smokum

Hey guys i love the rotary engine and am a big time lover of the diesel, The question on my mind is when are the 2 going to come together???
2 great taste that taste great together...
What is holding it back Diesel needs RPM rotary needs Torque.
not here to ruffle feathers just the question that has always been on my
mind.

phinsup

I too share a love of the oil burners... lol both rotary and diesel.

All that said it's an interesting thought, a year ago I would have said it's unlikely it would work due to the diesel's high compression, however Mazda's new Sky-d diesel is only running 14:1 compression.

Could you imagine a rotary with torque? Diesels have come a long way in the last decade... the rotary not so much. I'm still amazed at the torque in my new Mercedes e320 cdi, 0-60 in 6.8 seconds in a giant luxury car..... it sure makes the ricers do a double take when I blow by them and leave a nice thick cloud of exhaust.

Anyhow, I think Mazda is going to put most of their engine R&D into the skyactiv platform, I don't foresee them developing a rotary diesel, we'll be lucky if we ever see another rotary from mazda again.

smokum

Yes i was following that excelent move.
Mazda Engine News: Mazda Sky Gas and Diesel Details – Car and Driver
you can always make up compression thru forced induction, a rotary engine vs a diesel engine of the same size is 1/2 or 1/3 differnce in weight.
The other thing that caught my attention is i seen guys running waste oil mixes in there diesels, you can easyly get by running waste oil and fry oil for a cleaner result.
Running a car that way cost almost nothing, IMO i think its the begining of the Diesel not the end. VW's 260-MPG Diesel Hybrid Concept May Actually Get Built | Popular Science

Signal 2

Is it the diesel fuel that makes torque or the crank stroke of the typical diesel engine? If it's the latter I don't see much hope increasing the torque of a 13b that way.

phinsup

Short answer no, if it's running low compression it won't have torque. The high compression is what gives diesels torque.

smokum

When some one says forced induction everybody thinkis turbo right off the batt, BUTT Blowers were on diesels from the start and provide instant compression boost on startup, Even if you had a rotary that can only do 14.1 the blower can handle the rest. What does a rotary engine weight?

Lynn E. Hanover

Everyone has a piece of the puzzle.

Diesels are compression ignition engines. This means that heat of compression is so high that a separate ignition system is not required for them to run in most situations.So, once started and so long as fuel is supplied no electrical devices are required to keep them running.

You have noticed that diesels sound like it is being fed scrap metal for fuel. And they are loud. That is mechanical sounds from the crank case. They operate in a constant state of detonation. Extremely high pressure injection systems inject all of the fuel for each cycle at various times (close to TDC) depending on RPM. So all of the fuel is injected into high pressure air that is well above the flash point of the fuel. In addition there is a huge excess supply of oxygen. So the burn is very fast and the resulting cylinder pressure (spike) is very high. So high that the pistons may be made of cast iron and, or have removeable tops so that worn out ring lands can be replaced regularly. The crank cases are more than twice as heavy as gasoline engines to support the stresses involved.

GM years ago made the small block 350 into a diesel engine on the cheap. They even put it into Cadillacs for one year. Then they had to buy them all back. After they put the 3rd engine in each one under warranty. They would blow the main bearing webs into the oil pan. DUH.............

Diesels with their huge mass usually are flat out at 2,000 RPM like over the road trucks. Since the more air that can be pushed into the cylinder the better it runs, most have big turbochargers and, or mechanical superchargers, like the GM 671 that the dragsters use. They or stock on the GM V-12 2 cycle diesels.

The (so called Wankle) engine was designed as an air compressor for big diesel truck brake systems.

Swiss engineer Bernard Mailard working for truck manufacturer Adolf Saurer had a pattent in place, and NSU was turned down when they tried to patent the Wankle. Mailiard gifted the pattent to NSU at no charge.

Since the thing is actually a compressor ( I was going to make one into a compressor) if my shop compressor ever quit. It's still running.

A British company built a Wankle diesel. A big wankle used as a compressor, spinning faster than the smaller diesel Wankle to jack up the effective compression high enough to get compression ignition. All together in one big casting. Yes, it works fine. Even higher revs than regular diesels. But big and heavy and not competitive price wise with conventional diesels.

I have a picture here somewhere. I will post it if I can pull it up.

Lynn E. Hanover

Lynn E. Hanover

Everyone has a piece of the puzzle.

Diesels are compression ignition engines. This means that heat of compression is so high that a separate ignition system is not required for them to run in most situations.So, once started and so long as fuel is supplied no electrical devices are required to keep them running.

You have noticed that diesels sound like it is being fed scrap metal for fuel. And they are loud. That is mechanical sounds from the crank case. They operate in a constant state of detonation. Extremely high pressure injection systems inject all of the fuel for each cycle at various times (close to TDC) depending on RPM. So all of the fuel is injected into high pressure air that is well above the flash point of the fuel. In addition there is a huge excess supply of oxygen. So the burn is very fast and the resulting cylinder pressure is very high. So high that the pistons may be made of cast iron and, or have removeable tops so that over sized ring lands can be replaced regularly. The crank cases are more than twice as heavy as gasoline engines ti support the stresses involved.

GM years ago mad the small block 350 into a diesel engine on the cheap. They even put it into Cadillacs for one year. Then they had to buy them all back. After they put the 3rd engine in each one under warranty. They would blow the main bearing webs into the oil pan. DUH.............

Diesels with their huge mass usually are flat out at 2,000 RPM like over the road trucks. Since the more air that can be pushed into the cylinder the better it runs, most have big turbochargers and, or mechanical superchargers, like the GM 671 that the dragsters use. They or stock on the GM V-12 2 cycle diesels.

The (so called Wankle) engine was designed as an air compressor for big diesel truck brake systems.

Swiss engineer Bernard Mailard working for truck manufacturer Adolf Saurer had a pattent in place, and NSU was turned down when they tried to patent the Wankle. Mailiard gifted the pattent to NSU at no charge.

Since the thing is actually a compressor ( I was going to make one into a compressor if my shop compressor ever quit. It's still running.

A British company built a Wankle diesel. A big wankle used as a compressor, spinning faster than the smaller diesel Wankle to jack up the effective compression high enough to get compression ignition. All together in one big casting. Yes, it works fine. Even higher revs than regular diesels. But big and heavy and not competitive price wise with conventional diesels.

I have a picture here somewhere. I will post it if I can pull it up.

Lynn E. Hanover

smokum

Lynn E. Hanover i know you ar stating things that most of us all ready know, is this old tech from the 70's and 80's suppose to be the reason to disreguard this idea?
I remember a while back people all over the world were beating up on the OHV pushrod engine saying it was dead and the only way to make any reasonable power would be to jump on the OHC bandwagon.....Were are we today with that? The best engines around are the LS1 - LSX simple lite powerful and cheap to moddify. So tell me then a rotary engine pushing out 1000HP some how makes less preasure than a diesel version putting out 300HP? please explain?

Lynn E. Hanover

Well, the physics from the 70s is the same today, so data and outcomes from experiments will report the same findings. If all perameters are the same.

Every idea is valid. Period. How can that be? Because attempts to verify a fialed premis produces many more ideas. More than half of all inventions are produced as a result of trying to cure one problem and blundering onto a useful piece of data that can applied to other situations remote from the problem at hand.

Did you mean a 1,000 HP rotary would have the same cylinder pressure as a diesel engine? No, if it is a 3 or 4 rotor turbocharged engine on gasoline. If it had been modified to be a diesel, the minimum effective compression must be at least 14 to one and had the strength to maintain its shape at that output, probably not. Ask the British. Hard to do even when you are desining the castings to be stiff enough for the job.

The question was can a rotary be made into a diesel?, and the answer is yes. If the question was can a rotary be made as a diesel and be competitive with current say truck engine diesels? The answer is no. Not yet.

If the question is, has it been done as a prototype, the answer is yes. Pugeot has been winning Lemans lately with piston style turbo diesels. Do I think a turbo diesel Wankel style rotary just a few model years away> no I do not.

Note that Mistral had a 2 rotor on the dyno running real strong on Jet A commercial jet fuel. They went broke.

Curtis Wright produced a stationary multi fuel 2 rotor of over 1,000 HP that passed a 2,000 hour test for the Navy. But it was not a diesel.

Designed to replace the Colt industries 38D81/8 giant OP (opposed piston) diesel.

Designed to run on whatever a Navy tanker might be transporting. From raw crude oil to Jet A to bunker C (an oil that looks like black mud).

Lynn E. Hanover



Lynn E. Hanover