highest reving automobile engine

[86corolla]

I'm trying to develope a new head design that wont have any rpm limit. I would like to use an existing long block to lower costs but I'm not sure which would be best. I'm leaning towards a four cylinder HONDA because parts are cheap and available. This would become the prototype engine with a lot of custom work so any engine would actually be fine as long as the long block could survive 10k+ rpm.

Any suggestions

 

[patprimmer]

Try to use a very short stroke so piston speed does not become the limit.

There is no such thing as no limit. There are already several designs where the ports are the size of the bore.

Regards
Pat
See FAQ731-376 for tips on use of eng-tips by professional engineers &

http://eng-tips.com/market.cfm

for site rules

 

[Azmio]

the first thing that will limit your engine rpm is the phenomena called valve float. Inertia of the relatively heavier intake valves is likely to make it difficult for the valve to return to the seat at high rpm.

If you see blue smoke coming out of F1 cars, that's probably due to the intake valve hitting the piston and broke into pieces.

I've worked on racing engines before, we normally used less aggrasive valve lift for the first few races just to make sure that we move cautiously to define the limit.

 

[dcasto]

the Honda s2000 (with taps in the background) had a 9000 rpm limit: 2,157 cc (132 cu in) F22C1 I4 Since this engine is alonger stroke version of the 1,997 cc (122 cu in) F20C I4, I'd look at putting the crank from the F20C in a F22C and use the correct set of piston and rods along with the s22 head.

 

[ivymike]

there were some ferrari engines which (according to video games I've played) could rev to 14000rpm or higher without grenading.

Perhaps what you should do is set up the engine so that the performance at higher rpm is miserable enough as to prevent further increases in engine speed. In other words, for an unloaded engine, make sure that power output at 14000rpm (or whatever) is zero. For a loaded engine you could probably do with a torque curve that falls off steeply above 50% of max allowable rpm.

a detail to bear in mind is that sometimes the fastest an engine turns is when it is being turned by something else (like by the transmission, when going down a hill).

 

[evelrod]

Ten thousand rpm might have been impressive in 1960 !!!
Definitely not in today's automotive circles.
With NASCAR 358 cu.in. engines running in the mid 9000's for 500 miles and more with no problems...with F-1 engines limited to <20,000 (they would certainly be over that if it were allowed)---I watched a dyno test on a small four stroke Honda motorcycle engine at the R&D facility in Gardena back in the 70's that turned 22,000+. I have ridden several motorcycles that revved to well over 10,000.
Our ancient little 'A' series BMC 1380cc engine revs to 9500 and our vintage Lotus twincam is safe to over 10,000 (although we do not rev it that high).

I'm trying to develope a new head design that wont have any rpm limit.

Sorry, that just does not exist. There will always be some limiting factor, be it mechanical or flow related.

Rod

 

[StefanHamminga]

Go for the gas turbine! Or tell us some of your other restraints (like desired power, usage, lifespan, package size, budget)

Stefan Hamminga
EngIT Solutions
CSWP/Mechanical designer
Searching Eng-Tips forums

 

[patprimmer]

he designs I mentioned have no moving valves so vale float is not a issue. Durable valve sealing however was an issue.

Regards
Pat
See FAQ731-376 for tips on use of eng-tips by professional engineers &

http://eng-tips.com/market.cfm

for site rules

 

[SomptingGuy]

If you want revs, check out any of the 4-cyl 4-stroke 250's that the Japanese makers produced (cbr/gsx-r/zxr/fzr/abc/lmnop). I will never forget seeing a red line at 19000 on one of them some years ago.

- Steve

 

[BrianPetersen]

... and don't forget the Ducati motorcycle engines that use cams to both open AND close the valves (desmodromic valve actuation).

But, as others have noted, there's still an RPM limit ... Spin ANYTHING fast enough, and something's eventually gonna go boom.

 

[dmelacom]

I too have thought about building a high revving IC Engine. Desire + no time = no engine. There is so many things to consider as I've read above. Critical load limits on the reciprocating package, induction, exhaust, the perfect port design, valve control.. etc etc. My interest has been to reverse engineer a high revving motorcycle engine and plug all the data into maybe Engine Expert or Dynomation or both and go from there.

 

[SomptingGuy]

I am sure I saw a V4 50cc (Honda??) engine at Sammy Miller's museum a few years ago. Anyone got any info? I bet it was a high revver.

- Steve

 

[WGJ]

evelrod: Ten thousand rpm might have been impressive in 1960 !!!

And what about the 1948-on BRM V16 exceding 12,000 rpm?

http://members.madasafish.com/~d_hodgkinson/brm-V16.htm

Bill

 

[patprimmer]

Yes Bill

12,000 rpm, but less than a 2" stroke.

Regards
Pat
See FAQ731-376 for tips on use of eng-tips by professional engineers &

http://eng-tips.com/market.cfm

for site rules

 

[WGJ]

Vrooooom vrooom......

Still a feat in 1948. They must have used a lot of the materials technology from WW2 lessons.

Bill

 

[Pud]

SomptinGuy, way back when 50cc bikes were raced for World Champs, Honda had a twin cyl, 4 valves per, which had peak power at 21,000rpm. IIRC, it also had 12 gears. Saw one at Mallory Park and it sounded like an angry wasp!

Ridden by very small Japanese racers.

Harry

http://www.tynevalleyplastics.co.uk

 

[evelrod]

Yep, Harry. That's the one I saw at the Honda R&D facility. Noisy little bugger, too.

Didn't BRM or some F-1 team do some experiments with an H-32? Seems like I read something a long time ago.

Yes 12k was quite a fete in '48...So was my drive in a Honda S 600 in the 60's...Buzzing around Forrest Lawn at two AM shifting at ~10,000---fun, fun, fun. Especially coming from a Vette owner (at the time).

Rod

 

[patprimmer]

I seem to remember a BRM H32. I think it never made it to a race.

Regards
Pat
See FAQ731-376 for tips on use of eng-tips by professional engineers &

http://eng-tips.com/market.cfm

for site rules

 

[JohnLear]

"I seem to remember a BRM H32. I think it never made it to a race."

There was a 3litre H16, effectively two flat 8s stacked on top of each other. I can't recall if it ever raced.

The BRM 1.5litre V16 makes an utterly astonishing sound, there are some recordings of it floating around on the net. It's well worth having a listen to this engine, but to really get the full sonic impact copy to a CD and play loud on a big stereo (be warned, tape down the hairs on the back of your neck...).

 

[turbomotor]

Hello 86corolla,

While valve train dynamics may dictate engine speed capability, mean piston speed is also a factor. I use two seat-of-the-pants limits: 10 meters per second mean piston speed for constant speed service (such as aircraft piston engines) and 25 meters per second for engines that hit peak rpm for very short durations (such as many motorsport applications). Thus a 100 mm stroke engine should be limited to about 3000 rpm for continuous speed service and maybe about 7500 rpm for highly variable speed service.