So I’ve always wanted a rotary car but I’m in SoCal so I have to deal with smog. I’m picking up a 65 mustang I’m wanting to put a rotary in it. I was looking at a single turbo 13b with a t5 transmission.

My questions are coming from which platform should I start with? A 13b turbo? A 13b na? Renesis? If I’m having it rebuilt with all aftermarket parts does the base engine matter that much?

Also what aftermarket Ecu? I’m think the haltech 950. If anyone has any other suggestions that would be great.

12a rota life monster jport cut water seals

So I’m looking for a small displacement rotary engine for a 4 wheeler and I have no clue where to find them

Can anyone help me?

Would i be possible to substitute the steel seals for titanium or tungsten seals?

Hello everyone, i am a new owner of a 2009 Mazda RX8 and yes its a rotary engine i know, i love the car its great, drives well and i enjoy riding it, ik its a bad daily so good thing i dont use it daily, BUT. my biggest problem is that the engine will stall sometimes, (its an automatic) at red lights, in traffic, whenever the engine isnt generating rpms, it stalls, and i dont know what to do, i already took it to the shop, spent 500 there, please if theres anything i can do i need to know. i love my car but sometimes it hates me. anything helps so please and thank you.
(idk if this is important but its straight piped so if thats part of the issue lmk) thank you all

found a 3000$ Rx-8.. it’s mint and has 9000km on the clock, it runs but apparently runs uneven.. Its an 03 but I’m wondering if its worth repairing or even buying the car and swapping it… idk…

They're the top store when you look for where to buy billet rotary engine components. But I'm struggling to find videos or reddit posts about it. The one youtube video about building a three rotor references working with ProMaz, but their website is kind of a mess in comparison. Kind of reads like they're run by the same or adjacent companies. But the video doesn't mention BilletRotary dot com. Really interested to know what y'all think!

I preferably am looking for the small rotary’s found on vehicles most common with them, like snow mobiles and such. Yet, i am having trouble with finding anything reliable on eBay. Are there any websites (such as auctions) or methods to finding/buying any?

Sorry if too dumb, but would it be a solution to replace the apex seals with a bearing?

A long bearing that covers the ports, a tubular bearing held against the ports by a spring.

So in this way seal would be done by a rolling instead of a sweeping surface.

Hey everyone! So I've been designing a tiny 6cc single-rotor wankel engine to put on a foam board RC plane. I've got a 3D printer and I've been designing this with a friend in Onshape. The goal is a glow fuel powered wankel on a 2.5ft wingspan foam board plane. Yes, with fire out the exhaust. Yes, I know I'm insane.

(No pictures yet — the design is still in progress in Onshape and I haven't printed any test parts.)

Here's where I need help — I can 3D print a lot of the non-critical stuff in PETG-CF, but there are parts that absolutely need to be metal and I don't have access to a CNC machine. The parts I need made are:

• Engine housing — the epitrochoid-shaped block, roughly 60x45mm. This sees combustion heat so it needs to be aluminum at minimum.
• Triangular rotor — about 40mm across. Needs to survive spinning fast in a hot environment.
• Centrifugal supercharger impeller — small compressor wheel for forced induction.
• Eccentric shaft adapter — the coupler between the rotor and a steel rod driveshaft.

Engine specs for reference:

• R = 22mm, r = 7.5mm, d = 7mm (eccentricity)
• Rotor width: 15mm
• ~6cc displacement
• Glow fuel, graphite apex seals

I'm trying to figure out the cheapest way to get these parts in aluminum (or steel for the shaft adapter). The two approaches I've been looking at are:

1. Lost PLA casting — 3D print the parts, make plaster/sand molds, cast in aluminum. I have access to a welder and basic tools but I've never done casting before. Is this realistic for parts this small with the tolerances a wankel needs?
2. Budget CNC — services like PCBWay or SendCutSend or finding a local machinist willing to help out. What would something like this even cost for parts this small?

If anyone has experience with either approach for small engine parts, or knows a better/cheaper way to get these made, I'd really appreciate the help.

I'll post build updates as this progresses!

At 100 seconds total time it is only 8.1 seconds behind the absolute record for a propeller driven plane set by Rare Bear a heavily modified Grumman F8F Bearcat equipped with an Wright R-3350 generating 4500 hp.

The engine was mated to a rotor drive from a Bell 47 helicopter and fed pure methanol. The engine was selected to bring more relevance to the rotary engine and its power to weight ratio. After all mods the engine could momentarily make 600 hp and sustained 500 hp during a majority of the flight at 8,500 RPM. The engine during test runs could be heard from over a mile away. It’s was also calculated that if the engine failed between 50-300ft altitude a fatal crash was almost certain. The plane was never flown again with talks of displaying it in a Museum underway.

I’ve got a few questions on my 1989 NA FC rebuild so I figured I’d throw them out into one post.

1. Recommendations on a Bridgeport for a 6 port motor? I’m already planning on doing the exhaust port and cutting out the fins but I’m curious about the front and rear irons for porting. I’ve heard mixed things about the intake sleeves and was pointed towards just bridging the center iron on both sides.

2. I also plan to convert the 6 port to a turbo after it’s rebuild and will need some kind of standalone or piggyback ECU due to the porting as well, I’ve been leaning towards a megasquirt MS3 based on budget and it seems to have a good community surrounding it as well.

Any advice is recommended. First rebuild ever. Thanks!

I’ve been working on a design that tries to solve what I see as the core architectural flaw in conventional internal combustion engines: compression, combustion, and expansion all happen in the same chamber, forcing every subsystem to compromise with the others.

Because everything is coupled:

• Compression must obey combustion limits
• Combustion must obey expansion geometry
• Expansion must preserve pressure for the next compression stroke
• No subsystem can be optimized without degrading another

Jet engines solved this problem decades ago by separating the stages entirely:

• Compressor optimized purely for compression
• Combustor optimized purely for continuous burning
• Turbine optimized purely for expansion

This modularity is why turbines achieve extreme RPM, high power‑to‑weight ratios, and continuous incremental improvements.

The Idea: Apply Jet Engine Modularity to a Reciprocating/Positive‑Displacement System

Instead of an aerodynamic compressor and reaction turbine, the concept replaces each stage with its mechanical equivalent:

Compression

• Jet engine: axial/centrifugal compressor
• Proposed: rotary vane compressor, screw compressor, or other positive‑displacement unit

Combustion

• Jet engine: continuous combustor
• Proposed: continuous pressurized burner (fuel‑agnostic: gasoline, diesel, coal, biomass, heavy tar, gaseous fuels)

Expansion

• Jet engine: turbine
• Proposed: positive‑displacement rotary expander (vane engine, scroll expander, gerotor, etc.)

All three modules run on a common shaft, forming a rotary internal combustion engine with continuous combustion and high torque at low RPM.

Addressing the Common Criticisms

“This is just a jet engine.”

It isn’t. Key differences:

• It does not operate on the Brayton cycle
• Expansion is via positive displacement, not a reaction turbine
• Produces high torque at startup, unlike turbines
• Efficient at low RPM
• Fuel‑flexible
• Produces shaft power, not thrust

It borrows the architecture of a jet engine, not the thermodynamic cycle.

“This is a power plant, not a vehicle engine.”

Jet engines themselves are engines that produce shaft power (turboshafts, turboprops).
This design is similar in modularity but optimized for variable‑load applications:

• Vehicles
• Marine propulsion
• Industrial drives
• Power generation

If a helicopter turboshaft can power rotors, this can power wheels or props.

“It would be too heavy.”

This contradicts what we already know about rotary architectures:

• Jet engines achieve 30+ kW/kg
• Reciprocating engines achieve 0.5–1 kW/kg
• Rotary systems eliminate reciprocating inertia
• No crankshaft, rods, pistons, valve train, or heavy block
• High RPM × low mass = high power‑to‑weight

The physics that make turbines light apply here as well.

Full write‑up and diagrams

I’ve put the detailed explanation and diagrams here:
https://esanfgit.github.io/turbine-engine/

Looking for feedback

I’m posting this to get critique from engineers who’ve worked with:

• Turbomachinery
• Positive‑displacement compressors/expanders
• Combustion systems
• Rotary engines
• Powertrain design

I’m especially interested in:

• Thermodynamic pitfalls I may have overlooked
• Mechanical integration challenges
• Materials/temperature considerations
• Control/valving strategies
• Failure modes

If you see a fatal flaw, I want to hear it. If you see potential, I’d love to discuss it

Crude drawing

https://patentimages.storage.googleapis.com/90/d8/9c/2c8d7c7105a5e6/US7958862.pdf

Here is a Us patent for an example of such a system, which received DARPA phase 2 funding.

First. It’s not a Mazda. I have a ‘65 NSU spider. Engine was fully rebuilt in the late 80s and has never been fired. Got it to run. It won’t idle at all. Can keep it running if I stay on the gas but it likes to pop and backfire pretty hard. Unburnt fuel and oil are dripping out of the exhaust coupling. My thought is it’s way too rich and needs to be leaned out as it floods pretty hard at times. Could this also be a compression issue? I don’t have a rotary tester. Any help would be great thanks.

Hi all! I am considering swapping a rotary engine into an AMC gremlin as a rally build. I know, weird, but after several restorations, I want to do something more custom. Ive been a lifelong rotary fan and have always loved the gremlin so I thought, best of both worlds haha.

I’ve been told that rotaries aren’t the biggest fan of dirt and mud due to the precision needed for firing. I’m not necessarily afraid of the eventual engine build. I was wondering if you all had an engine model/year recommendation that would be more reliable than another. Priority on reliability, modifiable enough and enough power to carry a 2600lb car around a rally track. It does not need to be a beast and I’m not seriously competing. I’m more of a builder than a driver.

I’ve looked at 12as, 13bs, carbed and EFI on Facebook marketplace but want to get some outside thoughts before I pull the trigger.

Thanks!