Imacco イマッコ

18/09/2026

Mazda Renesis front timing cover clean up and rebuild. The RX8 timing cover has a bit more going on inside than the earlier Rotary engines. They contain a built in reservoir and multiple primary and secondary bleed off holes for the oil metering pump. The only way to sort them out and return them to factor working specifications is to fully strip them and clean every bit of the front cover. All carbon has to be removed, galleries and bleed holes cleared and checked to be free of debris.

11/09/2026

First drive for Chris in his Left hand drive RX3 Wagon. 13B bridge port fresh rebuild.

11/09/2026

RX3 Wagon Lefthand drive. Start up day for the 13B Bridgeport 3B engine and a little drive. Imacco イマッコ . Exhaust by Metal Sculpt.

10/09/2026

Rotary counter weight cracks. This counter weight looked like it was going to do the job fine until it was cleaned properly. The extensive use of glass media blasting wet or dry in the Aero industry is one of the best and approved ways of cleaning up engine parts. The shiny appearance quickly shows up any issues with components that may lead to failure. Before cleaning it looked like every other old counter weight. Even looking at the item while cleaning it under light inside a cabinet it looked fine. Once removed and inspected it shows a nice crack most likely from mistreatment at some point. The counter weight would have failed with a big rev and the entire counter weight, clutch, flywheel and bellhousing destroyed. Lots of damage and maybe a fire. Cleaning up parts to a level worthy of aviation use is not just about looking good. Its about finding all the hidden details that could potentially cause a fault or failure.

02/09/2026

Mazda's electronic distributor, the strange looking contraption which gave the Rotary engine a lot more reliability and performance. A simple unit that can be rebuilt and modified with ease. Provides easier starts and when offered with the Series 1 RX7 in the late 70's allowed the little Rotary to show its true potential. Still in use today and coupled up with a Turbo in the early Rotary Turbo era, was capable of some seriously quick times on the drag strip.

23/08/2026

23/08/2026

A little Sunday night inspiration for the week ahead. Get those spanners rotating in the right direction.

19/08/2026

Some random pics of recent works, description on pictures.

31/07/2026

Rotary Riot 2026
Queensland Raceway Ipswich, one of the spectator viewing points on the balcony. Mazda Rotaries practice roll racing session.
Chris Johnson RX7 Imacco イマッコ

28/07/2026

You might hear people talk about misalignment with Mazda Rotary stationary gear oil galleries. In the photo of this RX8 6port stationary gear you can see the inlet feed oil gallery in the gear with a dark round stain off to one side. The stain is caused by the dirty oil over time. But it clearly shows the miss alignment of the oil galleries once the engine is assembled. Most engine builders will sort the problem by simply using tools like a die grinder to blend the hole so there is no chance of a restriction on a engine that might see high rpm or horse power. It can happen in all Mazda rotary engines produced over the years, front or rear stationary gear. Even if the stationary gear and engine plate combination was a factory set up, they are not all perfect.