Modifications

This page describe modifications that I performed to make the engine work in the sandrail.

Intake Manifold changes:

The stock 12A intake manifold has a whole bunch of junk attached to it that is used for emissions control. I’m not sure what all the junk does, but it seems to be a group of valves that control the flow of the smog pump into the exhaust system. Since it was an ugly conglomeration of junk, I decided to do away with it and fit an aluminum plate (milled with a sherline milling machine) over the opening. Below is a picture of the parts that I removed, and the plate that replaced them.

Above: ugly old intake emission valve assembly Above: Aluminum plate fitted over hole in intake

Eventually, I just said to hell with the whole mazda carb mess, and ended up going to a modified holley carb.

Simplified wiring Harness:

My engines didn’t come with a wiring harness, so I had to make up my own. Here’s the bare minimum necessary to make the engine run:

  (Click the image for a full-size schematic)

Comments (1)

  1. Bradley Shephard says:

    Hello Scott,

    I am currently converting my 1981 Toyota Corolla to rotary power using a 12A. Unfortunately, the link on your site to your wiring harness diagram is broken. (https://www.smbaker.com/sand-rail/mazda-rotary-conversion/modifications) and I cannot view it. Could you attach this file in an email reply?

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