Carbon Pistons

[cmw]

Bringing out a little bit of history of CMW Motorsports/CMW Racing
Carbon Carbon Pistons that we ran in the 1990's . We made these for testing for the future piston technologies utilizing same space age material supplied to the space shuttle.

We also started using ceramic piston ring technologies.

We were also way ahead of our time for marketing. But never the less they are way cool.


These are the only ones in the world as far I know.

I thought I would share

[Flieger]

So... how did they perform? Any cracks around the pin bore? I imagine the cost was too high even for Porsche parts?

[chris_seven]

There is a NASA Report as the early work was carried out at the Langley Research Center.

There seems to have been plenty of work carried out on piston manufacturing techniques but I have never seen much reported work with regard to fatigue properties.

The basic characteristics of the material looks sensible - although the Modulus is a bit low at around 15GPa.

I would also like to see some data on the KiD behavior of these materials when subject to repeated impact loading.

http://www.schunk.pt/EN/catalogos/carbon_pistons_for_internal_combution_engines.pdf

There seems to be some work being done on 'ringless' designs in the last few years.

All very, very interesting.

[Cory M]

What kind of testing did you do? Did you adjust the geometry to compensate for the differences in thermal expansion?

[stownsen914]

I'll take it!

Seriously, pretty cool stuff.

[Elombard]

Yes how did they perform? Are they significantly lighter than forged aluminum? Very cool

[chris_seven]

Originally Posted by Elombard

Yes how did they perform? Are they significantly lighter than forged aluminum? Very cool

On a like for like design basis about 30% lighter

[Tippy]

So that means the connecting rods can be carbon too???

[chris_seven]

The carbon-carbon material used for these pistons doesn't have a great modulus and I don't think it would be very good for con rod manufacture.

If you increased the section sufficiently to provide the stiffness needed then the weight saving may not be great.

Trying to lay up a high modulus fibre to provide good compression and torsional stiffness could be tricky.

Padden Engineering has some quite interesting concepts.

Padden Design Engineering, LLC

[thotdoc]

Originally Posted by chris_seven

The carbon-carbon material used for these pistons doesn't have a great modulus and I don't think it would be very good for con rod manufacture.

If you increased the section sufficiently to provide the stiffness needed then the weight saving may not be great.

Trying to lay up a high modulus fibre to provide good compression and torsional stiffness could be tricky.

Padden Engineering has some quite interesting concepts.

Padden Design Engineering, LLC

OK that is some cool stuff. Fantasies develop.

[cmw]

Originally Posted by Cory M

What kind of testing did you do? Did you adjust the geometry to compensate for the differences in thermal expansion?

We ran these on a normally aspirated 46 IDA Webers twin plug 3.0L engine. Lots of changes in the tune up over a conventional piston. We tested for a couple of years both on the engine dyno and on the track.

[chris_seven]

What did you measure?