rarson

I just had a thought. Ebay Renesis' have dropped to about $2500 for a full motor. Granted, they're not quite common yet, but they are low mileage. Using Renesis 13b's would allow us to take advantage of the higher revs, lighter rotors, stationary gears, etc. Plus I think it would be interesting to build an all-side-port 4-rotor. If we wanted to keep the factory intake manifolds with the 6-port functions, it would be possible too, since they're basically 2 self-contained engines connected together. It would just require 2 throttle bodies.

Michael_Rudy

That would involve spending more money then any of us would like i think, plus then you have 1 mm apex seals or whatnot, and since you have to rip it apart to do machining on the eccentric shaft. i donno about you guys but i am going 4 rotor do to the ratio of power to cost, and its well neat too lol

10sec rx7

its run a 7.24@191mph

jeffs parts are working a treat

Jobro

iTrader: (2)

The way mazda did it is the way to do it..

The other great thing about having 4 rotors is an even more linear torque curve, and we allready know its great. It sounds like its the most balanced, will have a unique exhaust note, much like a 20B, and will probably rev the hardest.

With the talk about power on demand that is completely stupid when talking about 4 rotors and PPs.

Having thumbnail ports (those tiny ports used on the original 12AT's), combined with a turbo that doesn't boost until high up in the revrange will give good lowdown power, and an insane highend...

as for the 1mm seals debate, its a given mazda decided to use smaller seals because it was a better option.

It has been discussed that 3mm seals handle detonation better than 2mm seals, but 2mm seals create less friction and other things, all using seals that last longer in an engine that is detonating is hiding the fact that your tuner doesn't know his business well.

Michael_Rudy

Wow 7.24@ 191mph, they are coming up fast on the 6's, i thought it was kinda wierd that they were only running low 8's last year or whatnot, because 13b's can do that

As for the 1 mm apex seals, the sure will last longer in a N/A engine, but with the turbo they don't last, thats why companys have had many problems boosting them, and they do have good tuners.

Whizbang

2mm seals are the way to go. 1mm is just well....

and 3mm, though more durable, make so much for friction and take forever and a day to seat.

savana

renesis seals are 2mm i have a rotor from one sitting in front of me

Michael_Rudy

Really? I wonder why they have so many apex failures with them when boosted then? well thats totally off topic.

rotarygod

iTrader: (1)

Mazda doesn't have an engine that uses 1 mm seals. The Renesis seals are still 2mm. They just aren't as tall.

Whizbang

well im about to kick off my project. i have a few ideas im going to tests on a CAD design program that can do finite elements testing so i dont have to make the part before finding out it wont work! I got three 13bs lined up and then i can start sorting this mess.

rarson

Good luck, I hope you make something good!

abefroeman

Is it possible to connect 2 13b's with something like a center differential?

Smilodon

I would think that the most vibration-free way would be to join the two engines with the cases lined up but the eccentric shafts 90 degrees out of phase, for one power pulse every ninety degrees of eccentric rotation. Smoove!

Michael_Rudy

it is smoothest with 90 degree out of phase but most difficult to build and design, well at least for just putting to engines together.

Smilodon

Why would it be more difficult than having two engines slapped together and the two eccentrics IN phase>?

MrDirt

I was wondering about that one as well. It seems that if you can machine something to be perfectly aligned at 0 degrees, it should be just as easy to do it at 90.

Michael_Rudy

it is just harder for balancing reasons to have them phased 90 degrees apart well at least for my project

Smilodon

Where would the balancing be executed on one that was at 90 degrees compared to on one that had both in phase.

HAI-TEK7

iTrader: (31)

http://members.tripod.com/~grannys/4rotor.html#

fahque99

Where is this link? I have done a search but I have not found anything.

ported13b

dont know if you've been to this site but they designed and built their own 4-rotor they made it out of a 12a http://www.autotechmotorsports.com/index.htm

Jeff20B

iTrader: (13)

Is Autotech still with it? I sent them an email a few weeks ago with no reply.