Jermyn
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| posted on 2/9/04 at 03:50 PM |
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Best Rotary Donor Ever?
Not available for me in the States. But for those of you in Europe. Check this option out.
Mazda Eunos Cosmos 20B rotary 3 lobe! Produced in 1990. Sequential twin-turbocharged 3-lobe rotary produces 280 horsepower @6500 Rpm. (Before any
tinkering) Torque numbers 266 ftlbs @1500rpms peaking at 297 ftlbs @ 3000rpms.
I would think you'd be able to squeeze another 30-40 hp out of it easy. Besides that the donor weighs over 3400 lbs so whats the horsepower
conversion to a Locost on that? like 600??? 
Car only came with a 4-speed automatic but since the motor is a 20b I would think you could bolt-up an RX7 5-speed with no issues.
Don't know what the suspension is like but I'm sure any competant builder could convert it.
Anyone out ther built a Locost with one of these??? 
Heres a link
http://www.monito.com/wankel/cosmo20b.html
If life is a race do you want to be the first one to finish?
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stephen_gusterson
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| posted on 2/9/04 at 03:54 PM |
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we didnt get that in the uk
atb
steve
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Jermyn
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| posted on 2/9/04 at 04:10 PM |
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After careful review....looks like Japan only Maybe some made it across to Europe.
If life is a race do you want to be the first one to finish?
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Mark18
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| posted on 2/9/04 at 04:50 PM |
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There's a company in the states called Laminar Concepts which do rotary powered sevenesque cars - They're potting a 20b in one, but I
don't think it's anywhere on the internet.
Mark
"I don't know what I may seem to the world. But as to myself I seem to have been only like a boy playing on the seashore and diverting myself
now and then finding a smoother pebble or a prettier shell than the ordinary, whilst the great ocean of truth lay all undiscovered before me." -
Isaac Newton
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mackie
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| posted on 2/9/04 at 05:13 PM |
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I have a video of a Toyota Corrola (rwd) with a 20B 3 rotor with a massive single turbo (I think it was NA originally) and it made about 600bhp.
They video shows the Corolla accelerating *very* quickly away from it's pals in a following car. Looked like fun
Would be an awesome engine in a locost. How much extra space does the twin turbo gear take up? I'm thinking it might stick out the side...
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adampage
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| posted on 2/9/04 at 05:15 PM |
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They should be on the net...
on http://www.laminarauto.com/ but it appears to be a dead link at the mo.
Sounds interesting, though.
When I was first looking into kit cars I saw a website of an american who built a n/a rotary locost, and it looked fantastic.
I'd love to see one of the crazy turbo ones!
Adam.
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heinlein
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| posted on 2/9/04 at 06:13 PM |
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Laminar concepts
As I've always liked rotarys I searched the web for info. One site listed the car at 1710 pounds (777 Kg) and another the price at $82,000. I
converted pounds to kilos, but $82,000 is way too many pounds for me to bother. Seems like both price and weight need reducing to me.
When you're lying in the midst of the Afghan plains and the women come out to cut up the remains; just roll to your rifle and blow out your
brains and go to your god like a soldier.
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Jermyn
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| posted on 2/9/04 at 08:01 PM |
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quote:
Originally posted by mackie
I have a video of a Toyota Corrola (rwd) with a 20B 3 rotor with a massive single turbo (I think it was NA originally) and it made about 600bhp.
They video shows the Corolla accelerating *very* quickly away from it's pals in a following car. Looked like fun
Would be an awesome engine in a locost. How much extra space does the twin turbo gear take up? I'm thinking it might stick out the side...
You think with Mcsorleys +4 it would still come out the side? I was thinking I may increase the side width dropping down a little to get more of a
formula look anyway. Still messing around with the drawings but I think it could be cool...... sort of a Locost F1 combo!
I also found a bunch of other stuff on 3 and 4 rotor rotarys! This guys page is an awesome resource for someone who wants to build a high-power rotary
locost....
http://cp_www.tripod.com/rotary/pg20.htm
If life is a race do you want to be the first one to finish?
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DaveFJ
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| posted on 3/9/04 at 08:50 AM |
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There is a cambridge based company that produces a 1000BHP version of the (IIRC) the 20b engine......
Dave
"In Support of Help the Heroes" - Always
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Jermyn
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| posted on 3/9/04 at 02:57 PM |
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3 rotor available in US
In searching, found this guy who imports front clips from Japan.
fcfirst1@yahoo.com
Says he can get me a 3-rotor twin turbo Mazda Eunos Cosmos front clip for $3500 delivered. Don't know what the Pick-up price is. I'm
checking on that.
Maybe to some that might be more mid-cost than locost but I'm thinking I'll have spent about $5k on the car by the time I'm done
anyway. So maybe $2800 to $3000 might be reasonable.
Anyway, just wanted to let other rotary enthusiasts know.
Course it still might be cheaper to bolt two two-rotor motors together and have a specially designed mainshaft made.
If life is a race do you want to be the first one to finish?
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Bart Vangampelaere
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| posted on 7/9/04 at 07:16 AM |
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you can't just bolt two engines together. And it's not a mainshaft, but an excentric shaft. To build a custom three or four rotor
you'll need a special e-shaft and a special centre plate. Expect major money!
It's not really usefull anyway: you'll never be able to get 800+ hp (four rotor) to the ground in a locost (which wouldn't be a
locost anymore anyway). Even the 20B is way overkill. Rated at 280hp it's more likely to be just over 300hp in reality, and that's
seriously holding back. 450-600hp are no problem for a reliable 20B. More's possible, but that'd be less reliable.
To bolt it to a manual gearbox from a RX-7 (anything less then a TII one will be shatered to pieces btw) you'd need a special flywheel and
counterwheight.
It is possible, but not worth it, in my opinion.
To obtain Caterham JPE or R500 style performance, you'd need no more then a well tuned 13B. A street ported NA could go over 200hp if done
right, if more is required you could go turbo. But I wonder if it makes sence to have 350hp in a locost
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mackie
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| posted on 7/9/04 at 08:06 AM |
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The Westfield SEight had something like 330bhp from it's quad carbed rover V8.
Mags used words like "insane" and "rediculous" and apparently it even spat petrol at you
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Jermyn
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| posted on 7/9/04 at 04:59 PM |
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Bart's right
quote:
Originally posted by Bart Vangampelaere
you can't just bolt two engines together. And it's not a mainshaft, but an excentric shaft. To build a custom three or four rotor
you'll need a special e-shaft and a special centre plate.
What do you mean you just can't bolt them together Seriously, I didn't figure it was that easy. I figured someone would take offense
to that. Certainly other parts would have to be specially engineered/made as well as the excentric shaft (Sorry, didn't mean to step on your
mainshaft  )
I agree with you about the clutch/ transmission. My direct bolt-up comment earlier was moreso directed as to not having to sort out bellhousing
issues.
As far as cost is concerned, there are folks out there who have already done the 4-rotor and I would think they would be willing to share their info
for free or maybe a modest fee. Especially since there is not too much demand these days for 4-rotor designs with some of the rotary-banned racing
limitations.
However, I could see it getting very expensive if you were starting from scratch and the benefits of a four-rotor design are negligible. That's
why I suggested this donor as a good alternative to building your own.
As to the sanity issue... I suppose it take a certain amount of insanity to build a locost anyhow.  Not to mention, almost every supercar design
probably started with that word. (insane) That much horsepower in a locost does seem almost stupid. But, I never claimed to be smart.
If life is a race do you want to be the first one to finish?
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derf
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| posted on 9/9/04 at 01:23 PM |
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The 3 rotor is available here in the US as cheap as $1000 for a high mileage and low compression (read as very broken). Most that Ive seen go for
2500-3500 plus shipping. There is a Japanese importer in Georgia, somewhere around the Atlanta area, you could save on shipping that way. When I was
looking into buying a 3 rotor front end from them they quoted me $375 shipping to my door in NJ.
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derf
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| posted on 9/9/04 at 06:32 PM |
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jhot exports in augusta GA
JHOTexports.com
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Bart Vangampelaere
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| posted on 12/9/04 at 08:32 PM |
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quote:
Originally posted by Jermyn
quote:
Originally posted by Bart Vangampelaere
you can't just bolt two engines together. And it's not a mainshaft, but an excentric shaft. To build a custom three or four rotor
you'll need a special e-shaft and a special centre plate.
What do you mean you just can't bolt them together Seriously, I didn't figure it was that easy. I figured someone would take offense
to that. Certainly other parts would have to be specially engineered/made as well as the excentric shaft (Sorry, didn't mean to step on your
mainshaft )
I agree with you about the clutch/ transmission. My direct bolt-up comment earlier was moreso directed as to not having to sort out bellhousing
issues.
As far as cost is concerned, there are folks out there who have already done the 4-rotor and I would think they would be willing to share their info
for free or maybe a modest fee. Especially since there is not too much demand these days for 4-rotor designs with some of the rotary-banned racing
limitations.
However, I could see it getting very expensive if you were starting from scratch and the benefits of a four-rotor design are negligible. That's
why I suggested this donor as a good alternative to building your own.
As to the sanity issue... I suppose it take a certain amount of insanity to build a locost anyhow. Not to mention, almost every supercar design
probably started with that word. (insane) That much horsepower in a locost does seem almost stupid. But, I never claimed to be smart.
The reason why I said you can't bolt them together is because that's what some people think! No kidding! Some guy even did this, and it
turned out a whole lot of wasted money
The problem is that very few people can build a decent E-shaft, and the ones who can are easily asking very high prices (like $1000 upwards)
A 20B would be a better choice, but it's not easy to get an ignition system for it. You are looking at costs here that will make your car more
pricey than a good Caterham or Westfield.
And I think it'll just not be very easy to drive a 400-600hp locost
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Jermyn
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| posted on 13/9/04 at 03:23 AM |
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Sure, Sure... a 400-600 hp locost would be crazy to drive. :p But that definitely ranks it up there in supercar status and who wouldn't want to
build a supercar?
I think the cost wouldn't so much kill me as I am looking at my build as more of a random-cost than low-cost. Spread it out over a period of
time and it doesnt hurt so bad. Besides, I don't have the up-front dough to lay out for a Cat or Westie. Even if I did , I'm not sure I
would want to.
Please don't tell me it's a locost builder who bolted 2 rotarys together.......
If life is a race do you want to be the first one to finish?
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Bart Vangampelaere
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| posted on 13/9/04 at 02:21 PM |
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not really; it's a guy who build a racecar.
If you do want to go 20B, make sure you get all the sizes of that beast first. It shouldn't be a big problem to fit, but some tweaks might be
needed.
The main issue will be the gearbox (a 89-91 TII box will be the number one choice) and of course the engine management. You cannot use the OEM ECU
(unless you go for an automatic box and airco ) as it will go to limp home mode if the accessoiries aren't hooked on.
Turbo's are controlled by the ECU, aftermarket ones don't provide the output for sequential turbo's (as far as I know) so
you'll have to convert them to non-seq.
Think well about the engine: they are basicly 1.5 13B's, so they'll be about 50% more expensive to rebuilt in case you need to.
If it get's rebuild make sure to get it doweled, and you might want to port it: that's gonna get you into supercar-levels for sure.
Think carefully about where to fit a decen't radiator, oilcooler(s) and intercooler.
And then: enjoy!
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NS Dev
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| posted on 13/9/04 at 05:06 PM |
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anyhoo.........getting back to the subject, I have looked into this idea for my autograss car. 20b engines are imported into the uk by a few
companies, have a look on the mazda rotary club site to find out who, that's what I did. For the 3 rotor in good low mileage condition you are
looking at £2500 incl ancilliaries and I think including gearbox but not sure. For that money it seems you can get a Honda s2000 engine which I would
rather have! (240hp with no turbos in factory trim, a set of 48mm throttle bodies and some wild cams and rip out the VTEC and could be
interesting!!)
The problem with the Mazda 3 rotor is very surprising (to me anyway) in that having extolled the virtues of it's lightness to everybody that
would listen, I was rather put out to find that is was quite a bit heavier than a Rover V8!!!!
Doh, plans foiled so I have thrown that particular wondrous idea in the bin.....back to the drawing board for my grasser, I think Saab 2.3 turbo with
a small eaton supercharger for a companion might be interesting.............hmmmm, maybe not, too heavy again!!
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Jermyn
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| posted on 14/9/04 at 04:09 PM |
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Seriously? That is surprising. What are the weights of the two? Are you talking about just the block weights or the total with all ancillaries
attached?
But should we still be so quick as to toss that idea into the garbage
Aside from the weight issue on it's face....I would think the the horsepower-to-weight ratio would be much higher on the rotary versus the Rover
V8. No to mention even a ported, turbocharged 13b can develop much more HP than a tuned Rover V8.
Then there's the cost issue.. Rover V8=big $$$ Tuned Rover V8= stroke
Although, I would give the V8 the edge in torque....You really got to ask yourself....How much torque do you need in a 1500lb locost anyway?
Then again, It's all about what you want. Maybe you are planning on towing your boat with your locost
Sorry, didn't mean to change this topic into Rotary v/s V8...
If life is a race do you want to be the first one to finish?
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12a RX-7
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| posted on 14/9/04 at 05:59 PM |
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20B's belong in JC Cosmo's they are rare enough already with people ripping them appart just for the engines.
a 12a or a 13b or a custom single rotor is a much better option for a small lightweight car. Afterall what is the point of a huge excess of power that
you cannot use ? hardly in keeping with the original concept of the lotus 7.
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NS Dev
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| posted on 14/9/04 at 06:04 PM |
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think you've hit the nail on the head!
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Jermyn
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| posted on 14/9/04 at 06:50 PM |
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Ok, I concur this may not fall into line with the original concept of the seven. But, I would have to say that I'm going for Locost inspiration
and not Lotus inspiration
What I mean by that is:
Sure, part of the Locost inspiration comes from a Lotus seven, but IMHO, Champion's main drive was to build a cheaply made kit-car with his
son, thus designing and developing your own vehichle from the ground-up. Along the way, learning and making mistakes. And in the end, having a car you
built that you can be proud of, not one you put together out of a box.
And, because that requirement is all about donors and sourcing parts from other cars, (regardless if you want to build your car with a rover V8 or a
mazda 3-rotor, or Lotus twin cam) anything certainly falls within the Locost spirit.
Besides, IMHO the Eunos Cosmos was a little short in the looks department anyway. Sorry, if you are a Cosmos fan. I don't guess Sierra fans
take to kindly to Locosters robbing their cars of pieces either
If life is a race do you want to be the first one to finish?
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Bart Vangampelaere
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| posted on 15/9/04 at 01:58 PM |
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the Eunos Cosmo 3 rotor is indeed a rather rare piece of automotive engineering. Yet most of the engines on the market come from crashed ones, so I
guess they aren't that rare in Japan.
As for wheight: a 20B can be putting 500hp on the road easily. That should make a nice power to wheight ratio. I have no idea about wheight of a 20B,
nor a rover V8. But it seems unlikely that a 20B would be that heavy. A 13B stays under 100kg. Of course that's without the stuff around the
engine, but that counts for all engines. After all, an exhaust for a V8 won't be light either will it?
But it's also a matter of what you need and what's best suited for that job.
Let's say you want supercar performance. You'd want a 500kg car, and about 300hp. A slightly tuned 13BT could deliver that. It's not
very heavy (even with accessoiries) and it's compact.
0-60 times in the region of 3.5-4.0 sec. shouldn't be any problem.
Want even more? A well tuned (ported etc) 13BT could deliver 400-500hp.
But if you're on a budget, a 12A can be ported and carbed to deliver 180hp or more. 180hp for less then 500kg, that will make supercar
performance aswell!
If I would have the choice I'd go for a 13B EFI, but built a non-turbo (for simplicity) one with 4-port turbo sidehousings. Port to a serious
street port (with such a light car a more narrow powerband and a bit less torque aren't a problem) and you can achieve 200hp. More then enough!
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Jermyn
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| posted on 15/9/04 at 03:59 PM |
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I agree. And, because I'm on a budget I think a second generation turbo RX7 is a much better choice. Only thing that bugs me about that ..... it
has been done before.
When I build my car, I wanted something different and interesting. Something another Locoster would look at and admire or say "I've
never seen that before" I guess the three-rotor option does that for me. It's rare in the US and exotic (in a small sense of the word)
with the ability to make big power.
However, the costs drive this out of my budget and I think with the abilities of a good 13b, it might even be silly to go down the three-rotor road.
After all, I am building my car to impress me....not everyone else.
Perhaps I should put a 3-rotor in my MGB? MG does stand for MAZDA GEARING right?!
If life is a race do you want to be the first one to finish?
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