I had an old 13B sitting around from a Rotary Truck. It's actually a 12A converted to a 13B. At one time, it was a nice motor but then it sat for years after losing a coolant seal. I needed an engine for my MazdaSport Magazine project car, so I tore it down and cleaned it up. It's not ready for assembly yet, but I took another picture of it to compare the before and after refurbishing. Startling how far it has come.

I media blasted the plates and had them surface ground and lapped, ported them and painted them red. The rotor housings were just media blasted and will be ported shortly. It's not an extreme engine but the transformation is pretty cool.

 

Looks nice, what paint do you use?

 

It's just some Duplicolor Engine Enamel. The color is Ford Red. I was going to powdercoat it, but my deadline wouldn't allow it.

 

all i can say its DAMN. Those dont even look the the same parts.

 

Here is the side-by-side before and after of the rotor housings. Cleanup only required media blasting with glass bead.



The side housings were surface ground and lapped, then I finished them off by hand with a stone, so there was a bit of crosshatching for oil retention.



For painting the side housings, I mocked up a motor with junk rotor housings and front cover, then blocked off all the openings and capped the threaded holes. Finally, I scraped any excess paint off with a razor blade.

 

Very nice job! So your saying basically i can bead blast my housing to look new again?

 

Nice work as always..

 

Super nice work!
But, I'd worry about the paint next to the exhaust ports on the side housings, especially with the center housing?
I would think the paint would "burn" and cause a pretty good stink?


-Ted

 

nah, ive painted a few engines with the same stuff, never had any problems. Its supposed to be 500F rated, so i guess the housings never get that hot, even next to the ports. I cant remember looking at the exhaust ports on any that were torn down, but i dont recall seeing any blackened paint or anything, and i painted the rotorhousings too. That paint will flake off if the engine sits for too long tho..I sold a car to a guy with an engine taht i did, which sat in his yard for a year or so, looks like crap now....

looks like you did a nice job.

 

Never had a problem with burning paint. Even normal spraypaint holds up pretty good in that area, let alone the engine enamel. Powdercoat works great too.