Rotary applications
 

Hey guys, what's up?

I've been studying the rotary engine and all of its glorious possiblities.

I wanted to ask everyone who views the thread what they thought of, "What if an investment were made in developing a 3-rotor engine, that would replace v-8 piston engines in many of today's modern SUV's, would you be interested in seeing it?

Specifically, I wanna' try to raise capital and develop a 3- (possibly even 4-)rotor conversion engine swap for something like a Toyota Sequoia (sp?) or GMC Yukon XL Denali to improve on fuel efficiency for these gas guzzlers. This would obviously be test-case prototype stuff, but just for my own fun; would anyone else be interested in something like this?

Opinions? Other vehicle suggestions? Tech info. about the feasibility of this undertaking?

I think it would be feasible, only because a 4 rotor engine should be around the size of the V8 but put out signifigantly more power.

However, fuel efficiency is where I worry on this, specially with that much power I don't know what kind of gas mileage the engines will get.

Besides the only company right now that can produce a reliable rotary is Mazda, so it will have to wait until the public demands better and then turn to Mazda for their expertise in this area.

With a 3 rotor I am not so sure your going to get that much better gas efficiency. My fams New Tahoe with towing package gets over 20 at times. If the 3 rotor is the just adding a rotor to the renesis I bet your gas mileage would being hovering right at 20. Rotaries aren't that incredibly gas efficient and I don't expect the Renesis to be that great either maybe 25 on highway with just 2 rotors.

wow, you are a major rotorhead... WELCOME TO THE FORUM!! :)

what to say... hmmm...
well, there have been "home made" 3 rotors before...
there are lots of people (shops) you can go to for help with the practicalities of making a 3 rotor...
this COULD be a very good idea, and it would be markedly better if you could manage to make a 3-rotor RENESIS... you can't really make a "home made" RENESiS without enourmous, vast, huge mountain ranges of difficulty (where the new exhaust ports are, there's water in the older engine block)... so maybe it'd be better to make a 3-rotor 13B...
also trying to find a tranny that'll stand up to this punishment, have the "right" cogs in it, and bolt onto the back of your rotormotor will be tricky too...

back onto the theoretical side of things (where, MAYBE, i could offer something of value), i don't mean to discourage you, but rotaries aren't exactly econo-savers on gas, despite their diminutive displacements...
i'm completely unfamiliar with how much you know about them, but i think the biggest advantage they would have over V8's would be their smaller size and mass, allowing you to put more engine (for worse gas milage, but more power) into it without making it a whole lot bigger on the front side of things... but they aren't torque monsters, even in a 4 rotor version, i still think you'd be hard pressed to equal some of the torque outputs of the V8's out there today...

then again, that might not matter, 'cause most people who off-road or need to tow things just buy trucks so they don't look like yuppies ;)

so, in that case, this still sounds like a super cool idea... have you contacted Mazda of North America to see what they think?? i mean, they'll call you crazy, but maybe they'll pay attention... ;)

the SUV's that you've target as the body of the mule are all really huge, and i don't know how much you'd be able to improve the gas milage in such gargantuan vehicles, as it's more the whale-heavy weighs than the big engines that contribute to their low numbers... hmmm... how about a Mazda Tribute with a 2-rotor instead of a V6??

Why don't you investigate the possible installation of a modern transmission in such vehicles as a Chevy Tahoe and Toyota Sequoia.

The 5 speed automatic transmission was introduced in 1990, and the one of the earliest applicant was the 1993 BMW 530i.(ZF's 5 hp 18) So for a decade the 4 speed automatic has been obsolete. The 6 speed automatic has been out for over a year now, ZF 6 hp 26 (BMW 745i), and now the new Beetle convertible has the first transverse 6 speed automatic.

CVT (continously variable transmission) are starting to take off, Audi multitronic, Nissan Xtronic.

Automated manual transmissions are also reaching maturity. BMW has its second generation of it SMG (sequential manual gearchange) Same with Ferrari's F1 type powertrain.

http://www.sovereign-publications.com/auto-art-2.htm

me new to rotary,.. me don't know much

but, isn't rotary lack torque? and supposely, suv and pick up needs torque to climb and haul?

now if it's a SAV like Caynne or x5, that is not made to see dirt. maybe, but would 3 or 4 rotor be able to haul 5000 lbs of car alone, little to say haulling and stopping another 20' power boat and trailer??

isn't that why turbo disel is still around?

i love the technology of high reving engine but i still have firm believe in nothing replace displacement

A 2-Rotor engine is the equivalent of a 4-cylinder piston engine. So a 3 or 4 rotor engine will be the equivalent of a V6 or V8. The torque output of these larger engines is much better.

And about your feeling that nothing replaces displacement.....the RENESIS makes 192hp / liter, and has the capability to make 230hp/liter. Just imagine a 2.0 liter 3 rotor, or 2.6 liter 4 rotor engine utilizing the same technology (I don't think we will ever see one of these go into a production vehicle).

Trust me, there is a replacement for displacement, it's called efficiency, something American car manufacturers don't understand. BMW is a perfect example of a company who appreciates the benefits of a tuned N/A engine, their S70/2 that powers the McLaren F1 makes 627hp out of 6.1 liters, and that engine was developed in 1992! Same goes for their engine that powers the E46 M3, 333hp out of 3.2 liters. *Shakes head*, when I look at Dodge's new Viper, I appreciate the disgusting amounts of torque it produces, but I can only laugh when it is making 60hp/liter out of an 8.3 liter V10...... Oh well, to each their own

I am not disagreeing with the point that you are making, however the 6.1 liter BMW S70/2 engine was designed strictly for racing. Dodge however designed their 8.3 liter engine for cars that the general public can buy, that is a big difference.

The McLaren engine (S70/2) was NOT a race engine.

Quoted from 'Driving Ambition' "The new power unit just proliferated with race-bred features, yet was very much a road engine. It had to be road tractable, moderately stressed to achieve a respectable service life and practical maintence shedules. In Munich Motorsport's engineers even put it through the same 500-hour bench test to which any other BMW road-going power unit would be subjected. Nominal service interval was settled upon as 5,000 miles."

Exactly, I have the same book. Unlike Ferrari, the designers wanted to make this a Road car from the get go. That is why it has a plush interior, specially made sound system with 10 disc changer, A/C, etc. These were reliable cars with reliable engines, unlike some of the newer Ferraris and Maseratis.

Anyway, back to the topic. I think it is a novel idea to try and make a 3 or 4 rotor engine for a truck application, but considering the reliability and refinement that the current V8's exhibit, I don't think many buyers would be swayed. It would be cool though.

actually velociti, the power stroke frequency of a 2 rotor is identical to that of a 6 cylinder engine, and like wise a 3 = 9, and 4 = 12... maybe you were confused with the 4 ignition wires?? whatev, no big deal...

i'm not going to comment on your post terrence, just read around the forum, it's all already there.

the main advantage that the 3 or 4 (!) engine would have over a big-bore V8 would be only its compact, and low mass design... in a vehicle designed only for touring around, and being a general jackass on the road in, a rotary has no real advantage... it wouldn't be more fuel efficient as the low mpg's they get are from their huge masses and moms driving them like sedans... their high specific horsepower and redlines wouldn't be an important thing to buyers, and they'd need to be geared like crazy to compete with those stump-pullers, further hurting fuel efficiency...

<<sigh>> not gonna work, not in that application...

Ah, I was under the impression that there were two power strokes per rotation as opposed to one in a cylinder ---> 2 rotors = 4 cylinders. My mistake :o . Damnit, I thought I knew this stuff...ugh, I got more reading to do.

Hi Wakeech,

If I am not mistaken, a 2-rotor wankel rotary has 2 power strokes per output shaft revolution and a 4 cylinder engine has 2 power strokes per output shaft revolution.

1 full rotation of a rotor has 3 power strokes. Since each rotor in a Wankel rotary rotates at 1/3 the speed of the output shaft, each rotor has 1 power stroke per 1 revolution of the output shaft.

A 1 cylinder 4-stroke engine takes 2 revolutions to go through it's 4 strokes. A 2 cylinder 4-stroke engine has 1 power stroke per 1 revolution of the output shaft. A 4-cylinder 4-stroke engine has 2 power strokes per 1 revolution of the output shaft. Just like a 2-rotor Wankel rotary yes?

Brian