virii01 - Thank you for being understanding.

Perhaps I did get a little 'overheated'. Thanks for being 'gentle' with your response -- and I appologise for rudeness.

Detonation in the overpressurized turbos is usually something that happens in the intake ... not in the actual ecliptoid housing of the Wankel itself ... it is the detonation of the turbocharger then blowing higher pressure into the engine that causes failure.

I misunderstood exactly what you are speaking of -- and for that "jump to conclusion" I appologise. I do not like or deal with super or turbocharged engines. Can't stand the concept so I have a "disdain" and a mental block against them. (my "blind spot" prejudices coming forward to embarrass me). No, I won't go with a 3800SC for the same reasons. I'm convinced that it is going to destroy itself. I have an equal disdain for NOX. I'm convinced NOX is an attempt to destroy the engine.

(I know -- but it's my blind spot and I'm keeping it!!)

My comments as to the "impossiblity of detonation" are in the perspective of a normally aspirated engines ... and therefore your comments about detonation may well be accurate. I don't know.

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Other side topics.
The accusations of "horsepower and torque misrepresentations" are always present with Mazda and their rotaries. As Manufacturers report these things based on formulae rather than dyno tests, and production run engines have some variance in output, there have been observations of up to 10% difference. "your mileage may vary" ??

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And as to the intake/exhaust.

Every Wankel I have seen has the intake ports high on one side, the compresson and sparkplug(s) on the other side and the exhaust ports low, to middle on the same side as the intake. All so far, follow the same physical layout:

My Rx-7's had (viewed from drivers seat) the Spark plugs on the drivers side of the engine, the intake/exhaust on the passengers side with the pulleys and belts forward.

Rotate that orientation to a Fiero and the belts are to the passenger side, the spark plugs to the firewall and the intake and exhaust to the rear. But I would think that proper mounts and adapter plate could 'rotate' the engine to a position where canted a few degrees towards the front of the car, the exhuast more in the "up" reference and then clearance for the exhaust. But again, that exhaust is VERY, VERY hot. There may be a need to replace the trunk with a cooling coil!!

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and As I remember, the Merceedes C111 4 rotor Wankel test car (70's) was being developed just about the time of the Oil embargo and phenominally rising interest rates. Like I said previously, these engines are looked at in similarity of displacement, not output so the 200 cubic inch Wankel (I thinK) was being compared to large six-cylinders not high performance V-8's or V-12's. and reportedly Merceedes didn't see a market for what would be an "Exoticar".

Right you are Jefry; the exhaust ports will come out to the REAR. Got mentally disoriented converting to our mid-mount. Ah well.
Quite a lively discussion here!

quote Originally posted by Tryxalon: Why? Physics. The principles of the wankel cycle absolutely prevent it.

I know you have subsequently revised the post to which I'm replying but I still have some bones to pick. There's no such thing as a Wankel cycle. The Wankel engine runs on the Otto cycle just like a piston engine, and ALL the same principles of combustion apply: preignition, detonation, etc..

quote You may have had a seal failure, but a "detonation", as would happen in a piston engine would have to not only have to stop the rotation of the rotor, but after overcoming all that enertia would have to completely strip the planetary gears on the output shaft. That means the entire engine would have been destroyed. You would not have been able to 'disassemble' it.

Think about this for a minute... Preignition does not stop or reverse the rotation of a piston engine. Why would it do that to a rotary? Preignition DOES put holes in pistons, which are considerably stronger than apex seals. Preignition in a rotary would DEFINITELY blow an apex seal or two.

quote Also, to 'detonate' and not be 'cleaned out' in the exhaust cycle (a requirement for 'blowing the seals')

What are you talking about?

quote it also means that your 'detonation' would have to have produced sufficient force to so destroy the engine. The amount of gasoline vapor required to have such force even at 20:1 compression ratio (2x compression in a wankel) cannot fit in the rotor chamber of a 13b. It cannot fit (without going to liquid form and therefore impossible to ignite) within any volume less than approximately 2 cubic feet.

Maybe if you're referring to the amount of gasoline it would take to put a hole in the casing, but other than that, you can fit MORE than enough gasoline in a combustion chamber to blow any seal in the engine. The only fuel for which one has to worry about hydrolock is Nitro-methane. I have never heard of anyone running a Nitro rotary.

http://www.1300cc.com/howto/how2/NOS.htm
The above link should explain a lot.
Dave

Wow. What a lively discussion this has turned out to be. Anyways. I saw custom built quad rotor engine that was put in a local sprint car. Now he just stacked the rotors. when he got it running he found it to be extreamly powerful but not reliable. But he said that if he hadn't just stacked them and built it diiferently he would have had better results. Im theory you could stack as many as you want. I'm just torn between having just turboed 13b or too do the tri rotor and turbo.

bump

quote Originally posted by Jefrysuko: You never really answered my question but maybe I need to explain myself a little better. I am assuming that you will use a transaxle like the Fiero used or most any FWD vehicle. I saw a 12A placed next to a Fiero transaxle and the exhaust output on the motor was only a couple inches from the passenger side axle. Even with a custom exhaust we couldn't see how a tight enough bend could be made. If when you do get to the point of looking into the exhaust I would appreciate you letting us know what you have come up with. We have come up with a possible solution but havn't looked into it fully. As for the Transmission I am going to have to agree with WILL. I don't believe there is a Transaxle that will bolt up to the Rotary. I would bet that an adapter plate would be the best option just like the V8 swaps. The adapter plate might be a blessing anyways as the Rotary motors use a rather thick clutch/flywheel design.

Hey! I have an idea! (first off, I don't like the idea of the rotary engine, but to each their own.. ) But if you need to make an adaptor plate... Why not "tilt" the engien somewhat away from the axle? I mean, as long as it ligns up with the tranny, the degree it's at realyl won't matter. I wish I can draw a picture.. but if you had the 2.8 in there, the trunk vavle cover would be high and the rear valve cover would be even lower below the rear window.

this may solve the problem for the exaust.

cheers!
Eric

I like the idea of the rotory, and have seen them in many applications, so they they should be deemed usefull and cost worthy. A fiero would be an interesting car if it had such a high red line..... I can just imagine the sound..

quote Originally posted by Ottawa_86gt:Hey! I have an idea! (first off, I don't like the idea of the rotary engine, but to each their own.. ) But if you need to make an adaptor plate... Why not "tilt" the engien somewhat away from the axle? I mean, as long as it ligns up with the tranny, the degree it's at realyl won't matter. I wish I can draw a picture.. but if you had the 2.8 in there, the trunk vavle cover would be high and the rear valve cover would be even lower below the rear window. this may solve the problem for the exaust. cheers! Eric

Yep this is what we have been thinking about also. I won't go into details but I hope you realise that you can't just rotate the motor without potential problems. It looks as if the oiling system would be adaptable to the change but there are other considerations like starter and accessory placement, cooling system peformance and servicability etc.

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I had an idea that I don't know if it would work or not. I need some suggestions. I'm thinking if I just get two 13bs and on the back of one motor and the front of the other put a shaft and a sproket on it. Now mount the two motors close together and use a double row timing chain to connect them. You could alter the balancing of when each rotor hit by moving the timing chain. So essentially you would have a 26b. For the trottle I would just hook them directly together to make it simple. Any ideas?

http://travel.howstuffworks.com/rotary-engine.htm

Figured I'd post a link to how a rotary works.

I stated earlier that Wankel rotaries don't detonate... Otay, I concede the point that it's possible under boost, but the design is ridiculously detonation resistant. Since the intake stays cold, and the air/fuel mixture stays cold until it gets to where the engine wants it to burn, it's really really hard to make one detonate. Turbo/Supercharging or the worst gas on earth are the only ways, your not going to do it on a normally aspirated engine.

Yes it's an Otto Cycle engine in that it's got intake, compression, combustion, exhaust. The big difference is that your not bringing an air/fuel charge into a piping hot combustion chamber to compress it, it moves in thru the intake port, moved thru the compression area, and then as it's reaching it's highest compression point it's also reaching the light off area. so no hot exhaust valves or carbon deposits etc.. to make it go boom before it gets to the sparks.

One of the problems with 4 stroke Otto cycle engines is that your compressing the air/fuel charge in the hot spot before you want it to light. If it lights off before the cylinder reaches TDC, the piston CAN force the crank back down reversing rotation or at least fighting the heck out of it for that stroke. It's pretty much a non issue except in the extreme that was brought up of supercharging when dealing with a Wankel.

Check out the link... wrap your minds around a really cool engine design. I'm glad Mazda brought it back to automotive usage.

Check out the Oct. edition of Pop Mechanics, page 69. Seems the Mazda folks have been burning the midnight oil.

Other new engines discussed here too, including a Direct Injection engine from Isuzu for the Axiom (never seen one), and a V10 diesel from VW.

TG

quote Originally posted by Scott-Wa: Yes it's an Otto Cycle engine in that it's got intake, compression, combustion, exhaust. The big difference is that your not bringing an air/fuel charge into a piping hot combustion chamber to compress it, it moves in thru the intake port, moved thru the compression area, and then as it's reaching it's highest compression point it's also reaching the light off area. so no hot exhaust valves or carbon deposits etc.. to make it go boom before it gets to the sparks.

While the case is constantly swept by the apex seals, rotor faces can get carbon deposits on them just like pistons. Don't forget that the rotor face has hot exhaust on it right before it starts pulling intake mixture.
Also, in order to clear the apex seals, the spark plugs have to be recessed into the wall of the case, which, along with the extended combustion chamber shape makes for poor light off characteristics. If rotaries had decent combustion chambers they wouldn't need trailing spark plugs.

quote If it lights off before the cylinder reaches TDC, the piston CAN force the crank back down reversing rotation or at least fighting the heck out of it for that stroke.

The direction of engine rotation might be reversed in a one cylinder engine with no flywheel, but otherwise THIS DOES NOT HAPPEN. When testing an engine for preignition (which is DIFFERENT than detonation), engineers will see a spike in EGT and a drop in power. Shut it down, pull it apart and there's a hole in a couple of pistons. THAT's what preignition does. It WILL NOT reverse the rotation of an automobile engine.

[This message has been edited by Will (edited 09-27-2003).]

I started checking into putting a RX wankel into my Fireo before I decided to put the diesel into it. I found that the exhaust ports were pointing toward the rear of the car. and would be close to the axle shaft.

The centerline of the crankshaft is much higher than a piston and with the transmission in it normal position the oil pan of the wankel would be sticking down below the engine cradle thus liable to damage.

That's why I went another direction. It looked like more work than I was willing to do.

Good luck, I hope you get it worked out.

Rick M.