youngfc

iTrader: (1)

it could rev to 15000rpm
im going for 250ccm 2rotor engine and yes i plan to make it.
what are your thoughts on it?
to me it sounds perfect because bio diesel and regular diesel for that matter is a lubricant.
thanx for all your opinions.

nazzy28

iTrader: (2)

I don't know squat about fuel sciences and all that, but since diesal produces more torque, that thing should be a beast. Probably better gas mileage too... probably.

Jdrift

My only thought it how are you going to get the rotary to build enough compression to ignite the diesel?

SpeedracerRX7

By no means am I any sort of expert but isn't detonation what you try to avoid in a rotary. That is what cracks and blows seals. This is why desiel engines knock so much and why if you look at the block of a desiel engine they are so stout. I know I have gone through 4 engines and 3 of them were due to excesive heat in the engine. This will also be a problem with a desiel because it burns at a much hotter temperature and therefore will need a lot better cooling.


This should not slow you down however as these are just obstacles to overcome. All great designs have had hurdles to jump and just maybe you can find a way around them.

Good Luck!

arghx

iTrader: (3)

There are multiple legit engineering papers written about spark ignited diesel and multi-fuel capable wankel rotary engines. PM me about them. You need to read through all of them and see what has already been done. Oh, and forget about 15,000 rpm. That's pointless and stupid. Mazda's own race engines never revved that high.

nazzy28

iTrader: (2)

Can you imagine the sound a 15k rpm race engine would make though? lol. VVRRRAAAAZZOOOM! lol

RotaryEvolution

iTrader: (30)

Moller industries, a company that produces another version of the rotary engine hasn't even finished development on the diesel powered rotary but from my understanding is they use a 80% diesel/20% water blended fuel to reduce the chance to detonate. this supposably would allow the fuel to be spark ignited versus run on detonation cycles which most all current diesels run based off of. diesels can run on less compression, which alternates the engines away from detonation firing versus ignition firing, so then the position at which the fuel is ignited can be controlled, leading to a smooth combustion versus violent in current diesels.

i really don't foresee spark ignited diesels making much power for any real applications though, even from moller they only plan on making the engine for generator purposes which generally do not need alot of torque or horsepower.

http://www.freedom-motors.com/index....Itemid=96#1.36

Jdrift

Lol, well either way keep us posted on your progress.

youngfc

iTrader: (1)

well for 15000rpm its gonna be small only .25l twin rotor and i plan to make it beefy. the e-shaft im making is out of titanium. i also found a way to get the compresion up in the e-shaft. kinda like a sroker.and then add a small twin screw supercharger im making for it.
i have read most the stuff iv found, but they all have the same problem like the rolls roys one(it cant seal or have compresion). i got the cooling system drawn out and all the numbers about it. i also have some rough blueprints that im refining.
And jdrift i will.

RotaryEvolution

iTrader: (30)

good luck... you'll need it.

youngfc

iTrader: (1)

thanks

gawdodirt

Wow. Some really old/bad info on diesels here.

Let's clear up some things first. First, most curent diesels are at about 16.5:1 to cut down NOx, which is made with compression and heat. And turboed because they usually don't have the porting and engine speed to be N/A. I worked on some Italian diesels that ran at 3.2 bar.

Second, Most, if not all current diesels have two or more injection phases. Pilot , and main . Pilot loads the piston, so it cuts down on the detonation, main is the power. This is how the TDI can operate cleanly and with little to no noise over a standard gasoline engine.

Diesels tolerate detonation. They don't thrive on it or use it to ignite fuel.

I believe that the torque a diesel makes is a product of stoke and bore, so the rotary won't magically produce tons of torque just because it uses a different fuel. Most diesels have longer stroke than bore, and a rotary is drastically the other way.

GD

gawdodirt

In addition to my earlier comments. Fuel burn rate is key as diesel burns slower than gas due to it's lower volatility. So 15,000 is a goal , but not a reality at this time. Figure out a way to capture a longer combustion power cycle with a rotary and you'll have a jewel. John Deere has a license for Wankel with alternative fuels and would be a great resource.

GD

CrackHeadMel

iTrader: (2)

Detonation hurts a diesel just as it hurts a gasoline engine.

Diesels operate off compressed ignition, there is a difference.

-Jacob

youngfc

iTrader: (1)

thats the key to it reving that high though. the rotor moves 1/3 the speed of the e shaft so 15000rpm means the rotor is moving at 5000rpm not to hard to do with diesel. and for the more tq it has more btus and in its case gas expansion, wich means more preasure at lower amounts of air and fuel.
thanks for the imput though.

ronbros3

something to think a bout,

try to make TORQUE NOT RPM, you will be way ahead on a USEFUL engine,

rpm is a lot of trouble for many drive systems!

12arotary.

the torque won't really go up drastically even though it has 13k btu's per gallon more than gas what will happen is you'll just end up with a lot of incomplete combustion as it has no time to burn before its shoved out the exhaust port- as said before diesel's have longer strokes giving time to extract maximum power out of each burn. Diesel rotary's have been done. the comp temp can be over come by adding a pre-chamber and heating the fuel before injection as well as bumping up the compression ratio- It always seemed the best candidate for diesel would have been a 13a style engine , the larger diameter rotor would give more distance for the ignited diesel to burn properly and with a shorter apex length to increase strength it could handle an increased comp ratio-

arghx

iTrader: (3)

Did the OP ever do the work of reading about the diesel prototypes that have already been made? You can't engineer something new without understanding what's already been done. The Wright Brothers didn't really just invent powered flight in their garage by tinkering around. They looked at all the other failed flying machines, identified the specific issues and failure points, and then addressed them in order to have a successful flight. The same thing happened when Edison invented the light bulb. He had a library and a whole staff of guys who just read patents and books about inventions that had already been made.

youngfc

iTrader: (1)

im working on it and i think that if u make it so it mimics a longer stroke and a better position of the combustion chamber, and moving injectors down on the housing like a s4 vs s5 houdings. the way i look at it if this fails il still have a really high compression and DPI wich would take out that nasty det. prone zone between 1500 and 4000rpm. and i really think rotaries would benifit from DPI. gas or not

13beez

iTrader: (10)

Subscribed

goonie

If you make this motor work flawlessly I will buy one and I know a few other who will buy one

flaco

iTrader: (7)

good luck

damic

Mercedes Benz had a 3 and quad rotor diesel, so they know to what is possible.
http://www.youtube.com/watch?v=t3jIIS3FFAQ
Picture of the engine 400HP of a diesel.

http://www.der-wankelmotor.de/Fahrze.../mercedes.html

Even Roys-Rolls know it

http://en.wikipedia.org/wiki/Wankel_...#Disadvantages

A full article.
http://retro-motoring.blogspot.com/2...1_archive.html

msdg137

I could see a diesel injection rotary working just fine. You could run an injection pump cam off the eccentric shaft that would drive the fuel to the delivery valves and time the injection. A dual pop injector would help with ignition timing. Crafty thought if ever.

youngfc

iTrader: (1)

Well its almost the 2nd semester soo ill have to have a runin model soon.