ok, Im still learnin this stuff, im gearing up (slowly) to rebuild the engine that came in my '79, according to what is shown on mazdatrix, or one of those sites, the engine is a california EGR engine (the car came from cali),
what i want to know is what the difference is between the EGR engine and the regular engines, i know it has something to do with rcirculating the exhaust gas' back into the combustion chamber (kinda like the rx8?).
will this effect the performance as opposed to a normal engine (i wanna port it etc. etc.)

thanks

 

The EGR just recirculates some of the exhaust as intake air, allowing the engine to re-burn the exhaust in an attempt to reduce some of the unburned fuel (Hydrocarbons, or HC on your emissions "sniffer" test)...

It's not really needed, and most are plugged up anyways. It shouldn't affect performance or porting either...

 

What he said

Zachstylez

 

egr when in working order defiently effects performance, think about it the more exhaust in the chamber the less air! However when its blocked off the risk of detonation is much higher! so go from there