Post whore, but for good reason.

no i have a diesel nissan. i have a fitch, i think it works but only around 7% not the claimed 15 or 20 or whatever. I would like to know about the vaporite they recon it works well too.

The concept is not so revolutionary, it has been around since the thirties. Like 4 valve heads, sleeve valves, desmodronic valve control, not a great deal left under the sun, so to speak.
The big advance must surely be sequencial fuel injection by electronic control, though I dread the day I have to buy one of those with an engine where I cant even find its spark plugs. I need a lot more km's out of my '85 "carburated" Honda Civic I think (& hope)
kesh

desmodronic valve control ? ducati ? always wondered why such an amazing engine never really made it into passenger vehicles - that was until i was with a mate who tried to work on one and geez how many springs and bolts and nuts and washers and little strange metal things flew everywhere, dunno what it cost him to get someone who knew the engine to put it back together but he couldn't afford to go to the pub for a long time.

i hear you, but this thing does not seem very complicated at all. It makes so much sense to have one piston made for one job. These guys also claim to have overcome some problems of similar engines like this one in the past. I may have been sucked in but do the full "how it works" read through and you will find the arguments are compelling.

"Sarich Orbitals went the same way
as well as various other designs"

Pretty sure the Sarich injection system is the one used on the Johnson/Evinrude 2 stroke outboards now? Or a variation of it.

I'm sure you're right Fisho.
One of the larger outboard manufacturers ran with it..

Guys I'msure you will find they use only the fuel injection system and that after modification/refinement, but NOT the orbital engine which is doing not much of anything in the combustion engine world.

The Orbital Engine refers to the combustion process developed by them. The original engine wasnt followed since decades back.

Having long since ceased development of Orbital's original rotary engine, engineering effort was focused on a complementary invention that became Orbital's core technology and that powers its customer's products today. This technology is termed the Orbital Combustion Process (or OCP™) and simplistically is an air-assist direct fuel injection system.

In the early 1980s, the company recognised that its OCP™ technology could also be applied to conventional 2-stroke engines, overcoming their traditional deficiencies of poor fuel consumption and excessive exhaust emissions. The application of OCP™ meant the traditional benefits of smaller, lighter and lower cost 2-stroke engines could be retained. This led to a decision during that period to improve existing 2-stroke engines in marine applications and the proprietary development of a unique automotive engine available for licensing today.

Sorry Cabbage but the Wankel (Rotary) engine has not dissapeared with or without a whimper. It is still made by Mazda for the RX8 and is also made by a company called Miller as an engine for PWC's and also for unmanned target drones. Mazda have also proven it to be an extremely efficient engine to run on straight hydrogen.

And yes I own one and have raced them so I have a bit of a soft spot for them :).

I thought the Sarich injection was the one used by mercury Optimax and Tohatsu but I may be wrong on that one. Definitely the engine he designed did not come to fruition. I think it proved to just be too complicated and had too many seals that could fail to be commercially viable. Frankly a lot of the advances made in modern engines that come from things like new materials have made them extremely efficient so it is no longer easy for any other engine type to stand out and be worth the effort. The advances may not seem like much by themselves but add them all together and the engines have come a long way.

Tim.

"The Orbital Engine Company (OEC), a joint venture of BHP and Sarich Technologies Trust, has reached a turning point in its quest for world-wide commercialisation of its technologies following the recent signing of two Agreements in the USA. The first Agreement involves the manufacture and marketing of its unique fuel injection system and related components for use in automotive and marine engine applications. Under the second Agreement, OEC granted rights to Outboard Marine Corporation of USA to use the Orbital Combustion Process (OCP) in marine, lawnmower and certain other industrial applications. Outboard Marine makes Johnson and Evinrude outboard motors and is believed to be the largest manufacturer of out-boards in the world."

read and weep!

for a 4 cylinder engine you still only need 4 cylinders because although it's a 4 stroke engine, one piston takes care of compressing the air and it can do this every stroke. the other just burns the charge and can do this every stroke. so a 4 cylinder has the same power from 2x compressor pistons and 2x power pistons. I dont know anything about these but i think it is efficient. other benefit is the pistons have less friction because all they do is one job each. the compressor piston never see's fuel and carbon so it would opperate cooler and smoother, cleaner no build up and so it would last longer. + the compressor piston can be larger than the power piston so the charge it delivers is much larger than a normal piston compressing it's own air, this is without a turbo or supercharger and this would be more efficient, every stroke a charged superstroke!. There are not that many parts, the only extra's are the charge delivery tube and valve.

True about the 2/4 stroke. But wouldnt you have a similar effect with a GM 2 stroke but with an intake valve instead of a port?
quote
+ the compressor piston can be larger than the power piston so the charge it delivers is much larger than a normal piston compressing it's own air,
unquote

but this is just the same as running your boost much higher and the result of this is detonation, whether petrol diesel or LPG? Fuels can only handle up to a certain compression before detonation, depending on the octane rating?

with detonation, yes in a normal engine this is a problem but they state on the site that this engine does not suffer from this effect because the charge is released after TDC not before TDC like a 4 stroke. This means the expanding flame front is actually chasing the cylinder as it moves away from the charge insert point. In a normal engine this is bad because it is less efficient but the compensating factor in this engine is that the burn happens very fast compared with an normal engine. So it solves all of these problems. Right now though there is no proof and no pudding because this is only computer simulations. But simulations these days are very accurate.

" But simulations these days are very accurate."
Only with a known quantity to measure against.
As with statistics, only as accurate as the person doing the interpretation.

"For reliability you cant go past a gas turbine. Hundreds of thousands of hours per engine shutdown, and most airline pilots will NEVER have to shut one down in flight during their careers. "

Not quite that good buddy, about 4 thousand cycles between full re-builds if you are lucky ( cycle = start cycle) hours vary due to flight sector length (of course).
And the fuel consumption isn't something you want to be paying for :-))

Fuel up a 330 or 747 and watch at least 70,000 tonne of juice go in :-0

at the moment i'm building cfm-3's (737) and cf6-80c2 (767 & 747) mainly doing the core section which is the main rotating components, and the cost is phenominal, one new shaft spool section is $400,000 plus. a complete compressor shaft and blades is around 2 million. and i hate swinging em off cranes into the balancing machines etc.

BUT the quality of the components is magnificent, i regularly work with tolerances on runouts to within tenths and hundreths of a thou. but for the cost they'd wanna be good.

Sure, I understand that, however correct me if Im wrong but items such as the shaft spool sections and blades etc are only replaced if ultrasonic/xray etc testing shows it to be needed?
And 4000 cycles is the equivalent of driving your car to and from work for 8 years

"Fuel up a 330 or 747 and watch at least 70,000 tonne of juice go in :-0 "

probably should be 70,000 litres!!? And that will likely take a 400 tonne 747 6000+ miles.

Still, some quick arithmatic tells me that 4000 cycles, taken, say, on a jumbo on a shorthaul route as in japan with absolute minimum 1 hour would be absolutely minimum 4000 hours between rebuilds? 4000 hours in ya car at 100 kmh is 400,000 km between full rebuilds. And I would guess that very very few jumbos would average 1 hour turnarounds?
Who would put their life on a 3.0litre Nissan motor at 400,000 or even 300,000 km? or even (god forbid!!) a Toyota motor? Imagine if every Nissan 3 litre that blew up was a 747 with 400 passengers on board? Boeing (Rolls Royce or Pratt and Whitney) would have a fair old warranty claim going then?

However I digress, I think the rough statistics show that gas turbines ARE quite reliable in design??

Forgive me, Bradley if I have taken liberties with my guesswork figures, and feel free to correct any inaccurracies!!

QUOTE"For reliability you cant go past a gas turbine. Hundreds of thousands of hours per engine shutdown, and most airline pilots will NEVER have to shut one down in flight during their careers. "

Not quite that good buddy, about 4 thousand cycles between full re-builds if you are lucky ( cycle = start cycle) hours vary due to flight sector length (of course).UNQUOTE

whoops forgot to add the most important bit!!you appear to have mistaken "shutdown" (meaning unplanned) for "full rebuild"

in the theory of operation page they confirm what i just said

the russians had a military rotary engine which was replaced every 20,000km. My guess is that the engine rocks but is under so much load/stress/pressure that the materials we make em from just cant cope.