sup3rbad

i'm new to rotaries. i know the basics of how they work. i was just wondering how you can have an all motor set-up with a rotary. enginge rebuild, bolt-ons, etc.

wakeech

you mean what to do??

power = force (torque) * speed (rpm)

because it's difficult to simply increase the torque made at any speed beyond a certain point (for an atmospheric motor), what you wanna do is make as much torque as you can at the highest rpm possible.

yes, a teardown and rebuild is in order to really increase the motor's capacity for power making.

making the most possible torque is all about efficiency, and that's the tricky bit: optimization of everything.

are you asking how you can increase the efficiency of a rotary at a high level of output??

sup3rbad

i think thats what im looking for. higher revving, higher output. i jsut want to get as much power as possible without having to go with FI. if possible

rxphink

Well unfortunately since this motor is so new no one (state side at least) has figured out the proper port shapes for porting the engine.

Porting a rotary is just like port and polishing a piston engines heads and dropping in a new cam.

Porting deals with timing the charge in the engine and I'm not sure anyone has spent the time to study the phasing of the rotors in the engine to get the perfect port timing down. Rough guess porting is probably available now but that wont give the best possible results. There is a lot involved in NA tuning of a rotaries ports so you can make sure that you are getting the best flow at both ends and avoiding reversion in the exhaust.

Whis brings up another point I've been thinking of, what's up with the header designs that are out there currently. They seem to address the center ports with a splitter that sticks into the engine, but I would think that having those two ports split up for even a bit longer would prove beneficial.

Any way I'm sure Paul Yaw is working on all these details currently.


As far as getting a rotary to rev higher it is more a matter of ignition timing and getting the engine to deal with harmonics at high RPM's. It was a common belife that a 13B peri-port engine could rev quite easily to 12K but much over that and the engine would have problems with harmonics and need more bracing ie. more dowl pins and a stonger eccentric shaft.

SA22C

Like the others have said, it's a bit early for the aftermarket, but stay tuned to www.racingbeat.com they've been the major source for rotary performance parts for the better part of 30 years. They sell items like hardened gears to allow safe operation in the 11,000 rpm range for old-school rotaries.

wakeech

then that's easy: perhipheral port.

...illegal in most levels of racing, this port is what made the V8 fear the rotay in the 70's. make +300hp (at like 10k rpm), shoot mad flames, have a sky-high idle, and really unbelievably bad fuel milage.

now, if you mean as much horsepower within reason, then it gets tricky

wakeech

actually, any amount of phasing overlap between the expiration and inspiration cycles can be overcome with rpm getting p-port motors to idle just means adjusting it upwards to ~1500rpm.

header design is going to be a bitch on this motor. having a longer baffle between the exhaust pulses isn't going to do anything if you're feeding them into the same runner anyway. rotarygod has been struggling with his feature of the motor for a while: he's the guy to talk to if you have ideas (oh and read the Helmholtz thread for the intake side of the equation).

other things that can be done to help deal with high-rpm operation is reducing the mass that's movin' around in the engine, like drilling out chunks from the e-shaft, and shaving the hell out of the sides of the rotor (along with the race clearancing, harder outer gears, and whatever else...).

sup3rbad

that awesome, but i think within reason is the idea i was going for.

wakeech

s'what i thought.

sup3rbad

well the reason i ask all this is, even though a piston engine and roatary are diferent i wanted to know if the same techniques could be applied, i.e. engine rebuild,to getting a higher power motor. my friend told me about his cousins h22 motor (honda prelude, and yes i am aware that u dont like hondas) redlining at 10k and getting top speed in 3rd gear. that car was one of the most feared sleepers in that part of los angeles. i want to know what the rotary is capable of.

the h22 was in a 91 accord. crappy shitbox looking thing

wakeech

:D i don't hate Hondas!! i think they're very well made and designed cars, i just hate what people do to them (no, tuning a motor like that is not something i hate)

yeah, even though the mechanics are different, all the same things are accomplished in mostly the same way... from the design aspect and the tuning aspect there are differences (such as running UNBELIEVABLE ignition advance, because the e-shaft turns 3* for every 1* of rotor rotation... so hitting near 30* of advance is not unheard of, not to mention the 2 plugs per rotor thing). the flow pulses are different (in duration and pattern), and have to be accounted for in design... so yeah, there are some differences in what you do, but getting power is done in the very same way.

sup3rbad

sorry for my previous assumption. i guess i misinterpreted one of your previous posts. looks like i gotta do more research. thanks a lot for your input and i'd like to get some more information. i'd like to know where you learned about all motor tuning and where i can get some more info.

sup3rbad

btw. the engine rev up to 10200, but it could have gone higher. a shop in l.a. bought it and turned it into a track car. same motor set-up, but it's just completely gutted.