Finally I've started on my build. After thinking about building a 4-Rotor for a long time I finally disassembled a few n/a engines I had lying around and started work. It's not purpose build for drifting or racing or anything, I'm pretty into fabricating my own parts, so this is more of a hobby project to keep me busy than anything else. The chassis is a basic red S4 FC, with Tein HA coilovers and SSR Type-C wheels. It's not the most pretty thing ever, but I don't mind. I'm not going to do anything outrageous with the chassis, just make sure the suspension and everything is in good condition, maybe remove some of the interior like the back seat's you can't use anyway but that's about it.

Now for the interesting bit, the engine. I can type out a really really long story about the engine, but I'm just going to let the pictures speak for themselves. All these pictures were taken within the last 6 weeks:

 

 

 

http://www.youtube.com/watch?feature...&v=UDCborFfCmU










Progess so far, the e-shaft is coming along great, need to drill the final holes tomorrow, so the shaft can go out for heat treatment.nThe rotor housings are also coming along well, the ports are all in, need to add some epoxy in the water channel near the intake port though. I'm also planning some further modifications to the housings, but I need fuel injectors for that so I have to wait for the ID1000's to get here before I can continue with that. No worries though, lots of stuff to do in the meantime.

 

jeezus h. christ!

 

this is extremely awesome

 

Excellent work John, keep us posted.

 

Interesting exhaust sleeves. I'm very curious how that will turn out. Also, I see GSL-SE/RESI rotor housings. Any particular reason for using those rather than the more readily available later style housings?

Can't wait to see how you do the center stationary gears.

Edit: I just noticed the slide throttle. I've been wondering how a slide throttle right up close to the ports like that would work out. Are you going to use round holes or teardrop ones?

 

When u get it running, make me one as well.

Thank you sir.

 

 

Very nice. It must be wonderful to have a machine shop at your disposal.

I'm wondering why you chose that design for the exhaust sleeves? Mazda created them in the shape they did so that the gasses could rapidly expand once they exited the port. I'd expect a smaller design would be a fair restriction at higher flow levels. About the only engines that Mazda had such narrow sleeves on are the 20B and 13B-RE, which are designed as low/midrange engines.

Those are FC housings. Earlier housings have coolant o-ring grooves in the housing. As does the Renesis.

 

There are some things for you to consider regarding port and manifold design. PM sent...

 

These are S4 N/A housings. I wasn't sure if I could succesfully modify the housings without warping them or anything so I took the cheapest and best available housings there are, S4 N/A housings. They are used, but still have a lot of life left in them. I might replace them with better ones when the engine is running and dialed in and has done some miles, but I'm a very very very long way from that.

The slide throttles will have round holes (or, well with a small cutout), because the peripheral port inserts in the rotor housings are round, and the intake manifold is also round. I'm going for uninterrupted laminar smooth flow here.





Well, It's something I wanted to test for a while. I did a lot of flow simulation's, and I found that this sort of port doesn't increase backpressure like you would think. It does improve gas velocity however which should be good. I actually wonder if the expanding shape has something to do with the air injection system. The flow is very turbulent when it exits the rotor housing, I tried to make a straight uniform shape which should convert the turbulent flow to a laminar flow very quickly. This shape also makes it easy to create an anti reversion lip.



I think it will be fine, there is another topic about it here:
https://www.rx7club.com/rotary-car-performance-77/custom-exhaust-sleeves-explained-120200/

I also looked at the 26B exhaust inserts, they also aren't as large as you would think. This is not a turbo where you need to cram a lot of energy through the exhaust channels.

 

Well, I stand corrected, but those are the weirdest looking S4 rotor housings I've ever seen. Must be a Europe thing. I just saw the smooth castings and oil injection holes and assumed GSL-SE/RESI. Now that I look closer I can see the lack of coolant seal grooves, but otherwise they look exactly like GSL-SE housings except for the emissions tubes by the exhaust ports.

 

I love these diy builds!!

 

curious to see how you work out the lubrication system and modified center stat gear plate.

been working on the design but going a slightly different direction trying to adapt as much OE parts as possible. as my aim is to produce modified 26B's.

 

I'm posting just so I can subscribe. I love you, man; if I had your resources, I'd be doing the same mf thing.

 

This is amazing... Very very interesting build here. I have definitely subscribed.

Great work so far!

 

Are you planning on modifying the firewall to fit this? how about mounting it? drivetrain?

Very impressive skills, keep the pics coming

 

bad ***, don't know what it is but love watching anything and everything getting machined.

 

John, mind me asking what tool steel did you used, oil or air hardening?

 

Greatest. Build. Ever. And the engine isn't even done yet.

 

Did you weld the inserts to the Chrome surface for the intake?

 

subscribed, very awesome build man

 

that is savage man i am very exsited