Shiver77

Hi I was looking at rx8 cars because I love the suicide doors then started reading about rotory engines. I found a 1972 Opel GT that only weighs 850kg or 930kg. the car is so light, the engine is either a 65 or 100 hp engine. I started thinking about swapping a rotory engine into it. The car looks like a mini corvette. I think it would be very cool to keep the power to weight ratio high with the rotory. I don't have the skills or money to afford dropping a new engine into it so I'm hoping to find something very cheap to learn to rebuild or find someone selling one. I would love 200hp but anything over the 140hp mark would work. I was thinking of using an electric turbine from a RC jet plane to use as a supercharger with it for added hp. They can provide 10-25psi. These aren't the 12v ones that do nothing.

I'm in Vancouver BC Canada. I was told a 10-12b rotory engine would be a good choice. I'm hoping to figure out a way to bolt accessories like starter and alternator to the manifold or transmission or engine bay so if I need to rebuild the engine later again, I wouldn't have to spend hours taking parts off the engine.

I hope I could get some advise on how I can go about doing this on a retired budget. That means low priced or free parts I can use to fix. The car is old so doesn't have electronics. I'm hoping I could slowly figure out how to swap a motor into it. Mounts, bolts into the transmission, connecting the drive shaft to the rear end, throttle, fuel pump connection. It sounds doable but I know I'm getting into something that I most likely won't be able to finish due to money, knowledge or physically be able to do it.
This is what I would want it to look like after repairs and painting it. Mini Corvette or the woman's corvette

diabolical1

iTrader: (3)

again, welcome ... (i just finished posting in another of your threads)

i remember those cars. yeah, they're pretty cool looking.

for the sake of clarity, are you saying you already bought one?

anyway, for the engine, my advice would be to do yourself a favor and find a NA13B (6 port) from a Gen 2 (FC) Rx-7. i've never seen a 10A for sale, but i would imagine they would not be cheap and i would also imagine parts would be either NLA or prohibitive for a the average person - retired or not. 12As are likely much cheaper as a whole, or as parts, but ... given your situation, i don't see an upside to getting a 12A. let me clarify what i'm saying about 12As a bit, if you already have one and you're looking for parts for it, you can probably find them, and it won't be cheap, but it probably won't break you either. for you, starting out with no engine, i would say just go for Gen 2 13B ... and here is my reason why ....

13B parts are still available new and used. on the used market, prices vary, but every once in a while you can still catch a break. 13Bs don't have a front and rear, like a 12A does, so even if the engine you get is half dead, you're not stuck looking for specific parts to complete it. you have many more options with a 13B in terms of what you might want to build - turbo vs. NA, but NA 13B parts can still be had, it just might take a little patience. that statement was more about housings than a rotating assembly, but again, you have options. if push came to shove, you can use rotors or a shaft from any 13B - older or newer - as long as the rotors match and you can get everything within a reasonable balance. if worse came to worst, then you can have your parts balanced. in summary, i think it just makes better sense to start there. it does come with it's own pitfalls (questionable or broken side housings aplenty), but brand new is one of your options.

you can achieve your power goals with a solid NA block.

that brings us to the project itself. you will need some fabrication to get it done. so you either have to learn or pay someone for that.

if you don't already have the Opel, then in my humble opinion, an Rx-8 might be a decent option to get your feet wet.

WJM ROTARIES

Welcome to forum

diabolical1

iTrader: (3)

just want to correct what i said here:
that is ... unless you decided to go with MSP (Renesis/Rx-8) rotors, in which case, like the 12A, there is a specific front and rear. however, keep in mind using those rotors in the older engine requires machining of the apices. that work is not cheap (i think Mazdatrix charges like $500), but that said, i think i see more Renesis rotors for sale than the old NA rotors these days. decisions ....

TeamRX8

iTrader: (2)

because they’re not generally reusable like on a 13B, not for long term or max performance use any way, after having run with any significant mileage using the standard shallow Renesis apex seals.

Mazda made a number of Renesis specific changes to address the unique Renesis conditions that don’t exist on the earlier 13B engine. So when somebody with the 13B mindset goes machining off the sides/tips of the rotors on a Renesis engine without fully recognizing what that means with side exhaust ports that don’t exist on a 13B as one example, things go downhill really fast.

Same for porting. You can find all kinds of brapping vids, but very few real dyno results. Those you can find are mediocre to poor compared to the best blueprinted stock port engine results. The rotor sealing is so much more critical on the Renesis relative to it’s output performance. Which is directly related to it intentionally not having any (as in zero) exhaust-intake overlap port timing
.

diabolical1

iTrader: (3)

i did not know this. what exactly happens with them?

yeah, i get why the Renesis, as a unit, doesn't react to the things old heads are used to doing to rotaries. i think i may be one of the few people that actually appreciates it for what it is, and is totally happy with what it does. i accept it for it's strengths and weaknesses.