Whizbang

how are you planning to run the mounts for the engine? im thinking about modifying two cradles and have a total of four mounts.

Bob's #45

iTrader: (1)

I was thinking about using the adoptor plate like a mid plate & put mounts on each side, then build some off of the front. Total of four . Great minds think alike........ha ha

rarson

I think if I were to do this, I'd pick up a TKO tranny. It's only rated to 600 hp but I'd be going N/A anyway. The TKO is the same as a T5, which looks to be quite a bit shorter than the RX-7 transmission. So this right there should give you a little more room for the engine.

I really like the idea of a splined coupling but I am also having trouble understanding where the two different spline counts comes in. It seems to me that it should be possible to just machine the rear shaft and bolt an adapter to the front shaft, without having to otherwise modify it. I think I'd also either use two oil pumps or have two supplies from one pump with a greater capacity. It seems to me like keeping the two halves seperate as far as oil and coolant goes would be easier.

I'd actually rather do this with 2 12A engines. Not only would it be shorter, but the shaft should be stronger and the engine should rev better. I know Scoot made theirs with 12A engines.

Michael_Rudy

Rarson, the reason i am going with 2 differnt splines on 2 differnt diameters is to fit my coupler bolt properly, and to machine the rear end of the front shaft down the the same diameter of the front of the rear shaft doesn't leave enough material to spline. The bolt doesn't go all the way through the front shaft it just bolts the coupler to the front of the rear shaft. Once i find a scanner it will be much easier to see what i am trying to say.

We are going with a built C4 auto tranny, with a 9.5 inch converter that stalls at 5,000 rpm, it has a transbrake and is full manual, we also built it with te 6 gear planitary gears.

I also went with 12a's because of the length/weight. Plus i have a dozen or so laying around.

Michael_Rudy

What are you guys using for an ignitions? I am using 2, 1985 gsl distributers, in an old modified dual distributer 12a front cover, then using 2 mallory box's

andrew lohaus

i'm no ems expert but i think i could be run (i the 2 motors chained together, in parrallel set-up) on even a single stock ecu. youde just have to wire the injectors in parallel and replace the stock coils with multiwire ones that would give twice the spark. it would baisically be running one engine like normal and a cloned one right behind it that for all intents and purposes the computer doesnt even know is there.

but youde have to put a dummy afm in front of the #2 engine to keep the flow rate the same. ghetto but it could work.

Bob's #45

iTrader: (1)

You mentioned that with this coupler you would be able to adjust the end play on both engines seperatly, how are you doing it on the rear engine? Thumbs up on selling kits I think it will be a hit. Alot of people would love to build a 4 rotor.

Bob's #45

iTrader: (1)

Thats a good idea, are those Front covers hard to find?


Heres another way I thought was pretty cool,

Lynn E. Hanover explains how to build your own crank trigger set up with using very inexpensive off the shelf chrysler pickup coils.
You can find it at Nopistons.com under........ Engine Building and porting
The topic is.........90 Degree Opposed 4 Rotor .. Hes got some other good info as well.

Michael_Rudy

Bob, as i have said the rear couple is slid onto the front of the rear engines eccentric shaft, it has the same spline as that side of the coupler. when you bolt it on, it will be just like bolting the regular front en peice on like a regular engine, and then you add, or take away shims as needed, we thought up many other ideas but this seemed to be the simplist, as it in effect adjusts the play the same as stock. Then from there you will slide the front engine onto the splines with the plate inbetween the front and rear housings and voila, you have a 4 rotor block.

The dual distributer front covers arn't very hard to find at all, they are regularly on ebay, i was just lucky enough that the i have still has the bottem part of the distributer on it.

I have read the ignition set up that lynn had suggested, it seem fairly easy, somewhere in there it said if you send him the parts he would build if for you too.

Whizbang

this is one reason that im going to use the 13b. electronic igntion. much easier to work with.

Whizbang

im surprised that some of the rotary heavy hitters on this forum seem to not add anything. I would really like to know the effects of different methods or even how long a PP with run for. Something is better than nothing. That is how think tanks work.

Bob's #45

iTrader: (1)

Ahhh.........Shims , Thats what I was looking for. Thanks for your time. Bob

Whizbang

here is my idea for fastening the mounting plate.



PC paint is the only this i have availible right now but the general idea is there. and photobucket resizes crap. but what the little black lines said was, add dowls between the plate and the two engine sections. and also extend the bolts that hold each engine together into the plate. that should hold the plate and reduce flexing between the two engines.

Kenku

*shrug* The coupler method's one way to do it. Personally, I'd rather go to the trouble of designing a multi-part e-shaft though; it's not that complicated, and depending on how your design ends up, it's not necessecarily even that complicated to machine, though obviously the bearing surfaces will have to be ground.

I'm more curious about how Granny's did the water rerouting internally, actually.

c00lduke

If your going to make and eshaft then just make an intermediate plate with stationary gears on both side. Replace the front and rear plates with this plate and coolant flow could be normal straight though setup.

Whizbang

making an eccentric is alot of work.

10sec rx7

there is a 4 rotor in australia here that has run low 7sec passes at high 190's down the drag strip, it is a jeff bruce shaft from NZ with a turbonetics thumper turbo on it,

Dale

Bob's #45

iTrader: (1)

What brand and model E.C.U. would be the best to control timing & fuel, for a 4-rotor with boost?

Michael_Rudy

ppfffttt be a man and use a carburator lol

10sec rx7, what car is that ?? the only one i remember is the bmw, is it going low 7's at high 190's now?

I have heard about jeffs shafts and housing conversions, its a shame i am poor though, lol

Whizbang

yeah 10k my ***. ill build one over the course of a few years instead.!

rarson

I've got an 86 FC that I'm currently building. Right now it's using an N/A 13b. I'm very interested in obtaining another 13b down the road and making this coupled setup.

That'll be awesome: 4 individual exhaust pipes exiting through the front fender right behind the wheel.

Snotcycle

4 rotors, 4 words: rear engine all-motor

rotarypower101

iTrader: (1)

I have always wanted to devise a setup that had a load sensing device and could automatically engage start and seamlessly double the usable HP and torque on demand of 2 inline rotary engines. The problem would be finding the correct type of clutch, perhaps a electromagnetic clutch.

Think of only having to haul around the extra ~300Lb and be able to engage it on demand. Though I suppose it would be a little hard to phase the power, but for size length and weight what could be better for running twin independent engines?

Whizbang

that is what some of the new suv are going though. "displacement on demand" or some crap like that.

Michael_Rudy

does anyone know what port the grannys motor had?