Simple idea, IMHO, but obviously, not at all simple task. But damn, it would be a fun project and even better once it's running!

 

Some dude actually made a four rotor for a Sprint Car engine. I remember the hubub about it and it was the loudest friggin thing I ever heard in my life,, this was like 10-15 years ago, It was peripheral ported, and spat fuel at idle and flames going into the corners. I don't think he ever got past the experimental stage with it, something about not being allowed to run dry ice to cool the motor, or some other restriction, i know nuthin about sprint cars, just remember this guy talking about the motor in the pits while my dad was racin in an Enduro

but DAMN it was cool.

 

Pipe dream.

Why not go 3 rotor 20B NA?


-Ted

 

My dream is building a 3 rotor or 4 rotor from 13b housings. It seems just buying the 20b is very costly. I like the idea of fabbing up my own 3 or 4 rotor.

 

That's a much more realistic idea. It'll have side ports instead of peripheral ports for starters (i.e. streetable), and availability is about a million times better.

I know a guy with an internally stock NA 20B in a 70's Mazda 808 wagon. Sounds awesome, goes like a cut cat.

 

Damn Aaron! You keep surprising me...It's not enough that your building the 12A Scooter? I wonder what other Ideas you are going to put In my head when we continue building my Engine. I'm broke b'c of you.

 

Reality check: you will not be "fabbing up" a 3- or 4-rotor motor as a cheaper option. If you want a 3-rotor then buying a complete 20B will be cheaper than finding all the bits to make one. If you want a 4-rotor then you will be paying more just for the custom e-shaft than the cost of a complete 20B, never mind the many other custom parts required.

 

Even if I get a few 13b engines cheap?

 

Of course you should look at it.
If it's close to what he says- why not weld on a whole rear clip from front crashed turbo?

 

Yeah....I miscounted... I had just assumed he wrote "4" instead of two...

Collecting the engines is easy. It's the rest of the work...Do you really have any idea what this kind of project invovles? Large amounts of percision machining (I can't do it, so I'm contracting it out), a good amount of guesswork, and some seriously expensive aftermarket parts...All told, I'll probably be dumping $10K into my 4-rotor 12A, and I'm not even sure if I can make it work...Of course, I'm crazy...

Your support never ceases to amaze me...

Anyone bulding a PP 4-rotor should not be concerned about streetability...

The projects are as follows:

1. Finish TINA!!
2. 12A chopper
2.5. AWD electric barstool
3. 4 rotor

Now all I need is TIME...

 

sounds like a neat project,

Best of luck

 

you should get some pictures of it major bigtime!

 

Like stated, you can't go to a machine shop and say hey make me a 4 rotor eccentric shaft. They could make one but I wouldn't ever bet on it even starting. If you actually wanted it to work, it would have to be at least two peice to keep from flexing, you would have to get it balanced, and gauge it so it is absolutely precise on where the rotors are, you miss it by a degree and the shaft will snap. I think I saw a 3 peice 4 rotor e shaft for 40,000, and that's cheap. This isn't a project for anyone without connections, an engineering background, and extensive experience with rotary engines.

- Steiner

 

Aaron, have you been on GenMay lately, I just noticed your website popped up from somebody

 

No, that's not cheap. There's a company here that makes 4-rotor e-shafts for considerably less than US$40,000 (the FD in the link I posted uses one), but it's still going to be a major cost in the project.

 

I'm sorry, that's the cheapest one I had seen. Unfortunately I don't have the funds to even dream about doing something like that right now so I haven't investigated it that much But still the costs are very high.

- Steiner

 

Call me a cynic...

Too many pipe dreams like this just don't make sense.
I bet only a handful of people here have access to such resources to build such a thing.
If anything, it's a royal waste of time and money; for the amount of time and money spent on making this motor, you could have one helluva monster 20B turbo.

If you're thing is being "different", then by all means go for it.

I find it a waste of time trying to debate a subject that has almost zero possibility of being conpleted.

Do you remember how many threads I've commented that I thought wasn't going to be completed?  So far, there's maybe one or two that have been completed and HUNDREDS of others which faded into the distance.



-Ted

 

Explain to me why not? Do you think that Mazda just picked one off a tree or something? Of course not. They had their machine shop make one. It's not a difficult shape at all. Any machine shop worthy of being called a machine shop could make one if you're willing to pay. My machinest has over 60 years experience (he's like 79 or something) and basically said "no sweat, but you gotta' pay for it".

Yes, my shaft is two piece. The engine would be impossible to assemble if it was a single shaft.

What is GenMay?

I definitly understand where you're coming from...I'm sure you can imagine how many newbie-turbo-NA PMs I get in a week...People thinking it's somehow cheap, straightforward and easy...But, I am completely serious about this. Not immediately, but in a few years. I have a few ongoing projects right now, including a 12A motorcycle.

 

where in louisiana is this guy? Close to Lake Charles?