What are the chances that a 1988 Mazda RX-7 will run after sitting in the same place for about 16 years?
If the motor ain't locked up, we have a chance. You might pull the plug before turning and squirt something in there before turning. If it is locked up, you could take it apart and examine what? but the running seals wear out quickly, see, regular pistons go up and come down, able to cool in the process...this design is 'balls to the wall' and tends to burn up what would be piston rings on a conventional engine. These have alwasys been impressive, but ultimately begin a smokin',,,here's your chance to get your hands dirty rebulilding on your kitchen table as these are SMALL for the power. I love this design and was given a clear model of this WANKEL engine at the age of four.
Impressive acceleration! always been impressed with these. could just turn the key. Maybe she'll kick 'round and 'round.
You see, I'm 16, i don't know how to do any of that stuff. And my dad would probably mess it up more if he tries anything. That's my problem.
But thanks for the suggestions
These are cool. Expect to rebuild the engine A LOT. Get used to it if you own one. hopefully will not be a 'factory smoker' (a joke, the name of a cigar from the 20s), but accurate as these were never designed with lasting power in mind. good luck my friend, I'd buy it, but my wife would serve my balls with pasta.
These are Easy! totally less moving parts than an old piston engine....and simple. so you're sixteen...cool, nows the time while you still have an open mind. If you love chess and are good fixing things probably can do this yourself- take the ASVAB (armed services vocational aptitude battery) it was by taking this test (came up number 2 of the group) was able to realize the common sense mechanical nature of things- give it a shot, if you fall on your face, you can always SELL the thing!
my neighbor lady had a car powered by a wanker so she claimed i was just a kid , always said " hi sonney going shopping got the wanker in my car by,by" and her and her old man would drive away
with the modern materials, what would provide seals for space flight, you'd think a modern polyceramic would mesh nicely. It's only a max of 9000 rpm. This design is like a PUMP, pumpin' fuel on thru without rest. That is why it has such TREMENDOUS nonstop acceleration...very impressive...waiting for someone to realize we have the technology to fit these seals with these modern materials. I believe suzuki made a rotary engine model bike, or perhaps kawasaki?
Because it is hell and high water, it really hasn't got good fuel mileage, suprisingly--neither does my MINI, but if you really love a design, none of this matters~
Before trying firing it up, remove the spark plugs and squirt some motoroil in the spark plug holes. Make sure the (new) battery is fully charged and try to crank it with the spark plugs still removed and the injector and fuel pump fuses pulled. If the starter engages but it doesn't want to turn over you are best off taking the engine apart and rebuilding it. Chances are the apex seals have corroded onto the rotor and rotor housing. If it does spin freely do not start it up until you've totally cleaned out the fuel system from tank to injectors and have replaced the coolant and engine oil. Put in fresh spark plugs and wires and a new air filter. After all that you can try and really start her up. Remember that Wankel rotary engines need regular maintenance and that there is no such thing as overmaintenance for an RX-7. Oh, and before considering driving the car I would replace all four tyres and free up the brakes if I were you or you might end up not going anywhere or into someone elses car...
oh wait, yes there are two rotary cylinders, forgot the staggerd design. Not only the seals corroding and not being able to turn, the internal gear drive whines like a banshee, when it's working correctly. Now you'd have to cover your ears for the noise!
So its a good thing if it whines?
I've never heard properly running rotaries wail like that, maybe you heard one with a couple of buggered up bearings?
Lars, when I was four was given a clear model of a wankel engine as a gift, and there are INTERNAL gears! how do you think the power gets from the lobes to the crank. With a gear. Do gears make sound. yes they do. This is what they sound like, gears meshing under tremendous force. You'd know the sound if you heard it.
...well, like a jet engine, you can hear it trying to hold back under the tremendous power that is transfered to GEARS instead of reciprocating olde tyme ole engine 58 stylie~ You can HEAR the restrained power, and like a turboprop is there, and yes kind sireney. that's the way johnson rolls~
Actually the gears are static, power goes to what you call the crank via excentric lobes on the shaft (it is actually an excentric shaft). The gears merely provide a guide for the rotor to run in its epitrochoidal motion. The only time the gears actually whine are if they have a severe lack of lubrication. Unlike a turboprop there is no reduction box directly mounted on the end of its shaft.
http://www.animatedengines.com/wankel.html as you can see the teeth take the torque!
Bob, please explain to me how a stationary gear that is bolted to a housing can take torque to anything other than the engine mounts. As I said: the stationary gears are a guide for the rotor's motion, the excentric lobes on the output shaft then transfer the torque to the flywheel. It's not like a radial engine you find in a vintage aircraft where the engine itself is spinning and the crankshaft is fixed to the airframe...
Lars, what this animation doesn't show is direction of rotation...the eccentric lobes turn about the teeth which transfer the torque...I guess an animated is better than words...at any rate these engines don't go vroom vroom, more like an angry vacuum cleaner gone bad.
Bob, you're not looking at the animation right: the black gear you see is stationary (AKA the front and rear stationary gears on a two-rotor Wankel engine), the red gear is the gearing on the inside of the rotor which is a guide to ensure the rotor doesn't slip position during its rotation, the blue thing is the output shaft (see picture) which transfers the torque from rotor to flywheel. I've owned and worked on rotary engined vehicles for over ten years so I know how they work.
gm invested millions, scrapped the plan when the gas prices were in jeopardy as rotors were fuel hogs as i remember ,though a good concept ,
A rotary is only marginally less fuel efficient than a piston engine, especially with the newer renesis engine. The difference is that the power output per displacement is a lot higher and it has a lot less moving part and virbration. Don't forget that there's been over 125 years of development on the Otto-cycle piston engine by tonnes of manufacturers whereas the Wankel rotary engine only had a first working prototype in the 1950s and a brave few pioneers that believe in this engine. If the same development funds had been sunk into the rotary, who knows what sort of improvements could be made...
don't get that as a 1st car if you can't fix it yourself.
that guy is just a kid. His dad can't even fix this one. Frankly most mechanics are going to scratch their head for a few minutes before layin' a claw on this one.
Back when I was still a mechanic (for money), a customer rolled in with a rotary that was smokin' and hard starting....Sadly, there was nothing I could do, put new plugs in it, but did not stop it from smokin'---was not a happy day.
True, some specialist equipment, a couple years of experience on piston and turbine engines and a factory service manual will be needed before starting work on a car like this. Better off getting something cheap and cheerful like an old VW Beetle or 1980s Golf to start off with. It lets you get to grips with the basics before you move on to the rotary league :)
@Lars, you and I both know that we've had ceramics that can stand up to this CONSTANT motion with hot enough to melt steel on one side and a vaccuum on the other. really quite the tricky puzzle, I'm sure the first ones were molybednum alloy, and after they figured out that a piston goes up for a rest, then comes down for a rest, but the triangle piston turns turns turns and keeps turnin' takes a mighty mighty alloy to stand up to that level of torture...that's why. Don't want to pay for very special alloys on the consumer level, like electric cars have been around at least one hundred years. ya think,,,?
All a matter of cost per unit Bob, development of high tech composite ceramics into a durable component don't come cheap and you'd still need a spring to keep the seal from losing touch with the housing that would keep its strength after being subjected to continuous temperature changes. All in all you'd need quite a massive development budget and the materials and machinery to turn it all into a mass-produced device. As for electric cars there have only been major advances in batteries in the past twenty years the energy density ans service life of a lead acid battery or a lithium-polymer are the only viable power sources so far and the lithium battery has only been around since the late 70s. Also advances in electric motors and control units have made a few leaps in the last decades. All in all it needs more than one developer to advance engine design in great leaps unless a huge budget were allocated to do so.
...let's hope they can make with the goods, Wankel rotary is a better engine, any day of the week for the NO VALVES and fewer moving parts! light, like a gaspump...not a gas pump but a pump that pumps the gas (combusted vapor) nonstop- spiffy design, hope everyone catches onto this level of technology- not fuel efficient, put the weight/performance cannot be beat.
Great conversation. I rebuilt that with no experience. (Im smart with these things, horrible at most others)
Search Mazda RX-7 Questions
Mazda RX-7 Experts