I grew up with RX2 and my favorite RX3’s, the RX3sp, which was just a temporary until the RX7 could get to our shores here in America. What makes it so special? You have to drive one to appreciate one. It is truly a love or hate it scenario at the track. Back when we had megaphones out the back, it was easy to hit 120 db sound limit from a long ways away.
Porting and polishing is the way to get the most out of this little 1146 cc engine. Add in some lightened rotors, competition bearings and the right sized side seals and of course ceramic apex seals and go racing.
We like to do upgrades like add a front port for oiling to the front bearing (vs. waiting for that oil to get all the way through the eccentric shaft to lube it) to keep things slippery. Port out the oil galleys and add in a larger oil pump if you are using the stock front cover.
Another is to add in a larger, fully baffled oil pan to keep more oil and let it get as many bubbles out as possible before the oil pump picks it up and pushes it through our larger than average Setrab competition oil cooler and back into the front and rear bearings at 120 psi. To keep things inside clean under pressure, adding a Peterson inline oil filter means that it is easy to check for bearing wear.
Because it has been years since Mazda Competition made 12A parts, these motors are getting harder and harder to find the old tired 12A automatic engine for parts. Most of the manual tranny cars were driven a lot harder, so I’ve seen customers come in and show me an automatic one and ask if I can build one good motor out of two old engines.
I have my original 12A bridgeport motor sitting on a cart in the corner, it still runs and got me to the Runoffs every time I put the effort in, and it made a solid 272 hp with a weber carb.
Yes, there are a lot of tried and true 12A tricks to make these motors scream. A lot of time went into the flow bench to get those kinds of numbers reliably. You do get what you pay for.