Cheap electric onboard air setups

[ntsqd]

On a short bed pick-up they were hidden under the bottom edge of the bedsides between the cab and the rear tires. I'm thinking of the same location on the Bronc-up.

Not sure of a good location for a std. EB.

 

[nvrstuk]

The only thing I would worry about with the direct engine air is think about how different the fuel you get now vs back then. Look at how it destroyed all of our rubber hoses, what could that fuel do to the inside of your tire? I know it's a very tiny amount so it might not be a problem just something to think about. I'm efi so I would just pull the fuse for the computer and crank her over. No power to the computer = no spark no fuel.

You might need three batteries to crank the engine over for five plus minutes straight that it will need to fill your tires! My pack a spare starter also .

If you really wanted to use engine air, why couldn't you filter it? Not saying that I want to pull the spark plug and do it the old way but. ..

 

[gnpenning]

As a side note I finally got a chance to get some pictures of the spark plug system. And yes it's a pump using fresh air. Like I mentioned previously none of us ever had a tire problem do to using the pump.

 

[66broncoCT]

You might need three batteries to crank the engine over for five plus minutes straight that it will need to fill your tires! My pack a spare starter also .

If you really wanted to use engine air, why couldn't you filter it? Not saying that I want to pull the spark plug and do it the old way but. ..

you know after I typed that I thought about how little air you would be pumping with only one cylinder and knew that wouldn't work. So with those old systems it would start and run off the other cylinders? this would be real easy for me with the straight 6, don't even have to worry about the hot exhaust to pull a spark plug. Seems like the easiest way to get OBA I wonder why they fell by the wayside?

 

[EB70]

I used to play in the snow extensively-a lot. At the end of the day, everyone was running an engine driven compressor. I ran the Dodge V-twin style with good results but always ended up back with a York. You can take a 38" tire from 1 PSI to road drive able pressure in minimal time. Basically set the idle up, walk around your truck, chat for a minute and then move onto the next tire. No time at all.....


Unless you're spending an hour, I wouldn't mess with any budget compressors that are electric if I could.

I will say that there was a red colored one on Amazon that was mentioned here and people had good things to say about it. You needed to tap a hole for a standard thread or something but people here liked it.

It seems like it was about $75 or so....FWIW

 

[Nothing Special]

you know after I typed that I thought about how little air you would be pumping with only one cylinder and knew that wouldn't work. So with those old systems it would start and run off the other cylinders? this would be real easy for me with the straight 6, don't even have to worry about the hot exhaust to pull a spark plug. Seems like the easiest way to get OBA I wonder why they fell by the wayside?

An engine will run fine down one cylinder (or at least fine enough for this kind of use). A new computer-controlled engine might set some codes though.

I don't know for sure why the "tire chuffers" mostly disappeared (although BigB did find one again). They've got to be blowing fuel/air somewhere, so even if it's not going in the tire it might not be the safest thing in the world, and not the most environmentally friendly. Either of those might have been a factor.

Also, how fast do they work? I wouldn't be surprised if a lot of the mid-range electric compressors can blow one of those away now (bad pun intended). Maybe the chuffers are fast, but if not, that could explain them falling away.

Also people have gotten lazier and engines have gotten more complicated. It used to be easy to reach spark plugs and everyone with a truck changed their own pretty regularly. Now almost no one changes plugs, and if you were to try on a new vehicle you'd spend a lot of time just finding them. So the market probably isn't as big for this type of product anymore either (especially with other options becoming available).

 

[lonesouth]

CF per Liter = .035315
302 = 5 Liters
CF in 302 = .176574
Cylinders = 8
CF per Cylinder = .022072
RPM = 800
Compression Strokes = 1/2
CFM = 8.83

I doubt you'll get that kind of output from any electric short of oasis.

Per this thread, you need 14.4cf to inflate a 31x12.50 from 10 to 22 psi. So, roughly 1:37 to fill each tire.

 

[Broncobowsher]

CF per Liter = .035315
302 = 5 Liters
CF in 302 = .176574
Cylinders = 8
CF per Cylinder = .022072
RPM = 800
Compression Strokes = 1/2
CFM = 8.83

I doubt you'll get that kind of output from any electric short of oasis.

Per this thread, you need 14.4cf to inflate a 31x12.50 from 10 to 22 psi. So, roughly 1:37 to fill each tire.

Math doesn't match reality. The spark plug hole inflator uses it's own piston. You would need to know the bore/stroke of that, not the engine driving it. Even then the math isn't so easy. Not 100% of the air compressed goes out, there is a head space in the compressor where the squished air will bounce back. We can go off into multi-stage compressor theory if you really want to chase that tangent. I don't feel like going there.

So ditch the spark plug hole pump and go actual engine air. Still not recomended even if you unplug the injector. You still get intake pulse reverberations that will get some fuel vapors down the hole. Another is the engine is throttled back at idle. You are not getting full cylinder pressure that you see with a compression tester. The intake is pulling a vacuum, there is very little air actually getting into the cylinder. So there is little to compress. Here is a fun one, put a compression tester on an engine and start it. After it is running reset the max pressure on the gauge. You would think your engine was dead with those numbers.

Along these bad tangents, I have even thought about how much boost we can see on a turbo diesel engine. And the CFM they flow while doing so. If you could get a little boost bleed, and find some way to load the engine enough to build boost while filling tires. Yea, bad idea. But not completely new either. Old Mack trucks could be had with a system where a dedicated turbo compressor wheel was used to pump filtered (from a seperate air filter) air through the intercooler. So when the turbo spooled, the cooler cooled. Look for old Mack truck with an air cleaner on both sides of the cowl. OK, far enough down that tangent.

 

[lonesouth]

i was figuring a check valve in the spark plug hole, using direct engine air.

 

[Nothing Special]

Yeah, but the question was why the spark plug-driven air compressors had fallen by the wayside. If there ever were commercially available systems that pumped engine air in, the answer to why they disappeared would be common sense and lawyers.

Looking at the picture in the link BigB posted, I doubt the piston in that compressor is more than 1" bore, 1" stroke. If that's right, it's 0.78 cubic inches of air every compression stroke, so 800 rpm gives 0.18 cfm, or 79 minutes to air up one 31" tire. Lots of wild guesses there, and no saying you need to be at idle, so I think it would actually be quite a bit faster than that. But as I said above, maybe they're fast, but I wouldn't be surprised if a $100 electric is a lot faster.

 

[nvrstuk]

I'm thinking it has nothing to do with common sense which about 90% of US citizens don't have anymore and everything to do with lawyers and someones pinky getting blistered on a header!! : )

 

[gnpenning]

Yeah, but the question was why the spark plug-driven air compressors had fallen by the wayside. If there ever were commercially available systems that pumped engine air in, the answer to why they disappeared would be common sense and lawyers.

Looking at the picture in the link BigB posted, I doubt the piston in that compressor is more than 1" bore, 1" stroke. If that's right, it's 0.78 cubic inches of air every compression stroke, so 800 rpm gives 0.18 cfm, or 79 minutes to air up one 31" tire. Lots of wild guesses there, and no saying you need to be at idle, so I think it would actually be quite a bit faster than that. But as I said above, maybe they're fast, but I wouldn't be surprised if a $100 electric is a lot faster.[/QUOTE

I wish I could remember fill times, but what I do remember is it was so much faster than the electric. I wouldn't waste my time having the electric do one tire while the engine pump did another. I know it's not as fast as my compressor.

The one Big B posted has a 5' hose. The one I have has a 16' hose. Not hard to add length. For the price and space it sure came in handy.

I would love to have a York, but since it's been awhile since I've been to Moab I don't do much trail side airing up any more. If I could find a pump off a diesel that wasn't direct drive I would take a good look. Not sure how the cfm of a York compares... when I drove truck I carried a 50' air hose that hooked up to a glad hand and used it many times. I do have a air tank off a semi I never plumbed in. Great size with a water drain.... Dang now I have to go find it....

 

[ntsqd]

Keep in mind that all A/C compressors are essentially a 2 stroke. A pressure/volume pulse every revolution.

The large York is a little over 10 ci displacement.

The Mopar V-twin A/C compressor that I used in the pic that I posted in this thread measured a bit over 11 ci. It is not a compound compressor, both cylinders intake from and discharge to common plenums. Unlike the York, they can only be mounted V up as they have a crankshaft driven gerotor oil pump and a dedicated (bolt-on!) oil sump. Tilt them over that that system won't work and the bearings will likely seize.

The air tank that I have for the Bronc-up came from a big truck parts house and is intended for air brake service. Was a LOT less than what some of the OBA business' want for the same size tank.

 

[lonesouth]

something like this?

~6 gallons

http://www.easternmarine.com/velvac-8-flange-mounted-air-brake-tank-035102-0

 

[ntsqd]

or: https://www.ryderfleetproducts.com/sloan-461001/air-tank-p-slo-461001

Can also find them used in commercial truck wrecking yards.

 

[nvrstuk]

HUGE! This isn't a pickup, where do you mount something so BIG!? No way would I have room for that hot water tank! lol

My air tank is my front bumper, has been since '00. Works great, gotta have one anyway. Take a plug for isolating the "tank" so if you rip your bumper off when grinding a new path thru the rocks on the trail...you still have your compressor. I take a plug but haven't had to ever use it.

 

[ntsqd]

I don't know what your problem is, fits fine under mine inboard of the frame on the right side behind the muffler.

;D

FWIW the tank under this Puma compressor would be an excellent tank for more space constrained vehicles. They are what I'm using for OBA on the 4rnnr & though the compressor mount is still to be built I have the tank sitting above the stock spare location. For scale that pressure gauge on the tank is 1.5" OD.
https://www.amazon.com/PD1006-Puma-Volt-Compressor-Gallon/dp/B00W1TNO6U/

 

[nvrstuk]

Yeah TS, I saw that rig when it was being built over a decade ago! No fair buddy!!

I did have enough room to mount my in-line high-pressure filter though-- that's about it for space under my rig!!