I am in the process of building a bridgeport 12A had some questions about the oil pressure. First this car is not going raced in any way, however the area where I live has very little stop and go and plenty of highway for the engine to reach it's full potential. Wanted to know what oil pressure mods were necessary. rear and front oil pressure reg, stronger oil pump, e-shaft oil jets ect. Engine is 83+ 12A. Thanks.

 

Hi there, Im building a 1980 bp. I shimmed the front reg, crushed the rear, cleaned the oil pump , new chain, removed the screen on the pickup and added a trumpet.

 

Modifying the front and rear oil press reg is what I had in mind. Also wanted to know if modifying the e shaft oil jets was needed.

 

Idk. I'm honestly not sure about the e-shaft jets. If I had no help, and no knowledge just going off common sense then I would do it. Besides that, I don't think you have to worry about oil pressure at all, IMHO. But, my Monster port with it's shimmed regulator has no problem hitting 100 psi cold idling. Which is pretty good.. If anyything to much. I would worry about oil temp/capacity before pressure honestly on the street. Both just as important on the race track.

 

Use the larger 17.5mm oil pump too. New. What rpm are you going to rev it to? You need to make 10psi of oil pressure per 1000 rpms. I'd only replace the oil jets with the Weber carb jet if you A: spend a significant amount of time above 8000rpms and b: don't mind low oil pressure at idle.

The Rx8 e-shaft has some nice chamfered oil ports stock, and still uses the factory oil jets. And it redlines @ 9000rpms of street driving.

Replace the both oil regulator plungers and springs too. Those things are rarely in spec.

You can get an aluminum oil pan from MAZDA that increases oil capacity by 1 quart.