Backup to On-Board-Air/Inflator w/ Modern take on Chuffer Pump?

[Brewtus]

I ran across an interesting concept buried about 6 years ago in this forum. Apparently in ye olden times, before ARB, there was something called a "Chuffer Pump" that you would temporarily replace a spark plug with. You then hook an air hose up to it and use the compression in the cylinder to drive a pump that would air up your tires. Interesting concept, but apparently they were extremely slow, noisy, and would get very hot. The way it was set up, you weren't filling your tires with air/fuel mix from the cylinder, that air was used to operate some sort of diaphragm pump. This was done because you wouldn't want air/fuel mix in your tires as they would effectively become bombs.

But that got me thinking, with a modern multi-port or direct fuel injected engine, it's fairly easy to disconnect an injector and prevent fuel from getting to an individual cylinder. A compression tester screws into the spark plug hole and has an air fitting on the back of it. So similar to the original concept, in a pinch, you could use your engine to inflate a tire after say a flat repair simply by using the compression tester hose and disconnecting the fuel injector on that cylinder. In this case, you would be using the air from the cylinder to inflate the tire so it should be a lot faster than the diaphragm pump. I suppose you'd probably have a CEL and need to clear codes once you were done and had everything re-attached.

Not a super elegant solution, but possible?

Thoughts?

 

[dwh]

Aerostitch still sells them:

http://www.aerostich.com/engineair-power-pump.html


Another old school trick was to just bleed air from the 3 full tires to air up the flat to you get you moving. I've done both. Either way was a colossal PITA. I had better luck and less hassle just carrying a bicycle foot pump that could go up to 100 psi. Takes a while though.

 

[dwh]

Oh, I see what you were saying.

By shutting off the fuel, you can safely use the full output of the compression stroke.

Yea, that would be faster. Still a major PITA if you ask me.

 

[AFBronco235]

Nothing new about this idea. I've read about farmers using this trick all the time with their fuel injected engines. Unplug the injector, replace the spark plug with an air line and some will even hook up a tank to help prevent compression waves in the hose and store some of that air for later. You're right about the error codes and such though its not a big deal for older rigs. But it is a kind of "emergency use only" type of deal. If you expect that you'll be airing up tires, you might as well bring a pump or air tank with you.

 

[Brewtus]

Nothing new about this idea. I've read about farmers using this trick all the time with their fuel injected engines. Unplug the injector, replace the spark plug with an air line and some will even hook up a tank to help prevent compression waves in the hose and store some of that air for later. You're right about the error codes and such though its not a big deal for older rigs. But it is a kind of "emergency use only" type of deal. If you expect that you'll be airing up tires, you might as well bring a pump or air tank with you.

Agreed, not a good first line of defense. I have two 12v inflators in the truck at all times and am planning to replace them with On-Board-Air when the $$$ come in. Planning for a 5000 mile trip through Alaska and thinking about emergency backups without carrying double or triple of everything.

 

[Scoutn79]

I think the idea is sound.
You would want a check-valve somewhere in line.
I would do a dry run before you go to make sure it all works as you want.
Not the best idea but certainly better than nothing.

Darrell

 

[Robert Bills]

Apparently in ye olden times, before ARB, there was something called a "Chuffer Pump"

Aerostitch still sells them:
http://www.aerostich.com/engineair-power-pump.html

I had one in the 1960s. Trust me, nearly any other source for air will work better, but if that is all you have it will work in an emergency.

 

[rayra]

Here, get busy. I'll spell you in 5mins.

 

[dwh]

 

[Brewtus]

I agree, those will work as backups, but they take up space. At least in my rig, space is at a premium. The on-board-air system will likely never fail within the life of the truck, considering the odds of failure I'm fine using this as a backup. I will be running a test of this set up at some point in the next couple of months just to confirm the concept. I'll throw a video up when I do.