i'll start off by saying i'm not an rx7 guy but i am a rotary guy, i have been running a 13b in my VW for over a year, and blew the apex seal last sunday

i bought another engine yesterday, at a junkyard. The car was an 86 FC, but it had obviously had some changes. it had a 4 port nikki manifold (with all blockoffs) tigged to an aluminum adapter plate to 6 port.

the ignition was gone and was replaced with igniter style distributor and coils.

The engine has obviously been taken apart and rebuilt at some point, so i don't feel that i can go off of the water pump and thermostat housing, which is the kind with cap.

there is no egr on the center iron

there is a mechanical OMP

on the top inspection plate on the rear housing it only has one bolt

the ports in between the intake ports, that are coolant on my 4 port 13b, are filled? or at least nothing comes out

there are two ports above the intakes, one each side, and they have bolts in them plugging them

so basicly it is a 6 port engine that was stripped of all EFI and Ignition stuff

will pics help?

and if so pics of what?

any other distinguishing marks,

 

n/a 13b

 

^ yep. sounds like a s4

 

what would make you lean towards s4, it has a flywheel on it

is there a difference in flywheels?

 

s4, because it is out of a 86, s4 is from 86-88, s5 is 89-92
does the intake manifold have black letters that say 13b injection?

 

And S4s have the mechanical OMP. As for the EGR, was it blocked off, or was there no provision for one? S5's have no EGR, so it may have S5 plates or something.

 

If it doesn't have an EGR opening on the center iron, then at least that part is from an s5 engine.
Here is a link to ID the rotor housings: http://www.banzai-racing.com/faq_housings_ID.htm

Basically, it doesn't matter a whole lot. The only real difference is that the spark timing is changed slightly on the s5 rotor housings, so you need to use the front pulley from the same series as the rotor housings. The front cover o-ring casting on the s5 front iron is larger as well, more info here: http://mazdatrix.com/faq/oring.htm
The rear irons are functionally the same. There is an extra ear near the flywheel inspection plate on s4's, I think, but it doesn't make much difference. If you plan on using an s5 intake with it (which I doubt you will) then you just need to grind that ear off.
The center irons are the same other than the EGR, which doesn't make any difference, really.
If it was rebuilt, it could have come from many different year models. I have engine parts from 4 different cars (s4 and s5) in my engine, for example.

What exactly info are you needing? Rebuild parts? If so, then they use the same parts on the engine rebuild. The only difference is the front o-ring casting, as described in the link I posted, and the external gaskets for intake, etc.

 

Island, I was just saying that I pulled the engine out of an 86rx7

there was no fuel injection setup
instead a modified carb intake from a 85 down rx7 with a plate welded to it

and no there is no EGR , not just blocked off

deffinately regular OMP on front plate

if it has s5 plates, will it be s5 rotors and a s5 counterweight?

or can it be mixed and matched?

 

It can be mixed and matched. My car has s4 irons, s5 housings, and s4 rotors (and s5 intake and s4 OMP.) You won't really know about the rotors until you pull the engine. Here is a link showing the different counterweights: http://mazdatrix.com/faq/Rcounterweights.htm

The OMP in your case doesn't really tell you much about the rest of the engine. The mechanical OMP is much simpler and basically always used with carb setups (unless they premix)

 

thanks, sideways7, for the banzai link

they are s5 n/a rotor housings

i'm going to assume its an s5 with an s4 front housing

i premix anyways so i will be deleting the OMP

now i need to search for an auto counterweight

thanks for the help guys

 

You need to make sure what series the rotors are from. You should be able to tell from the flywheel that was on it (if it didn't already have a counterweight.)

If it didn't have either, then the only way to check that I know of is to rotate the engine until you can see the face of the rotors. On the bowl of the rotor (the part that is indented) look at what the surface looks like. S5 rotors will be smooth, while s4 rotors will be very rough, like a casting.

 

it still has the flywheel on, what am i alooking for?

thanks

 

Here you go:http://mazdatrix.com/faq/flywheel.htm

Ok, time for bed. Good luck with the build.