Can you make a 20b+20b?
 

So the idea came to me last night that I needed to build a car. Now I have seen people do FDs with 2 13b's put together... so I was thinking could I do that with a 20b?

Now before people start going on with how long it would be, how it will not fit in anything...ect ect this would be a new car! I want to make the frame/body all of that from scratch. Don't give me the BS of ''if you have to ask you cant afford it''. Now there is about a cap of $500,000.01 on the project (and yes k500 is doable)... so dose anyone think that this could be done for that?

No this is not a project that is going to start tomorrow haha as all of you could guess... I am just looking in to it to see if it can be done, it will take years to start any of it, but I feel we need a super car powered by rotary and I want to make it :001_005: I would like this thread to be fun and toss around ideas on what could happen. So don't put it down and just say this is stupid, I would just like to know what the rotary community would think and if they had any ideas on how to help get it made.


Thanks for you guys time, have fun.
Zane

I'll buy one.

There actually is some pics of a 6 rotor engine out there. Not sure if it ever worked or not.

you can couple anything together. just the effects of flexing acting across the coupler.

Pretty sure the E-Shaft would be an issue.

Ok so I guess the best thing to ask now is how have guys linked 2 13b together?

+1 but since money isn't an issue then start looking...I know the Australians produce 4-rotor e-shafts...unless you know people with the right machinery here.

If you do go through with it then it belongs in this:
Factory Five GTM kit car.

http://cache.jalopnik.com/assets/res...Five%20GTM.jpg

From what I understand, they taper the end of one shaft, and insert it into a matching hole bored into the end of the other shaft, and use a key to connect them (like the front hub to e-shaft, etc). I imagine you could also spline them, but that would be harder to machine.

I don't really know anything about the subject, but those seem to make sense to me.

Let me see if i can dig up an evil forum thread from a while ago that touched on this subject...
EDIT: Yeah, here it is http://www.rx7club.com/showthread.php?t=697696 some good insight in there.

Not what I had in mind but god damn! I have never seen one of them and they are only $20,000 its just awesome! Damn good looking car but a corvette motor seem to be fitting vary tight in there... I don't think a 6 rotors would fit in there :(... hell come to think of it how long would this thing be?

:suspect:

Thanks for the link some good stuff on there...

Now as for machining it don't matter how hard it would be. If it can be done and be done better then that's the way it will be done. With the power that this would be making (1000+ :) ) there is no need to make the E-shaft out of anything but the strongest mineral I can get my hands on even if it adds a bit of weight.

when you put it that way :o11:... ya it can be done haha

Stock RX8 eshafts have been known to take the abuse of 1000+ hp.

I'm just gonna say it.................................. why?

yes RX8 shafts can take that. but the length of the motor is what I am worried about, my guess is would not be able to take the stress and just twist its self in to pieces...

as for why? why not. yes there are better things in the world to spend it on... I could have a army of FD and FC in full race prep for the price but why would I do that? why not make something new and why not make it as fresh and crazy as possible.

Ive had the crazy thought of the 6 rotor go through my mind before.
But just now I had a great idea.
Ive heard somewhere a couple of times of making a car with two engines, like a front and rear configuration.
So the idea is get two 20b's, make a car with one 20b in the front an one in the back.
Then you can just call it a 6 rotor. :)
Or you can push the envelope with two 4 rotor engines, an call it an 8 rotor :D
How exactly you make a car with two engines, one powering the front an one powering the rear, is still a little bit of a mystery to me.

Look into tractor pulls, it's not uncommon for them to couple a pair of big block motors producing shit-tons of power, front to back. It involves a flywheel like toothed disk on the back of the crank (and taking the place of the flywheel/clutch/etc) of the front motor, and in place of pulleys and whatnot on the nose of the crank of the back motor, a duplicate disc. When the motors are positioned front to back in the chassis, the two discs line up, and something similar to a double motorcycle chain is wrapped around them, producing a solid coupling. I don't see any reason this couldn't be done with a pair of rotaries. The back engine will need to have a remote mounted electric water pump, but that's probably a good idea for both of them, and personally I would remove the oil pump from the rear engine also, and use just the front CAS and a standalone ECU (make sure the engines are in sync!) and basically strip the front cover off of the rear motor entirely. Then use a large electric water pump pumping into both engines, and a dry sump oil system pumping into both motors; you could pump into the rear iron where your oil cooler returns.

And flex isn't an issue, because a properly done setup will have -each- motor solid mounted to the chassis 4 times, with front motor mounts on either side, and with a block plate attached do the bellhousing bolt holes in the rear, so the car's frame absorbs any flex.

Then you just treat each engine independently for tuning and whatnot. It's probably worth tuning them separately on an engine dyno, to make sure their power output is reasonably similar, although it won't hurt you if one is; you just won't be at your potential.

Now personally, were I to attempt something so big, I'd go for serious gusto, and pair a couple of 4 rotor peripheral port engines that could crank out 400hp or more NA. An 800hp NA rotary? I would pay money to hear that. The temptation to even mildly turbo it and run double that or more would be pretty terrible, though. (On a side note, the sequential controller I'm working on has plenty of spare inputs and outputs... fully sequential quad turbo, anyone?)

This thing is going to weigh so much.

But if you go through with it... twin 42Rs. Must be done.

Now I don't know about the front and rear configuration haha that seem to be a bit out there and but it would be fun to try.

Well thanks to Phoenix7 I am now looking at doing a warm up car... Factory Five GTM kit car. With a LS7 its around 2350lb, Drop that heavy thing and go with a supercharged ported 20b with aluminum side housings and shoot for the car to be under 2000lbs and as for hp 600+ Yes now that's a Enzo killer!

But hey how long is the core of a 20b?

pimp, should be done much faster than a custom 6-rotor.

I'm pretty sure the 20B weighs more than a LS7, since a fully dressed REW weighs about as much as an LS1. Although, aluminum plates should offset it some.

Either way, it would be way cooler with a 20B :coolgleamA:

A good friend of mine did the math one time he said that if you do the aluminum plates and lighted rotors it would not be anymore then a 13b... in theory...

Yes it would be much cooler with a 20b in it make it scream like a F1 car not growl like a vet.

But for giving me the idea phoenix i just might have to take a trip down to cal to give you a ride haha. But the only thing now with that GTM it how use the Porsche tranny...

IDEA! Wait till the 16X is out and make a three rotor out of that...

I think the two engine idea is doable. #1 you don't have to go with the expense of a 3 or 4 or even 6 rotor engine.
Right of the top of my head a way to do it is get two 2-rotor engines, 12a, 13b, etc. get two fwd transmissions (automatics might be easier to link together, as far as controlling them goes) find a way to mate the rotaries to the tranny's. One engine an tranny is in the front of the car with steering, the other engine an tranny is in the rear. Control is used with throttle cables, cables can be used with the auto tranny's, 1 gas tank with maybe 2 fuel pumps, tune the engines the way you want, oh the possibility are endless.
You could set it up where one engine is running at times or have both running at times. It could be rwd, fwd, or awd. And the car will have 50/50 weight distribution.
Great Idea! If only I would attempt it.

Soooooooooooooooo where are you going to lose the extra 350-400 lbs?

IDK why I had it in my mind that the LS1/7 where a bit more weight then the 20b. but I still think it could be done... maybe.

That's been done before; by putting one of the trannys in drive and one in reverse, a car setup like this won a burnout competition I was at. It was fairly awesome, watching him just sort of rotate in a circle while the wheels turned against each other.

I've seen 2 13BTs side by side once with this crazy transmission that bolted to both engines. It was nutty.

How serious are you about a 4 rotor?? And is your budget really 500K??

4? I did not say anything about 4. I said 6! haha 4 rotor in a GTM or maybe just a 20b was one idea. As for the 500k I said it is doable to shut people up from saying I could not pay for it... when yes I could (I am used to RX7 club where people just shot down ideas even when you just trying to have fun and see what other people think) no this can not be done this min but yes 500k is at reach.

I call shenannigans

Yes I am counting chickens before they are hatched... but the joy of land is they stopped making it and this is good. its in a town people want in to and good people from cal keep calling and trying to get it to put condos on. last time they called it was up to 3.5 mil. Sad as all the pride of my dads is in this property so hes not letting it go anytime soon, even at that price. As time goes on the land its worth will be more and more... maybe my dad will sell it or he will leave it to my brother and I after he passes, both ways there is going to be cash. so yes at some point in time I will have alot to blow on doing cars.

if you think or if that makes me sound like I want my dad dead so I can have cash your wrong. I have been trying to get that guy to sell the damn property so he can enjoy his retirement, do all the crap he has always wanted to and stop being like his cheap ass dad and just have some fucking fun and spend it. Its good to save but your 65... what are you waiting for, have some fucking fun! IDK I don't get him.

I like where your head is at. Unfortunately I don't see a 6 rotor being practical in a car any smaller than an old Cadillac.

Now a boat on the other hand... You could make one heck of a speedboat with a 6 rotor in the back, or better yet two 4 rotors.

So you want to spend more than 1/2 of your inheritance on the development of an engine.

The point was that I have cash to work with. (cuz I am used to people just saying if you got to ask then you cant bla bla bla) The 500k was to make a whole new car not just a motor, that would be crazy to spend that on a motor... yet I guess you could say the same on spending it on a one of a kind car too. But ya in the real world I would not spend 500k on one car (no crap right), but you add making practices cars say like a 3 rotor GTM then make a 4 rotor GTM and the cost of that would be over well over 150k+ in the 2 cars.

In the end this is just a idea I was playing around with, and wanted to have a fun talking with people about it and toss ideas around and see what kind of crazy things we could do with 20b... am I going to do a 6 rotary motor? ya maybe someday... or I could settle with making a 3 or 4 rotor GTM or my dad could give away all the land to the Lions or Rotary Club or somthing like that and I be SOL. you never know.

I like how this thread has turned into a discussion about money. :icon_no2:

6 rotor engine would have to have 5 piece Eshaft and easiest would be peripheral port and stack housings. Cooling and oil would be interesting problems to work out. and would power to weight ratio would be better than say 2 or 3 rotor??

Bottomline, I personally don't think it would be worth it.. except maybe just to say you built one.

That seem to be how they always end... sucks.

I think you guys are overblowing how expensive it would be.

Let's take a quick rundown of the prices for a theoretical double 4 rotor engine: Most of this is way over generalized, and some of it I just made up, but it's still an educated guess. Some of the info came from this site: http://www.holy-cow.org/faq.html

First, the big parts. kiwi-re sells a 4 rotor kit for $9500 that includes:
1:- Eccentric Shaft
2:- Front counter weight
3:- Rear counter weight
4:- 2 x Centre plates
5:- 2 x Stationary gears (modified)
6:- 2 x Stationary gear carriers
7:- 2 x Stationary gear external oiling mods
8:- Rear main nut
9:- 2 x eccentric shaft end caps

Also, the coupling for the two motors, using the example of the tractor pull motors, would include a carrier to bolt to the rear motor's snout, that would accept the other end of a stub shaft what would slip into the clutch disk on the front motor. Although a simple design would leave the clutch locked all the time, but the possibility is there to disengage the clutch and effectively turn it off. Also, via their method, you'd want brackets to bolt the two engine blocks together to help keep them from twisting relative each other. I'm going to call this less than $3000, and could be done by most competent fabricators/machinists. We'll count it as $5000, just because someone will whine about the number no matter what I put down.


So, our quick price list:
Block/internal
2x $9500 - Quad rotor kit
$5000 - Engine coupling
8x $1048 - Peripheral port housings
2x $1615 - Aluminum front plate
2x $1425 - Aluminum rear plate
4x $2365 - Super lightweight 9.7:1 rotor pair
2x $3159 - Dry sump kit
8x $1299 - Single rotor ceramic apex seal kit (all springs & seals)
Total: $64,634

Intake/Exhaust
4x $250 - Peripheral port IDA intake
4x $965 - IDA Style EFI Throttle Body w/ Rails
$316 - A1000 Fuel Pump
$140 - A1000 EFI Bypass Regulator
16x $59 - 75lb/hr EFI Injector
$461 - Megasquirt ECU w/ Relay board, custom built
2x $199 - LC-1 Wideband controller/sensor combo
2x $1500 - Custom header & exhaust
Total: $9,658

Misc:
$500 - Twin oil cooler, thermostat, remote mount filter & AN Fittings & Lines
$400 - Fuel lines & AN Fittings
2x $280 Remote mount electric water pump
$500 - Custom heavy duty radiator
Total: $1960

Granted, there's a -lot- not on the list; you'll need to adapt the motor to a transmission capable of handling the ~800hp this beast could make, then you'll need the torque converter or clutch to reign it all in. You need other miscellaneous hardware, adapters, and hoses. You'll need to have the motors tuned. You'll need a large dry sump tank to supply both pumps and engines. You'll need coilpacks to provide spark, but you could use stock FC/FD coilpacks, and simply split the ECU signal, assuming the engines are phased identically, otherwise the ECU can be modified to provide individual signals.

My parts count comes to $76,252, and counting 25% extra for whatever else isn't included (I usually count more, but given the high price of certain individual specialized parts, I don't think that would be accurate), that's just a bit over $100k. Turbocharging could be accomplished assuming you can find a place to mount everything, and honestly it wouldn't be that much more expensive, in the grand scheme of things. Another $20-25k or so. That would include 2 very large turbochargers, lines & fittings, another fuel pump, and the water-air intercooler you'd almost have to use. Power output at that point is as close to unlimited as your chassis & drivetrain budget would allow. A performance built TH-400 can handle 800-900hp easily, but the 2000hp you could get out of 8 turbocharged p-port rotors without breaking a sweat? That's a whole different world.

I'm going to say this:

Having that much money, and waiting to start this project, I would invest my money into a rotary engine a different way. Mazda has been developing the 16x rotary engine for quite a while now, and it should be done sometime soon if they decide to put it into production. Now, this will be a brand new engine, and no one will know how to work with it in the beginning. If I had 500k, I would buy a few of the new cars that come with the 16x and begin to do R&D on tuning these engines, maybe even making a 32x 4 rotor engine out of two of them. If you're willing to spend half a million dollars on a car, why not just start a business and have a "job" doing what you like to do?

Doing a 6 rotor seems like an expensive way to figure out that it doesn't work and is not practical. I'm sure that in the development life of the wankel engine, engineers have figured out that it doesnt work well, or we would have 6 rotor busses, heavy duty trucks, etc. out there right now.

You need torque not RPM's to move those things around and the rotary just doesn't produce it the way a TDi does

enter the torque vs hp debaters

As for your idea of developing a 32x - WAY better than a 6 rotor. I like where your head is at on that one.

On the last page (pg3 if this new post makes it up to pg5) I did say something about doing a 24x... (20b from 16x's). Ya direct fuel injection in a 2.4 liter would be awesome, but a 3.2 liter 3216cc's must be done! and what did I read it was pushing 260-ish? So that would be over 500HP N/A with out even trying! Cant walk away from that idea haha been thinking about the 16x alot also for doing the build. Mazda better bring them out in 2011.