It seems that TRIANGLE POWER has failed Mazda!

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Hell I have been in an RX8 on the left lane of the autobahn before a few times as a passenger and nothing can match the exhilaration of revving that rotary wankel all the way upto 9000rpm.

He's got a point. Rotary engines are just so exhilarating. Not only does it rev way up to near the double-digits, but it has a very unique ability to grab it's power at about 3,000 RPM and then hold it all the way up to the high-RPM redline. Most engines have to gradually build up their power, but the wankel is just so much more efficient in the way it gathers and holds onto it's power. This also means that the gearing can be shorter because it will have the same-or-similar top speeds per gear as other similarly-powered non-rotary-engined cars, but it will accelerate more quickly through each gear. My 240SX, for example, has about the same power, and much more torque than a 2nd-gen RX-7; but the RX is admittedly much more exciting and quite a bit faster; solely because of the attributes of the rotary engine.

And, an RX-8 with 220-some horsepower could easily be a V8 Mustang-beater, I'm sure. I'd love to drive one of those things some day.
 

Blind_Io

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Lets remember that when Clarkson drove the RX-8 he was thrilled with it - his only gripe was that the stock tires got squirlly in the wet, if I recall he even said it was the best car he had driven by that time (although the later retracted this when he complained about the tires). For a man who drives Ferraris and Lamborghinis on a regular basis that is high praise for a $30,000 car.

The rotary engine has hardly failed Mazda, a few engines have a minor problem with the equivalent of the piston rings and Mazda realizes its more cost effective to just swap engines than rebuild all of them. I'm sure these old engines will be rebuilt and sold as individual units or replacement parts.

You can't impeach an entire engine design just because of one minor fault, if that were the case we never would have gone from sail to steam and the piston heads' engines would have never made it off a workbench.
 

zenkidori

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Blind_Io said:
a few engines have a minor problem with the equivalent of the piston rings
actually it's the equivalent of oil seals, because that's what they are. This recall has nothing to do with the apex seals.
 

kaBOOMn

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The way I read the article I'd agree with zenkidori (there is a first for everything :lol:)

Still its inherent in the design that its going to burn more oil, and the other problem with combustion chamber shape (look at a shaped explosive charge, look a normal pent roof combustion chamber then look a Wankel engine) and the other problem is the power band (torque band) its going to put out. I know you can add combustion pressure from a low RPM, but its not the best idea.....more stroke is easy to get with a piston engine to get more bottom end grunt....but a Wankel?

(and yes I know what gearboxes are for..... :p)

Still I wonder if you could use a needle roller as a seal with its own suspension system?
 

JipJopJones

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My Dad had to replace the engine on his 93 RX-7 2 times, But he still loved that car... best japanese car ever made!!! IMO :thumbsup:
 

zenkidori

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kaBOOMn said:
Still I wonder if you could use a needle roller as a seal with its own suspension system?
There are actually a few people working on this. It seems it would stand up to detonation a LOT better(perhaps even more than a piston right) but the problem is the high RPMs it would be spinning at. Also there could be oilers on the rotor side of the seal oiling it as it runs along getting rid of the need for any oil injection.
 

kaBOOMn

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Yeah....

Yeah....

Fair call, I suppose you could "float" the needle roller on a bed of high pressure oil like a convention engine bearing?

But still you have the inherent problem of a poor combustion chamber design requireing the use of two sparkplugs....which is never going to work. But really can you improve it by altering the shape of the rotor?
 

zenkidori

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Re: Yeah....

Re: Yeah....

kaBOOMn said:
But still you have the inherent problem of a poor combustion chamber design requireing the use of two sparkplugs...
poor design? that's quite the statement, and quite the wrong one.
 

Chambers

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okay can someone just tell me if its really 1.3, 2.6, or 3.9? the revs of the output shaft to rotor and power stroke to revs kinda confused me a bit..
 

kaBOOMn

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Re: Yeah....

Re: Yeah....

zenkidori said:
kaBOOMn said:
But still you have the inherent problem of a poor combustion chamber design requireing the use of two sparkplugs...
poor design? that's quite the statement, and quite the wrong one.

Fine explain to me why? I'm not being narky, I 'd just like to know :)

I mean I can understand stageing the plugs to keep the flame front moveing in the correct direction (same direction as the rotation of the engine) But a big long banana (well sorta! :p :lol:) chamber is never going to be as good as a small tight pent roof system. Also why do they sculpt a section out of the rotor. Is that to alter the compression ratio?

I know I'm working on what I deal with when playing with "normal" piston engines like the Alfa Romeo boxer engines. They have the valves flat in the head and the combustion chamber in the piston, so you can play around and do what you want.

Still if I have it totally tits up well, I'm wrong then :p
 

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Re: Yeah....

Re: Yeah....

kaBOOMn said:
zenkidori said:
kaBOOMn said:
But still you have the inherent problem of a poor combustion chamber design requireing the use of two sparkplugs...
poor design? that's quite the statement, and quite the wrong one.

Fine explain to me why? I'm not being narky, I 'd just like to know :)

I mean I can understand stageing the plugs to keep the flame front moveing in the correct direction (same direction as the rotation of the engine)

they ignite at the same time, it's not to keep the combustion going in the right direction, but because the surface of the rotor is so big, and a flame travels to slowly, so with only 1 spark, in the outer corners there would be leftover mixture which hasn't ignited

but you can perfectly run it with only 1 central spark plug. the biggest gain they get from 2 spark plugs, is lower emission, since the difference between 1 and 2 sparkplugs is a powerincrease of only about 5%
 
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