VW Drag Racing Piston Lightening

[Infernostar18]

looks like those jaws are off a lathe, am i right?

[dslandrey]

it doesn't have to get hot... you must do heat treatment to every part after a machining process in order to take the stress that you have put into the grains. You can't machine a part, withoung puting stress into its grains.

[alvin82ng]

skim it n soften it, not a wise way, like killing ownself,

[paky66]

so, how did it do on the track?

[fiatnutz]

@paky66 - This was for a client at my shop.

[paky66]

@fiatnutz i understood that from the start, but i thought you got some feedback about how did the car perform

[dslandrey]

Βy machining the piston, you are puting a lot of stress to the metal...(inside the crystal structure) because you change the shape of the surface grains... To correct that you need to quench that piston in order to lose all that stress and for the grains to become as in the beggining... (sorry for my english if you don't understand anything... i study mechanical engineering in Greece)

[zapwatt]

@dslandrey I don't think there is anything to "quench". The work piece (piston) did not get hot during this machining.

[bergomynkia]

AHHAHAHAHAHHAHHAHAHAHAHHAHAHHA­HAHAHHAHAHHAHAHAHAHHAHAHAHHAHA­HHAHAHAHHAHAHAHAHHAHAHHAHAHAHH­AHAHHAHAHAHHAHAHAHHAHAHAHHAHAH­AHAHHAHAHAHHAHAHHAHAHHAHAHAHAH­HAHAHAHHAHAHHAHAHA xDD this only with engine 30 hp/liter pUAAHAHA xD so, only american motors prrrrrr :P

[JGMagoo]

DON"T TRY THIS AT HOME!

[batboyboogie]

@JGMagoo why not? No problem if you know what you're working with

[TRcustomengineering]

What if you cut some of the skirt off?

That will make it weight less and have less friction.

[DeanMLFlame]

@TRcustomengineering and also reduced piston stability cuz of a shorter skirt

[WTFGUY956]

WHY THE FUCK ARE YOU HOLDING THE WORKPIECE WHILE MACHINING IT?

[TheFelixWankel]

@WTFGUY956 his hand helps to absorb vibrations which can produce an unwanted texture on the grind surface. (which is why brake rotors have a large rubber band around them when being turned) Plus it helps to quite that awful noise

[jboram1]

@WTFGUY956 why are you holding the shift key while typing? Is a bit weird though, probably for reassurance.

[iceman86694]

I think that piston isn't for a turbo engine right? I see the head of the piston and didn't have the large hole on it as a turbo engine piston...

[TannerDee]

I DO NOT KNOW ALOT ABOUT MOTORS BUT WHY DO THEY NOT MAKE LIGHT PISTONS OUT OF TITANIUM I THINK IT IS LIGHTER AND STRONER AND MOORE DURABLE THAN ALUMINUM.

[M0T0RCRAFT]

@TannerDee Simply the price. I asked titanium connecting rods and the set for inline 4 engine was more then 4000£

[Element7744]

@TannerDee price in materials

[elvee88]

@TannerDee im not sure but it might have something to do with the pistons having to be softer than the cilinder walls

[maverick223]

@TannerDee if you have a piston harder than the cylinder walls, you will grind the walls down. if you have them the same, it will gall (seize). they're made of aluminum so they don't do either of those things.

[transdetendal]

@TannerDee it s somthing bout the heat transfere and size difference when hot and cold ,you cant get the same result as in alluminium alloys

[barthoedemaker]

@TannerDee F1 has

[lands3r]

why ar those 2 round chavings on the top of the piston? what thy do.....

and can you do it on 50cc or 70cc pistons to.....when yes why thy dont do it xD

[maverick223]

@lands3r reliefs for the valves so they have a little clearance. some engines don't need them.

[locoporgolf]

good job

[stueyrandall]

ummmm lightend pisonts in the very high revving drag engine in sory if im wrong but i thought making something lighter would affect its strength and i assume in a drag engine you want quite a strong engine so it doesent keep blowing

[cortinaboy69]

why is he holding it with his hand? is he gona catchit when it gets ripped out of the chuck....lol also why so slow, alloy has a high cutting speed

[jhareng]

@cortinaboy69 Two things its absorbing the vibrations which is movement and feeling for the job moving.

[jhareng]

@cortinaboy69 Initially i thought way too slow as well. For whats been done there a rotary table not required, thought he was gonna cut the inside rad as well but didnt.

Also why index rotary table then pass horizontally, only Y bed to move across.

Looks like a longish cheap cutter that flexing as well, hear the chatter.

[traxxaslover123]

watch those pistons blow up because there're too weak to withstand comustion forces

[qzbikowski]

Are those Wisecos? Out of a 20 valve turbo or maybe a 16 valve 2.0?

[localvic]

If you want things done right, you have to do it yourself.

[stevenJEDI3]

thats what i say too

[eddohan]

@localvic

Or let John do the work hehe

[spoontuner]

im not a big fanatic on pistons, arent these things supposed to be balanced wiehgt on each side of the piston and such?

[kingzuko06]

They just need to match each other as in piston to piston.

[MrMindfucker]

CNC has made a lot of kid's lazy to the old way's.... I suppose they will need to go back to benchtop machining with files for a while to put back in touch with what it's all about. Which is that machines are made by man.

What is wrong with cutting piston's? It's not like they are made of carbon fiber you know!

I love odd job's like this!

[muchoos]

jajaja....

[alekos198]

xaxaxaxaxaxaxaxaxa for 30,8gr exm. 4x30,8=123,2gr xaxaxaxaxaaxxaaxxaax no way. Custom Pistons for CP and game over.

[lfk156]

oh fuck off kid this is how it was done before your cnc machines were availible and for me id prefer john to do this to my car then to let some little chinese cunt fuck my shit up with half a mills worth or machinery

[4thedirtbikemaniac4]

your a goof. how do you think the process was done before cnc was available

[cmbarker1979]

Before CNC about 20years ago. Well they would nigger rig that shit up like he is doing now. CNC has been out for a VERY long time and no hand cutting will ever get the tolerances or clearances that a CNC will produce. I'm just stating that if your going to do it right, DO IT RIGHT. Would you use mid evil practices on a die person to save there life or would you use modern technology to try and save them. Perhaps you would give them a lobotomize to try and cure a crazy person

[wackedoutdude]

There is nothintg wrong with old methods mate. When a lathe bedway is cnc surface ground (very accurate). The only way to get it more perfect is the method of scraping which is done by hand but takes a very long time and lots of skill. Cylinder heads that are cnc ported are very good but again the only way to get them perfect is to finish them by hand. Cnc is amsing but for ultimate finesse you carnt beat skill and hand tools somtimes.

[fredtflail]

@cmbarker1979

thats not rigged

[chickeneggs4u]

It's amazing to me that you still have all of your fingers John. Please ,anyone watching Johns vid's ...Do Not put your hands anywhere near a spinning cutter.

[boxer3main]

the three main and balance is critical. this guy just slaps a piston around with a drill bit...something I would do.

[ArtieinAus]

Its actually a 4 flute end mill cutter in a mill. Not something you could/would do.... I think he may well know what he's doing....

[nikulll]

u might wanna use some type of lubrication or u will end up with cracks not visible to necked eye.

use so0me dye penetrant to check for cracks at the end.

u probably know this already

[citydriver]

i kinda think i might be wrong but i think johns uuuhm 2 decaids or more or machining work alows him to know what hes doing

[shocwav3]

When machining aluminum coolant is not required in most applications, the material dissipates heat fast enough that it doesn't typically reach a point that cracking would become likely. The exception is running a spindle at very high speeds (10,000 rpms) and taking a half inch cut at 50 ipm.

[joness105639]

I suppose you have to strike a balence between lightness and strength. shave too much off and the pistons toast, but you still want it to be as close to the limit of what it can take as possible in a race engine I imagine.

[devo4g63]

It doesn't look that hard, i'm going to cut the end off a drill bit and use my hand held battery drill, to lighten my new HKS pistons! LOL.

[vitsou1]

I wouldn't do that to my brand new forged pistons

[PLUSHAIRPLANECARPET]

wont this create a piston slap after a while

[JRBeaman]

PLUSHAIRPLANECARPET : Piston slap is when the OD of the piston is reduced which enlarges the gap between cylinder wall and piston skirt. Removing material from inside piston does nothing to change the spacing between cylinder and piston.

[enginemasterbuilder]

i wish you had a set of harley flywheels. show me how to get 80 percent balance factor. 60 is good. I KNOW you can Get 80perecnt balance factor

[1skiinIan]

can't you buy a piston that to your required wieght and diameter? I would think that that would weaken the piston. no?

[masterd151]

The removed material shouldn't cause any issues.

[tmedhat]

is it only 2 loose weight?????

[badVWbug]

Yes, it is only to reduce the weight of the piston. (Imagine the crank it is connected to, when the piston (actually connecting rod it is on) pushes down on the crank, the crank rotates, then has to use its momentum or another piston's downward force to push the piston back up. When U look at it like this, it's easy to see why you would want that piston to be as light as possible. I also gave you a thumbs up to even out the negative one sumone gave you. U asked an honest and fair question :)

[paulmerz]

I understand why you would want to lighten them..but, are the weight savings really "real-world" noticable or is piston lightening mostly for racing engines? How much would this typically cost?

[badVWbug]

Hi, Lightening pistons is ussually just for racing/performance purposes. The charges really depend on the shop/persons who are doing the work (machine shop is ussually about $80/hour where I'm from). You might notice it in a dailydriver situation by the engine's response (rev a little more freely, but depending on what your goal is it is not always a good thing to be light (less momentum). The REAL important thing is that the rotating assembly is BALANCED. you WILL notice this alot. :)

[62chevrolet]

You are reducing rotating mass. Kind of like how an aluminum fly wheel helps a motor accelerate quicker.

[ArtieinAus]

Actually hes reducing reciprocating mass. not rotating...

[talleyho12]

@badVWbug yes but heavier pistons have more torqe because of the rotating mass.

[badVWbug]

@talleyho12 Close, but the piston isn't rotating, it's a linear movement. The crank weight would affect this, as well as external parts mated to the crank which turn in a circular motion such as a flywheel. Even with this extra weight it is not creating torque, but it has increased momentum which allows the motor to sustain a higher torque curve with the same throttle input for a moment in time (such as taking off from a stoplight) but also requires more time/effort to get it up to that speed.

[tmedhat]

i just wanna know why u did that 2the piston

[TECHKLEC]

Probably less reciprocating weight for higher engine speed.