ESE's works engine tuner

[SwePatrick]

Successfully relocated pins:

[husaberg]

[Pursang]

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EFFEN Football!!??

Is this the ESEsWET Jumping the Shark Moment?



Cheerless Daryl.

[41juergen]

May be some of you have seen that, I like it...

http://forum.2temps.fr/viewtopic.php?f=8&t=19432

[SwePatrick]

When designing a crankshaft, Lesson number one: Do NOT exaggerate the interferencefit, sometime somebody maybe want to rebuild it.
Quite disappointed now as the bolt wouldn´t move when pressing with a shitload of force(over 40tonnes).
And the material around the lighteningpockets on the inside collapsed instead.



Sad day.

[F5 Dave]

Oh. That's upsetting

[TZ350]

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If the big end and rod are completely ruined the trick is to hold the rod in a vice. And cut through the rod and big end pin with a disk grinder. Then you have the two flywheel halves to deal with separately. Much easier to place one crank half in the press to press the remains of the pin out.

[guyhockley]

Presumably it took a lot, or excessive, amount of force to assemble it in the first place, and was difficult to align?

[SwePatrick]

It was almost impossible to align the crank i noticed earlier, it took very high forces to get it to move just a couple of thousands of a millimeter.

[Ocean1]

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If the big end and rod are completely ruined the trick is to hold the rod in a vice. And cut through the rod and big end pin with a disk grinder. Then you have the two flywheel halves to deal with separately. Much easier to place one crank half in the press to press the remains of the pin out.

I once had a similar problem, compounded by a lack of intelligence in failing to support crank halves immediately surrounding the pin and over enthusiastic use of a very large press. Better tooling might have worked, but experience with similar assemblies suggested another approach. Pushing the end of a shaft swells that end and increases the radial pressure against its bore, I've felt this many times where it takes more force to remove a shaft than it took to initially install it, in some cases the increase in force is indeed enough to distort the shaft beyond it's elastic limit, at which point you're buggered.

One solution is to make the pin hollow, (which is common enough) but not for its full length. Pressing against the bottom of this pin hole is effectively the same as pulling it out, which slightly stretches it, microscopically reducing the diameter, the opposite effect of applying force to the upper face. The force required to disassemble the shaft where I first used that design is about 60% of the original with the same fit.

[husaberg]

The mother country had this stuff sorted years ago

[TZ350]

The Yamaha KT100 kart engine used steel plugs inserted in the end of the big end pin to expand it and lock it in place.

To disassembly it, before pressing, you drilled one plug out and then tapped the other side out with a pin punch.

Pushing the end of a shaft swells that end and increases the radial pressure against its bore, I've felt this many times where it takes more force to remove a shaft than it took to initially install it, in some cases the increase in force is indeed enough to distort the shaft beyond it's elastic limit, at which point you're buggered.

One solution is to make the pin hollow, (which is common enough) but not for its full length. Pressing against the bottom of this pin hole is effectively the same as pulling it out, which slightly stretches it, microscopically reducing the diameter, the opposite effect of applying force to the upper face. The force required to disassemble the shaft where I first used that design is about 60% of the original with the same fit.

I like Ocean1's approch very much.

[andreas]

Why not disassemble it from the other dirction, one half at the time?

[Michael Moore]

The problem of breaking shafts was solved by fitting a shock absorber.
Something like old English bikes had....

It appears that the twin cylinder Seadoo model 580 2T that takes the rotary valve drive from between the cylinders has a spring on the drive shaft that may let the skew gear float a bit which might serve as a damping device.

cheers,
Michael

[ceci]

If the sleeve thing doesn't work, we will just lower the exhaust ports and re cast as an FOS cylinder.

Sorry, I'm curious, your new project is related to this statement.