Just thought everyone would like to see what I\'ve knocked up with a file and a hammer and chisel in the garden shed.(Its supposed to be a secret so don\'t tell anyone).
Amazing what you can acheive with a coarse b@stard file :Giggle
Looks amazing....
Only thing... Isn\'t the melting point of aluminium about 660.32 °C
I\'m not sure what the combustion temperature is inside a rotary engine but would it possibly be higher that 660°C at high/prolonged RPM.
So have you made your own Bob?
http://www.eastcoastparts.com/html/billet_rotor.html
This are the people who make them in the US, they have been tested on a 8 second drag car as well. Rotaryarts over here are UK dealers over here
Looks nice.
I\'d be interested in the long term durability of these parts. Engine temps for long exposure times could significantly reduce properties over time in alu. Would look up the curves but they gave only the temper and not the actual alloy?? Would want to see some calcs to reassure me they know what they\'re doing ;)
Quote from: monkey-fd3s;588620Looks amazing....
Only thing... Isn\'t the melting point of aluminium about 660.32 °C
I\'m not sure what the combustion temperature is inside a rotary engine but would it possibly be higher that 660°C at high/prolonged RPM.
Can you see the irony in that statement? :rollin :rollin
well it wouldn\'t 660.32c if you weren\'t at sea level.
I think the intake cools it down quick to not allow it to melt. Combustion temps are probably near 1000c.
Oh dear, you are all missing the point here. Aluminium/silicon alloy has been and will forever continue to be used in internal combustion engines, the things called pistons haven\'t been made of iron since the first world war.Aluminium cylinder heads are now de rigeur on most engines particularly on performance engines where the extra heat dissipation allows the tuner to use higher compression ratios- high cr.s=high power-without the engine knocking itsself to death.Titanium inserts for the apex seals will ensure seal/rotor longevity. Oh,and the melting temp of al/silicon alloy is approx. 800c.
Ps these definately are not Eastcoast rotors.
Those aren\'t the eastcoast rotors, although they have dyno run them and got some stupidly high figures off them lol should be able to rev the engine to 15k+ lol :D
P.S. Can I have two :)
Very impressive. When is someone gonna build some titanium rotors.
Or carbon fibre ones lol they would weigh nothing lol :D
Hahahahahaha! Have you any idea how much titanium is? I have 8 titanium screws in my head(no I\'m not joking for once) and they were £150 EACH!!It serves no purpose to make them from titanium anyway, aluminium with titanium inserts is more than adequate.
Ps. apparently carbon fibre pistons are being developed and no doubt are being used in F1 as we speak. How light do you think something has to be to rev to 19000!! They also have a really short stroke also. Balsa wood might be the future, they just have to figure out how to stop it burning(oh dear, I\'m getting silly again, time for my medication).
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
Quote from: m1tch;588678Honda 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.
Quote from: Martiny;588679saw 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
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.
I think the best idea is to get rid of these inefficent pistons :D sorted :)
Quote from: m1tch;588699I think the best idea is to get rid of these inefficent pistons :D sorted :)
hahaha +1.....
Is that full scale ?? Isn\'t it missing the grooves for the seals ??
Very nice bit of machining by the way :D
Shaun
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.
^^^^^^ crazy mofo :rollin
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
Quote from: HaywardRotary;588769Felix ....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
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!
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.
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
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.
The ones over in the states retail for about £1,800 each :(
So where are the combustion recesses?,or are these for 15:1 compression ratio?
Rotor housings survive because they are full of water,which is cooled.Cast iron rotors survive because they are oil cooled.
East coast ali rotors are cooled by using methanol as a fuel.Road legal? No.
Quote from: m1tch;588699I think the best idea is to get rid of these inefficent pistons :D sorted :)
and the rotary is (more) efficient ...?!
Quote from: rx7_bhp500;588956and the rotary is (more) efficient ...?!
Its more efficent regarding power per displacement, eg:
Stock FC3S turbo II (single turbo)= 153bhp per litre
Veyron (4 turbos) = 125bhp per litre
Quote from: Bob Monkhouse;588609Just thought everyone would like to see what I\'ve knocked up with a file and a hammer and chisel in the garden shed.(Its supposed to be a secret so don\'t tell anyone).
nice cup holder
Quote from: Timrxmotors;588934East coast ali rotors are cooled by using methanol as a fuel.Road legal? No.
East coast ran 600 road miles on unleaded petrol.
Top fuel engines are running Ally pistons and each piston is making around 1000hp,yes that\'s right 1000hp,they are 11 liter V8\'s with NO cooling whatsover and they make around 8000hp.
I have a piston from one.
Regards
Carl
Quote from: m1tch;588969Its more efficent regarding power per displacement, eg:
Stock FC3S turbo II (single turbo)= 153bhp per litre
Veyron (4 turbos) = 125bhp per litre
not so efficient on my wallet....
half the mpg {compared to piston engines} translates as less efficient to me...suppose lpg is the solution....
Quote from: shaunwil;588910If 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
Again I\'m not trying to say that an aluminium rotor can\'t work just that the temps have to be considered carefully when you design one. The temperatures the housings see will have been accounted for when they were designed. Their static strength and fatigue resistance will have been calculated based on those operating temperatures and they will be thicker as a result of it. Same goes for any other aluminium part properly designed and used in any other engine [or any application for that matter]. The stock alu parts mentioned earlier will have been designed this way and anything developed for motorsport will be the same.
A rotor sees high cycle fatigue loading, you may not discover that the heat has degraded the material properties enough to cause a fatigue failure for 5,000 , 10,000 or 20,000 miles. Without checking you can\'t know.
Selecting what alloy to use and determining the design of the rotor to withstand the loads is the hard part IMO. Actually manufacturing it is the easy bit.
Neil
Out of interest how hard would it be to make a carbon Fibre Rotor ?
Shaun
interesting stuff this..... my old man has a couple of those rather large Merlin / RR engines!:chat
(http://www.k-p.co.uk/fil_auto/rx7/P8190025.JPG)
(http://www.k-p.co.uk/fil_auto/rx7/P8200029.JPG)
Quote from: HaywardRotary;588769Felix ....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
wow looking at the back of the engine it looks like a massive supercharger if im not mistaken
Indeed Blitzen - I believe they are supercharged too!:Thumbs-up
Quote from: BlitzBoy;589080wow looking at the back of the engine it looks like a massive supercharger if im not mistaken
27 litres engine?
That seems about the right number Blitz but not 100 % sure TBH. Sounds like your a little knowledgeable on these big beauts?!
Must admit tis more my old man\'s interest and hobby - he builds, re-builds and restores old MG\'s / BMC\'s in addition to allocating huge amount of man hours to his other hobby - yep, you guessed it..... building planes!
He pretty much built a Spit that had it\'s inaugural flight back in May 2006 - actually I think this is the second one he\'s built!! eek :god:
Couple more pics of the engine for you to deliberate over...... and one of the plane down oat duxford or the like! :Thumbs-up
(http://www.k-p.co.uk/fil_auto/rx7/P8190026.JPG)
(http://www.k-p.co.uk/fil_auto/rx7/P8190027.JPG)
(http://www.k-p.co.uk/fil_auto/rx7/P1010004.JPG)
Quote from: BlitzBoy;58908927 litres engine?
The Merlin was indeed supercharged and 27litres. Its younger brother theGriffon engine was 35 litres and was initially developed for the Lanc. Even with four of these the Lanc had difficulty getting to 22000ft where it would then drop the biggest bomb ever-the 10ton Grand Slam. Apparently the wings on the lanc used to bend on take off!!
Wow and holy ....e!! :2eek
Quote from: Bob Monkhouse;589094The Merlin was indeed supercharged and 27litres. Its younger brother theGriffon engine was 35 litres and was initially developed for the Lanc. Even with four of these the Lanc had difficulty getting to 22000ft where it would then drop the biggest bomb ever-the 10ton Grand Slam. Apparently the wings on the lanc used to bend on take off!!
Ps. what a beautiful engine and an even more beautiful aeroplane, there nowt to send a shiver down your spine than the sound of a spit and the sight of one doing that classic roll.You lucky bugger.
Indeed Sir..... even though I\'m far more interested in modern stuff.... with age one realises that these are some seriously impressive engines / planes... and to be frank could well have been a v good idea to soak more of the opportunities when a child!.... events, garage workshop, learning the ropes etc etc....
Am pretty sure he\'s got another fuselage in the making atm! :mmmm
Quote from: Bob Monkhouse;589096Ps. what a beautiful engine and an even more beautiful aeroplane, there nowt to send a shiver down your spine than the sound of a spit and the sight of one doing that classic roll.You lucky bugger.
Going back to the heat concerns of the alu. rotor. These things are expected to make11000+ rpm. An engine that is making those kind of numbers isn\'t going to be doing 20000miles between rebuilds, we\'ll see how they do on test. Bob.
Yep, fairplay and back to the thread!:Thumbs-up
Will be watching this Bob with baited breath! sounds v interesting.... :3gears-lh
Quote from: Bob Monkhouse;589098Going back to the heat concerns of the alu. rotor. These things are expected to make11000+ rpm. An engine that is making those kind of numbers isn\'t going to be doing 20000miles between rebuilds, we\'ll see how they do on test. Bob.
Hasn\'t someone put one of them in an old Rover?
Whats that, an aluminium rotor or a merlin engine? Rover actually campaigned a gas turbine engine in a race car in the sixties(thats a jet engine). Someone also put a Merlin in a Modified Ford Capri in the seventies, that was apparently rather quick!!!By the way fil, Iam an orphan (well, my old mans an ex parrot and I\'m sure I could hurry mumsy along) so if your dad wants to adopt someone to work on his Spits. and the Merlins I\'m your man!
Sorry for being a bore, but is it a mark IX spitfire? It seems to have a four bladed prop and also a bubble canopy, I thought the bubble canopy came with the later five bladed props on the griffon engine. They ran 18psi of boost on the blower apparently.
Quote from: Bob Monkhouse;589098Going back to the heat concerns of the alu. rotor. These things are expected to make11000+ rpm. An engine that is making those kind of numbers isn\'t going to be doing 20000miles between rebuilds, we\'ll see how they do on test. Bob.
Fair point that :D if you\'re happy to accept you may need to replace the rotors every so often in order to get the extra performance then no probs. Are you willing to tell us what alloy and temper has been used just out of interest? I\'ll stop rabbiting on now :Yawn
As for a composite rotor I\'m not too clued up on high temp resins. The highest we use if bismalemide [BMI] which I think you can take to about 230C. After that you\'re looking at polymides which go to 300C ish but I don\'t know how either these would stand up to the fuel/oil. Could always use carbon reinforced aluminium or ceramic lol, not sure anyone is going to shell out for something like that though! Maybe the F1 boys.
Be interested in how this goes, I hope it\'s a success as this is the sort of thing we need people to be doing. Sorry if I\'ve seemed a bit negative :p
btw Tiddles there are a few merlin engined cars, not least \'The Beast\'. A quick search on google/youtube should find you some amusing videos. Check EVO magazine\'s site as they did a feature on The Beast a while back
I suppose the other thing to consider is what coatings are available to aid in getting the temps out of the engine and away from the rotor.
http://www.camcoat.com/1.Thermal%20Barriers/Thermal_barriers.html
Shaun
Cool thread. Love the sound of Griffons and Merlins, or any of the big old V12s for that matter. IIRC, good Merlins are getting pretty rare now so those might be worth a fair bit.
Composite rotors is a tricky one. If the heat soak temperature for a rotor is in the low hundreds of degrees C, then things like BMI/polyimide-based composites or similar may well have a chance. There will also be higher temperature systems someday, it\'s all in the chemistry.
The thing that worries me is that you\'ve got a transient much higher temperature when the flame front contacts the material, and the local environment is full of lots of nasty reactive oxidising species. Given that carbon fibre is essentially just carbon + "stuff," it\'s not going to be great in a high temperature oxidising environment - you may find that it disappears incredibly quickly.
In theory, you could put a composite centre section (over a metal former) where the temps are lower and the environment less harsh, and then put metal around the outside. It would require some clever high precision manufacturing processes and serious consideration of coefficients of thermal expansion, bonding methodology and the like. No idea if it\'s actually possible.
Chris.
i agree this is a awesome thread and great reading, i know nothing about what you are all talking about but its still great to read :Thumbsup!
As you say thermal expansions will probably be the biggest problem with covering carbon composites as they have very low expansions and most suitable metals have fairly high. Where we link large machinings with composite skins we often get more load coming from the differences in thermal expansion than we do from flight conditions.
The coatings Shaun linked to were interesting though and would possbily do the trick. One last concern on this would be thinking where the heat goes, there may need to be an additional thermal path to the centre of the rotor in order to effectively cool it.
I love threads like this, lots of good points being thrown about. I would say from a fatigue point of view you are looking at two main areas; high cycle fatigue caused by mechanical loads (combustion pressure mainly, assuming the rotor is perfectly balanced for analysis sake) and low cycle fatigue cause by heat cycles.
The problem I see with the rotary compared with pistons is that at all times, part of the rotor will be being subjected to combustion temperatures which overall is likely to increase the overall temperature of the rotor during operation. The entire piston is likely to see lower overall temps, but a higher difference during the cycle. A bigger swing in temps is generally worse from a fatigue point of view, unless the material temps have been raised sufficiently to reduce the materials properties.
I guess we can only discuss all this in theory, unless someone wants to run such an analysis on a rotor...
The idea of using composites interests me too from this point of view, but I have little experience with these materials myself. My day to day job involves structural analysis of large diesel engine components, most of which are cast iron (even our pistons), so this is where most of my experience comes from.
It\'s great to see these threads as it helps me to learn new things :)
When ya cutting the apex groves into the Rotor Bob?
So it seems we have three people in the Rotary community doing Billet Rotors.
Bob
Eastcoastrotary
Hayward
Quote from: Bob Monkhouse;589098Going back to the heat concerns of the alu. rotor. These things are expected to make11000+ rpm. An engine that is making those kind of numbers isn\'t going to be doing 20000miles between rebuilds, we\'ll see how they do on test. Bob.
Not worth making then,my 12A engine revved to 13,000+ rpm,with cast iron rotors!
I said 11000+, thats what its going to tick over at!!
Cool cool man - I\'ll keep my ears peeled and if he needs some help, I\'ll put in a good word for you! :rolleyes:
Quote from: Bob Monkhouse;589131Whats that, an aluminium rotor or a merlin engine? Rover actually campaigned a gas turbine engine in a race car in the sixties(thats a jet engine). Someone also put a Merlin in a Modified Ford Capri in the seventies, that was apparently rather quick!!!By the way fil, Iam an orphan (well, my old mans an ex parrot and I\'m sure I could hurry mumsy along) so if your dad wants to adopt someone to work on his Spits. and the Merlins I\'m your man!
To the below bud - wouldn\'t be able to help you there.... you defo seem to have more knowledge than I! Did find the below though which certainly shows a boost gauge on the dash!! :mmmm
(http://www.k-p.co.uk/fil_auto/rx7/PB030025.JPG)
Quote from: Bob Monkhouse;589134Sorry for being a bore, but is it a mark IX spitfire? It seems to have a four bladed prop and also a bubble canopy, I thought the bubble canopy came with the later five bladed props on the griffon engine. They ran 18psi of boost on the blower apparently.
yehhhaaaa old skool boost gauge!!
I know! I\'ve seen a few of these in the garage back at home..... not sure if they\'ll work that well on the rex though?! ;)
Quote from: BlitzBoy;589291yehhhaaaa old skool boost gauge!!
Thanks for that, I\'ve never been lucky enough to sit in a Spit. I somehow don\'t think the rotary would take the amount of boost the blower on the Spit would deliver!!250 cfm I would guesstimate, thats a b i i i g mother ....er blower.
just to add the Rover SD1 with the Roll Royce engine had a Meteor which was a non supercharged verson of the Merlin which produced 600hp
Probably still a bit nippy then?! :driving
Quote from: BlitzBoy;589306just to add the Rover SD1 with the Roll Royce engine had a Meteor which was a non supercharged verson of the Merlin which produced 600hp
The blower on the Allison V12 (27l Ali block) takes something like 300-400hp just to turn it, and that\'s a lower output engine than the Griffon. Can\'t remember if it\'s a 2-stage or not?
Chris.
Quote from: BlitzBoy;589306just to add the Rover SD1 with the Roll Royce engine had a Meteor which was a non supercharged verson of the Merlin which produced 600hp
This one?
http://www.mazdarotaryclub.com/forums/showthread.php?t=52003
Have to say, I\'ve never seen anything I\'ve wanted so much as a genuine Spitfire boost gauge! That is the coolest thing ever! :Giggle
we have a nice new shiney 27 litre Meteor engine in the shed in a crate waiting for a donor car.
Does anyone in this country make 3 or 4 rotor E shafts, that seems to be the way forward
Quote from: antnicuk;589373we have a nice new shiney 27 litre Meteor engine in the shed in a crate waiting for a donor car.
Does anyone in this country make 3 or 4 rotor E shafts, that seems to be the way forward
We do.
Regards
Carl
Hey od404, nice to see someone else from the world of stress :D
Having been very priveledged to work on both a Lancaster bomber and Mosquito I am very familiar with the Merlin engine.
Standing less than 10 feet away from one on start up with 6 foot flames coming from the exhaust stacks is pretty amazing!
Reagrds
Carl
Rule of thumb on compressors is that 1hp=3cfm.Top fuel Drag cars are running aroud 2400cfm, stick your head over the blower intake and it would suck your brain out through your ear. I am actually imune to this having donated my brain to medical science years ago,
Oh, the blower on the merlin is two stage and (I think) three stage on the griffon
Carl,
Give it a go - I nominate myself as the test bed for any extreme rotary developments.
Might be bleeding edge rather than leading edge and require a spare engine to hand of a weekend, but we have M3\'s and M5\'s to beat!
S.
//www.oddballracing.com
Quote from: Bob Monkhouse;588668Hahahahahaha! Have you any idea how much titanium is? I have 8 titanium screws in my head(no I\'m not joking for once) and they were £150 EACH!!It serves no purpose to make them from titanium anyway, aluminium with titanium inserts is more than adequate.
Titanium is a bitch to machine :Talking1 but comes into its own when you can machine compensators for some groovy auto\'s :Typing and not cars Im talking about :wiggle