video
Kind Regards form Austria
Hi,
Well done again with all the work, it is great to see how it is coming along.
I thought about the shoulder or ring, and I think that despite needing a hard stop I keep thinking if it is sufficient. If the grab screw move the top eccentric, maybe it is worth considering having the internal piston sliding with interference in the skirt. I mean the cylindrical part of the internal piston be tight to the internal diameter of the skirt. This will give you concentricity, and then the shoulder will give you the height.
Personally I am not a fan of the side grab screw either, I would put it underneath, but that is purely a personal preference.
Keep it up, the engine looks faster and faster at every step!
Andrea
Good idea but assembly and dis-assembly would be challenging.
As I said earlier, the piston ring may ultimately end up taking on the appearance of an internal circlip, with the 'plier holes' in a ramp form engaging with pins mounted in ring groove on the opposite side to exhaust port center.
Please gas port the pistons to help with sealing!
I was wondering if it would work . may blow the ring out in the port.
@@jnljnl8485 there’s no pressure at the bottom of the stroke so I very much doubt it
u can tap holes in your drill press, thats what the pros do. it saves time, and u are sure the tap is straight to the hole, wich can bedifficult, specially if u tap
Top work
Your cylinder with several inlaid vertical ring guide pins of Trinium alloy would allow a regular piston and rings to be used for testing. A suitably tough material could be thin enough to perhaps not affect your flow too much.
I forgot that the Trinium mine planet buried their stargate. The planet I recognize out our front window has plenty of Naquadah. Maybe a trade?
if it's loose, try put some washer made from extra thin metal inside, maybe it will help, idk im not engineer, but it's worth to try
Alex, you can solve the skirt problem installing 3 screws, located in 120 degrees steps.
u can tap holes in your drillpress, it works really well
Just an idea: I don't like the grub screw screwed into the sleeve. It could push the piston's top-end ever so slightly out of allignment with the piston sleeve.
I'd tap the threads into the top end of the piston and either make a grub screw out of a m3 or m2,5 screw by grinding the head into the diameter of the thread, or make the hole in the sleeve as big as the screw's head.
for cooling the casting after heat treated don't used water use mineral oil or oil not water because it can crack the cylinder
for the thermal shock
Before you go making any new pistons, I thought of a way to retain your skirt with a circlip. I described it in a comment on your last video. It might be a worthwhile concept or just get you thinking about different solutions.
Can you drill through the set screw hole to make a mark on the inner part then the tip of the screw doesn't press against the inner piston but enters a little cavity so the screw tip keeps it from rotating relative to outer part. Like the drive pin in a collet.
That's what I've done👍 I think shim between the parts will do the trick, and Mark is working on a batch of redesigned ones.
Add 4 set screws. its just for testing but then you can set depth as you like.
You truly inspire me with your brutal persistence and determination. Keep up the awesome work 👍
Some advice on heat treating: don't do any machining before the treating, you will warp the block and every machined surface
Once the heat treating is done, machine the parts
Hey mate the ring land doesn’t need to be right at the join. Or dose it?? Have a standard type ringland below/above the piston join, the ring locator peg can be trapped in a hole when the 2 piston parts are screwed together. It will save the extra comlecations!
Those ultra thin rings will be harsh on the bore and ports.
Keep up the good work 👍👌✌️🤘cheers 🍻
fantastic machine work on those pistons!! they must have taken a lot of effort and time to make.
Surely you don't need to make a little spacer ring to sit behind the piston ring, can't you just put either part of the piston back in the lathe and make the step in the ally part? The step you machine will become the gap for the piston plus clearance and mark's original faces will now clamp together tightly as long as there is enough extra thread length. Putting the step in the skirt side won't affect the squish.
Also, I'm not sure a 2 piece piston is needed any more since you don't have that T-shaped land like before. A normal piston would work but with an extra pocket for the lump on the ring and then a pin inserted from under the skirt to fix the hole in the ring?
👍😁👍 I'm not used to thinking like I own a lathe yet...
Good idea Kai. I am going to eliminate the problem but making a separate spacer as the bottom ring land. I showed this idea in one of my videos last year but haven't implemented it. The nice thing about the two piece is it still gets rid of the wrist-pin hole and the round skirt I think is much better than the cammed skirt.
Try Teflon tejp on the thread should eliminate the thread gap...
I can see future issue of the combustion compressing the piston crown over time slowly squeezing the ring. Put it together and check. Then smack the crown with small dead blow. See if it compresses.
Dude, once it clicks, it's done. Done over-click it. A click is a click. Have another beer and...well, no, don't do that.
You also might want to heat the piston in boiling water when setting ring clearance and set hole. Include the ring as it will expand less.
Teflon tape on the treads of the poston/skirt to take up gap/play in the threading.
How about cutting 3-4mm flat grove in the outer piston tube and machine a moly impregnated nylon flat ring. This would take out the slack.
Maybe shims would help you get the right groove height and tighten up before you lock it with the grub screw.
No! Cylinder distortion is normal. Even in a Iron block V8, the bores will distort when mounting the heads. That's what honing plates are for!
Awesome channel,I enjoy watching Your progress.When I get a Block honed with deck plates they use a head gasket to duplicate a running engine.if You are running a base gasket I would use one when honing also.Just my opinion.Keep up the Great content.👍
Maybe outher shell piston (crown, ring seats and skirt) with screwed in part with wrist pin? Should solve clearing issues, altought locking the ring and skirt is still a must.
You probably already know this but I've seen Pistons with a pin in the ring Groove to keep the ring from rotating, of course you would have to file the end of the ring to fit the pen
Nice progress, awesome
And use shims under thread land to set pist ring gap so it’s evenly touched down all around
07:40 Noch nie so einen Kolben gesehen. Never seen such piston before. Irre! Amazeing!
Perhaps already said, Just skim off as necessary for clearance you want. :)
try a soft coating on your pistons wearing away while running. i think the perfect geometrical match at operation temperature is most important. Than you can run without piston rings like a RC engine. Also a much oil helps sealing the combustion. maybe 1:15 oil ratio.
Keep up the good work. Your getting there. 👍
You could try loctite 638 on piston. That wil remove the wiggel. But it will be a pain in the ass to dissasemble. You will need to use heat.
Dident watch the Hole movie before commenting.
Just an idea. To get more Patreons so you can do this part time or full time.
Try showing the Patreon logo and maybe the names of your Patreons, like you have done in some videos.
It can be real quick just a cople of seconds scrolling the names four or five names per row.
You can do a voice over so it dont get boring for non patreons.
It rubs peoples egos to see their own name and will probably get you more people donating.
And also it reminds people that you have a patreon.
Could you make it in one piece and just press the pin in that holds the ring from underneath maybe above the wrist pin so it can't come out. Just requires machining the ring Grove the right size.
I wonder if you could modify a standard 40mm racing piston to accept your new ring design. Drill a vertical hole down through ring groove & press in pin & peen over? Will need to machine back of groove at that location for clearance.
I haven't watched all your videos so forgive me if I'm missing something, but have you considered other ways to split the piston in two? Wouldn't it be better for the crown and the skirt to be made as one piece with ring grooves and all, and have the pin assembly attached internally, from the bottom? for example, with bearing caps and bolts, similar to the crankshaft end of the connecting rod. Or, with a large diameter threaded locking ring, securing the pin assembly, again, from the bottom side (edit: snap ring maybe?)
Now there's just so many things to go wrong at the same area: the ring grove, the set screw, threaded aluminium-to-aluminium connection...
Looking forward to seeing it all come together...and hearing final concept at full noise...
Trying times, seems to be the theme of November. Keep at it, soon it will sing like a mad cat!
i think pistons should be forever assembles using an interference fit that extends the entire length of the skirt. after assembly with small end bearings, rod and pin already installed turn the outside on a lathe. or use a close fit with many tiny groves on both pieces that youl fill with epoxy to secure the parts together. also permanent assmebly but would not require turning after
I would rethink the sets screw in the piston if it backs out like set screws love to do it will destroy you’re cylinder.
7:36 that ring gap is horrible lol
Yeah, should've done the last little "by hand" to straighten it up.
Alu can be hardened with cold temperatures. Try some dry ice.
Привет с России. Greetings from Russia. Thank you for the video. I've been watching you for a long time. 👍👍👍👍
I'm not sure heat treating is the answer, you actually want a little elasticity and you already have a nice hard cylinder coating. If you were to remake the block I would suggest working on the geometry a little - a thicker cylinder wall and try to keep the radial supports/cavities as consistent as possible. There is a reason two stroke engines are usually cast iron or sleeved. My 2 cents, but if you harden it then find it doesn't hold it's shape throughout temperature changes don't' say I didn't warn you.
if its possible or economically feasible you should try and get the cylinder CRYO Treated. the increased hardening and reduced coefficient of friction could assist in preventing the piston seizing to the bore or at the least elongate the time you have to shut it down or come to a stop before total destruction. in theory.
from what i understand about the most effective way to cryo treat parts. the process also involves heat treatment processes. its a combination of both that makes a significant gain in internal strength , reduced internal stresses , and decreased coefficient of friction.
21 people have no idea what is going off in this mans garage
Some people dip their cylinders in liquid nitrogen, I don't know what it does, but it happens. Isn't a screw thread always going to give you variable 'squish' on your piston ring?
I dont know about aluminum cylinders, but I know they cryogenically treat steel gears and shafts. It takes the stress out of the metal increasing wear and fracture resistance. Liberty gear does it to transmissions
@@comedicsketches Thanks
So many dynamic forces in a complex part like this during heat treating... Not sure if there's enough material movement on a part this small to be a concern, but I imagine that the quench could cause stress fractures in any weaker areas, voids, or thin spots. Not that it's practical, but would pouring the casting and throwing it into a vacuum and cooling as slow as possible help if heat treating proves destructive?
How about torquing the 2 halves together. Machine the ring gap and set screw then reassemble with correct clearance?