|
Post by pdxjim on Jan 17, 2020 6:42:53 GMT 1
|
|
|
Post by earthman on Jan 17, 2020 9:44:10 GMT 1
Looks interesting, I do wonder about longevity/durability though, normally turbo charged 4 stroke engines can suffer in that respect, dread to think what it could be like for a 2 stroke.
|
|
|
Post by veg on Jan 17, 2020 10:27:16 GMT 1
The performance is not that startling though, when you think what 1000/4 put out whilst potentially the engine is less complex as a 2stroke you are still going to have impellers spinning at 200,000 rpm.
|
|
|
Post by headcoats on Jan 17, 2020 10:47:25 GMT 1
Well my 865cc Bonneville puts out 69BHP after intensive tuning LOL
|
|
|
Post by reedpete on Jan 17, 2020 10:58:23 GMT 1
Haven’t read the detail but I think the key point is that it’s not a crankcase compression 2t. The turbo is needed to just provide enough scavenging pressure. There’s a limit to cylinder pressure as you can’t avoid port timing overlap. Exhaust will always be wide open when transfers are open. I think we are going to hear more about this as efficiently is topic with such engines mooted recently to perhaps emerge in F1 2025 regs.
|
|
|
Post by veg on Jan 17, 2020 11:50:35 GMT 1
That’s me reading the headlines and no details dooh 😬
|
|
|
Post by cb250g5 on Jan 17, 2020 12:58:58 GMT 1
Haven’t read the detail but I think the key point is that it’s not a crankcase compression 2t. The turbo is needed to just provide enough scavenging pressure. There’s a limit to cylinder pressure as you can’t avoid port timing overlap. Exhaust will always be wide open when transfers are open. I think we are going to hear more about this as efficiently is topic with such engines mooted recently to perhaps emerge in F1 2025 regs. Does it have or need transfers? Blow pure air in, using the 4psi low pressure turbo, will clear the combustion chamber of spent gasses whilst exhaust port open, once inlet & exhaust closed inject fuel using computer controlled fuel injection, and off you go, no un-burnt fuel out of the exhaust.
|
|
|
Post by veg on Jan 17, 2020 13:06:56 GMT 1
Whatever happened to the two stroke orbital engine thought that was the way forward?
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Jan 17, 2020 17:28:17 GMT 1
Evinrude E-tec, Mercury Optimax outboards have a similar system
Most of it stemmed from the Orbital Engine Company started by Ralph Sarich in 1972 Perth W Australia
it was based on the Wankel Rotary engine found in RX-5, 7 etc, an engine was not really produced, only bench running prototypes, the engine could never be properly lubricated or cooled, it could also be driven by air or steam and used as a pump, however the combustion process Orbital Combustion Process was produced and gained notoriety
OCP was fitted to the 3 cylinder Suzuki 2 stroke car engines, after that Sarich built his own engine, it produced 67kW but only weighed 41kg, it produced more power than GM's 1.6L 4 stroke J engine that weighed 128kg, it was also very noisy and not very reliable either
From memory he sold off the rights of Orbital Combustion to Mercury Marine, OMC (Evinrude/Can Am if you like), VW did some trials as did Fiat, the OCP was also installed in Aprilia two stroke scooters
The intellectual property made Sarich a very rich man, as far as I know no reliable Orbital engine was ever produced, only the induction side of it was successful
|
|
|
Post by veg on Jan 17, 2020 17:34:19 GMT 1
Sure I remember reading about ford looking into it as well, my old man was fascinated by the wankel and spent many an hour chatting to a bored teenager about it (me)
|
|
|
Post by midlifecrisisrd on Jan 17, 2020 17:40:05 GMT 1
Not read through it (I've skived enough today) but would think if it's a ski-doo it's a high torque reliable motor
They were getting 190 hp out the 500 gp bikes but hey they wouldn't make it across the arctic without popping
Sometimes struggled to do a race weekend 😄
Steve
|
|
|
Post by cb250g5 on Jan 17, 2020 17:58:47 GMT 1
Sure I remember reading about ford looking into it as well, my old man was fascinated by the wankel and spent many an hour chatting to a bored teenager about it (me) Ford certainly played about with 2 stroke cars. I saw one of these Fiestas, when I was running my Wartburg Estate "In 1992, Ford revealed an experiment to equip the Fiesta with an engine that looked as though it had been consigned, through its inability to meet increasingly demanding emissions regulations, to the dustbin of technology in the 1960s. A 2-stroke was equipped with a compressed air fuel metering system so precise that its emissions were relatively clean. Unburnt hydrocarbons no longer escaped in such profusion and the virtues of fewer moving parts, no valves, springs, camshaft or pushrods, 30% less weight, 12% better economy and 10% more power, persuaded Ford to run a programme running 3-cylinder 1200cc 2-strokes in 50 Fiestas for field trials. They were astonishingly smooth-running with none of the popping and banging associated with old-style two-strokes. A tank under the bonnet supplied oil to the engine for 12500 miles without refilling, but it turned out to be problematical in service and the experiment was concluded. Weight: 870kg Engine: 1.2-litre 3-cyl, 80bhp @ 5500rpm, 90lbft @ 4000rpm. Sarich forced-air 6bar fuel injection system driven by reciprocating pump driven off crankshaft; sealed crankcase, reed valve intakes, engine 100mm lower and 70mm narrower than 4-cyl, roller-bearing forged one-piece crankshaft. Max speed: 104.7mph 0-62mph: 10.7s Average 49.6mpg"
|
|
|
Post by earthman on Jan 17, 2020 18:20:25 GMT 1
Could you ever see 2 stroke engines becoming popular in cars no matter how big the oil tank were? Most drivers don't seem to want to lift the bonnet/do anything nowadays,.....same maybe said for the likes of that Mazda RX7, rotary engine that used engine oil/needed keeping an eye on shall we say.
|
|
|
Post by pdxjim on Jan 17, 2020 21:20:27 GMT 1
From reading (skimming) the article, it seems clear the main objective isn't peak power, but maintaining peak power at high altitude.
The sled debuting this tech is commonly used for "high marking" which is basically like American style motorcycle hilclimb.
Grab your buddies, pick a mountain and see who can get up the highest.
In this hype vid, they really play up not only peak power, but how the turbo e-tec maintains peak power at high elevation where the normal model falls off. They claim 40hp over the normally aspirated model above 8000ft. Meaning, they both make 165hp at low elevation, but at 8000ft where the normally aspirated model has dropped to 125hp, the turbo is still making 165hp. Then at 10,000ft where the normal one is down to 112, the turbo is still at (presumably) 152.
What will be interesting is how/if this tech will trickle down to their UTV's and side-by-sides which (seem to be) a much bigger piece of the pie..
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Jan 18, 2020 0:39:35 GMT 1
Could you ever see 2 stroke engines becoming popular in cars no matter how big the oil tank were? Most drivers don't seem to want to lift the bonnet/do anything nowadays,.....same maybe said for the likes of that Mazda RX7, rotary engine that used engine oil/needed keeping an eye on shall we say. I suppose the practical way to go would be to ensure the 2 stroke oil tank held more than enough oil to last between service intervals, topping up the oil would then become a service task. Would need a reasonably large tank to go 10,000kms if my Lc is owt to go by.🤣
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Jan 18, 2020 2:56:13 GMT 1
Yes Ford did have play with the orbital engine, however the engines was noisier and revved a lot higher than its Fiesta made in that era The engine was also unreliable so the work was abandoned
|
|
|
Post by earthman on Jan 18, 2020 9:02:55 GMT 1
Could you ever see 2 stroke engines becoming popular in cars no matter how big the oil tank were? Most drivers don't seem to want to lift the bonnet/do anything nowadays,.....same maybe said for the likes of that Mazda RX7, rotary engine that used engine oil/needed keeping an eye on shall we say. I suppose the practical way to go would be to ensure the 2 stroke oil tank held more than enough oil to last between service intervals, topping up the oil would then become a service task. Would need a reasonably large tank to go 10,000kms if my Lc is owt to go by.🤣 One of my wife's friends said that about the windscreen wiper fluid bottle, she never lifted the bonnet, when it ran dry she booked the car into a garage. Lol
|
|
|
Post by tipfinchy on Jan 18, 2020 9:27:55 GMT 1
Could you ever see 2 stroke engines becoming popular in cars no matter how big the oil tank were? Most drivers don't seem to want to lift the bonnet/do anything nowadays,.....same maybe said for the likes of that Mazda RX7, rotary engine that used engine oil/needed keeping an eye on shall we say. a guy at work is building a heavily modified RX7 and he will be running it on premix , I will have to ask him what ratio , I don't expect it to be too economical mart
|
|
|
Post by cb250g5 on Jan 18, 2020 10:47:05 GMT 1
The oil consumption on my RX7 wasn't too bad (I fitted a later 13B engine) It certainly wasn't a worry at the side of the fuel consumption. Lovely revvy smooth engine though.
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Jan 18, 2020 11:48:41 GMT 1
It may surprise you that the RX7 motors were bench tested to about 20,000 rpm
A bridging port always helped even on the AP series of the RX5's
|
|
|
Post by rigga on Jan 18, 2020 13:05:08 GMT 1
Someone I know solved the issue with his rotary engine
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Jan 20, 2020 13:10:14 GMT 1
That would have been interesting task to shoe horn an LS3 under that bonnet particularly a twin turbo one
|
|
|
Post by earthman on Jan 20, 2020 13:25:43 GMT 1
That would have been interesting task to shoe horn an LS3 under that bonnet particularly a twin turbo one Yes, from an engineering aspect, I'd like to see all the mods required to make it fit.
|
|
|
Post by steeley on Jan 20, 2020 15:38:10 GMT 1
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Jan 20, 2020 16:04:05 GMT 1
That would have been interesting task to shoe horn an LS3 under that bonnet particularly a twin turbo one Yes, from an engineering aspect, I'd like to see all the mods required to make it fit. An LS3 is not a small donk, add two turbos and the appropriate plumbing to with it and it doesn't get any smaller Limited vertical space under that low swept bonnet too I reckon Yamark might have had a hand in this
|
|