Anyone have some easy things to remeber when telling the difference between S4/S5 engine parts, housings, irons, rotors, counterweights... I have some turbo engine parts laying around and would like to label them.
Keith

 

No one knows? What does everyone do, just guess?

 

For S4 and S5 housings, on the spark plug side down by the legs of the housing, 86-88 have a slanted edge whereas 89-91 are rounded.

Thats all I can think of off the top of my head. It's easier to notice things when I have a block sitting in front of me.

 

yes people know, no we don't want to sit and type out things you can learn on your own by using the search feature.

 

S5 rear irons have a larger rear casting around the dowel, though some S4 irons are like that as well.

S5 middle irons don't have EGR passages.

The o-ring boss on the front iron of S5 irons is milled out larger to accept the teflon o-ring and rubber o-ring. However, some S4 irons are like this as well.

S5 rotors have a milled compression bowl instead of a rough casting.

No idea. Weigh them?

 

Tried that, without much info besides how to tell n/a from turbo.


Aaron thanks for the info, the egr passage would be right below the intake ports on the irons? All mine including the center have that.

For the housings isn't there another hole above the spark plug holes on S5? For knock sensors or something.

 

Mazdatrix has a guide to tell apart counterweights and flywheels.

 

Cool thanks man. Any other notable differences in the rest of the parts?

 

rotors are like aaron says

rotor housings; s5+ have knock sensor holes above the spark plugs

center irons;

s4 na has the egr right on top, and a round freeze plug under the intake ports

s4 t2 has a threaded knock sensor hole by the oil filler pipe. also t2 vs na, the t2 has an additional intake manifold bolt above the intake ports.

s4 t2 and all the s5's all have the rectangular PORT AIR passage under the intakes.

REAR iron; S5's have a thick dowel land. and the contour by the clutch cover plate thing is different to clear the intake.

the front; they use a different casting # E vs D i think, but other than that i'm not sure what you'd be looking for

 

s5 center iron would not have knock sensor by filler neck?

Thanks for all the info guys, this thread should be the one attached to the FAQ.

 

You can measure rear counterweights with a caliper to tell what series they are, how to measure and the sizes are on the Mazdatrix website.

 

Is there any rotor housings that could be mistaken for a turbo rotor housing. I know the N/a's have the baffles, but that is s4 and s5. What about earlier rotor housings for example an 85 or earlier 13b? The reason I ask is I have a Frankenstein motor and trying to figure out what I really have.

 

the 84-85 housings are flat on top, the fc gets shrunk a little and have the tension bolt ribs

http://rotaryresponse.com/RHousings/housingsal-2.jpg

FC on the left, the thermal reactor ones are in the middle, with the "ribs", and then the 81-85 housings on the right

 

Thanks, that helped me out.