I'm working up to picking up a project that I found semi-local.
It's a Locost (replica Lotus7/Caterham) that is partially complete & set up with a (dead) rotary engine.
It was being built as a track car, so needs a lot of wiring done for lighting & needs a bit of the suspension finished.

Mostly wanting to dig into some specs/data on the 13B & either rebuilding the current engine, or sourcing a replacement.

Many many years ago I had a 1988 RX-7 with 13B engine. Got it used and loved that car for a few months until some asshole ran a red light and totaled it.

Not sure current sources. I used to get a magazine with parts and info from Racing Beat. We are talking before the internet was what it is today. They where one of the go to for rotor engine stuff. Looks like they have a website. No idea if they have good info anymore but back in the day they did.

I would also search for Mazda or RX-7 forums.

Why is the engine dead. I know apex seals could be a problem and leak but not really kill an engine. Not alot of moving parts in them.

That was the smoothest revving car I ever owned.

I'm still working on getting details from the seller, but the short answer I got was that the engine in the car currently is just a placeholder & non-running.

His intent was to build a dry-sump 13B & use the car for Autocross.

Hoping I can get some 'play' money' saved up before he sells it elsewhere.

I have an '88 Convertible. The 13B is a solid engine, but some of them need a little bit of help from time-to-time to generate enough compression to start. The rotors use spring-loaded seals that can get "sticky" in their slots, and not do their job. For you piston heads, think what would happen if your piston rings got stuck in the bottom of their groove in the piston. That's right, no compression. The "solution" is to squirt a little ATF into the combustion chambers before trying to start it. This will usually free the seals enough to get it started, and kill all the mosquitoes in the neighborhood as a bonus. After that, you usually won't have a problem any more, (until the car sits without running for more than a few months).

Many people who encounter this phenomenon, give up, and are convinced their engine is "dead." Of course, sometimes the seals are too stuck to be revived by the above procedure, this is tear-down time. But even then, engines can usually be resurrected, and do not have to be replaced.

Mazdatrix used to be my go to for replacement parts and accesories. With Mazda no longer selling Wankel-engined cars, who knows when they may move on. It is much much harder to source parts than it was ten years ago.

BTW, a "dry sump" Wankel doesn't sound too viable. The Wankel is a 2-stroke engine, the 13B has a mechanical metering pump driven by the rotating assembly (no crankshaft or camshaft/cams/valves in a Wankel) that adds sump oil to the fuel, and the engine depends on this lubrication.

I learned about the oil metering yesterday.
Spent most of a slow workday reading through a build log of a 13B Locost.

Guy deleted the oil metering system (his Megasquirt didn't support it) and went to adding some premix with every fuel up.

Good to know that a rotary can be revived. With only a couple moving parts, there doesn't seem much to really go wrong, as long as there aren't extra holes in the 'block' or major damage to the 'cylinder' walls.

I think the current owner's reasoning for dry sump is high-G cornering in Autocross. Premix there would be practical, as the car wouldn't see any real mileage.

Will have to look further into running a separate sump for the rotor oil, or retaining the metering system, or just going to premix with each fill-up.

The way most soup up a 13B is to cut bigger holes in the rotor housing (the "block"), this is called "porting" and it allows pumping more fuel and air through the engine. I have read that it isn't too hard to get 650HP out of the 1.3L 13B with a little porting. Real aficionados start with a 20B (three rotor) of even bolt two 13B's together for a four rotor. I have heard that the latter can reach 1200HP which is a huge amount of power in a car as light as an Rx. The sandwich construction of the Wankel encourages this kind of experimentation. The problems with the rotary is not power/weight or longevity, but environmental (to include mileage, pollution, and noise).

Given that these Locost cars are typically around 1200-1600lbs, I think a stock N/A 13B should be more than sufficient for a start.

I've seen a few wild 3 & 4 rotors builds. This is going to be an occasional use fun car. Probably see a bit more mileage than I was putting on the motorcycle, but not daily driver mileage.

Probably at least a year from the time I get it before it's legally on the road, I'm guessing.