[flankr7]

Some of you may have seen this in the January issue of Cycle World. The guy has a working prototype and claims to have fixed the "oil in cylinder" issue. I am going to hold my comments and see what some other opinions are on this. But at first look, this tech appears to have great potential to evolutionize the internal combustion engine.

 

[limenine]

The proof is in the pudding - build a race motor and see how it does!

I read the same article, and it seems impressive, if it works as claimed. An old idea made workable by new materials and technology.

 

[flankr7]

Could you not potentially have an unlimited rev range?

Would the power curve continue to go up?

Would you even need a transmission any more?

Could an oil be made to withstand the pressure and stress of 30,000 RPM?

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[1slowF3]

[ QUOTE ]
flankr7 said:
Could you not potentially have an unlimited rev range?

Would the power curve continue to go up?

Would you even need a transmission any more?

Could an oil be made to withstand the pressure and stress of 30,000 RPM?

/wwwthreads/images/graemlins/confused.gif /wwwthreads/images/graemlins/confused.gif /wwwthreads/images/graemlins/confused.gif /wwwthreads/images/graemlins/confused.gif

[/ QUOTE ]

The same things were thought when the Wankel (rotary) engine was developed.

30,000 rpm isn't a big deal. Turbos can spin at 150,000 rpm.

 

[OldFatGuy]

[ QUOTE ]
1slowF3 said:
[ QUOTE ]
flankr7 said:
Could you not potentially have an unlimited rev range?

Would the power curve continue to go up?

Would you even need a transmission any more?

Could an oil be made to withstand the pressure and stress of 30,000 RPM?

/wwwthreads/images/graemlins/confused.gif /wwwthreads/images/graemlins/confused.gif /wwwthreads/images/graemlins/confused.gif /wwwthreads/images/graemlins/confused.gif

[/ QUOTE ]

The same things were thought when the Wankel (rotary) engine was developed.

30,000 rpm isn't a big deal. Turbos can spin at 150,000 rpm.

[/ QUOTE ]

The rotary valve engine is still limited by piston speeds, so the rev range wouldn't go on forever. But it would certainly eliminate valve float as a factor.

 

[flankr7]

[ QUOTE ]
1slowF3 said:
30,000 rpm isn't a big deal. Turbos can spin at 150,000 rpm.

[/ QUOTE ]

I do not completely agree... If you have a big V-8 with a rev limit of 6k rpm, then a new rev limit of 30,000 rpm is a big deal. 500% increase... But what does that mean? Will your power curve continue to climb?

 

[Kricket]

I didn't read the article, but is not a problem of high revving the fact that you must balance things like the crankshaft ever more precisely? Then there's friction (which isn't completely eliminated by oil)...and the ability to get air and fuel in, burned, and out quickly enough...

 

[limenine]

Right - piston speeds will limit rpm in a piston engine. You won't see 30000 rpm with a "big v-8" just by eliminating valve float.

And yes, friction becomes more troublesome as revs increase. I'm reminded of an article I read some years ago (Kevin Cameron in CW) mentioning the Muzzys Kaw 750 superbike effort. They tuned it for more and more rpm (I don't remember exactly how high, but it was WAY up there) experimenting, and did not see any of the expected power increase. They were able to achieve stratospheric rpm, but friction cancelled out any power increases.

 

[BigAl_009R]

fwiw - friction does increase exponentially with RPMS in modern 4 stroke engines....

 

[1slowF3]

[ QUOTE ]
flankr7 said:
[ QUOTE ]
1slowF3 said:
30,000 rpm isn't a big deal. Turbos can spin at 150,000 rpm.

[/ QUOTE ]

I do not completely agree... If you have a big V-8 with a rev limit of 6k rpm, then a new rev limit of 30,000 rpm is a big deal. 500% increase... But what does that mean? Will your power curve continue to climb?

[/ QUOTE ]

I was refering directly to your question regarding oil withstanding 30K rpm. Pistons at 30K rpm is a whole 'nother ballgame. :wink:

Though it occurs to me that model airplane or car engines run some fantastically high rpms... though they are 2 strokes if I remember.