Rotary vs. Piston
 

http://www.streetracing.org/boards/s...ad.php?t=52357




Kind of interesting thread about the RX-8 engine before it was out on the street.

I question the whole thing when he says Fist off, it is the 'Abrams' tank and it is propelled by a Honeywell AGT 1500 gas turbine engine. There are a few special made Wankel powered aircraft and helicopters but I know of none that are mass produced with a Wankel engine. Is he getting mixed up in that a helicopter is considered a "Rotary aircraft"? :confused:

Wow. you just posted complete crap. (no offense to you, of cource. Just my two cents on the topic.)

At very high rpms the eccentric shaft can in fact flex causing rotor to housing contact so it isn't impossible.

Just went and read that thread. That guys knows just enough to not know anything and he apparently even owns/owned one. 240 hp from a peripheral port? Come on man! They can get up to 350 hp.

RG not to question you (I dont want to go to heck), but to put the "shaft flexing" in context, the referenced link states that rotories will never see more than 8.5k rpm because of the shaft flex.
EDIT: Wrote this before your second post.

maybe so, but it is still interesting.

haha. this guy is pretty dumb, he says a rotary can be just as reliable as a honda/acura vtec motor LOL noob.

he also says half the reliability problem is mazda, theres nothing wrong with mazda, besides end user neglect, the only thing i can think of that really causes engine failure is bad tuning. mazda makes engines fine, in fact if you take care of any of mazda's naturally aspirated rx-7s properly they will last over 200k. 12as do it reguarly and more than enough 13bs have. the only real fuck up mazda has done was the FD3S, they are ticking time bombs from the factory untill you do reliability mods and cooling.

rotarys are sexi.. and rx8s are sexi and since we all here own an rx8 , we are also sexi



that will be the end of this topic.. good day..



LOL JK

Agreed. Although I've never had a RX7 b4, but from what I've read I think they really fuxked it up with FD3S (Mostly do with Cooling)

but hey, most of the of its just the end user side of problem. They abused it like theres no tomorrow, when something happens they went back to complain.

You might ask everybody does that in every car out there but consider the RX-7 user base is quite small, and most of the people in that "small" group abuse them everyday.

..........There's no tank rotary engines....................

um, maybe I'm showing my age here, but alas, there were rotary engines in German tanks in WW2. It was so cold, they simply left them idling overnight, becuase quite often they wouldn't start next day.

Well, he says that they use it in the "Abrahams" tank. Interesting, I didn't realize they named their tanks after biblical characters ... LOL whatta dipshit that guy is.

As pointed out above, both tanks and choppers use GAS TURBINE engines - which are JET ENGINES that have been optimized for shaft horsepower rather than direct thrust.

I suppose our rotary has something in common with those - they both rely on rotating, not reciprocating motion, both make cool noises and both consume prodigious amounts of fuel, but also produce prodigious power-to-weight.

But a gas turbine is not a rotary engine nor is a rotary engine a gas turbine.

...it's just the OTHER things like transmissions, clutches, electrical which bother/worry me :)

yup. first production wankel wasn't ready until '51. 6 years after the war was over.

I haven't read the article, but I do have a little input on the talk about rotary tank engines. John Deere's experimental engine division actually marketed a multi-fuel rotary engine for many different applications back in the late 1980s. Don't know whatever became of it, but I got interested because of my work. As I remember, and this hazy, they had three different sizes each of which could be stacked for different power outputs. They were touting this engine's use for a variety of applications ranging from emergency generators for the small version up to tanks and other large weapon systems for the big engines.

I'll look in my files and see if I have any old info on these things.

What's so funny about that? A nonturbo rotary is absolutely reliable. Like every other engine, the key is in taking care of it.

He's confusing rotary with turbine. Most helicopters use turbine engines as does the Abrams. He assumes that if it spins it's all the same.
-R.

and in addition the abrams tank(which i think is what he was trying to say) is a US tank not a german tank i believe and the americans certianly woudn't have rotary engines in their tanks

well, i know the first production wankel was not until the 50's, but wankel was german and he had alot of data and tests by the 20s. Im not saying this is accurate or anything, but is it possible that the german army used wankels for anything before it was mass produced publicly? I mean, wankel was part of the Nazi party and then tried to back out when he found out alot of their engagements and future plans. So, who knows what happened.

;)

He was developing 4 stroke engines with disc and roller valves for the Nazi's. (They use less overhead space than traditional engines and could have been put in places where space was limited (e.g. torpedo)).
Like Wernher von Braun (the saturn rocket guy), Wankel was also greatly funded by the Nazi's. Although I don't know what his political views were or if he had any at all.

I remember seeing pics of potential rotary motorcycles back in the 70's

Whoa, nice thread bump. Those bikes were not potential, they were made.

Woke up from 8 years of hibernation...

Can u imagine their performance!