Hi, I'm new here and I've done some lurking before I registered, and obviously a lot of youtube and wikpedia, but I've still got a few questions..



I recently blew my 340 hp ca18det in my fastback s13 and now I'm looking to build a three rotor turbo replacement. I want to build it ground up, not blow a load of money on a 20b then a whole load morereplacing everything. What is the best motor to source the basic rotor housings and such from? Are they pretty similar from early two rotors to the latest renesis motors? Are they differences that would be more expensive to replicate on an older model rather than fork out for a newer one? I understand that the rotary engine is modular, but to what extent? Could you, for example, snag the "crankshaft" (iim sorry, I ant remember, is it called the eccentric shaft?) From a 20b and combine three rotors from two older motors? I know I'm probably sounding stupid, and I'm not actually insinuating that I would actually do that, I'm just asking hypothetical questions for greater understanding.



Furthermore, I couldn't really find a custom engine building section.. these forums seem more like people who already have engines and are trying to build them. Is there a more technical section or forum I'm missing?



Thank you in advance for all your help, I have many more questions but ill see if I can figure out some more of them with a little more searching.



By the way, I plan on putting the final result of all this effort into the engine bay of my s13 hatchback. Should be fun

 

I don't have an answer for you, but you should check out the 20b section if you haven't already.

 

I will take shot at answering a few questions for you.



Yes it is possible to make a hybrid type 3 rotor using 2 rotor parts. As I'm not well versed on the subject, I have heard of a few examples. I'm not to sure what they use for the extra iron/plate, A custom E-shaft would be needed & manifolds.



I'm sure you are aware that the 20B was offered in the Cosmo so if a 3 rotor is what you want I would start.



Now I'm curious as to your goals for the car, your CA18DET was in the 340hp range right? You can achieve those numbers & higher with a 13B 2 rotor as well as keep the weight down & saving the difference in money for other areas of the car. Just my opinion, but it's your car so you build the car the way you want it. What ever the route you take good luck.

 

All it takes for an rew (the 2 rotor in an fd) to make 400hp is a single turbo conversion, some porting and fuel upgrades. Well, and an aftermarket Ecu too of course. To make it reliable takes a few other mods such as intercooler, radiator, and deleting some or all of the unnecessary accessories.

 

As badass as the 3 rotor sounds, the consensus seems to be that it'd be a headache to do yourself unless your really saavy with rotaries. I'd say just go with the 2-rotor. Although some of them like my 12a only produce approx. 105hp stock, it pulls for a small engine and it helps with the weight cuz it's remarkably lighter. 13b is prob the best bet cuz they're easier to find parts for( I know from experience) and like stated above you can make great power out of them. Even if you don't force induction it, minor porting, a, full exhaust and an upgraded intake can prove to be very powerful. That's just my two cents. However you do it I'd like to see how it comes out.