Multi Rotor

[Hellbilly]

Hi everyone,

Just thought I\'d use my first post to ask if an \'old-wives-tale\' I\'ve heard has any substance to it...

It has been suggested that it is possible to use a couple of 13B engines to build a 3 or 4 rotor engine?
If this is indeed the case;
a) how is this done?
b)where do you draw the line? Is it possible to build an 8 rotor engine, for instance, or do vibration/balance problems increase as the engine gets longer?

Also, what is \'dowelling\'; as I have seen it mentioned in relation to drag-racing RX7\'s but can\'t find any information as to how (or where) it works...

Any info would be greatly recieved on either question.

Stu

[Grizzly]

You can build what every your Finances will let you.

No you can\'t just bolt two engines together, you need Custom plates and a Custom E-Shaft to start (thats the easy stuff), then you would have the slight problem of having 2 primary ports in the same chamber.

To explane Dowling, The dowl is the Steel Tube that is used to A. locate the Housings etc when assembling the engine and B. Used to reduce the Twist effect of the engine. Basicly Dowling is where a Engine builder will Add more dowls (usaly to the Plug side of the housing/plates) to add more Strenth and to stop the Housing moving around between the Plates under high Load.

Chris

[g11ary]

madzas cosmo already has 3 rotors and several cars have used it, there is 1 in ths club being shoehorned in to a fd over the winter and one of our gurus on this forum is having a 4 rotor built in an fd.

//www.evil7.com

//www.4rotor.com

[Grizzly]

Yep Cosmo\'s do use the 20b but Evil 7 is\'nt a Cosmo 20b.

Chris

[g11ary]

and Glens is not not two 13b\'s
It was just an example for without getting tech, coz I cant do tech.

[Grizzly]

LOL

ITS A 13B TRIPLE!!!!!!!!!! LOL i spend half my life saying that. the Diffrence is i have spent 3 times as much on it and had three times as many sleepless nights.

There is a few quite big Diffrences too , My engine is about 40kg lighter than a 20b and about 2-3" shorter.

Nice to have the two next to each other. LOL :cool

Chris

[g11ary]

have you used the ali plates to keep her lighter?

I know you can build a very light weight tripple, almost back down to 13b wieght.

[scooby_si]

dangerous question but what sort of cost are you looking at for a basic (har har ) 20b or 26b type engine. Sure it will depend on spec but as a very guide line ball park figure..... scare me go on:D
Si

[<--rYaN-->]

easily up to around 15k if you want the mutts nuts

[20B_boy]

Buy a 20B for a few grand.

Rebuild it, buy turbo, management, fuel system, fit it to car, tune it etc etc etc £££££\'s.

Do the same with a 13B short crank triple and add another £10-15K to the bill, eh Chris

[Grizzly]

I\'m not far of 30k and it isn\'t running yet.

No I didn\'t use Alloy Plates, to be honest they are a waste of time and money. My weight saving over a 20b as Rich has pointed out is found in the smaller 20b plate (extra Stationary gear centre plate) and the shorter Crank.

By the time I have lost the Air con,PS etc and added a rotor I am (give or take a few pounds) not far of my stock weight.

But and this is a Big BUT!!! if I had to do it again I would think twice due to the amount of Fab work that is needed to get something like this running, I could not use any of the 20b Manifolds,Sump etc and they all had to be made for my engine at a cost, i had too do alot of research into correct Inlet/Ehxust runner lenths and how to make Rotary manifolds it is\'nt as easy as it sounds there is also alot os Secrets that people dont like to share.

There is a lot to be said for the 20b swap! and when i set out to build my triple did not relise how much work it was.

All i can say is when it is done (hopfully all goes to plan this summer) it will be a one off Turbo 2 Traffic lights car.

Chris

[g11ary]

Cool, top man, admire anyone who has the ability to do it them selves.

[Grizzly]

As i say it dont Run yet!

Chris

[bill shurvinton]

There was 3-rotor PP on sale in australia a few weeks ago for about 5 grand.

I don\'t know if hurley still make 3-rotors but they used to do one based on 12A parts, so an 18A I guess. I lust after one of those for the westfield.

Grizzly: what are these \'secrets\' in rotary manifolds. I have yet to see anything external to the engine that isn\'t just common sense and reading up on the subject

Bill

[Grizzly]

Ok, The P/P has a short life so 5k is proberly about right for one with some miles on.

Has Hurley had one of there Custom engines Running with a Turbo? The last time i Checked they had got to the Stage of fitting a T2 with a 20b?

The 12A is a Good way of keeping the Port size the same throughout but 12A plates are hard to source and i wanted to go Full P/P Triple so the 13B was the way to go.

Chris