Hey people,

So I've got an S4 NA shell out in the backyard, and am considering reviving it. I have an extra NA transmission of unknown condition, but that's about it. No motor, no wiring harness, etc. I live in Maricopa, and I can't find S4 NA engines locally to drop into it. I have no idea why, but craigslist and RX7club have been fruitless in this respect. So, I've been considering engine swaps.

From what I understand from the online searching I've done, the only parts about emissions regulations I need to worry about with an engine identical to the original that came with the chassis is the sniffer and charcoal canister. Outside of that, it doesn't really matter if all emissions components are in the car, it just needs to match or best the numbers.

However, with engine swaps, since Arizona doesn't have explicit ordinances on this, it defaults to federal law. The EPA fine print sames something to the tune of engine swaps having to be from a car of the same year or newer, with all emissions components intact and operational.

My recent (actually ongoing) endeavor to decrypt the original S4 T2 emissions system has been a year-long nightmare, so I'd rather stay away from the complication if possible. Frankly, I was thinking of dumping a used S4 NA motor in with most of the emissions removed since I was going to have to redo the wiring anyways. Then try to get that to pass emissions. All else fails, just slip some alcohol in the tank while no one's looking.

Since the idea of getting an NA motor got shot down by local availability, I also considered the T2. If I'm going to go through the pain of sourcing a reman, I reckoned I may as well go turbo instead. If it's regarding different engines from the exact same model, would the emissions regulations on swaps still hold? If not, that would be perfect, but if not, I at least understand the S4 T2 emissions system well enough to wrestle it into compliance for registration. And hell, I could even throw caution to the wind and dump a JDM turbo motor into it and see if luck is on my side.

Although, with respect to rotary swaps, would the emissions testing facility even understand the difference? Say, if I was to build up an S4 NA motor and turbocharge it aftermarket, would I be able to pass that through emissions as well provided the charcoal canister was there and the pollutants met the targets? If so, what difference would it make in bringing in a T2 motor and just saying it's still an NA motor that was aftermarket turbocharged? (of course, using the bare minimum of common sense and switching to an FMIC to avoid suspicion from the conspicuous labeling on the stock T2 TMIC) And then extrapolating from there, would they even tell the difference if I brought in a 13B-REW? A 13B-MSP? Hell, even going to the lengths of performing an NA swap on any of the turbo motors. Although, that's approaching costly territories and the point of this revival was to be as cheap as possible, since just buying another car is also fairly cheap. I guess this particular vehicle has sentimental value, which is why I'm bothering at all. But if it has a motor with more potential, then I suppose it could be justified.

Then comes the subject of the satanic piston... If, say, I was to swap any number of different piston engines into the shell from a 350 to a Miata engine, what is the likelihood of the emissions testing facility actually checking for all of the original factory emissions equipment being present, intact, and functional? Since this is kind of a hazy grey area for Arizona emissions regulations, is it even likely they'll test for anything outside of the canister and sniffer? If not, a bare bones carbed 350 would be the simplest to get the car up and running, especially since it only needs 3 wires to start it. Alternatively, an MX5's drivetrain shares so much in common with the NA RX7, I would imagine there would be less hassle relative to piston engine swaps. Moreover, it's a dinky gutless four banger, but infinitely less polluting than the original rotary motor on a good day, so I imagine a sniffer would be a breeze.

That's about all I've got. If you guys have suggestions or want to fact check me, go ahead. I'd like to hear your opinions.

 

Another point to consider...

Arizona's regulations on alternative fuel vehicles demand all alternative fuel vehicles be emissions tested for registration, except for brand new alternative fuel vehicles, all electric, all solar, and all hydrogen powered vehicles.

A bit of a sidetrack, but would "hydrogen" include hydrogen combustion engines? From most of its usage in political discussion, hydrogen almost always exclusively refers to hydrogen fuel cell vehicles, though a hydrogen combustion engine is still technically a "hydrogen" vehicle. I know Mazda has made a hydrogen version of the MSP, and while it's pointless to consider since it's not within the realms of your average backyard mechanic, would a hydrogen rotary require emissions testing under this wording of the law?

Okay, back on topic. By these regulations, would an alternative fuel vehicle that was converted from a gasoline-powered vehicle require all of the original emissions equipment from its gasoline-powered guise? If not, are there any conditions in which an AFV conversion would fail an emissions test? If not, then an E85/LPG/something not gasoline or diesel might be an altogether easier proposition.

Failing all of the above, I suppose a battery electric vehicle is another possibility. Although, the thought of sticking a forklift motor and the equivalent of a Ford Superduty's mass of batteries into an RX7 is making me want to vomit. That, and the person who this particular RX7 is intended for doesn't like the idea of an electric vehicle anyways.

Again, thoughts would be appreciated.

 

smog pump, cat and charcoal canister and clean sniffer and you should be fine with any rotary, or classic car insurance then no emissions testing required

 

Is the FC insurable as a classic car? I know Haggerty will insure FDs that way. I'd go that route, if it's possible.

 

I have experience in this area, done a lot of swaps in a lot of cars.

What they will be looking for is the air pump and verifying it's hooked up, catalytic converter, charcoal canister and fuel cap. They usually pressure test the canister and fuel cap as well.

As far as swaps and mods .... these guys aren't highly trained experts. They are just guys doing what they are told and nothing more. They cannot tell the difference between different rotary engines and they do not examine engines for serial numbers or model numbers.

Swapping a V8 into a miata would be pretty obvious though and you would be sent to a referee for a detailed inspection.

As long as it has the required emissions equipment and passes the sniffer test, there's no issue with [similar]swaps/turbo installs.

 

Guys,

In AZ we have ARS 49-542(J)(2)(k) any car over 15 years old can be registered as a collector car as long as you have collector car insurace you do not have to deal with emissions. I just registered my 94 FD.

here is a link with all the infos.

https://www.azdeq.gov/environ/air/vei/motor.html

 

I'm going to leave this here

https://www.azdeq.gov/environ/air/vei/motor.html

just registered my single turbo FD emissions exempt, just get collector car insurance and you are set.

 

I honestly wanted to avoid going for the classic car route. I understand it's a lot less head scratching, but the higher insurance rates and the limited annual mileage puts me off. I'll keep this as a last resort.

So say I have a T2 swapped S4 FC, completely gutted of emissions equipment, but with a high flow cat hooked up to an electric air pump, with the evap canister working, and a working fuel cap. As long as the target numbers are hit on the sniffer, this should pass?

 

"So say I have a T2 swapped S4 FC, completely gutted of emissions equipment, but with a high flow cat hooked up to an electric air pump, with the evap canister working, and a working fuel cap. As long as the target numbers are hit on the sniffer, this should pass?"


I had the same equipment as you and I passed. Turn air pump on throughout the test. Make sure cat is relatively new. Fresh oil change also helps.

 

Collectors insurance is much cheaper than regular insurance. My FD and REPU total for the year is under $400.
True on limited usage. You can insure for up to 5000 miles a year and there are restrictions like driving to work and keeping in a garage. But I used to pay about $100 a month for just the FD, and it only gets driven 1-2k miles anyway.