I have an sa22. While re-assembling the stock 12a engine I noticed that the rectangular opening in the center steel plate that I thought was intake is not covered by the intake manifold. It's open to the air. What's up? Herb

 

if its under the primary intake ports, you have an 81-85 center iron. it is the passage the air pump air gets to the exhaust manifold.

so if you have the full 81-85 engine, that will be an exhaust leak. if you have just the 81-85 center irons with SA rotor housings, it probably isn't

 

This is strange. I have two engines both have the same opening in the center plate. One is from an engine I bought as a reman from mazda in 86. The other I took out of an April '78 car that supposed ly had it's original motor.

I do have thermal reactor rotor housings. So am I OK? Herb

 

The opening will need to be covered or fill it with JBWeld or other steal putty. I did an engine swap into a 1980 and had the same problem. I worked the JBWeld into a putty and it worked great.

Here's what that port looks like on my recent 1985 RX-7 build.

 

This works better.


You also need a couple of brass freeze plugs in 20mm for a complete "cool manifold mod"


Clean the port


Then smoosh it in there.

 

Thermal reactor housings usually mean you're ok, unless they have an additional emissions hole like this, which yours probably don't. divindriver knows what it's all about for his CA only 1980. I had the 13B j-spec version.



Notice the brass freeze plugs and quicksteel.

 

For all you guys who are painting your irons, does it hold up well over time? Assume your using a high temp paint? KC, I hope you removed that masking tape on you rear iron before final assembly....

 

I was thinking the same thing when I saw the tape. The engine has been sitting for so long I couldn't remember. Just to make sure, I'll be pulling the intake off just to make sure.