rx7speed

well here are those picture I was telling you about

rx7speed

here is another one

rx7speed

should have more pictures up soon and even a vid I might be able to send you


but if you see the picture of the rotor (pic number 2) that is what spins in the motor round and round,
there is no crank shaft in the motor it is called a eccentric shaft and that holds the rotors like the crank holds onto your rods
the eccentric shaft is spinning at 3 times the speed as your rotors are so that is going to help with the high rpms these cars can get.
the shape of orbit the rotor takes in the housing you can see in my avatar
you are going to have intake ports on the side of the housing like so
you have two of those ports on each side of each rotor that pull in fresh air. big hole in the middle is where your e-shaft goes through and then all the holes around the edge of the housing is for water to flow through to cool the motor. oh yeah the housing though is of a turbo car. the N/A has another little opening right above the intake that will open up at 3800 rpms read below for further talk on that

then you have the exhaust ports that look like so though this one is ported a little bit

the intake and exhaust ports sit on the same side of the motor while the spark plugs ( 2 per rotor) are on the other side.
looking into my avatar you can see how the movement of the rotor pulls in air (top intake bottom exhaust) starts to compress it then the two plugs fire and then push it all out twords the exhaust.

the rotory motors have the two plugs on the car b/c of the wide combustion chamber and how if there was only one plugs you would have lots of unburnt fuel in there. the two plugs though do not fire at the same time you have the leading (bottom) plug fire first then the trailing (top) plug fire second. what this does is creat a even flame pattern so you burn more of the fuel that made it into the combustion chamber and that gives you better power and less emissions.

also since the oil really would have no way into the motor itself to lube the apex seals there is also a set of injectors at the base of the intake that will shoot oil in there. that way the apex seals do not wear out real fast. the rest of the oil is used to flow the the e-shaft to lube the bearings cool the rotors ( oil flows inside the rotors, kinda like having oil float inside your pistons).

you also have two fuel injectors per rotor for a total of 4
when you are just put put around town (such a thing in a rx7??) you are only using one per rotor but at 3800 rpms your second set open up
on your turbo motor it is b/c you have boost going into the motor so you need to have more air
on the N/A you have these second set of itakes (almost like vtec since it gives more intake timing and duration) these second openings are on the outer housings so you have it brings the total of 4 intake openings up to 6 on a N/A motor.
sounds cool when they open up
just think of a weedeater with a 4bbl on it or in my case when I had the N/A in there like a chainsaw with a 4bbl on it

sorry if this is a crappy way of telling you how it works but it is early in the morning here and I kinda tired but I figure between this and the other link I gave you that you should be able to piece it out

but tomorrow when I wake myself up I will read and see what needs to be added or you could always ask me some more questions


oh yeah
picture of how things kinda fit together

IROCKER

That thing is just weird! Of course they probably said that about the 4-stroke combustion engine when that first came out many years ago.

davecamaro

wow

that looks really messed up!
But its a cool system, the way it works haha!
My buddys say its crap? but I dunno looks cool to me!
and if the car is quick!? so its gotta be a good design thaN!

skidoo68

Very simular idea as with a Ski-doo Rotax engine.Has a rotary valve.

skidoo68

Very simular idea as with a Ski-doo Rotax engine.Has a rotary valve.

palric

iTrader: (1)

So where do the muffler bearings go ?

rx7speed

a lot of ppl have a bad idea about the cars

like they are not reliable and stuff like that

so far I have put 171 on my N/A motor and it was still running strong last time I took it out
I have heard many stories of ppl pulling way in excess of 200k wihtout a problem

the early rotary motors have had some problems with the seals breaking on them but mazda mae a lot of changes and the things can last forever

though with the turbo motor reliability has gone down a bit due to the nature of forced air and detonation. and the problem b/c worse on the twin turbo cars
also those things are a nightmare to take care of iwth al there vac lines (over 40 feet) and other junk that control the whole setup.
also another problem is these cars need to be taken care of. a lot of ppl can neglect a piston motor for a while and it will still run but these cars need to have there oil changed filter changed stuff that you should be doing if you had a piston motor as it is
if you do that then they can last you a long time.
most of the N/A cars can pull in about 200-250k miles without problem if you take care of it. also if you baby the motor while driving it all the time you are going to kill it also b/c the carbon will build up in the apex seals which will prevent them from omving like they are to do and then either can chuck an apex just have it stick in place which will make you lose compression.
they get great power for there size (1.3L)
they can rev like crazy.


honestly they are not as bad of a motor as ppl make them out to be. ppl forget stuff like how to take care of the car that you run in to real problems

palric

iTrader: (1)

Hey I was just poking fun.

I had a friend who had a sky blue '87 TURBO II that was heavily modified. Hotchkiss all the way. The car dyno'd at 280hp rwl which is who knows how much at the rotary ????

Well, that car not only looked great but was SCARY fast. As I remember it had two turbos, a low-end and mid-range setup. Interesting, the car had one turbo from the factory even though the car said TURBO II on the panels. My buddy tossed the factory unit and installed two hypo units. Made for alot of temp under the hood as I recall.

He ran it to lean one day and blew up the motor. Sold the car at a heavy loss and bought a Ford Taurus. Go figure. Now he has a '73 TR6 that he has rebuilt and is converting to a Syclone/Typhoon setup. I think he needs more life insurance...

RP.

junkyarddog

what should I look for when checking out a potential used rotary car that's any differentl than a piston car? I'm looking for a cheap ride ($1000) just to get around.....but not be a total POS either. I've seen a few in the paper w/150k+ that seem to be in my price range,mazda rx7s,nissan 240s...like camaros,these cars are likely to be ragged out.....however,the typical telltale signs should be similar enough to a piston car for me to regognize?? i.e. knocking,exaust smoke......I'm concerned because I have no experience driving rotaries and I know they sound funny,so how do I know if something is wrong with it? thanks!

rx7speed

stuff to look for?
well smoke is a big no no

you will want to check the oil make sure that it is nice and clean
also if you are looking for a rx-7 ask the guy if it eats oil
if he said no then just walk away
these cars are to use a quart of oil every 500-1500miles depending on how yo udrive it

if you can have someone hold the motor at 4000 rpms and look to see if there is any smoke comming out the exhaust if so blue means you are going ot eat more oil then you should. white means with a sweet smell could mean coolant leak.

if you can pop the top rad cap comming right off the block and start the car water should not come gushing out if so walk away
might churn a bit though and that is ok just better not start to gush out of there

and ask if the car has ever been overheated if so walk away.

when you drive the car around make sure you are able to get it to the redline and that it will go there nice and smooth.
these cars do have a small miss at idle on most of them. dont worry about it as long as it is just every now and then

dont let a high mile rx7 scare you either
the N/A motors last a long time
my N/A motor when taken out was still pulling nice and strong at 171k miles on the clock.



depending on what year you are looking at also there are other things to look at but you can prolly figure most of them out
oh yeah the 86-91 do have a IRS rear in them and sometimes the diff mounts break. easy way to tell is to kinda on the gas and if you hear clunks comming from the rear you might have a bad diff mount other then that if you know what to look for in a car you should be ok
most the stuff on the motor is just making sure your compression is good and your oil and water seals are holding up.



if you have any other questions feel free to ask me on AIM my name is rxspeed87 or just post them on here

and also you can take a look a this post

https://www.thirdgen.org/techbb2/sho...threadid=75254


I say take a drive in one they might not be that fast stock but they are easy to get there
these cars respond so well to mods it's crazy

but hey good luck man

Paul_Hughes_87 T/A

why is it bad to overheat the rotary?

rx7speed

well need to see my picture below

this is of the side housing
if you see my red little lines those are water seals( Iknow can't draw)

coolant will flow between those two red lines in the gaps that yo uare seeing

when the water gets too hot it can cause those to deform and then they will allow the coolant to go into the motor and also allow your vital compression to go into your cooling system and in doing so will make you have a loss of power and eat coolant

doesn't happen a lot
for the most part only have seen it if you dont take care of your car. you know like no changing of the coolant or making the car overheat all the time stuff like that.

again remember with this motor you do have to maintain it. if you do so then it should last a long time.

rx7speed

well kinda want a different look as to how a rotary works just look at my sig

you can see the exhaust port in the lower part ofthe housing and the intake in the upper side portion of the housing


any other question feel free to ask

also notice in the middle of the rotor the little thing moving around with the arrow pointing
that would be were the e-shaft sits
notice that it will do one rotation for each 1/3 rotation that the rotor makes

so with 2 rotors you are going to have just as many comb as a 4 cyl 4 stroke motor