ALU. Rotor. SHHHH!TOP SECRET.

[Martiny]

Honda have created \'rotary valves\' on piston engines, which rotate at the top of the cylnder meaning that a race engine can rev to 25k lol *sigh* lol

saw that on top fuelller drag cars about 15 years ago.

[m1tch]

saw that on top fuelller drag cars about 15 years ago.

Yeah, not sure why they havn\'t caught on as it reduces weight and there are less parts to go wrong lol

[Bob Monkhouse]

Teflon seals on the rotary valves have a fairly short life. I could be wrong but an American tuning firm first developed the rotary valve head for a small block Ford.High rpm on any reciprocating engine is governed by material in the conrod and piston, even with high silicon pistons the mean piston speed can\'t go much above 4000ft/sec. Piston acceleration is another factor with speeds in excess of 160000ft\'sec. To counteract these important factors, piston rings are made ever thinner(.5mm) and strokes and conrod lengths are reduced, the shorter the stroke the higher the engine will rev.Four strokes are limited to around 10000rpm using so called \'poppet\' valves, this was where the rotary valves came into their own. The last time I saw a top fuel engine they were still using poppet valves and two per cylinder at that. 8000bhp@ 10000rpm.

[m1tch]

I think the best idea is to get rid of these inefficent pistons sorted

[Rzla]

I think the best idea is to get rid of these inefficent pistons sorted

hahaha +1.....

[shaunwil]

Is that full scale ?? Isn\'t it missing the grooves for the seals ??

Very nice bit of machining by the way

Shaun

[Bob Monkhouse]

Its not finished yet, we are experimenting with methods of cutting the seal grooves. One method we tried was putting two hacksaw blades together and cutting the apex seal grooves that way. Unfortunately my hands shake a bit(old age creeping in) and they weren\'t accurate enough. The sideseal grooves are hand cut on a milling machine by old Albert feeding both the x and y axis together. Unfortunately the old bugger has too much of a liking for Tetley bitter and regularly consumes eleventeen pints on a friday night. A few he\'s machined on a saturday morning have looked a bit like crinkle cut chips and were due to be scrapped. However, being the ever resourseful guy I am, we are now experimenting with the blades from the said chip cutters as side seals, these have the advantage of being cheap (as chips-hahahahahahahahahaha-I\'m a ....ing comedian-oh sorry, with a name like mine I AM a comedian)!!!, and also have a bigger surface area for more efficient sealing.

[BlitzBoy]

^^^^^^ crazy mofo :rollin

[HaywardRotary]

Felix ....el developed rotary valves for Junkers Jumo V8 engines before and dring during the war that were used in torpedoes,the reason for this was that the heads were too high to fit into the standard size of torpedo that German subs were using during the war.
Subsequent development of this valve system was used in the Daimler Benz 601 engine used in the Messerschmitt ME 109 fighter which was a V12 somewhat similar but not a copy of the Merlin V12 as used in the Spitfire,the superiorority being that it was running fuel injection.The Daimler engine ran inverted as compared to the Merlin,and the fuel injection enabled a dive to be implemented by pushing the stick forward which Spitfire pilots could not do as they were on carburretors so had to roll into a dive or the engine would stall due to negative G force!
Very clever the Germans.
Regards
Carl

[matt p]

Felix ....el developed rotary valves for Junkers Jumo V8 engines before and dring during the war that were used in torpedoes,the reason for this was that the heads were too high to fit into the standard size of torpedo that German subs were using during the war.
Subsequent development of this valve system was used in the Daimler Benz 601 engine used in the Messerschmitt ME 109 fighter which was a V12 somewhat similar but not a copy of the Merlin V12 as used in the Spitfire,the superiorority being that it was running fuel injection.The Daimler engine ran inverted as compared to the Merlin,and the fuel injection enabled a dive to be implemented by pushing the stick forward which Spitfire pilots could not do as they were on carburretors so had to roll into a dive or the engine would stall due to negative G force!
Very clever the Germans.
Regards
Carl

Cool post!

Thanks for the history lesson:Thumbs-up

[Bob Monkhouse]

Hence the classic Spitfire roll. Did you know that the Hurricane, whilst slower than the Spit. could actually out turn both the Spit, and the Me109!

[najiru]

Sorry to go back to the temperature issue but..... the sustained temperature of the rotor would still worry me. I work in design doing stress analysis for aricraft parts made from high grade aluminium alloys and it doesn\'t take particularly high temps over prolonged periods to start significantly reducing material properties. People keep discussing melting point but this is irrelevant really since the part would fail way before ever being able to reach it.
 
Does anyone know what average temperatures the rotors see during normal use? For example divergence of 2219-T852 forged alloy occurs at about 125C for 100 hours exposure iirc. What sort of stress does a rotor see and how does it\'s at temperature yield strength compare to this? I\'ve no doubt a suitable aluminium rotor can be designed, i\'d just want to be sure it had been done properly if I was shelling out for some.

[shaunwil]

If sustained temps where such an issue why is the housing made out of aluminium ?? Surely they will see the temps that the rotor will ??

Aren\'t mazda designing an all aluminium version of the new 1.6lt twin rotor ? Plus racing beat produces Aluminium side plates too.

Shaun

[Bob Monkhouse]

Heat and aluminium, hmmm.The rotor housings are aluminium and don\'t melt, some earlier rotary engines were all aluminium. Air cooled two strokes run aluminium pistons and barrels at around 200c without any problems. The rotor above will be tested fully before being offered for sale. Watch this space.

[m1tch]

The ones over in the states retail for about £1,800 each