Hi guys, I'm in the process of removing the 2 air pumps and associated plumbing from my '86 460 however at this point I'm not ready to remove the crossover pipe and exhaust manifold air injection lines.

My question is this; can I just remove the rubber hoses from the air injection manifolds and crossover pipe and then cap them with plugged off 3/4" heater hose and be good to go?

Second question? Can I run it this way permanently?

Please let me know what you think.

Thanks!

 

I'm not an expert on the 460, and hopefully some of those will be along soon, but heater hose won't like too much heat. However, if the manifold and air injection tubing is long enough that the ends thereof aren't hot then it should work. You won't have any flow so the heat will just be from conduction in the metal, and a tube cools across it's length pretty quickly.

As for running that way indefinitely, I don't see why not. Yours isn't computer-controlled - right? If that's true there's nothing monitoring the downstream gasses, so it shouldn't matter.

 

The steel lines should have a check valve in them near the ends, if they are good it won't leak.

But if you just leave it on there, it may last a year or two, but it will eventually rot out and start leaking exhaust. Without the air from the pumps pushing through the lines, they fill up with condensate and acids from the exhaust system, and that will eat holes in them. Been there, done that.

 

Mine was *partially* removed when I got the truck because the pumps were frozen. I just capped (plugged) the hoses that were there, and pulled the pumps. Plugging the hoses didn't affect things one bit, but I did it "just in case". It Ran fine! Long about last Thanksgiving, I finished "cleaning up the engine compartment" by removing that engine, and installing a 429 from an earlier truck. Now, the only remnant of the entire system is the Alternator bracket, and the "EGR" light that comes on at startup.....


Check your local laws before doing anything - they might prohibit you from taking things off.

 

Good to know, Dave. Are the 460 heads like the Windsors with tapped holes that can be sealed with a short bolt?

 

My 460 heads were tapped, but I am told that is rare......

 

That's the easy way to plug them if you an get to the back of the head, like Brnfree can. The Windsors have a hole tapped 5/8-11 and a very short bolt, about 5/8" long, will plug it. I used PTFE paste on the threads and a copper washer under the head, but that was probably overkill.

 

My truck had everything plugged off and the pumps long gone when I got it years ago. All the check valves were removed and replaced with pipe plugs.

You may be able to remove the injection manifolds from the exhaust manifolds and plug the manifolds themselves. I just tossed them for headers.

For the crossover at the back of the heads, you have 4 options, you can plug off the line into the crossover tube, you can take the tube off, turn it around so the flat side is against the heads and bolt it back on, you can install another set of welsh plugs like the front of the heads have, or you can tap them for pipe plugs.
By far tapping the heads is the best way to go. I cant remember the size offhand but I know it is a smaller pipe thread that works, definitely not 5/8 like the small blocks.

 

Thanks so much for the replies! Much appreciated.

In preparation for replacing the water pump and installing a staight up timing chain I removed the two air pumps and vacuum controlled valve at the front of the motor, but when I started it I had some air flow coming out of the open tubes so I'm not sure the check valves are still good.

While there is no legal requirement to do so I considered keeping it stock (if it ain't broke...) But with space at such a premium in the van chassis, and the engine bay looking so nice with all that stuff out of the way, I really think it's time to say so long to the old thermactor system.

Long term the goal is to eliminate the crossover pipe and exhaust system air injection lines and who knows, maybe with all that stuff out of the way I'll finally be able to replace that pesky passenger side valve cover gasket!

Besides the possibility of a legal requirement, nobody I've talked to says removing the air system is a bad idea. So after years of thinking about it I thinks it's finally time to make it happen!

Thanks again! If you have any additional wisdom or advice please let me know.