300 engines with pollution plumbing

[Flareside Jeff]

I have a question for anyone, My 82 F150 has the 300/6 and it has all the smog stuff on it, I would really like to remove all that stuff, and I was told that all I need is the proper carb from a non-smog engine, and remove the spacer that sits on the intake manifold below the carb. Any thoughts?

[Gary Lewis]

Does your engine have a computer? I doubt it does as the Canadian vehicles didn't get the same emissions stuff the US vehicles did, but we need to make sure we know what we are talking about. On an '82 the computer will be under the driver's seat, or it has been on all the 82's I've seen.

And you are sure you have EGR into that spacer? I ask because, again, the Canadian vehicles didn't get it for some time after we did.

[Flareside Jeff]

Does your engine have a computer? I doubt it does as the Canadian vehicles didn't get the same emissions stuff the US vehicles did, but we need to make sure we know what we are talking about. On an '82 the computer will be under the driver's seat, or it has been on all the 82's I've seen.

And you are sure you have EGR into that spacer? I ask because, again, the Canadian vehicles didn't get it for some time after we did.

My truck doesn't have a computer, here's a pic of the manifolds and carb base.

[Flareside Jeff]

My truck doesn't have a computer, here's a pic of the manifolds and carb base.

[Flareside Jeff]

[Flareside Jeff]

and here's the smog pump that I would dearly love to toss!

[Flareside Jeff]

and here's the smog pump that I would dearly love to toss!

I was also not aware that the U.S Trucks had computers in some of them. My three trucks are Canadian built, and I assumed that they were the same as their American counterparts, other than the fact that ours up here read in kilometers not miles.

[Ford F834]

I was also not aware that the U.S Trucks had computers in some of them. My three trucks are Canadian built, and I assumed that they were the same as their American counterparts, other than the fact that ours up here read in kilometers not miles.

Most 300’s didn’t get computers until 1983, but I have run across one 1982 300 six junkyard truck that had a computer. It was on the driver side fender apron. For EGR delete you need to block off the port on the spacer or source one of the nifty Canadian non-EGR factory spacers 🙂

And just as a side note, you can remove the solenoid from a feedback YF carb and block off the hole and it will run on a DSII ignition straight six. They sometimes come this way from the rebuilders carrying a sticker that says the part may not look identical to the original (shortage of proper cores). I have put this block off plate directly on a working feedback carb (nothing changed during a rebuild) and it worked fine. I’m not claiming ideal calibration but the truck ran well.

[Gary Lewis]

I was also not aware that the U.S Trucks had computers in some of them. My three trucks are Canadian built, and I assumed that they were the same as their American counterparts, other than the fact that ours up here read in kilometers not miles.

Yep, you clearly have EGR. So yes, you'd need the earlier base and an earlier carb to match.

And you have the air pump, so you have a cat? If so, what are your plans there?

Yes, I've had two 82's with a computer under the seat. They were both 351W's and I can't say that the 300's also had them in 82. But yes, there were differences between US and Canadian-made trucks. You didn't have the same emissions laws we did or, to say it another way, yours kicked in later in time. And since the emissions systems added cost, Ford didn't add them if they didn't have to.

I'll let those more familiar with the 300's jump in.

[RenoHuskerDu]

Yep, you clearly have EGR. So yes, you'd need the earlier base and an earlier carb to match.

And you have the air pump, so you have a cat? If so, what are your plans there?

Yes, I've had two 82's with a computer under the seat. They were both 351W's and I can't say that the 300's also had them in 82. But yes, there were differences between US and Canadian-made trucks. You didn't have the same emissions laws we did or, to say it another way, yours kicked in later in time. And since the emissions systems added cost, Ford didn't add them if they didn't have to.

I'll let those more familiar with the 300's jump in.

The dreaded air pump actually appeared first in Cali with air injection into the exhaust manifold, not cats. There'd be a tinny little mini-manifold that injected air from the pump into the exhaust stream close to the port. It was a kluge and would fail before other components. The hardware would rust solid from the heat too, making replacement difficult. We'd sometimes just put plugs in the holes. The smog inspection stations didn't do that detailed a check for the crappy little manifolds, under all those hoses etc. But they did check for the pump.

Later motors like the 400(m), built for smog, incorporate the air injection ports right into the cylinder head. Those motors are less desirable for those of us living in states like Texas where older vehicles are allowed to shed their smog junk.

In both cases, the primary complaint against air injection is excessive heat in the exhaust tract, shortening the life of the manifold and in the case of ports in the cylinder head, also affecting exhaust valve life. My first Bullnose was a 460 and it absolutely ate exhaust systems up, cracked manifolds.

The air pumps themselves were a bane, to the extent that they would freeze up in a few weeks if you took off the belt, but annual smog inspection required it to be in place with a belt on it. We shrewd Cali hotrodders would instead slide a snug-fitting cylindrical object such as a distributor condenser into the air pump's intake hose, leaving the pump spinning in a vacuum, consuming very little power.

fyi