I was at lowes today starting to design my own 4air system. I was talking to one of the older guys that worked there, he said that back in his offroading days, he would take out a spark plug, put an air line on there, and run the engine. would this really work as a simple air compressor for filling tires? it sounds too good, and easy, to be true. also, would you have to put a one way check valve on there so the compressed air wouldnt just go back into the cylinder on the down stroke? how about the gas getting in there?

any insite on this?

 

ummm i am going to say no... with out the spark plugs the engine wont run. you could run it off the starter but that would take a long time and you would be throwing gas into your tires.... i think hes blowing smoke up you

spend the money to get a real OBA. $60 should get you an mv50... problem solved.


*edit* re-read it.. if he took out only 1 spark plug it would run, but will run like crap, it will take even longer, and it still is throwing gas into your tires.

 

I think it would work. You can run a vehicle minus one cylinder. Even a 4 banger. I'm thinking all you have to do is pull an injector wire to solve the fuel thing. The only downfall I see is the embarassment factor. Just think of it, everyone is airing up at the end of the day, reminiscing over the days adventures and here you are with your truck sputting and shaking with 3 cylinders while you air up your tires. I would probably laugh. But it would be fun just to see how well it worked.

Might want to put a regulator inline. I wonder how fast it would be.

 

let's try it


...on your truck of course

 

Ok you get the air fittings and I will let my truck be the guinea pig.

 

i cant wait to hear how it goes

PS, i already have an MV-50, i was just wondering how much air an engine would really put out

 

Thats gonna be some HOT air....

 

it would be some hot air, but i think you guys would be surprised at how smoothly a 22re will run on 3 cylinders.

92mmX89mm = 81.88 cc = 0.00289156491 cubic feet

you get a compression stroke every other rotation of the engine, if you idle at 1000 rpms you have 500 compression strokes

so you have 0.00289156491 x 500 = 1.445782 CFM

edit: other compressor comparison info

 

seems a little far fetched to me but if somebody gets this crazy idea to work post it up!

 

now that i think about it, if you have a compression tester, you already have the fitting you need to adapt the spark plug hole to a 1/4" NPT, so just screw in a quick connect!

 

do it and get some video

 

I personally have seen this done, and if I remember correctly, it aired up 33's in a fairly reasonable amount of time, and the 22R that was running ran pretty smoothly on 3 cyls. Me personally, I would probably just put together a compressor setup, but if you have no other options, it would def. work. In fact it wouldn't be a bad idea to carry what would be needed, just as a trail precaution. "Luck favors the prepared..."

 

This is a very old trick. I used to use it for airing up my jeep before compressors and CO2 tanks were common place.

It's actually quite fast and is pretty easy to do. The downside is that you get an accumulation of fuel in your tires that has to be purged from time to time and it allows your head to heat unevenly and that can contribute to warpage. The pressure in the cylinder FAR exceeds the pressure in the tire, so you just over fill your tire a bit, then bleed it down after you disconnect.

I might do it in emergency, but with the advent of affordable, reliable and portable air compressors and with the precision of todays engines compared to bucket of bolts jeep engines, it's just not practical to do all the time. I don't want to risk head warpage and I don't particularly like check engine lights.

 

so would this be 'safe' to test on chris's 22re and perhaps my 5vz? or should we not try it...

 

Give it a shot. I just wouldn't do it much beyond the "proof of concept" stage. You are likely to get a check engine light, so be prepared for that.

 

By the way, I should mention that you can buy hoses designed specifically for this task. Some offroad shops still carry them and I think some mail order places like JC Whitney and the like.

The specially made hoses have a check valve unit that threads into the spark plug hole and prevents back flow, although that is not stricly required...

 

Yeah, it sounds like a cool back-up plan if your compressor goes out, but I definately would not use it as a regular plan. For $40, I bought and use a Coleman unit that has air, jumper cables that run off it's own battery, and 2 dc outputs (cigarette lighter style).

 

The simplest air compressor I ever used . . . .

 

Dude, if you can air up a 33" M/T with that thing, "you're a better man than I, Gunga Dinn!:

 

Can you imagine packing up to head home and you see somebody pumping up their tires with a bike pump? I suppose it would work if you were in a all-out bind, but that would be freakin hilarious!