I just snagged injectors from a 1987 NA RX7 in a salvage yard.

All of them are black but I separated the ones in the intermediate iron from the ones in the manifold.

Now what? I've got an SE, are either of these injectors better than the SE ones and are all four the same?

I noticed on every 2nd gen RX7 there, all of them have had the injectors removed. I don't know if it's because they need new ones for their 2nd gen or are they useful in an SE?

Each injector was $7 so it'/s not like I spent a fortune. Does anyone have any thoughts?

Three of the 2nd gens had a 13b, one was a '90 with the tuned ports. I'm tempted to go back and grab the best of the three. If nothing else, I'll have a core and the '90 one has lighter and higher compression rotors if it's the engine it came with. Who know what it has if it's been replaced. All of them look like they are there from an accident so all three engines could be good.

Thank you!

 

The GSLSE had the biggest injectors of any if i recall right. I would imagine swapping injectors would probably mean you need a new tune as well? Not for sure on that, I'm staying carbed lol

 

the SE injectors are larger than the 2nd gen injectors. IIRC SE's are 680cc/min while N/A FC's are 460cc/min and the turbo are 550cc/min. the reason FC injectors are usually missing is because all rx-7's, compared to virtually every other production car, have very large injectors and are a cheap option for tuners to get high flow injectors. from personal experience, most of the FC junkyard injectors ive obtained were either clogged up or just plain inoperative

if i were you, i would grab that '90 block, as it has the ideal rotating assembly for an N/A 13b build (ie. lightest, highest compression, and better rotors in general)

 

Correct me if im wrong but se's only have 2 injectors right? So putting 460cc in it would render it undrivable. Plus the impedence is different most likely.

 

They are worth about $25 in untested condition honestly so sell them.

 

Well that depressing. They had an SE but someone had already snagged the injectors as well as the rear end. When I went back to get the engine and tranny, they were gone too.

 

yep

 

The impedance thing can be dealt with,plus depending on year of the donor, it could be the same. (86 & 87 were low,'88-91 high), But in the 2 injector format of the SE,the S4 injectors would maybe start and idle the car, but i wouldn't expect anything more than that

 

SE and 86-87.5 are low impedance.
It was a mid-model year change for high impedance injectors.
The 87.5 - 91 high impedance injectors have different locator tabs in the electrical plugs so you cant mix them up.The 89-91 units have oval plugs to furthur distinguish themselves from the older units.
If I remember correctly,the 12AT engines had (2) 800cc low impedance injectors,but those are rare engines,not sold in the U.S. Also,simply adding fuel without adding air wont make power.Youll need porting,a turbo or some serious intake/exhaust mods to make use of/justify the need for bigger injectors.

The SE injectors are 680cc and have to supply 100% of the engine's fuel. 2nd gens are only 460cc (550cc for TII) because there are 4 injectors. Each unit supplies only a percentage of the engines fuel needs,so they are less stressed,with the secondaries in the manifold only coming online above 3500rpms.Thats how I can run 800cc secondary injectors and still pass smog,they secondaries dont inject fuel during a low speed smog test!