ESE's works engine tuner

[adegnes]

there has to be a better/cheaper way than laser welding the pins shut.

Flux core welding the pin shut!

Frits, did you have lubrication problems with your alien technology plastic plugs?

[wobbly]

Yep, flux core is the real deal capable of fixing any goddamn thing in a frozen over place - ive seen it on the interweb so it must be true.
Shit with all the time/effort we all put into deciphering the Ryger bullshit episode, this has to be an easy task.
One small point - we MUST have the chamfer intact on the pin end that forces the clip outward into its groove if there is any axial float in the gudgeon bore.

[Grumph]

Yep, flux core is the real deal capable of fixing any goddamn thing in a frozen over place - ive seen it on the interweb so it must be true.
Shit with all the time/effort we all put into deciphering the Ryger bullshit episode, this has to be an easy task.
One small point - we MUST have the chamfer intact on the pin end that forces the clip outward into its groove if there is any axial float in the gudgeon bore.

What about a 3 piece pin ? Normal hardened hollow center piece maybe 4mm short of the finished length. Non hardened ends pressed in - maybe the end pieces taper bored inside to save weight. The 3 pieces with enough left on the OD for a finish grind. You'd only need a very small center register for grinding - or if you have a centerless grinder that small, no center needed.
Only the area where the small end rollers run needs to be hardened of course.
Just as a normal pin, you're relying on the circlips to prevent disaster.

[kanjeneroo]

Maybe Pankle's price was cheaper,shit it couldn't have been more surely.
No matter how you do it, plastic plugs using the clip for retention wont allow flow from the transfers to impinge on the outer edge of the small end pin surface
allowing lube into the pistons gudgeon hole bearing area.
Additional holes drilled upward from below the pistons gudgeon boss may help, but the TM pistons are pretty thin in this area.
The gains are huge from generating more blowdown flow,and plugs make the mod even better, but there has to be a better/cheaper way than laser welding the pins shut.

So.your saying a closed piston pin is way better then a normal ?

[husaberg]

Yep, flux core is the real deal capable of fixing any goddamn thing in a frozen over place - ive seen it on the interweb so it must be true.
Shit with all the time/effort we all put into deciphering the Ryger bullshit episode, this has to be an easy task.
One small point - we MUST have the chamfer intact on the pin end that forces the clip outward into its groove if there is any axial float in the gudgeon bore.

I seem to remember Wob used one to balance a stator.........
Useless or maybe interesting factoid/Question
What works bike ran a aluminum alloy RR77 crankpin with a hardened sleeve. that was reliable for 9500 hard racing miles with a future multiple world champion on it when he fitted one to his production racer model?

Works Vincent grey flash
So if Al is third the density of steel why not a solid Al Gudgeon pin?

Also how did Aprilia seal the big ends?


http://www.kiwibiker.co.nz/forums/al...hmentid=303952
http://www.kiwibiker.co.nz/forums/al...hmentid=303485
http://www.kiwibiker.co.nz/forums/al...hmentid=303484
http://www.kiwibiker.co.nz/forums/al...hmentid=302294

Honda on its 4t use little press in plugs also.

[Hemi Makutu]

What about a semi-permeable metal foam matrix?

One that transient gas flow will 'see' as solid, but will allow some liquid lubricant flow.

[wobbly]

Aprilia ended up with flush laser welded end plates on the pin.
The Honda style push in cup is no good as this still allows a major connection between the Aux and the A ports as the pin passes over both of them.
YES, I am saying there is a huge advantage to be had with closed pins in tandem with wide Aux.
You can have the Aux ports around to bore center, without getting the big loss in mid power I saw without them.

And even bigger advantage is to be had in the KZ10 engine if you lower the mod Ex Blowdown STA some by using the wide Aux but then reducing the timings.
Also the KZ10 main port is out at 72% - reduce this to closer to 68% with even wider Aux, with lower timings, and then way more power range can be gained.

But all of this is just conjecture, as rule 1A says we cant ADD material, only grind it away - unless of course the factory sees fit to manufacture cylinders this way.
When I get to work there very soon, its just one element of a raft of big mods I want to have tested to death in house.

[husaberg]

If the nylon pin plugs were centre drilled to allow a modicum of cooling flow effect, perhaps?

Has anyone tried 'golf ball' dimples on them for oil retention/anti-seizure purposes?

Or deeper, but still blind holes drilled, filled with graphite rods, semi solid moly or other anti-seize media?

Perhaps a lube slot in the conrod little end eye to match the big end for lube needs with the plugs?

A reed valve in the pin plugs?

Aprilia ended up with flush laser welded end plates on the pin.
The Honda style push in cup is no good as this still allows a major connection between the Aux and the A ports as the pin passes over both of them.
YES, I am saying there is a huge advantage to be had with closed pins, you can have the Aux ports around to bore center, without getting the big loss
in mid power I saw without them.
And even bigger advantage is to be had in the KZ10 engine if you lower the Ex Blowdown STA some by using the wide Aux but reduce the timings.
Also the KZ10 main port is out at 72% - reduce this to closer to 68% with even wider Aux, with lower timings, and even more power range can be gained.
But all of this is just conjecture, as rule 1A says we cant ADD material, only grind it away - unless of course the factory sees fit to manufacture cylinders this way.
When I get to work there very soon, its just one element of a raft of big mods I want to have tested to death in house.

With the press in plugs they just need to be used the other way arround, pretty sure a few are at least flush mount (xr200 i think) but i can't find a decent pic.

Regardless a pressin plug can be any shape, plenty of welch plugs are domed.

[jamathi]

Aprilia ended up with flush laser welded end plates on the pin.
The Honda style push in cup is no good as this still allows a major connection between the Aux and the A ports as the pin passes over both of them.
YES, I am saying there is a huge advantage to be had with closed pins in tandem with wide Aux.
You can have the Aux ports around to bore center, without getting the big loss in mid power I saw without them.

And even bigger advantage is to be had in the KZ10 engine if you lower the mod Ex Blowdown STA some by using the wide Aux but then reducing the timings.
Also the KZ10 main port is out at 72% - reduce this to closer to 68% with even wider Aux, with lower timings, and then way more power range can be gained.

But all of this is just conjecture, as rule 1A says we cant ADD material, only grind it away - unless of course the factory sees fit to manufacture cylinders this way.
When I get to work there very soon, its just one element of a raft of big mods I want to have tested to death in house.

My very first closed piston pin test was done at Garelli, in 1988
We machined the piston pin holes outside of the bearing surface to a much bigger diameter
4-5mm bigger, and closed these with aluminium caps.
So these could never enter into the transfers!
It worked quite well and was reliable.
Power was a bit better, but not so much.
Because I left the auxiliary ports and ducts as they were, way too small...
I still had a lot to learn, which I did at Aprilia

[Tim Ey]

Shit with all the time/effort we all put into deciphering the Ryger bullshit episode, this has to be an easy task.

Weld in Caps for Pistons 54mm+ with 16mm pin and up to 1,5mm pin offset




Looks worse than it is: In a 60mm Piston the volume of the remaining space is approx 0,25cm³


To Define befor somebody calls his cousin in china to press a thousand of those
- Diameter of the cap that allows a C clip to be mount and removed
- Chambfer width needed to press the clip in position (probably done with first point)
- Lenght of the cylindric Diameter (Z) - as the position of the clip differs from piston to piston it might need a few variations of those.

cheers
Tim

[Frits Overmars]

What about using something simple like a Welch plug ie core plug freeze plug... maybe silver soldered in? Using a paste form filler and high temp?

Using high temp? The temp reached by a piston pin in normal use may already melt the silver and send the plugs on an exploratory expedition through the engine.

So if Al is third the density of steel why not a solid Al Gudgeon pin? Also how did Aprilia seal the big ends?

Good suggestion, except that the small end bearing needles like to have some firm (hard) surface under their feet.
But then why not go all the way and use ceramic pins? They're even lighter and much, much harder than aluminium, and not affected by temperature at all. But they still wouldn't solve the aux/transfer short circuiting. Aprilia closed their big end pins with conical plugs, but that wouldn't solve the aux/transfer short circuiting either.

What about a 3 piece pin ? Normal hardened hollow center piece maybe 4mm short of the finished length. Non hardened ends pressed in - maybe the end pieces taper bored inside to save weight. The 3 pieces with enough left on the OD for a finish grind... Just as a normal pin, you're relying on the circlips to prevent disaster.

Past experience tends to point into the opposite direction: circlips can be very good at causing disaster.
And what about that 3 piece pin? Well, what about acceleration values of 5000 g around BDC and 7850 g around TDC (Aprilia RSA at its 14500 maximum rpm)?
Do you think any built-up contraption would stay together long enough under that kind of stress?

If the nylon pin plugs were centre drilled to allow a modicum of cooling flow effect, perhaps? Has anyone tried 'golf ball' dimples on them for oil retention/anti-seizure purposes? Or deeper, but still blind holes drilled, filled with graphite rods, semi solid moly or other anti-seize media? Perhaps a lube slot in the conrod little end eye to match the big end for lube needs with the plugs? A reed valve in the pin plugs?...
What about a semi-permeable metal foam matrix? One that transient gas flow will 'see' as solid, but will allow some liquid lubricant flow.

I'd love to discover a material that is closed to gases and open to liquids. Might get me a Nobel price, so I could fly to Stockholm, all expenses paid, and meet Bob Dylan.

The gains are huge from generating more blowdown flow, and plugs make the mod even better, but there has to be a better/cheaper way than laser welding the pins shut....
Maybe Pankle's price was cheaper, shit it couldn't have been more surely.

Then you don't know Pankl; they always live up to their reputation of being the most expensive supplier in racing.

we MUST have the chamfer intact on the pin end that forces the clip outward into its groove if there is any axial float in the gudgeon bore.

You're right about that, providing you use circlips at all. That is why I did away with them and click my plugs straight into the circlip grooves.

Weld in Caps for Pistons 54mm+ with 16mm pin and up to 1,5mm pin offset. Looks worse than it is: In a 60mm Piston the volume of the remaining space is approx 0,25cm³

Tim, the issue is not the volume of the remaining space, but the cross flow area of the leakage path between auxiliary exhaust ports and transfer ports.

Frits, did you have lubrication problems with your alien technology plastic plugs?

Talking about alien technology: I considered most of the ludicrous genial ideas posted above (and then some) before wising up and turning to the simplest solution I could think of: leave the circlips out (saves weight) and click the plugs directly into the circlip grooves. They will work fine in combination with a normal piston pin (saves a huge amount of money compared to a Pankl pin) and it reduces the aux/transfer leak path better then even the latest domed Pankl pin, shown in the picture below-left. Right is my simple, very light plug.

There were never any lubrication problems, only a problem when someone used plugs, designed for a Simson piston, in a Kreidler piston which has different circlip goove dimensions. One plug came out, passing through the engine without doing any harm, but then the piston pin started wandering sideways, scraping the cylinder bore.

Most of the research went into finding the proper plug material. And since I don't expect I'll ever get rich from selling plugs, I'll let the cat out of the bag:
the plugs are made of Torlon. The stuff ain't cheap, but you'll get about 20 re-usable(!) plugs for the price of one Pankl pin.

[Grumph]

A very neat solution Frits. Are they moulded or machined ?

[Frits Overmars]

A very neat solution Frits. Are they moulded or machined ?

Machined

After which www.kiwibiker.co.nz said:

The message you have entered is too short. Please lengthen your message to at least 10 characters.

So here is my new, improved answer: "Thank you Grumph; they are machined."

I wonder: why the minimum length? In other forums, when you agree with a previous remark, you can simply write: "+1". Saves a lot of keystrokes...

[F5 Dave]

Is it 4301? At least available easily enough.

http://nz.rs-online.com/web/p/plastic-rods/2577136/

[ief]

That's probably the reason why Frits