Could i possibly be able to rebuild a 13B n/a to run at 10,000rpm RELIABLY. exactly which parts would i need to replace and strengthen to run this high at redline, what size injectors would i need and anything else i need. which systems would you reccomend to control ignition timing and feul mapping? I realize this will require custom work and dyno tuning to run correctly at such high RPMs


Jeffrey

 

You just need to change the pully sizes so none of the belt driven stuff overspins. Afer that an upgraded or reprogrammed ECU to control fuel & air delivery above 7000/8000 rpms.

I believe the haltech can be programmed to control this. A 3rd / 4th set of injectors wouldn't hurt either if your running boost. Keep her rich above 6500 + 12+ PSI of boost just in case.

You do realize your powerband will be shifted - although wider.

Nothing needs to be strengthened (no pistons to break - it just goes around faster). Not sure on the transmission / flywheel though. I think some parts may be rpm dependent.

 

you do need to get some hardened stationary gears i believe, and you also need to have the motor balanced, more so than just a normal build so that at the higher rpms it doesn't want to vibrate apart.

 

I am wanting to go this same route. Racing Beat has some good info in their catalog. I think the important things are just like boingers, ie. balanced internals, proper clearances, etc. That being said, I think rotaries are much more conducive to high rpm use than boingers. Right?

 

I agree with OPEC, you definitely need the hardened stationary gears and everything should be balanced. Weve made these motors (NA) turn relatively close to that for 24 hours reliably with those 2 things done.

 

You probably need 3 window bearings too. And a racing clutch. And a scattershield for the trans. (Ever see a clutch come apart? Not pretty).

 

you need a proper racing clutch and light weight alloy racing type flywheel, anything else isn't rated over 8500rpm

basically lighten and balance all the moving internals - both rotor and the E shaft, cross drill the shaft for better oiling. get everything blue printed and have the clearances all correct, i would suggest using new parts not 2nd hand ones.

you need either bridge ports or larger cause nothing else is worth using to 10000rpm

on an injected engine to pull 10000 you need 4 x 800cc injectors or possibly larger

 

<rant>
Wanting to turn 10K rpm's is rice. Who cares what RPM you can turn, an F1 turns 17K, so the urban legend that a rotary revs more is plain stupid. You couldn't even drive a real 10K rpm car on the street since you would need a real port job. Anyway, if you have to ask, you probably can't afford it, nor do most people on this forum have first hand knowledge since everyone here is all about 1/4 mile and wiring functioning ports open.

</rant>

 

10K is used on rotary dragsters right?

 

The issue you run into at very high rpm is eccentric shaft flex. The eccentric shaft isn't supported in the middle, it only has 2 main bearings. If you look on the Mazdatrix website, you will see that the rotors for 89+ motors are significantly lighter. (Hence the different counterweights and flywheels for the different years.) Lightening the rotors and balancing would certainly help, as does "race clearancing" the rotors for high-rpm use. (basically they are narrowed slightly at the tip of the rotor.) This allows higher RPM before they start to gall against the end housings due to the eccentric shaft flexing.

 

If you want a reliable 10,000 RPM engine then wait and buy an RX-8. You will even get a warranty.

I'm of the opinion that reliability is inversely proportional to the rpm's. As one goes up the other goes down. Its the nature of things that are mechanical.

 

Mabey not... u need to keep your rotory above a certain rpm for reliability.. I think taking it to 8500 every now and then is no big deal.. I always take it to 8 but havnt enough mods for 8500 so. Anyways i have heard that 85 is safe for oil and cooling until anything over that. Thiers a reason why the red lines at 8k. I think your better off spinnign it at 8800 were the limiters at. Much safer. 10k is for racing engines only.

 

You have it right. The shaft flex is what the main factor is past 9k. Also the hardened gears are a waste of money. Shops tell you that you need them to take your money. How many of you have ever broken a gear? Ya I know there might be one guy on here that has but you would have probably broke it even if you were stock because it was a defect. Use a pair of good seasoned gears with 30k or more. No jk. The bearing's might not be that bad of an idea. But you realu only need them if your realy a drag guy. I also aggree that rotary have this reputation with every one, All I ever here is "oh those rev to infinity" and oh those turn super high rpm" Which is almost a joke. We realy only push 8k out of most engines. I mean I am building a 12a p port and I am not shy to say that It is going to be an 8800 rpm engnie not some 12k monster that most would think. The balancing doesn't hurt but Is it realy worth it? My engine turns some pretty high rpm and it feals smooth. smoother than any piston engine. Clearencing rotors might be kinda a good idea but once again watch what your buying or shops will take all your money. This is what I think, I am not trying to offend any ones intelligence I am merely stating MY Opinion. I hope you have a good motor built and you don't have any problems. Peace out.

CJG

 

I beleive i'm one of the very few people who have owned a 10k+ rpm engine and daily drove it on this forum.

Like HWO says, you'll need atleast a bridge port. However, unlike most people, i beleive apex seals are the next link. Steel apex seals don't like the rpms. They are safe to 8,500. They will turn more, but you're taking a chance. Carbon apex seals don't like forced induction. They will however take rpms. Ceramics are the way to go. Yeah, they are expensive, but if you want your turbo'd bridge/peripheral engine to last awhile, you'll need em.

Anytime the motor will go beyond 8,500, i know Rob at Pineapple will have the motor balanced. Just anouther saftey feature.

The lighter the rotating mass, including flywheel, the less e-shaft flex you'll get. So if you have some shaved or cut rotors, and an aluminum flywheel, you would be able to spin that motor to 10k all day long. I ran the **** out of my last 13B peripheral port for around 20k miles, before being sold. It had a stock 86 rotating mass, including flywheel. It was balanced though. Ohh yeah, i was also running upto a 150 of nitrous. So if anything was going to be flexing it would be the e-shaft. But then again, maybe the reason why i never had problems was because it was a Pineapple motor.

Hardend stationary gears are nice. Especially if you are going to be in the 8,500-11000 rpm range for extended time. I have seen lots of broken stationary gears. Mostly GT1-2-3 engines, that where reved the **** out of for long periods of time.

3 window main bearings are a must. Gotta have more oil, if you want bearings to live. Deep grooved race bearings are also nice.

If you plan on going peripheral, you're going to need a realy big turbo. I'm talking realy big. Talk to Rob or Rice for sizes.

Bottom line, plan on spending lots of $$.

CJ

 

umm guys, read what the man said at the start........

Its n/a not forced induction

Carbon seals are all good for your application then

 

Well, now i feel like a moron.

 

Ya, but mines turbo'd, so I wanted to know those things related to turbo engines. Thanks for all the input. Why doesn't someone point out this thread to Cris and those guys?

 

What about Hurley seals for High RPM/turbo app? I really dont want to spend $300 a seal for ceramic.

 

Just a little thing on the side about the revs. The DKM or Drehkolben Maschine, a rotory engine achieved such RPMs as 25,000 RPM. God i wish i had one of those. A down side is the fact of having to disassemble the whole engine to change spark plugs. And this motor was smoother than the KKM, Kreiskolbenmotor which is the begining of our engines.

 

If you insist on revving the engine to 10,000 RPM and beyond, then you should expect to be spending $$$ for the priviledge. If you're only going up to 8,500 or so, then you don't have to worry about exotic materials and such. What is the facination with 5 digit rpms? If you need to hit them to acomplish a specific purpose, fine, but if it's just a bragging right then I would suggest the effort is pure vanity. (I'm not picking on Mazdaspeed7; just the idea in general). BTW, Rob Golden of Pineapple Racing once revved his truck to 14,000 RPM in a street race (in his younger days) and blew the clutch, pressure plate, and flywheel to pieces. They could not even find the starter! A guy behind him pulled over and exclaimed that it was the coolest explosion he had ever seen. Fortunately, the REPU clutch is forward of the driver's feet so the shrapnel just tore through the cowl in front of him. He is now a big supporter of scatter shields.

As for Hurley seals, they're supposed to be great. Rob uses them for the 3mm rebuilds because if they break, they tend to crumble into powder and not cause subsequent damage to rotors and housings. He also would have "issues" with anyone claiming 3mm seals chatter by nature, or other such nonsense. Can they chatter? Yes. Generally if you overheat the motor and ruin the springs. Also they need proper clearancing and break-in. And it depends on not just the material but the manufacturer's design. And those who claim 2mm seals are perfectly fine at high boost levels are right BUT only if you are (1) a great tuner, (2) using a proven package (systems approach), or (3) have the cash to rebuild the motor if you screw up. A professional tuner in my area (dyno, WB O2, Optical RPM pickup, years of experience) blew his 470hp 3rd gen by accidentally pressing the wrong key while tuning the fuel maps. Do'h! 3mm seals are stronger and can take more ping before breaking, giving you a chance to back off and save the motor. Sorry for the non-specific rant, but there are too many BS "facts" floating around.

If you have any specific questions about what engine "package" you should use to meet specific goals, then I'd suggest you talk to your engine builder. If they can't help you, you should find an engine builder who can. And if you're going it alone, make sure you have liquid assets to cover your *** if you screw up.

BTW, listen to CJ (pp13Bnos). He knows what he is talking about from personal experience. How many here have driven everything from stock engines to peripheral ported 13Bs with NOS (daily driver) to twin turbo third gens? Next to Mark Goldby (another local guy), I think he's Rob's best customer.

 

I think Paul (yet anouther local guy.) takes the best customer award....or the most motors bought award anyways.

I don't know if you guys know this or not....but Blake is stepping into the 10,000 rpms (11k is probably more like it )club, with a 13B peripheral port engine, on a 150 shot, stuffed in a lightweigh first gen. By the way, how is the beast coming along?

CJ

 

Dead men don't count. Paul has been helping Rob in the shop lately. For example, yesterday Paul "helped" ruin two sideplates (one *new*). Rob really "appreciated" that! Paul was last seen being escorted to the river by two large men of Italian decent. Geraldo Rivera is investigating.

Car runs. Working on the fuel system and still need to install the 4.88 gears. Ari Yallon sent me some exhaust stuff. Royal Purple shipped me some oil. Still looking for a good deal on N2O. Russ at Racetech Fabrication is loaning me the use of some shop space and will help me do a cage and other bracing. Should be a fun ride. Also made arangements to borrow a truck and trailer for the 8,000 mile round trip to the competition in Florida in February. Then, this morning, I got a call saying the guy who committed to buying my GTUs has backed out, leaving me short of cash to finish the job and make the trip. Bastard. Now, I need to get another buyer, raise cash some other way, or put off the trip 'til next year.

 

You kinda missed the point of my question about Hurley seals. I was just wondering if they are better suited to high RPM's than the Mazda steel seals?

 

Nah, I just went on a rant about arbitrary goals and dubious "facts". If you look closely, I did say they were great seals. However, the only rotaries that get *any* benefit from super high revs are bridgeports and peripheral ports. Since these are almost always non-turbos, you might as well just use the carbon seals, which are not only the best thing for the job (super light, one piece, self lubricating, etc.), but they also happen to cost the least. Ceramics are only needed where boost is involved as carbons can't take ping. Not sure if the Hurley seals are particularly better in terms of high revs (how high?) but they certainly are better in other respects, so it wouldn't surprise me. While ceramics are the Gold Standard, Hurley seals are definitely a good upgrade from stock if you don't have a trust fund. Is that vague enough? More specific info can be obtained from Rob Golden at rob@pineappleracing.com

 

Ok Here is the down low on the internal modifications to make it possible to rev that high. First of all the gears in the rotors need to be pinned or snap ringed in. The rule of thumb is if they are not at the magic 8,500 RPM mark they will start to walk out of the rotor and hit the side housing. Second thing is the whole rotating assembly needs to be balanced. That includes pulley front counterweight, both rotors eccentric shaft, rear counter weight, and flywheel. Third thing is the apex seals and springs the stock 3 piece with two piece springs give good compression from idle to that magic 8,500 RPM mark again (some say it can spin up higher). To be able to hold compression you will need to have a good single spring with a 2 or 3 mm ceramic one-piece apex seal. The only thing about these is they seal great up top but they don’t seem to seal good from idle to approx 6-7K RPM. So from what I understand this makes this motor unstreatable and very not CA smog legal. Most of this information is in the Racing Beat catalog (Racing Beat rules call them up they got all sort of idea’s). And that is just the internal mods you need. You still need a lot of air an aggressive port fuel to match and some good spark to ignite all that. Hope this helped, later.