2 stroke thread (with occasional F1 relevance!)

All that has to do with the power train, gearbox, clutch, fuels and lubricants, etc. Generally the mechanical side of Formula One.
J.A.W.
109
Joined: 01 Sep 2014, 05:10
Location: Altair IV.

Re: 2 stroke thread (with occasional F1 relevance!)

Post

Bishop rotary valves are specifically proscribed in F1 tech reg's -"poppet valves only", & merit no mention in the Moto GP reg's..
.. but 2Ts are banned across the range of G.P. racing.. obviously - as a very real threat..

One notable disadvantage of 4Ts was demonstrated in today's French Moto 3 G.P. at Le Mans, when one of the unpleasantly
flatulent sounding 4Ts did actually drop its guts, spread copious lubricant, & brought down much of the field, like nine-pins..
"Well, we knocked the bastard off!"

Ed Hilary on being 1st to top Mt Everest,
(& 1st to do a surface traverse across Antarctica,
in good Kiwi style - riding a Massey Ferguson farm
tractor - with a few extemporised mod's to hack the task).

Muniix
14
Joined: 29 Nov 2016, 13:29
Location: Sydney, Australia

Re: 2 stroke thread (with occasional F1 relevance!)

Post

J.A.W. wrote:
21 May 2017, 15:08
Bishop rotary valves are specifically proscribed in F1 tech reg's -"poppet valves only", & merit no mention in the Moto GP reg's..
.. but 2Ts are banned across the range of G.P. racing.. obviously - as a very real threat..

One notable disadvantage of 4Ts was demonstrated in today's French Moto 3 G.P. at Le Mans, when one of the unpleasantly
flatulent sounding 4Ts did actually drop its guts, spread copious lubricant, & brought down much of the field, like nine-pins..
Like an engine failing has never happened during a race before. Funny how they just work forever & have infinite TBOs.

Noting many terrible sounding two stroke engines, you don't have the acoustic tuning possibilities as one does with a four stroke.

Just love the way they are reaching 50% TE and support multiphase combustion where they can nearly double Bmep with little loss in TE while reducing peak cylinder pressure reducing bearing friction losses and torsional issues. 36 bar Bmep with mild increase of inlet pressure above ambient, and above 20 Na.

I noticed a boxer twin indirect injected 500 cc 2T engine from Italy from a decade ago on LinkedIn yesterday.

From sleep deprived to over sleep.

For more info on the EU Commission investigation that went on for years into the FIM & FIA banning the Bishop valve. There is a summary at;
http://www.espn.com.au/f1/story/_/id/13 ... ormula-one

Essentially Bishop failed to show the importance of racing to demonstrate an innovation for it to be commercially accepted.

Australian companies need not apply.

By setting the engine provider to one make locked them out of the second attempt to demonstrate it.

By introducing difficulties at every attempt to demonstrate the innovation at every turn they effectively banned it, how long was this going to continue.

How long must a company continue only to have each attempt banned in order to achieve commercialisation.

When would they actually not ban it thought some means, a business can't continue this path and others are just not as effective. Everyones first comment for anything innovation is to day of it was any good they would be using it in F1.


We just had two bad F1 accidents let's form a review to see what we can do, this gives us special powers to change the engine spec.

Let's change the engine spec to ban the Bishop but not increase safety.

Within that article is the link to the Commission report. My journalist friend has more, think he is OS at the moment being a foreign correspondent.

Short answer is they were not allowed to, it's not like the FIM have never played politics or favourites before is it!

What the rules say and what you get approval to race with are not the same thing.

Using lawyers doesn't work with opinionated organisations trying to prove you are meeting the rules when they administrate them. You can argue till your blue in the face but you can't race your bike in our events.

I don't know what the MotoGP rules will be in the 2020s maybe with new owners the FIM will allow a twin cylinder 800cc mild hybrid with continuously​ variable phasing Bishop rotary valve, the 398cc version of the motor without topology optimisation is a 60 kW+ micro hybrid, a racing version would be wild but that is the domain of the 711cc powerplant.

Seems coordinating work over multiple continents I slept maybe 30 hours, been trying to sleep twice per day. I lost a day. Didn't start my sleep tracker alarm. Support from new tech partner has been great while I slept, should do it more often!

Check out Bastion cycles, brilliant Engineering of printed Ti4 and wound carbon fibre with some amazing meshed honeycomb Engineering. Check out images in there FB page. This would be the technique to make the MotoInno TS³, not on my bike targeting the mid high end, but for the Shockwave that MCI are building with TS³ a $200,000 bike it would be.
I would go the ti with fibre reinforced polymer over moulding squeeze cast for faster production and Aero shape.
Last edited by Muniix on 21 May 2017, 20:36, edited 3 times in total.

Muniix
14
Joined: 29 Nov 2016, 13:29
Location: Sydney, Australia

Re: 2 stroke thread (with occasional F1 relevance!)

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manolis wrote:
19 May 2017, 12:45
Hello J.A.W.

You write:

“The "simplicity is gone?"
Well, we've seen your illustrations many times, including the 3D rotary valves - for which you claim 'simplicity' as
a merit, so I'd hardly think that - essential - simplicity is lost.. by utilizing one, with a sufficient port-time area..”


The PatRoVa rotary valve is simple.

So simple that in mass production it will be several times cheaper (5 times? 10 time?) than a Desmo cylinder head of Ducati (yet it would allow way higher revs in the cylinder head and more power if the underneath engine can stand the “punishment”).

If you replace the cylinder head of a 4-stroke by a PatRoVa cylinder head, the engine gets undoubtedly simpler and shorter and more lightweight.

However if in a 2-stroke you add a “rotary valve” on the top of the engine, and a synchronizing gearing to drive it, the simplicity is not as before with the only three moving parts of the conventional 2-stroke.

If the improvement of the operation justifies the added parts / complexity / cost, OK.




You also write:

”I would be impressed to see the promise of your 'simple' 2T units realized - in metal, to validate the interesting ideas..”


The Opposed Piston PatATi prototype engine (youtube video at https://www.youtube.com/watch?v=aXvRaVqiHxs )

is “realized in metal” and works on gasoline.


To modify it from PatATi to PatATeco (previous posts) all you have to do is to turn the injectors to inject towards the piston crowns and to lubricate independently the bearings of the crankshafts.

800cc,
80mm bore,
80mm stroke (combined stroke: 80+80=160mm)
asymmetrical intake (without reed valves or disk valves),
asymmetrical transfer,
compact / fatty combustion chamber (loop scavenging),
perfectly balanced,
etc.

Here are a few photos of it.

http://www.pattakon.com/PatAT/PatATi_OP_Prototype_1.jpg

http://www.pattakon.com/PatAT/PatATi_OP_Prototype_2.jpg

http://www.pattakon.com/PatAT/PatATi_OP_Prototype_3.jpg

http://www.pattakon.com/PatAT/PatATi_OP_Prototype_4.jpg

http://www.pattakon.com/PatAT/PatATi_OP_Prototype_5.jpg

http://www.pattakon.com/PatAT/PatATi_OP_Prototype_6.jpg

http://www.pattakon.com/PatAT/PatATi_OP_Prototype_7.jpg

http://www.pattakon.com/PatAT/PatATi_OP_Prototype_8.jpg

http://www.pattakon.com/PatAT/PatATi_OP_Prototype_9.jpg

http://www.pattakon.com/PatAT/PatATi_OP ... ype_10.jpg

http://www.pattakon.com/PatAT/PatATi_OP ... ype_11.jpg



The priority is on the PatRoVa rotary valve 4-stroke engine.

In the mean time, if someone wants to get involved (whatever way) my e-mail is man@pattakon.com

Thanks
Manolis Pattakos
Have you done simple calculation on the air velocity required to fill the Superquatro 1285 cc engines 642.5 cc with a VE of 115% say. What would be the window sizes and the flow coefficient?

How big/tall does the valve need to be, to have the required inlet channels remember that turning a flow near 90 degree into the cylinder needs the pressure and velocity before through and after the window carefully matched, the window needs to be bigger depending on it flow coefficient and limit flow seperation and any turbulence like when the valve is past fully open the inertial energy in the flow means it wants to go straight past the window and not into the cylinder but keep flowing within the valve as it rotates. It doesn't have the geometry advantages of the Bishop valve here that turns the trailing edge flow a perfect 90 degrees.

Then the pressure waves returning when this happens as it reflects off the end of the inlet channel in the valve.

Don't know if you can turn these returning moles and there energy into an advantage somehow but that would be the ideal, convert a negative into an opportunity for improved cylinder filling or in cylinder turbulence.

But you want nice clean Laminar flow through the inlet channels, constant pressure and features to assist turning the flow into the cylinder and a long window so the angle of the flow through the window changes slowly from the leading edge to the trailing edge.

This is where 3D CFD is really needed to get this working well to do the topology optimisation. And testing different wild ideas even has worked for me lead to some interesting discoveries from the visualisation with paraview.

Long thin window are best. You maybe able to put in a gurney flap to create turbulence to create the 'feature' needed imatating the Bishop valve geometry just a lot smaller with greater surface friction and some loss of flow but the net benefit could be there.

Thinking of the cylinder filling in three stages may help visualising it:
1. when the window first starts to open and needs to be turned into the cylinder. How can the geometry help.

2. When nearly fully open.

As your valve is rotating in a different axis to the Bishop valve, you lack the nice geometry it has to turn the flow at the trailing edge of the window into the cylinder with the ideal radius so it flows straight down into the cylinder during the​ entire inlet duration. Creating the dual cross tumble vortices that gives it the fast burn, increased lean limit and favourable knock behaviour.

3. Past fully open and as it is closing, the pressure wave needs to be tuned for this period and run across the window as it closes so any geometric features to assist here like an angle matched to its speed so you close as the wave passes at the desired peak torque rpm. It all helps with trapped air mass which is the major parameter for potential power.


think of the geometry the flow will ideally need, draw the inlet geometries that work best for each of the cases and find a compromise, generating a vortice in the corner of the inlet valve to guide the air into the cylinder.

And the velocity of the flow as it increases above 0.5 Mach mean velocity the cylinder pressure starts to drop generally due to gas compressibility this will eventually pull in more air if you can time the valve actuation to take advantage of.

Then you have the issue of the Two flows facing of each other increasing the pressure in that area, the two flows inertial energy fighting one another with the piston motion the only thing in your favour so you need to match these three interrelated actions. Without loosing in cylinder turbulence.

Good luck with all these issues. I hope you have the resources to make lots of prototype valves and measure the flow volume and all the other important considerations to achieve good combustion and low heat losses. Cooling around the spark plugs is also important.
Thermal expansion
Gas sealing, the pressure will always cause assume leakage, lost energy and emissions.

All these things need optimisation. Liner temperature is also important.

J.A.W.
109
Joined: 01 Sep 2014, 05:10
Location: Altair IV.

Re: 2 stroke thread (with occasional F1 relevance!)

Post

Muniix wrote:
21 May 2017, 17:41

Like an engine failing has never happened during a race before. Funny how they just work forever & have infinite TBOs.

Noting many terrible sounding two stroke engines, you don't have the acoustic tuning possibilities as one does with a four stroke.

Just love the way they are reaching 50% TE and support multiphase combustion where they can nearly double Bmep with little loss in TE while reducing peak cylinder pressure reducing bearing friction losses and torsional issues. 36 bar Bmep with mild increase of inlet pressure above ambient, and above 20 Na.
Marc, FYI, a 2T G.P. engine failure, even a catastrophic blow-up.. with major components bursting out..
..simply could not result in a gout of engine oil dumped on track.. since they didn't need to hold volumes of it..

& no way are those Moto 3s making "36 bar".. nor are any other N/A engines.. wild claims notwithstanding..
..further, the BMEP of ~17 bar, that the 440 hp/L 2T G.P. 125cc engines did achieve..
.. was ironically, & in actual fact, a result of "...acoustic tuning possibilities..." having been realized..
"Well, we knocked the bastard off!"

Ed Hilary on being 1st to top Mt Everest,
(& 1st to do a surface traverse across Antarctica,
in good Kiwi style - riding a Massey Ferguson farm
tractor - with a few extemporised mod's to hack the task).

Muniix
14
Joined: 29 Nov 2016, 13:29
Location: Sydney, Australia

Re: 2 stroke thread (with occasional F1 relevance!)

Post

J.A.W. wrote:
22 May 2017, 02:00
Muniix wrote:
21 May 2017, 17:41

Like an engine failing has never happened during a race before. Funny how they just work forever & have infinite TBOs.

Noting many terrible sounding two stroke engines, you don't have the acoustic tuning possibilities as one does with a four stroke.

Just love the way they are reaching 50% TE and support multiphase combustion where they can nearly double Bmep with little loss in TE while reducing peak cylinder pressure reducing bearing friction losses and torsional issues. 36 bar Bmep with mild increase of inlet pressure above ambient, and above 20 Na.
Marc, FYI, a 2T G.P. engine failure, even a catastrophic blow-up.. with major components bursting out..
..simply could not result in a gout of engine oil dumped on track.. since they didn't need to hold volumes of it..

& no way are those Moto 3s making "36 bar".. nor are any other N/A engines.. wild claims notwithstanding..
..further, the BMEP of ~17 bar, that the 440 hp/L 2T G.P. 125cc engines did achieve..
.. was ironically, & in actual fact, a result of "...acoustic tuning possibilities..." having been realized..
Not counting the gearbox failing. Crankcases seal failure.

I never mentioned moto3 bmep, the only bmep data i have is for 300 cc F1 cylinders and various Turbulent Jet ignition engines with and without multiphase combustion using various fuels and strategies. These can do high bmep with low peak cylinder pressure due to the initial Ultra lean ignition with additional fuel added at HR50 to burn no more than 63% of available air to maintain low NOx and (??) can't remember atm some other recommendations, but this all changes depending on piston motion/expansion rate to burn rate. Maintaining high average cylinder pressure with low frictional losses and high conversion efficiency of cylinder pressure to rotational torque. Hence the high bmep.
With 191 degrees of power stroke with large offset from dual contra-rotating crankshaft arrangement the advantages just keep coming. So 16 bmep Ultra lean becomes really high with multi phase combustion. With very little piston friction, Bishop valve friction, or crankshaft bearing friction due to low forces and vibration with the p-v graph.

J.A.W.
109
Joined: 01 Sep 2014, 05:10
Location: Altair IV.

Re: 2 stroke thread (with occasional F1 relevance!)

Post

Muniix wrote:
22 May 2017, 18:52

Not counting the gearbox failing. Crankcases seal failure.

I never mentioned moto3 bmep, the only bmep data i have is for 300 cc F1 cylinders and various Turbulent Jet ignition engines with and without multiphase combustion using various fuels and strategies. These can do high bmep...
Marc, FYI, 2T G.P. racing machine crankcases do not hold a 'sump' full of oil to spill, unlike 4Ts..
& the gearbox also holds very little oil, & in a quite separate casing, so is most unlikely to be ruptured, even then..

Your unsupported claim of a putative, if fanciful "36 bar" BMEP was made sans reference to any other engine,
& directly after your attempt to excuse the Moto 3 debacle.. ergo, a "mention" by any reasonable means.

& no way any N/A 300cc F1 cylinder has ever made a BMEP of "36 bar".. its frankly impossible - on legal fuel, at least..
"Well, we knocked the bastard off!"

Ed Hilary on being 1st to top Mt Everest,
(& 1st to do a surface traverse across Antarctica,
in good Kiwi style - riding a Massey Ferguson farm
tractor - with a few extemporised mod's to hack the task).

Pinger
9
Joined: 13 Apr 2017, 17:28

Re: 2 stroke thread (with occasional F1 relevance!)

Post

Talking of acoustic tuning.... are these the first examples of an expansion chambers? Back in the 1930s.
Image

2T, this pic shows some cutaway detail of the exhaust port exit.

Image

Landinis, also 2T, use a similarly shaped pipe.

Image

Others too.

Image


Pinger
9
Joined: 13 Apr 2017, 17:28

Re: 2 stroke thread (with occasional F1 relevance!)

Post

Tommy Cookers wrote:
23 May 2017, 18:44
this (split-single 2 stroke) qualifies ?
http://cybermotorcycle.com/gallery/gare ... -350cc.htm
Yep, sure does!

J.A.W.
109
Joined: 01 Sep 2014, 05:10
Location: Altair IV.

Re: 2 stroke thread (with occasional F1 relevance!)

Post

Pinger wrote:
23 May 2017, 17:55
Talking of acoustic tuning.... are these the first examples of an expansion chambers? Back in the 1930s.
https://farm8.staticflickr.com/7571/160 ... 7ce19a.jpg

2T, this pic shows some cutaway detail of the exhaust port exit.
Thanks P, are we sure that a 'sonic thrust' - was an intent?
Or did it really serve as a 'spark arrestor" viz:
Image

& do you know what the function of the pipe - plumbed into it - is?
"Well, we knocked the bastard off!"

Ed Hilary on being 1st to top Mt Everest,
(& 1st to do a surface traverse across Antarctica,
in good Kiwi style - riding a Massey Ferguson farm
tractor - with a few extemporised mod's to hack the task).

J.A.W.
109
Joined: 01 Sep 2014, 05:10
Location: Altair IV.

Re: 2 stroke thread (with occasional F1 relevance!)

Post

Pinger wrote:
23 May 2017, 19:10
Tommy Cookers wrote:
23 May 2017, 18:44
this (split-single 2 stroke) qualifies ?
http://cybermotorcycle.com/gallery/gare ... -350cc.htm
Yep, sure does!
Does it?
Really?
Is there actual technical/scientific theory, or empirical results behind it, or was it a 'fashion statement'?

Here's a period 4T - using something very similar..

Image
"Well, we knocked the bastard off!"

Ed Hilary on being 1st to top Mt Everest,
(& 1st to do a surface traverse across Antarctica,
in good Kiwi style - riding a Massey Ferguson farm
tractor - with a few extemporised mod's to hack the task).

gruntguru
563
Joined: 21 Feb 2009, 07:43

Re: 2 stroke thread (with occasional F1 relevance!)

Post

Maybe it has a silencing benefit too?
je suis charlie

Pinger
9
Joined: 13 Apr 2017, 17:28

Re: 2 stroke thread (with occasional F1 relevance!)

Post

Without seeing inside them, I don't suppose we'll ever know (searched, but couldn't find any pics of the internals of the tractor pipes). Even looking inside a pipe from a RDLC is inconclusive - bulkheads and a baffle.

Tommy Cookers
617
Joined: 17 Feb 2012, 16:55

Re: 2 stroke thread (with occasional F1 relevance!)

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what J.A.W has shown is a 'Brooklands can' - a type of 'silencer' for road use afaik appearing after ......
Brooklands (oval track) demanded c.1925 a 'receiver' design (volume 10x engine displacement) for all running, including cars
the internal lengths and alignment of inlet and outlet pipes and fishtail aperture size seem to have been mandated (varying with engine displacement)
Morrison's book says the BC reduced noise only by the outlet fishtail area being rather small
twin port heads became widespread on 2 valve engines, probably because 2 (smaller ?) BCs gave more power than 1 usual
post WW2 Brooklands disappeared and BC style became unfashionable
though Velocette kept the theme in their (relatively quiet) systems that became winners in 500cc production machine races
http://www.voc.uk.com/net/docs/19.16/19-416-25.pdf
http://mc-engine-design.996302.n3.nabbl ... 12000.html
http://www.gracesguide.co.uk/Brooklands
the BC layout may have tended to give an ideal 'tuned' length to the pipe

the Garelli seems to have used a straight pipe before 1925
ie is the photo from Brooklands ? - are there later photos of Garellis ?

in a 1920s motorboating magazine the writer describes giving his motor a tuned length (plain) pipe by experiment with a slip joint
iirc gaining 6 knots from the inboard 2 stroke
Last edited by Tommy Cookers on 24 May 2017, 11:39, edited 9 times in total.

Pinger
9
Joined: 13 Apr 2017, 17:28

Re: 2 stroke thread (with occasional F1 relevance!)

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Tommy Cookers wrote:
24 May 2017, 09:30

twin port heads became fashionable on 2 valve engines, probably because
Helped clear the single frame downtube? The same reason I think that many 2T exhaust ports were offset to one side on single cylinder engines.

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