Hayabusa Pistons Part 1

[@dfkirby87]

I'm unable to contribute to you financially or with any cool swag at this point, all I can leave you is a simple comment letting you know that all of your content has given me so much knowledge and pride in my path to become a true machinist that I could never truly pay you back. You are a beast, a gentleman and a scholar. You have done a lot to keep this trade relevant. I know this is an old video that I am commenting on, but it is one of my favorites (I've seen it at least three times). Thank you for all you've taught me sir, YOU DA MAN!

[@hydroy1]

Been a machinist for decades, you just showed me a quick way to save time & tooling . After drilling the primary hole for clearance size of cap head, you just spot center the bottom half with the same clearance drill, Me I pull that drill out and use a extension center drill to spot it , then drill it for tap drill size #7 drill ----- Your way saves time & tooling. Nobody knows everything ! Thanks in advance :)

[@b_rod4380]

I love the problem solving you go through and explaining why. A lot of what you come up with can only come from experience. Makes me want to watch every video and soak up as much as I can.

[@Belano1911]

People who don't make mistakes, don't make anything. Thank you so much for these videos. They give a real insight as to how a craftsman thinks and works. Everyone engaged in any kind of mechanical work can learn a great deal from this.

[@kickstart63]

What a pleasure to see a master craftsman at work. The narration is great and is of professional quality.

[@Rail9222]

Automotive machining takes specialized machines. While there are some some projects the average job shop can do, it's best done on dedicated equipment. I applaud you for taking this on. Very impressed with your patience and attention to detail. Nice clean shop !!! Keep up the good work.

[@CraftedChannel]

I'm a little shocked here. Pistons in high performance engines are not round. The diameter at the skirt is bigger than perpendicular to the skirt. The top of the piston will also be smaller than the skirt. This is done for many reasons, one of which is to end up with a constant diameter at temperature and that temperature is different from top to bottom. The goal is to limit how much the piston rocks or misaligned with the bore so the ring surface stays as parallel as possible with the bore. Bores are custom fitted to pistons normally and are themselves round. Perhaps the customer is an expert builder. All respect, your doing what the customer ordered. From my race engine building days, these modifications seem very odd.

[@r2e316]

This! Your comment should be pinned at the top.

[@PhaseConverterampV]

Everyone gets the match the bore to piston thing. Adam said it was coated, say nikasil, or whatever, maybe there are reasons why it cannot be fixed, just relax everyone. He’s just making a cool video, with no commercials, change the channel if its to much for you to process, or, make a video yourself. They are a lot of extra work. Regards,

[@phuturephunk]

Bores are what? are what! I MUST KNOW!

[@michaelmorgan2880]

@@phuturephunk holes

[@michaelschuler7397]

Correct they are made wider at the skirts for a reason . This guy had the machinist remove that feature . Not the machinist fault but now the pistons will slap hard

[@brettb.7425]

You do great work, have a very knowledgeable mind, and can problem solve like there’s no tomorrow. I did have suggestions though I’m late to the show and have not read what others have written. A few things came up in my mind and they are only meant to be advice. If you know these things already, please excuse my eagerness to share with you. They are: 1. Pistons are tapered from crown to skirt so that has to be allowed for and machined into the piston. 2. Skirts are sometimes oblong in shape and not perfectly round. 3. Ring grooves are designed to be a certain depth. 4. Cylinders should never be bored without pistons in one’s possession. 5. I’m sure I forgot something. These are only a bit of my knowledge I’m passing along. Again you do great work and are an amazing machinist. I just wanted to maybe help if possible. You put this video up 2 years ago so I’m sure these things have been addressed by now but maybe I’ve said something that others might not have mentioned. Others probably said stuff I didn’t think of. I like when we all help each other out. Keep up the awesome work brother and God bless!!!

[@tedsykora1858]

dear Adam. I love your videos and learn a lot from them. I have seen a couple of youtube creators get overly negative comments and quit. So here is a double thumbs up for the instruction value. keep up your work

[@Gottenhimfella]

Indeed. Some machinists are like erupting wounds. Their posts tell us nothing about the person they are talking about, but everything about the person they are.

[@marvinblankinchip2535]

Gottenhimfella ... So true, so true.

[@jacobhawkins7949]

thanks for showing your mistakes! I get so sick of videos with mistakes edited out. like some guy just dreamed it up and it worked perfectly.... give me a break. That's how we learn. I guarantee nothing has ever been built perfectly the first time. Great videos.

[@bigears4426]

Jacob Hawkins everyone makes mistakes especially on one offs, it's always about overcoming those mistakes and making it work

[@MrGlossyEdits]

A breath of fresh air really.

[@venusreena2532]

Adam is real world.. and dont mind being real

[@markdavies8037]

I agree, if you aint made a mistake you are lying! 😉

[@PhaseConverterampV]

Nice video Adam. Thanks for taking the extra time to show what you do, it is a lot of extra work. You are a very good machinist, me being one. You are merely helping a guy out, its not your fault the coating may be undersize in the bore. Too many negative viewers: Please keep showing these vids.

[@MrJugsstein]

Adam thoes that live in glass Houses should not throw stones. I have learnt just as much from the odd mistake as from a perfect job. thanks for having the honesty and kohans to put it up as is. Enjoying it all and working through your back catalog.

[@yqwgjsg]

Funny how people are giving you hell about what the pistons should or should not be. Someone comes to you with a job and asks you to do a thing and you figure out how to do it. They didn't ask you to engineer a drag bike. Maybe your friend knows what he is doing or maybe not but I suspect he is not stupid and we all live and learn. Love your videos.

[@truracer20]

Who "gave him "hell"? It's all about helping a guy out. Maybe Adams bud Rodney will read these comments and look farther into what is being warned about and maybe change his mind on how to proceed? I haven't seen one nasty or condescending remark. Maybe Rodney gets lucky and his plan works, maybe he doesn't and the entire bike gets destroyed. I gave Adam MY opinion as a person who does build engines and I have had to decide on what type piston to use for an application. I am a huge fan and watch ALL of Adams videos and rarely comment. I'm not the do it my way type of poster but this isn't that type of critique. And I hope (and believe) that Adam won't be upset by my comment or any of the others that had the same warnings. In the end though whatever happens ain't no skin off my nuts...

[@yqwgjsg]

+truracer20 Chill out spaceman. My term "hell" was not meant to indicate that that the comments were not right, only that Adam is a master machinist. The enjoyment of his videos is how he devises ways to accomplish what he is asked to do. Yes the pistons would have almost surely been turned to junk and destroyed the cylinders but I just watched a video of Adam making a fixture. I see his friend has come to his senses but we did get to see this interesting video.

[@Abom79]

It's all good. We actually learned today from the comments. I talked to Rodney about what everyone was saying and he decided lets not machine them. he's going to have the cylinder honed to fit properly.

[@yqwgjsg]

+Abom79 That's cool. I ran into some stickers that cracked me up and when I get them I'm going to send you some. Not sure you can show them on your videos but I'm sure you will get a kick out of them.

[@johnbonaros589]

Hi Adam,if the pistons are indeed oval shaped i think your friend is going to have a very hard time to fit them, great vids Btw

[@TheMadManPlace]

You have to be kidding !!! Motor reconditioning is where I qualified as an artisan and we NEVER bored a cylinder without having the pistons on the table. EVER !!! We also had a "Piston Grinder" and that was a fun machine to set up and use mainly because a piston is oval and tapered. Vintage car engines have cast iron pistons a lot of times and when rebuilding them you had to grind the piston to clean it up then re-sleeve the bore to suit and after honing, the ring gaps had to be adjusted to the correct expansion gap. Thanks for another very nice video.

[@1sttofight]

I totally agree. This engine job will not end well. I do not doubt Abom will do a good job, the pistons just will not work the way they are being machined. The coating on the cylinders changed the bore size. The reason pistons are tapered is when they get up to operating temp the top and the bottom will be the same size. The top of the piston will expand enough to match the skirt because it has a lot more metal at the top than the bottom.

[@TheMadManPlace]

1sttofight I think this is for a dragster engine - their life is measured in minutes and they only "work" for 10 or 15 seconds at a time - not really enough time for decent heat saturation to happen within the piston itself which means that the sizing of the piston will be constantly changing during those few seconds. Machining the taper and oval requirements into the piston becomes academic in reality. But it would be very "iffy" to do so in a motor that has to do a 400 mile race. But then, "the customer is ALWAYS right" (sometimes ;>} ) - not so Abom?

[@1sttofight]

I would hope they get the engine up to operating temp before they make a run. To do otherwise is just asking for trouble.

[@jeffryblackmon4846]

It is good to see how relaxed and professional you are before the camera. Your teaching skills and desire to share your knowledge are great to watch. You teach and entertain at the same time.

[@Abom79]

it's something that I never thought i was gonna be doing, but since everyone enjoys it I continue to share the videos of the work. :)

[@jeffryblackmon4846]

I for one think it's great that you do this. Many thanks!

[@SantiagoHernandez-me7mq]

I'll tell you Adam when I have something to get done I'll be calling you cause you are the MAN.

[@EVguru]

Hey Adam, I'll steer clear of the actual piston mods, plenty of comments already! One common way of holding pistons for modification is to use the register in the bottom. You use a dummy gudgeon (wrist) pin with a tapped cross hole and draw the piston down onto a stub arbor with a bolt.

[@larrysnyder3475]

I'm very glad I found your channel. After working in machine shops for close to 38 years I still learn ALOT from watching you. Keep up the awesome job you do my friend.

[@johnscheer6820]

Being a retired machinist I enjoy watching these types of videos. I saw the offset of the clamping screws coming a mile away. After being in the machinist trade for just over half a century I can honestly say that I always worked off the centerline of pieces like this fixture. By finding the center, doing the math work and then going outwards from the center, you eliminate any mistake from not figuring the edge finder diameter because you only need it to find the center. As long as you go outward equal amounts you will automatically get the holes symmetric and ..... you can also bring the drill out in front of the piece and eyeball it to see if they are far enough apart. If they are installed and not out far enough , all is not lost ..... you can undercut the screws a little if necessary.

[@coelhofpv2086]

It's great to see a true professional in action. Watching you reminds me of the old days when I worked for HP as electro-mechanical tech who's specialty was prototype implementation. I was lucky because I had processionals like yourself coach me and keep me injuring myself and others in the vicinity. Over the 3 -4 years of my practice, I progressed from a true hack to novice and never did any "high visibility" damage. Precision machine work is a true art... ;-)

[@stevehageman6785]

Bill & Dave's HP was the best place in the world to work.

[@aly-tek7190]

Well after reading some of these comments I don't know what to believe. My Grandfather used to machine truck pistons (sorry not sure on brand/model) to use in his engine rebuild on 1918-29 Oakland's and all his engines never failed. Having said that his era engines aren't as highly stressed as a Busa engine. I guess at the end of the day Your video still shows us how to chuck something up in the lathe that needs to be held just right ;)

[@Marzec309]

The piston skirt area is intentionally out of round! Instead they have a larger diameter towards the bottom, between the base of the piston and the piston pin hole. ... Ovality, which means out of roundness, is necessary in all pistons to allow for thermal expansion. It also compensates for deflection of the piston skirt caused by side loads.

[@Gary3247]

Sometimes you just have to step back & say this job is not worth the headaches. I still enjoyed every minute of this video. I can't wait for the next one.

[@obfuscated3090]

Piston mods are common but most people don't know about them. Usually it's dome mods. Thanks for posting this video!

[@digger123698741]

I do not know about racing pistons but normal automotive pistons are cam ground to compensate for uneven expansion caused by the wrist pin. We were taught to fit pistons to the bore using a hone for final fit. Hone the cylinder until the piston without rings and with connecting rod would fall by gravity thru an oiled cylinder. Love your channel. God bless.

[@reallycoooool]

Nice video! I like your parking attachment on your mill! It’s very nice that you show a very high quality workholding. Your videos are like one of those books you like. Full of knowledge and good ideas.

[@james.d.8044]

Love the detailed description and walk through of the project ,great channel

[@jerhalco]

Like the fixture. Always good to see fixture ideas, if you do work in your shop of all types this helps anyone.

[@TheRuffusMD]

i really enjoy yore videos...it is always great to watch a genius , artist and master craftsman at work ...

[@quadmachine8434]

Adam, you do a great thing as you mentioned in this video, showing different techniques, I have watched several of your videos and you do a fabulous job. Some of us have different ways of doing things with the equipment available to us, and then how we were taught or figured out for ourselves. Keep going on!, you have a fan base!!

[@johnanderson-lb9zi]

I watch your videos frequently and just came across this. I own a Business Called WorldWide Machining & Welding in Superior Wisconsin. As well I have worked for the Factory Suzuki & Yamaha Race Teams in my younger years. Currently I still have my own Race Team and Build a lot of Race Bikes and High Performance Engines. I say all this as to lend credibility. When I heard that you received a lot of criticism for your approach to holding the Piston I had to chime in. I have used the same procedure for holding Many Pistons that I modify greatly. The fixture I built is similar to yours but yours has some better features than mine. In my humble opinion you have done it correctly.

[@johannwatzinger1122]

Do not take me wrong, but I am really happy to see that also professionals sustain mishaps. I am building modell Stirling motors and steam engines never having had any formal training as machinist. And believe me, I do a lot of mistakes, which cost me incredibly much time to correct them. As a matter of principle, I only use scrap materials, so the cost of my learning by trial and error is somewhat reasonably limited

[@eieghn]

Great video! Having worked in "the engine field" in The big 3, I learned that pistons are much more complex than most realize. The skirts on all pistons have what is call "cam drop", in that they have an oval profile, with the skirt having a tighter radius that protrudes out further than the pin axis of the piston. The 2 most common alloys used for forged pistons are 2618 and 4032. 2618 expands more than 4032, so are set looser than 4032 which is thermally more stable. 4032 clearances are usually 0.0015 to 0.0025 and 2618, up to 0.0035. The "right" way to machine the skirt is on a NC machine where the cam drop can be programmed in with consistency. Thanks for sharing! I'll keep watching as I have learned TONS from your series!

[@thomasguilder9288]

Wow I always start these kind of vids guessing "Hmmm how would I do this" and I love your ideas! Your clamp is more work as the work on the pistons but it's a great way to avoid scratches... I really appreciate your work!

[@Abom79]

Thanks Thomas

[@geraldswain3259]

what a beautifully organised shop very professional and clean .

[@vonleyser]

PIE JAWS, Your a smart guy, we all learn from our mistakes. Jobs like this is why I don't do favors anymore, to time consuming, customer is clueless, should have had pistons available to the shop who bored the cylinders. Looks like a decent shop you have Adam

[@craigleemehan]

Great content! I don't care whether your customer asks you to do the correct thing or not. This is a machinist channnel. I'm interested in how you solve machining problems. Once again, I commend you on showing your mistakes; it makes your show all that more real. Also, I don't know how you keep up your posting pace, it's amazing.

[@Abom79]

Thanks for the comment. People seem to forget what I'm trying to show with jobs like this, instead of what's right or wrong with an engine build, I'm coming up with ways to to do work at hand, no matter what the part is.

[@musiclovr2890]

always go with right issue is will it weaken the pistons yes- id hate to see it fly apart at 100+mph let alone 200+mph for drag racing

[@musiclovr2890]

it is his problem he is the one weakening the parts and its his friend that could get hurt if it flys apart

[@craigleemehan]

+musiclovr2 It's the customer's responsibility, not Adam's. This is a machinist channel. Adam's not giving racing tips. I know all you guys are super dooper experts, but if the customer specs it, I'm going to make it to their spec. Maybe Adam should go over and make sure the customers lug nuts are tight enough.

[@musiclovr2890]

thats not what its about dude if you knew something was wrong you would do it anyway - then your a f-in idiot, dont bother me anymore ok, i was commenting to adam to maybe save a life so piss off man

[@oddjobbobb]

I am only a gear head wanna be. So, not especially interested in the all the engine stuff in this series. But just watching you build tools and jigs and fixtures is why I hang on your every word. And of course I always have a towel to catch the drool when you open your wooden boxes. When I see a wooden box coming into view I know something good is about to happen. I loved how you had to twist the “1-2-3” blocks almost as if the had a thread or magnets holding them together, but it was just the super fine surfaces that formed a sort of vacuum. On another machining YT I read a comment that Starrett tool boxes are Cartier boxes for men. Some clever word-mavin needs to come up with a similar phrase for wooden tool holders. I never really learned much about my Dad’s transit level he used in his construction sight, but I marveled at the box in which he kept it.

[@togusa75]

I hit the "thumbs up" button 5 minutes into the video, without even let you finish the introduction because this is going to be awesome anyway

[@jackmehoff1565]

I love how you treat that arbor great tools for someone who knows how to use and treat them

[@Thunderstixx77]

Cool Adam. I love this stuff !!! Thanks for sharing this with us, Mr Rogers would be proud of you my friend !!!

Love ya machine shop Adam , Take's me back to 1985 when I started my trade as a machinist in a jobbing shop . Not many people know how to use these old gem's of machine's .

[@operator8014]

31:00 for little "eyeball precision" work, you can slap a 1/4" drive socket extension on the end of the tap to get some more clearance if you already have a good lead into the threads, I used that trick a lot in the automotive world.

[@keithhansen3963]

Nice Brad, great suggestion>

[@Gottenhimfella]

And if the tap doesn't have a regular shank square (1/4, 3/8, 1/2" etc) remember you can get 8-point sockets instead of 12 point, which will fit square shanks. Hard to get in "long", but you can extend them by cutting in half, hard turning spigots, and TIG welding a length of chrome moly tubing - worth it if you do lots of tricky tapping. These are also handy to have for square headed (usually dog point) setscrews often used in toolpost clamping, shaft collars and such.

[@619BossDogg]

Always awesome to see one of your vids on my feed thanks Adam!

[@tsw199756]

Adam as a precaution on critical measurements I always build a gage block stack to the nominal dimension and check my micrometer to the gage block stack this will take out of the equasion any screw wear on your micrometer. You have taught me a lot in your videos just thought you might enjoy a suggestion of mine. Keep up the good work my friend!

[@Abom79]

Nice tip, thanks for sharing!

[@apistosig4173]

Adam - I have watched many of your video's (enjoying them all) but this was I found decidedly interesting.

[@timmayer8723]

I am watching a modern day Leonardo Da Vinci work his magic. It is a privilege. Thank you sir.

[@rock4us2]

I have no clue whatsoever it is you are doing but i just love your work ethic

[@sciencemilitia1853]

All these engine experts in here I think deal with different types of engines than this kind. If you didnt know it already, you wont realize that this engine isnt a simple "Measure the piston, and then bore the cylinder" job. Its not an iron sleeve in those cylinders. Its raw aluminum that has to get a nikasil plating on it after your bore it. So you never know what the bore diameter will actually be until AFTER you get that nikasil plating done in the bore. Its not the same as like boring out a good ol chevy smallblock. I never even order pistons until I have the bores all plated and cross hatched ane and get a final measurement. THEN I order pistons. These guys were doing what they could, with what they had. And they did a good job!!

[@lindsayfog5246]

hopefully more people will now know that a piston is neither round, nor cylindrical. hard to believe any shop bored without pistons, as every piston is a different nominal diameter, so, especially for high performance, a bore need to be honed to fit each piston. (maybe the shop told the owner, who knows? we weren't there) love your machining work, and detail.

[@mr.jimmyjohnsr.ohyeah7835]

LOVE WATCHING UR VIDEOS !! WELL , LIKE YOU ALREADY KNOW BY NOW. .....JUST WANTED TO EXPLAIN TO YOU IF NOBODY HAS ALREADY SAID .....THE MAIN REASON YOU DON'T CUT PISTON SKIRTS IS BECAUSE THE PISTON IS ACTUALLY TAPERED BY DESIGN. IT IS MADE THAT WAY FOR EXPANSION OF MATERIAL DENSITY. THE SKIRT HAS LESS MATERIAL TO EXPAND THAT'S WHY IT HAS WIDER DIAMETER & THE CROWN HAS MORE MATERIAL TO EXPAND SO "OF COURSE" IT'S A LESS OF THE DIAMETER OF THE SKIRT. KEEP UP THE GREAT VIDEOS MAN. .. CHEERS

[@johnfraser1115]

"That's something that Rodney does, he likes to drag race" lmao love your videos

[@WarthogDoctor]

I appreciated that comment as well

[@monadking2761]

I love watching your videos and I'm not a master machinest like you are; however, I did work in a metrology lab at an aircraft helicopter manufacturing company. I picked up on your comment around (21:55) and you mentioned something like, this should be close enough for government work. Did you ever hear the definition of that? It's kinda like this. You measure it with a micrometer, mark it with a piece of chalk and cut it with a hatchet! Keep up the great videos and all joking aside, you are true in what you do and just making something is better than over engineering anything any day. I'm glade I saw this video since I have just restored a LaBlond 15"x42" bed lathe. I was very much inspired by you to just do it, by what you do and have learned alot since I retired from a major sports broadcast company as an audio engineer. I just got it running last night after picking it up last May from a local amusement park's machine shop. It's in pritty good shape since it was built in 1953. Now I'm planning on using it to trim some pistons that I'm reworking and was trying fo figure out how to clamp the pistons down to my 8" chuck. Now I'm looking for a L-00, 4 jaw chuck and a vertical miller. Keep the videos coming, I love them and Happy New Year too.

[@djyul]

Tell Rodney next,next time,Buy the pistons first and then bore to the pistons. How they used to do it in the old days,and a lot easyer!

[@dacutler]

Pistons in large truck diesels are graded for diameter. That is they run from 0 to 3 (sometimes higher) and are custom fitted in each cylinder, even in a mass production environment. Also, they are not exactly round (mainly because the bearing for the small end creates a varying mass around the circumference) which means it expands differently with the aim that the piston becomes round as the engine reaches working temperature. In other words, your friend gave you a task which is almost impossible! However, thanks again for another great video! Most enjoyable!

[@DYLANTRIES]

I make pistons at mahle in Morristown TN and I can tell you that pistons are "barrel shaped" and im not sure how important that is but I think you have enough experience as a machinist that no one should have any concerns. Great videos

[@zanelile2991]

I enjoy all your videos that I have seen. --- Thank you.

[@corbaneells3997]

Hi Adam! I enjoy your channel. I grew up in P-Cola too. I am a new machinist, but a long time engine builder. Those pistons are larger on the skirt than the crown because more thermal expansion will occur in the crown, especially with nitrous. Interesting to see how you are getting the job done, but if the crowns don't have enough clearance, things will get ugly quick! The cylinders should be rebored and replated.

[@Abom79]

Thanks Corban. we dediced to bail on cutting the pistons down.

[@marctennill8367]

Adam, another great video. I found a neat trick for the spill masters. Inside a computer hard drive there's a pair of super strong magnets, so strong that you can't hardly pull them off by hand. Drop one in your spill master and will stay in place anywhere at any angle. It also pulls the chips off your brush and keeps them from making a mess of your part. You can find them at any scrap yard or computer recycling center, most of the time for free. They also hold shields for your steady rest, rags for sanding and grinding, and shop drawings. The uses are limitless and to buy a magnet that powerful would cost a fortune. Keep up the good work!

[@Abom79]

Cool, yes I have some of those magnets that a viewer sent me.

[@blakewitt9501]

Incredible video man. That was really something else. Can’t imagine doing that myself

[@rustycowll5735]

just now saw the piston video. Yeah, you've already heard from a 1000 people that the pistons are usually cam ground, but I don't think it's a big deal to hone the cylinders at this point, it would have had to be done anyway. It's still an OK vid, warts and all. Most viewers appreciate your honesty and the video production value.

[@alexanderkuhn7416]

Hey Adam, pistons are usually held in the inside if the skirt. There is the perfect surface. It can be mounted in your 4 jaw. You only have to push the piston against the piston head with a flat on your monarch tailstock. I worked for years for a piston manufacturer an that's the way it is done. Just as an advice.

[@Abom79]

I see where the piston is counterbored about a 1/4" back on the inside, but only the skirt areas are machined. Perhaps you could turn a piece of material to just fit inside that counterbore and push on it to friction drive it.

[@alexanderkuhn7416]

+Abom79 agree. Or you can screw in a rectangular plate in the middle of the holder that just fits between the eyes of the piston. Here you wouldn't have to push too hard to create friction. Good luck from Germany!

[@directorgtr]

Great job as always! Love the content you give us all.

[@CompEdgeX2013]

Well, I get to watch one vid a month and it has my creation in it... Cool!! Awesome to see it get used. Colin

[@blindabinda1234]

What is your creation

[@JT-tz5hp]

@@blindabinda1234 20:55 The Colin Chippett made multi axis stop.

[@martindworak]

Awesome channel!! I’m glad I found it, kinda surprised I didn’t see it earlier.

[@robertrpenny]

A79, I believe PM is correct. Anytime I have had a bike cylinder bored the shop wanted the piston in hand. Then bored and honed cylinder to get desired clearance. That avoids machining nicely finished Pistons, reducing skirt thickness and chances of errors. Bob.

[@RobertPerrigoOkiechopper]

Adam, it's always a pleasure to watch you work & how you explain the process, you will be a fantastic mentor to many as the years float into retirement .

[@Abom79]

Thanks Robert!

[@chronicblazer84]

We use gauge blocks for calibrating 3 point measuring tables, and electronic gauges. I can only recommend getting a 3 point table (or fabricate one), and using a micron gauge.

[@millomweb]

18:50 Watched a few of your vids now and have noted how well the cutting/machining process has been. I'm pleased in this video, things aren't going quite so well - with the vibration while cutting. I suspect a lot of hobby machinists would appreciate a video dedicated to dealing with 'poor cutting' that causes vibrations - or is it vibrations that cause poor cutting :) ? I guess it's all down to: 1. rigidity of work and tool/cutter/mill 2. Tool sharpness and ground to the right angles for cutting the particular material 3. cutting feed speed 4. rotational speed of material (lathe), mill or shaper in fpm. 5. Coolant or not - possibly even coolant type - oil based or water based. Perhaps you'll consider making such a video - if you've not already done one ?

[@chieft3357]

Thinking ahead, a lot of people do not know that a gauge block is susceptible to temperature change, such as holding one in your hand even for a short time. I really like how you think through any job.

[@bcbloc02]

Nice fixture, but your buddy shouldn't be having you do what you are doing he will end up making a little problem into a pile of problems. As a guy that builds multiple thousand hp engines for people I have a pretty good idea, no need to make mistakes that have been made before just to see if the outcome is the same.

[@Abom79]

Thanks Brian. I talked to Rodney and we decided to bail on cutting the pistons.

[@sharkrivermachine]

I am glad to hear your comment. I just got a chance to watch the video. I was an automotive machinist for most of my life and I was yelling at the video. "Adam don't do it". Most piston skirts are not round they are cam ground. The bore should be honed to fit the piston.

[@bcbloc02]

Back in high school I helped a buddy put together a blow thru turbo setup for a 351 Ford in a Mustang, Knowing we didn't want melted pistons it was jetted way fat. Never the less he got in a mile long interstate race with a Mercedes and it ended up growing the piston tops till it pinched the rings in the bores and then it jerked the tops off the pistons, some it even pulled the pins out of instead and sent rods out the side of the block. It was the end of that engine. :-( I feared a similar result for this engine by getting proper skirt clearance but the tops being too tight especially for the demands of a nitrous motor. You can really get some harsh thermal swings out of one of those. I hate not getting to see Adam do the cool work though. :-)

[@shadowdog500]

Adam, FYI, Piston skirts are usually slightly elliptical to account for slight changes in expantion as the piston heats up. He might be better off sending those pistons back for ones the right size for the cylinder. Just a thought. Chris

[@TanTan-ni4mg]

Those pistons dont change shape by 2000th of an inch. Also Id get that coating off there. Once the piston reaches temp... That ceramic will delaminate. Tried using some coated pistons on a Racecare 3 years ago. Lost tonnes of power. When we removed the piston we saw craters and high spots where the coating literally came off. Looked like a pan of brownies.

[@Okipouros]

True, but if its for a drag bike, maybe it doesn't matter cause they run high tolerances anyway

[@salvadordollyparton666]

@Indosarnia yeah, there's a reason nobody else does this kinda thing. I mean maybe you would if you had some free pistons, or if you had some you just could not return and needed to use. But pistons are pretty cheap compared to a block, and definitely a complete engine. Especially once you add machine time and all to that block so you can't even just go grab one off the shelf to replace it. But hey, it ain't mine so what do I care? It does seem like somethin may have been off, just sayin. I wasn't there when he test fit em or whatever so what do I know?

[@BigBallinCarHaulin]

There's a reason you send the pistons with the block to be bored/honed to the correct size.

[@C0NR098]

@Indosarnia Completely agree, I'm a CNC machinist myself and have no idea what the application is for half the parts I make. Not because I'm ignorant, as it always interests me, but because I don't have the time to ask questions. If the component is in spec, its good, its down to the designer to ensure the finished product works correctly.

[@MotoWanderer]

Hi Adam, The piston is not round at all, it's oval and furthermore, it's tapered as well, meaning that the top should be smaller than the bottom. The rod pin axis is slightly smaller than the thrust axis and this is to help with thermal expansion and side loads. The head is smaller since it expands more as it is closer to the combustion. No one expects you to know these and you've done a clever job of making a jig for it but machining the piston round will guarantee a melt down in that drag bike. I wouldn't give you apple pie recipe as i don't know jack about pastries, but this is what i do for living, thrust me on that.

[@Abom79]

No worries. I informed Rodney of all the comments about this being a mistake so we decided not to machine them. Thanks for the tips.

[@MotoWanderer]

I cast and machine pistons round (but tapered) all the time but not for 4 cycle engines. A two cycle low power engine like a chainsaw is more forgiving, you can go undersize and you (maybe) just smoke a bit more and lubricate better. Now if this was for a 50cc scooter, by all means, a round piston would have done the trick but for a drag bike running nitrous, it would end in disaster. Also, you can hold the pistons from the inside the skirt, that's how I hold them all the time and take light cuts.Thanks for the Sunday content though, you should do more of these :)

[@jryer1]

@Adam - I have to say you're so freakin' smart, luvin' the shop and the ingenuity. You make Americans proud!

[@watahyahknow]

when i was in autoshop class they told me the pistons are ground tapered and oval tapered because the top of the piston expands more than the bottom and oval (at the underside) because of the expansion of the piston pin pushing the sides out think you could machine them but i think the best way to do it is with a cnc milling machine putting the piston in a 4th axis chuck

[@bdrrogers]

It may be difficult to replicate the surface finish

[@jkotka]

when i do pistons, i make a "cup" for them, then pull the piston back via nut+bolt which has a loop around the wrist pin against that cup which will hold it square, resting on the ends of the skirts. though this is the other way adam is going here, but i've never heard of anybody actually machining the piston to fit the bore. its done the other way usually. i've only ever taken material of the tops of the pistons to make the squish clearance right. still, no reason why this method could not be used for this setup as well.

[@calebperkins2351]

Awesome NSK towel man, that's where I work! Hub bearing plant in Franklin, Indiana.

[@scooter1391]

.002 clearance and running nos I wish him the best for his engine build evan with those pistons with no friction skirts. love the channel keep it up adam

[@guido1534]

I love this guy's channel!

[@samc5898]

Another awesome video. I can't wait to see more of these

[@wowonice1]

Yet another great video. Thanks for uploading these!

[@edsmith2562]

Never seen a round piston in a motorcycle application. A happy ET is a low ET, hope the best for your friend. Great job on the videos, dig your work man.

[@scottb8175]

I worked at a shop building pretty serious racing engines for a few years, and later as a diesel mechanic. I give much credit to Abom here as a general machinist as he is correct in his theory on how to hold the piston for what he wants to do (using a split collet fixture and applying evenly distributed clamping force near the piston head end and not the skirt). Work holding any piston for machining is no easy task. And yes, the cylinder bore is always machined to the piston, not the other way 'round (ahhh... pun) as the pistons are "cam ground" (elliptically machined) and tapered, pins may be "neutral" or "offset", ring lands are reduced "diameter", different alloys / forged or cast expansion properties, etc., so turning down the diameter is not the best advice offered in this video, although I have seen hand/custom made round/straight pistons in certain racing applications (nitro engines that don't run long enough to heat the pistons evenly anyway, and therefore running lots of clearance - up to 0.008"). But there are many other reasons to machine pistons - valve clearances (fly cutting), balancing, eliminating "hot points" (sharp edges), surface finishes (controlling carbon build up), modifying "dome shape" and compression ratio (dome volume), "squish" areas, plug clearance, gas ports, ring clearance (fit)...some racing pistons are supplied as "blank forgings" without any dome machining or top ring grooves cut (for advanced engine builders to apply their own "winning modifications") and the most difficult part is always holding onto the damn piston. Aluminum pistons can not be held in a regular lathe chuck - so don't try it. If you hold the skirt end (very weak) with enough force to keep them from flying out or spinning in the jaws, you will distort and damage the skirt, perhaps cracking it. Forget about holding a piston from the inside of the skirt. The piston head is stronger, but if you leave any marks or dents/dimples in the ring area, the rings will not fit/seal properly - and ring clearances are extremely critical! Holding the piston by the pin bore is unreliable and tricky at best, and I've only used that method (in a commercial "piston vise" which I regretted buying) when fly-cutting for valve clearance, and only if I didn't have a proper split collet holder of the correct size made already. In that case, I never cut more than 0.010" per pass, as clamping force was dangerously insecure. My final version split collet fixtures were 5" long. I used two relief slot cuts 2" deep, with holes (pre) drilled at the end like Abom's, at 90 degrees and an outer self locking taper at the end, like an R8 collet, that fit into a matching tapered sleeve, with a short counter-bored 3/8" UNF draw screw for added piece of mind. I always clamped the pistons as near to the top as possible. I could then chuck the fixture into the lathe three or four jaw or in a angle vise or rotary table on the vertical mill. I made the heavy use ones (e.g. 4.000" bore - a.k.a. SBC and SBF, with most "off the shelf" 4" pistons actually having 3.9975-3.9985" dia. skirts) from 4130 steel, the rest from 6061....I wish I had kept them when I left that job, too....

[@gsfbffxpdhhdf7043]

Scott B sorry not sorry. You never do this. This is only gonna cause problems. Although i think he may get away with starting bike not letting it warm up rip it then shut it off. It might survive a few dyno pulls and pulls on the track before needing to be rebuilt.

[@sweetpeaz61]

Pistons are designed to be both oval and tapered, being smaller on the head of the piston than the skirt diameter, this is all to do with thermal expansion..when the engine is at working temp the pistons have expanded to be perfectly round and parallel ..you really dont want to be machining the pistons..if they are tight hone the bores

[@KeepingitAnalog]

You, sir, are a genius! Outstanding!

[@zanelile8192]

I like your shop and your videos. Thanks.

[@74KU]

Nice to see someone who is actually worried about thermal expansion when using micrometers.. not sure if you know though, but that black plastic bit is the only part you are "supposed" to touch as it is there to limit thermal expansion on the micrometer.. the bigger the mike.. the more "important" this is.

[@dennisstephens7777]

I'm looking forward to the sequel(s). Did you consider using the difference in thermal expansion of aluminum and steel to make a no-slot, no-mar chuck that would hold the piston securely enough for light turning? Aluminum alloys, cast or wrought, expand and contract at about 0.000012 in/in/degree F. That's about double the coefficient of thermal expansion of steel. Cooling an 83mm piston (3.268") from 80F to 40F in your refrigerator will shrink the diameter about 0.0015", allowing you to insert it. When it warms up, it will be temporarily stuck in the steel holder, but will release without a mess using dry ice. Either ID or OD collets can be made for delicate work.

[@MrGarnet108]

Subscribed. I am an IT professional but finds your videos very interesting. Nope, I'm not thinking career change, I think I'll enjoy more by watching. LOL!

[@henrikstenlund5385]

Thanks for sharing this one. I noticed right away your mistake but thought that you corrected it while making the job. The mill blade thickness, of course!

[@ianrutherford878]

Hello, believe it or not I've actually worked turning pistons for experimental engines for a manufacturer. INSIDE the skirt was a turned and faced step we called the register.It was the first operation on the casting. The gudgeon pin hole was then bored. To secure the piston for all subsequent turning no chuck was used on the piston. Instead, a ring of the same diameter as the register was centered with a long eye bolt passing right thru the lathe's shaft. Piston on, dummy pin thru piston and eye bolt, tighten large wheel nut at back of lathe.

[@specforged5651]

You know that hypercoils are not the brand of piston? That box is from a coil spring. Those appear to be JE pistons in a hypercoil box. Not trying to call you out by any means, just letting you know. We can always learn more and I learn something new everyday from your channels. Thanks for sharing!

[@SirDeanosity]

From making a tie rod adjuster to being part of Team Drag Bike? That is quite a change in how one has to approach the day. If you would, please keep us connected to Rodney's channel to watch him race with your pistons.

[@URAL-174]

Sorry for my english! All of this tools are awesome.... And you Adam - 👍👍💪💪💪🤘✌️🤝

[@inspector8572]

@11:32 in the arm you installed is called a “DAVIT” is primarily used for heavy hatches on ships as well a a type of crane on ships.

[@NanoCottage]

I have seen this done before with pistons - machine a block that fits snugly in place of the con rod and locates the wrist pin. Leave enough meat on the block to let you screw in some threaded rod at 90 degrees and long enough to go through the headstock, and clamp with a plate out the back of the lathe. So the bottom of the skirt sits on the face of the chuck with the jaws removed. Depending on the skirt design and how much you trust the setup, you can always make something to locate the skirt to and prevent it walking sideways. Or just tread carefully and rely on the clamping force through the headstock, assuming the skirt is robust enough take it - a forged piston is obviously much stronger than cast. Have also seen someone use a con rod cut in half, small end mounted to the piston and bored to accept the threaded rod which is pinned through con rod.

[@Landrew0]

No pressure, but anyone who does these types of videos is subject to massive critiquing from experts and numskulls alike. Soldier on, my large friend!

[@Abom79]

LOL...yessir!

[@rapragermusic]

We call that "doing the Harry Hundge", when you drill/cut 100 out from whatever you measured! Cool project thanks for sharing.

[@Terry_Baker]

Nice work Abom. Don't let the mistakes get to you. As a manual machinist in a gun factory , I see and sometimes make mistakes too. All part of being human...

[@RichardHeadGaming]

You make the cylinders match the pistons, never the pistons the cylinder, balance is KING! More power is gained by matching the cylinders and freeing up the rotating assembly than any other thing you can do. And most pistons today are Hyperutechtic and are barrel shaped not round or flat sided.