Engine as air pump

Post by **grazza** » Thu Apr 17, 2008 12:02 pm

I have seen some old hoses that attach to the engine, replacing a spark plug, which can be used to blow up tyres.

Apparantly this method is not very popular anymore.

Can anyone tell me why? Does running one plug down damage the engine/electrics?

I believe the hoses used a schrader valve so the air was taken from outside the engine. Petrols only (or maybe take a glow plug out for a diesel?) and I assume only very low RPM would be used.

Without knowing any better, this sounds like a pretty simple and effective way to blow up tyres, since everyone has a bloody powerful pump called an engine...

Post by **coxy321** » Thu Apr 17, 2008 12:20 pm

A lot of rooting around just to be able to use your engine as an air pump. I'd say that this isn't done anymore due to the fact you can get a ball tearing electronic air compressor for under $300. Plug it in, pump it up.

Coxy

Post by **grazza** » Thu Apr 17, 2008 12:31 pm

Depends how hard it is to get a spark plug out.
If the plug is easily accessable (older engines) then it would be a pretty quick job.
Then, theoetically, you have a much faster pump than electric with 100% duty cycle. I am guessing...

Post by **coxy321** » Thu Apr 17, 2008 12:56 pm

You would have to have all of the intake/pickup pumbing already set up. Removing a glow plug would be a PIA too. Good in theory, but....

I'd also say that over time it would possibly effect engine mounts, and the HT lead probly wouldn't like bieng pulled on/off all the time.

Coxy

Post by **grazza** » Thu Apr 17, 2008 1:10 pm

Found some stuff on it:

http://www.barneymc.com/Toy_root/techta ... huffer.htm
http://www.4wdmonthly.com.au/forum/show ... p?p=683664

Looks like it may be too slow anyway. Oh well.

Post by **v6hilux** » Thu Apr 17, 2008 1:20 pm

An engine is an air pump!

It has fuel mixed with the air intake!

Post by **Jimbo** » Thu Apr 17, 2008 1:32 pm

I suppose it would be ok if you unplug an injector in an efi petrol!

Post by **macca81** » Thu Apr 17, 2008 2:07 pm

if you can stop the fuel getting into the cylinder then it should be fine... so a carby engine is out...

Post by **grazza** » Thu Apr 17, 2008 2:08 pm

The types I have been reading about pump the outside air - not the combustion chamber mixture...so thats a non issue...

Post by **Jimbo** » Thu Apr 17, 2008 2:10 pm

Whats wrong with filling up your tyres with 40psi of perfectly mixed air and fuel??? Interesting when u hit the skids

Post by **chimpboy** » Thu Apr 17, 2008 2:36 pm

Used to be fairly common.

I think it's just too hard on a modern engine these days.

I knew of a guy whose "air compressor" was a V8 engine with only one bank hooked up to fuel and spark. Basically one side of the V had power, the other side of the V was a motherfarkingly rugged air compressor.

Post by **Mr Sausage** » Thu Apr 17, 2008 3:17 pm

This really had me intrigued, so less than an hour ago, pulled apart an old compression gauge and clamped a tyre inflater to the hose.
It easily and quickly inflated some latex gloves (didn't try a tyre as the hose wasn't long enough! and I wasn't going to massacre my good compressor hoses!!)
With the injector solenoid dis-connected, there was no fire after a touch with the trusty Bic! But connecting the solenoid back up, it made a nice little fire-ball.
I'll post some pics later, once it gets a little darker to try and catch some flames on camera!
Conclusion: Works fine, but wouldn't be inflating tyres with an injection solenoid connected, or a carby engine! Diesel should be fine though, as it's not as easy to ignite.

Something else I will try later is letting the glove with fuel settle for a while, just to see how much fuel is actually being pumped through as gas.

Post by **Rockwolf** » Thu Apr 17, 2008 3:35 pm

Mr Sausage wrote:This really had me intrigued, so less than an hour ago, pulled apart an old compression gauge and clamped a tyre inflater to the hose.
It easily and quickly inflated some latex gloves (didn't try a tyre as the hose wasn't long enough! and I wasn't going to massacre my good compressor hoses!!)
With the injector solenoid dis-connected, there was no fire after a touch with the trusty Bic! But connecting the solenoid back up, it made a nice little fire-ball.
I'll post some pics later, once it gets a little darker to try and catch some flames on camera!
Conclusion: Works fine, but wouldn't be inflating tyres with an injection solenoid connected, or a carby engine! Diesel should be fine though, as it's not as easy to ignite.

Something else I will try later is letting the glove with fuel settle for a while, just to see how much fuel is actually being pumped through as gas.

Does diesel perish rubber? If it does, good way to kill a tyre. In any case, looking forward to pics.

Post by **Mr Sausage** » Thu Apr 17, 2008 4:15 pm

Rockwolf wrote: Does diesel perish rubber? If it does, good way to kill a tyre. In any case, looking forward to pics.

I'm not too sure about diesel having an effect on rubber (anyone?) But nonetheless, this system would seem like a good option if you were stuck without a compressor. Personally, I wouldn't be too keen driving around with potentially volatile wheels!

Whereas I have seen the old trick of getting a new tyre to bead onto a rim after changing it with a splash of petrol, and they never seem to have a problem of exploding!
You can see this here

Post by **chuckles** » Thu Apr 17, 2008 7:38 pm

more of an old school remedy (thinking jack absollum)when there was,nt cheaper available options about. pull a plug on the old holden six screw in the pump roll a durry have a cup of tea hey presto

Post by **evil_hitman** » Thu Apr 17, 2008 10:45 pm

A common farmers alternative to provide compressed air out in the field is to get an old VW engine being aircooled and all. Mod it to run on 2 cylinders and the other two act as a pump, mount it to a small trailer or back of the ute.

Post by **Gwagensteve** » Thu Apr 17, 2008 10:52 pm

Diesel will perish rubber.

I wouldn't use petrol to reseat beads - too hard to control the fire and a real risk of igniting the tyre, or everything.

Aerosol lighter fluid or equivalent volatile hydrocarbon ( aerostart, carby cleaner?) is the go. It can't create a burning pool as it evaporates too quickly.
The air pump will be fine with an EFI petrol with the injector pulled. Don't think it's feasible with a diesel.

Steve.

Post by **Mr Sausage** » Thu Apr 17, 2008 11:28 pm

Good point Steve,

meaning, who on earth would want to sacrifice an expensive set of 4wd tyres by letting a small amount of diesel ruin them by inflating with the engine!

and as you've mentioned, aerosols do work best on beading, although I have done truck split rims and tractors personally with petrol, and it will work fine (just don't want too much fuel!) just need enough for a flash, so just a splash over the bead into the tyre is all you need.

Post by **RoldIT** » Thu Apr 17, 2008 11:59 pm

I have one if anyone wants to buy a vintage, collectors item ...

Post by **trains** » Fri Apr 18, 2008 9:43 am

Ive pumped up 15" split rims with a foot pump, and even a t handle pump.

Takes time, but you will get there.

Thats all Len Bidell used when he was out back creating roads.

T

Post by **ricky1970** » Fri Apr 18, 2008 10:35 am

evil_hitman wrote:A common farmers alternative to provide compressed air out in the field is to get an old VW engine being aircooled and all. Mod it to run on 2 cylinders and the other two act as a pump, mount it to a small trailer or back of the ute.

State Rail used to have a heap of these for compressed air on site at rail works. Most would have gone to auction/scrap by now.

Post by **Nuttaa** » Fri Apr 18, 2008 11:45 am

When i was a kid my dad used to use one of these quite a bit to pump up tyres etc, we never had a problem.
It was an old fj40 petrol.

Cheers, Wayne.

Post by **amtravic1** » Sat Apr 19, 2008 7:22 am

I have used one of those pumps that replace a spark plug alot years ago when there was not much else available. May still have one around somewhere. They work well and I never noticed any problem with fuel mixed with the air.

Post by **V8Patrol** » Sat Apr 19, 2008 8:06 am

At one time these things were the only real option ppl had, especially for those in remote areas.

I still own a couple, although one is un-servicable the other is ready to go and is stored in a car....... my bash car !

Its more reliable than a 12volt 'plug in' air pump that we accept as the norm these days, it will work after many days of being covered in outback dust where as the 12volt pump simply cant handle the dust.

Its quicker to actually blow up a flat tyre using the addapter hose....

it takes up less room in the car.......

it will pump air for as long as there's fuel in the tank.....

it will pump even when the battery is dead !!!
( yes I've done this, screw it in then bump started the car )

About the only down side to these things is the hose...... they perish fairly quickly due to the fuel

Kingy

Post by **grazza** » Sat Apr 19, 2008 9:19 am

So Kingy, could they be used with a diesel?
And if they are pumping clean air, not air-fuel, then is there any other downside?

Post by **Gwagensteve** » Sat Apr 19, 2008 11:52 am

Where are you going to hook it in? Glowplug? You'd have to look pretty carefully at the engine design to see what was feasible.

It's really an old petrol engine trick. I'd be nervous about unscrewing a glow plug to pump my tyres personally, they can be a bit fragile.

Also, diesel isn't volatile like petrol so the fuel in the hose/tyres will be a lot bigger problem as it won't evaporate anywhere near as quickly.

I guess if you had a common rail diesel you could unplug the injector too, but I don't think lots of these run glowplugs now?

Steve.

Post by **Emo** » Sat Apr 19, 2008 12:17 pm

Here's one on eBay

http://cgi.ebay.com.au/SPARK-PLUG-AIR-P ... dZViewItem

Post by **droopypete** » Sun Apr 20, 2008 7:30 am

20 odd years ago I carried 2 of these in my 40 series, it had a 400ci small block so I would put one on each bank and do 2 tyres at once, I don't recall it being slow on my 35's but it was so long ago I would have been comparing it to a foot pump

The access in the 40's engine bay was good so it didn't take very long to set up.
Peter.

Post by **Bumpy45** » Mon Apr 21, 2008 1:11 pm

One of the prime things that had to be observed was to let the motor idle only, no revving the engine. Got one at home, haven't used it since 12v jobbies became the norm. One thing to remember was that they got hot and a pain to remove if you had no gloves.

By the way natural rubber is attacked by any hydrocarbon. Diesel is worse than petrol as it does not evaporate as quick. If you want to know what diesel does to a tyre talk to anyone who soaks their tyres in diesel prior to a burnout comp.

hey Mr Sausage, As for the glove, if it was a latex type then wait a while and see if it degrades, I would lay money that it will.

Post by **V8Patrol** » Tue Apr 22, 2008 7:42 am

grazza wrote:So Kingy, could they be used with a diesel?
And if they are pumping clean air, not air-fuel, then is there any other downside?

The "perished rubber" is over a long time, 5 - 6 years... and is due to the effect that the petrol has on the rubber rather than the natural ageing of the rubber.
The one I use at the moment has had the hose replaced with a good quality air-line hose and doesnt seem to be suffering as yet, its going on 3 years now since it was fitted but the car that this hose 'lives in' is run on 99% LPG..... posiably the LPG is not having an effect on the plastic air-line

The unservicable unit I have just needs the hose replaced and away she goes again !. This hose was used heaps and was often left with air/fuel still in it and just thrown back into the boot of the car..... a distinct lack of care and maintance resulted in the rubber hose breaking down very quickly.

There would have to be a more suitable replacement hose available today, the air-line hose is working for me well but only time will prove its reliability.

An hydrolic hose shop may be the best place to get a reliable replacemnt hose, especially one that deals also with diesel engines as part of their business.... they would have all the right stuff and sizes

I recon the "small hydrolic style" hose ya see on Gernie's etc would be prity good

Outer Limits 4x4 Board

Engine as air pump

Engine as air pump

Who is online