My 86 el camino smog legal 5.3 attempt

[jiho]

Only smog legal LS swap in Ca is the crate Erod kits from GM performance. The standard production LS engihes from junkyards use enhanced evap systems that can't work with G body gastanks. The erods are special versions with older style evap systems that will work in G bodies. Law is you can't downgrade a engihe's emission system, so you can't use the old style evap on a used engine that originally had enhanced evap.

This is no longer true. You can keep your G-body fuel tank and retrofit the LS pressure sensor to it. This is detailed in a recent update to the engine change guidelines in the official Smogcheck Reference Guide. They go out of their way to explain what makes a legal OBDII swap into a pre-OBDII vehicle.

There's a link to the PDF of the Smogcheck Reference Guide here (see question 3):

https://bar.ca.gov/Industry/Engine_Change_Guidelines.html

 

[jiho]

Is the El Camino a truck or a car? It was supposed to be a caruck, right?

As I understand it, the only case where you can legally swap a truck motor into a car is when the same motor was offered in two different versions, one for trucks and one for cars, and you swap the truck long block into your car but use all of the car stuff on it, basically turn it into the car version.

For example, you might use the VIN K truck TBI 350, but use the air cleaner and computer from the VIN 7 Caprice police motor. If you were desperate enough.

 

[Clone TIE Pilot]

This is no longer true. You can keep your G-body fuel tank and retrofit the LS pressure sensor to it. This is detailed in a recent update to the engine change guidelines in the official Smogcheck Reference Guide. They go out of their way to explain what makes a legal OBDII swap into a pre-OBDII vehicle.

There's a link to the PDF of the Smogcheck Reference Guide here (see question 3):

https://bar.ca.gov/Industry/Engine_Change_Guidelines.html

From the link.

"
9.
Emissions Systems
-
All emissions systems (including the evaporative system monitoring) from the donor vehicle must be
installed and fully functional. For example, the evaporative system components
,i.e. plumbing, canister, tanks, valves, etc.
must be present and functioning.
If a non OBD II certified vehicle is receiving an OBD II certified
replacement engine, the transmission and fuel storage/evaporative system from the recipient vehicle may still be used. However, these components
and systems must be integrated with the engine’s OBD II system such that the OBD system’s transmission and evaporative
system monitoring strategies remain operational."

That is the tricky part as you can't just easily slap fuel tank pressure sensors and fuel level sensors onto a older gas tank never designed for them. The remanded article is pretty much doublethink. For one thing, old steel gas tanks have too thin walls for the pressure sensors to snap on without fitting loosely and leaking. You could have a tank modified or a custom one made to accept a OBD2 fuel senders with those two evap sensors, but it won't be cheap. Those smog refs are not like typical smog station inspectors, they are very anal and are much more well informed.

As already stated, it is illegal to put a truck motor into a car which rules out most 5.3s. Then figure out how to install evap sensors onto a outdated gas tank not designed for them, and avoid flashing the PCM which is also illegal and the ref will check for it. Going Erod or staying old gen extempts you from such headaches.

 

[ortega]

Thanks for all the info guys. I'm just gonna stuff the ls1 gas tank in there with all the ls1 evap stuff. I hope my 5.3 long block will work, if they don't check casting numbers I think I'll be ok with that. If not I guess I'll need an ls1 long block. Anyways I haven't done much, I cut out a section of this thing so the tank will sit a little more level. I will box it all in.

 

[CaliWagon83]

One thought on the block is to paint it. If they can’t tell if it’s aluminum or iron, you could probably get away with telling them it’s an LS1 (which would be allowed) as opposed to an LM7 (5.3 iron-block) which may or may not be allowed. However, as noted, the CARB refs aren’t your run-of-the mill smog techs. They’re much more picky and discerning in terms of details. Good luck.

 

[jiho]

That is the tricky part [ ... ] such headaches.

Yeah, I pretty much agree and have no such plans myself.

Just updating that technically it can be legal.

Then there's the problem with captive computer-controlled trannies going bad.

 

[ortega]

So to box the notch in I flipped the same piece I cut, looks like it fit perfect. So its clamped in place, I still need to bend a piece of metal to box in the other notch for the charcoal canister and the other smaller notch. Once I do that I'll clean every thing so I can start tack welding

 

[CaliWagon83]

Man...You are committed! Good luck with everything. It's ridiculous how many rules California has with engine swaps and stuff. I think as long as you can make it look visually like an LS1, and have the cats, evap, etc., you might be OK. Of course, as part of the testing/approval process, they'll probably plug it into an OBD-II scanner, which will reveal it's a 5.3. I don't know if they'll let it slide or not, but they might. I'll be watching this thread closely...

 

[ortega]

Well the ecu that I have is off an ls1 so the vin is for a 5.7. The maf, tbody, injectors and everything else is off an ls1 and so is the harness. So I think everything will match up. I don't know how the smaller displacement will affect it, since that's the only thing that's not actual ls1.

 

[CaliWagon83]

Well the ecu that I have is off an ls1 so the vin is for a 5.7. The maf, tbody, injectors and everything else is off an ls1 and so is the harness. So I think everything will match up. I don't know how the smaller displacement will affect it, since that's the only thing that's not actual ls1.

You're probably going to have to get it re-flashed to 5.3 specs. The LS1 has a much more aggressive cam profile than the LM7. I would be really surprised if you plugged the LS1 ECM onto an LM7 and have it run perfectly right out of the box and not throw a few codes. As long as you're down for a journey of discovery, go for it!

Here's an old thread here on GBF that seems like a similar situation to what you're doing. It just kind of ended, and it doesn't seem like there was any final resolution to it. Don't know if he ultimately got it to pass. https://gbodyforum.com/threads/5-3l-into-a-85-el-camino-can-i-make-ca-emissions.15728/page-3