capri93

as the title says what does it take to do this? lighter race rotors among other things I have no real plans to of taking it to this extreme but 9-10k would be cool.

lovintha7

A ballistic shield for starters.

YapaKanichi

hey to talkabout ballastic shields where are they and how much

lovintha7

Maybe Jeg's or Summit?

capri93

yeah i know about that stuff like tranni blankets and and drive shaft cradle the safty eq

lovintha7

Tranny blanket = ballistic shield

Xavier8

get a renesis-9500 rpm fuel cutoff-just playing

lovintha7

Oh, btw there are 2 Renesis engines with computers on ebay, starting at $3k

capri93

boy are we off the topic here

85rotarypower

Lets see, to start off you would need:

-Carbon apex seals
-3rd gen seal springs
-hardened stationary gears
-race clearenced and lightened rotors
-lightweight flywheel
-LARGE carb
-upgraded oiling system
-underdrive pullies so you don't fry your water pump and alternator.

I'm sure thats not all. I am by far not an expert on this subject. I don't even know if its possible to make a rotary turn that fast. But thats probably a good starting point.

ScrapFC

iTrader: (5)

I've been thinking about this and I have a few suggestions:
First, you really really need a center support bearing! Eshaft deflection is going to be brutal at those RPMs if the eshaft is only being supported from the ends.
Second, you need the lightest possible rotors. Maybe start with Renesis rotors and shave them down like Racing Beat does with the earlier rotors?
Third, you need really strong side gears. Maybe dual side gears per rotor?
Fourth, you need a LOT of port area/timing. A large PPort should do it. Maybe a combi-port? (Side ports with a PPort that opens at high RPM)
Of course, you'll also need a flywheel/clutch/trans combo that can stand up to that sort of RPM.
Don't forget some SERIOUS scatter protection! When that mother grenades at 14K+ (think missed shift) it's going to have some INCREDIBLE KE behind it!

BTW, if anyone manages to build such a beast I WANT VIDEO!!

Junia

I think it simply just takes air and fuel. As long as you keep feeding the engine the air and fuel that it needs it should keep going until it just pops or something else in the driveline pops.

85rotarypower

At that engine speed, a stock engine wouldn't last more than 3 seconds. Supposedly 8500 rpm is the max safe speed for a stock rotary. At 8400 rpm the apex seals start to "chatter". If you hold the engine at 10000 rpm your steel apex seals are going to eat your housings for lunch.

REVHED

First of all, 14000rpm is a bit unrealistic. You'll find even the most highly strung peripheral ports will have a useable power band up to around the 10-11000rpm mark at the most. The only time you'd hold it for longer is if you're coming up to a corner and it wouldn't make sense to change into the next gear.

To achieve these sort of numbers you obviously need to start with an engine capable of making power at such high revs. This means a peripheral or large bridge port. As far as the engine internals go you'd need carbon apex seals, lightened, circlipped and clearanced rotors, tougher stationary gears and the usual oil mods.

Circlipping involves machining the rotor to accept a circlip that holds the rotor gear in place and stops it from "walking" at high revs. Clearancing is when you machine the sides of the rotor to provide more clearance between the rotor and side housings to prevent contact caused be the eccentric shaft flexing. Some people also clearance between the rotor tips and rotor housing.

There are other things you can do as well. Guru here in Australia have a two-piece eccentric-shaft that incorporates an extra bearing in the centre housing to prevent the e-shaft from flexing. They've also developed their own rotor/stationary gear profile which is supposedly far stronger than the Mazda design which hasn't really changed since the early days.

capri93

so this 14000 thing is a bit out there but you guys got the general point i was looking for and thanks i think for now im just gonna work with porting and turboing my 81 and 84 then maybe work up to the higher reving motor. What kinda rpms are people running with simpler upgrades like carbon seals, Br port, bigger carbs better exhaust the more common stuff

peejay

Four big bags of crack.

peejay

Now that that is out of the way...

If you want a really high revving power plant, a peripheral port won't cut it. You'll need a monster bridge in order to get the port area and port timing to suit.

But why bother? Internal stresses go up by orders of magnitude after about 8k, and accelerative losses from rotational inertia dictate that the best engine is the one that makes its power at the lowest RPM possible to make that power. There is no real point to building an engine to rev higher than 10k.

Stock 3mm seals don't start to chatter at 8400. They start to chatter at *6200*. Chattering becomes fatal at about 8500.

Junia

I've read in alot of places where people say don't rev the motor above 8500 on stock internals but I know plenty of people running stock internals running 10,000 on a regular basis without any problems.

vipernicus42

iTrader: (4)

There's no point to 14,000 RPM at all. As REVHED said, there isn't any usable power up there, and even JESUS PADILLA didn't go above 11,000.

It would take more money than it's worth, and there'd be no real benefit to it.

Jon

Junia

I don't think that he's worried about whether theres usable power up there or not. I think he just wants to know if it will spin all the way up there or not and what it would take to get it up there.

OtakuRX

iTrader: (1)

how do you get a rotory do 14000rpm

Very carefully

hotty

easily.. you rev it up to 18,000 rpm and smile like hell.
Of course i'm not talking a full size 12a or 13b, however, there are small RC engines like the Graupner/OS Model Engine 5 cc - 2500- 18,000 rpm 1.27 BHP

254HP PER LITER :O

I wouldnt waste my time revving a full size rotary about 10k EVER. even 9 is a LOT of rpm.
Daryl

rototiller1

25,000 Dollars

LEZNAY

i thnk the point is more if it can get to 14000 with out exploding it can do 9 with out exploding and you and force it better, meaning if you push it to do 14k 9k is walk in the park.

capri93

thats more what i ment i want to have my engine still running should i miss a gear or **** up a clutch at 8 or 9k not run 14k constantly i dont plann on ever hiting that mark i just want a little leeway in case of a screw up on my part