4wd Compressor To Fill Air Start Tank.

[monty]

Hi All.

I live is OZ and most of the macks in OZ have an air start tank to start the truck.

I in a few ocations have been left with out any air to start the truck. and in the cold can take a bit to start.

this is my proposal to place 12v 4WD compressor on to the truck to fill up to 90psi the air tank.

does any body know the volume of the air start tank?

and does any body think that my plan will work?

i have heard of stories of blokes having a small motor with a compressor to chug away for a bit to fill up the air start tank.

thanks heaps.

-Monty

Bushranger Max Air II Air Compressor

Bushranger Max Air II Air Compressor

The Max Air II is a handy compressor to have on board when you're out bush or on the sand. It makes reinflating tyres easy pumping up 31x10.5" tyres from 15 to 30psi in around 1 minute and 25 seconds, and 33x12.5" tyres in 2 minutes.

It comes with a carry bag, air hose, and features a snap on air outlet with a protective heat shield, and cast air filter attachment to make replacing filters simple. All compressor components are fuly servicable and the unit may be vehicle mounted and hard wired if required. The Max Air 2 pushes out around 52.5 lpm @ 30 psi, and offers a maximum of 72 litres per minute.

Specifications:

Maximum Air Flow: 72 litres per minute

Maximum Voltage: 13.8 volt

Maximum Amperage Draw: 29 A

Maximum Working Pressure: 150 PSI

Maximum Restart Pressure: 200 PSI

Maximum Ambient Temp.: 70°C

Minimum Ambient Temp.: -40°C

Maximum duty cycle time: 33% @ 100psi

[ThaddeusW]

Hi monty,

Well how about rigging up a hose or two that will hook to the tyres and use the air in them to fill the air starter tank. Then use the same hoses to fill them back up. Air start tanks are about 227L (60 gallons) in volume so that little compressor should take care of the problem in a matter of minutes.

[monty]

Hi monty,

Well how about rigging up a hose or two that will hook to the tyres and use the air in them to fill the air starter tank. Then use the same hoses to fill them back up. Air start tanks are about 227L (60 gallons) in volume so that little compressor should take care of the problem in a matter of minutes.

hey ThaddeusW

i have heard of using the tyers but as this thing is bob tail most of the time currently i will be redusing the pressure a fair bit in the tyers to improve the ride, so that means that there wont be much pressure in the tyers to start with, so there goes my backup plan, thats the reason for the small compressor.

i have gone out today get 20 meters of hose and fittings so i can at least get some air from to the tyers

I have also a suggestion of a small petrol compressor mounted on a rack behind the cab...or even hidden in a tool box

[HeyCharger]

Hi Monty and Thad,

I'm in the same boat as you Monty.

Can't use the tyres to charge as I run mine at about 30psi (again like you bob-tailing).

I also thought about the 4wd compressor but disgarded the idea as I think it would burn out,.

I vaguely remember working out that the air start tank was around 200litres.

What I have done on the odd occasion is flag down a 4wd enthusiast for a recharge. They are friendly and helpful.

I will tell you a couple of tricks I use.

I've installed an electric fuel pump in line with the injector pump. So when I haven't started the old girl for awhile, I turn on the electric primer and wait until I have continuous flow back into the tank before attempting a start. I leave it on until about 2 minutes after the engine is started and then turn it off.

Afraid I'm too old to be head down - arse up priming for hours.

Secondly, and you may have seen this already, when you hit the air starter button, HOLD IT IN UNTIL either the engine fires or you run out of air, whichever occurs first.

If you want to deplete your air supply really quickly then just push and release - you may get about 3 attempts.

You mentioned 90psi. To me that is really low and with mine, it may not be enough for an attempt.

Look for air leaks - use highly concentrated soapy water sprayed on all the air supply lines etc.

Just remember the air supply for starting is very simple - tank, a couple of lines and starter. It should not be supplying pressure to anything else.

I've also put a VERY cheap air pressure gauge on the supply tank. Keeps me informed.

Hope this helps. Rod.

[monty]

Hi Rod thanks for the responce and some ideas.

this is a post from the HCVC forum, http://hcvc.com.au/forum/YaBB.pl?num=1219710714/0#12

rod if you may have to get a higher horse power starter if 90psi is to low for you. i do remember that some time after the b model the horse power of the starter went in to doubel digets.

-Monty

[HeyCharger]

rod if you may have to get a higher horse power starter if 90psi is to low for you. i do remember that some time after the b model the horse power of the starter went in to doubel digets.

-Monty

Hi Monty,

My starter is a Ingersoll Rand 150BMP 32hp

http://www.irtools.com/airstarters/vane_guide.aspx

Regards,

Rod.

http://www.cvisairstarters.com/airstarters...lrand/150bm.php

and click on "150BMP Performance Curve"

So from this, you can see that initial air pressure is very important.

[monty]

Furrry Muff.

did you make it to dubbo in july?

-Monty

Edited August 27, 2008 by monty

[amberwood]

Not a complete solution but I carry a hose with a trailer service fitting one one end a has a glad hand on the other to fill the start tank. Then you just need another truck to fill you up. So far I have not needed it, fingers crossed.

DTR

[Ironman]

For the amount of times your going to possibly need a second air source.

The 12vdc Bush Ranger Max Air II is a great idea. Not real fast but it will get the job done.

I had a similar 12V compressor from an air ride system a p/u for my 57 chev.

So I'm sure it will serve you well as a secondary air source for your starter. and cheaper too

[Flying Pig]

I may be proven wrong, but I dont think the tire idea would work. Valve stems are very small and dont pass much air. Think how long it takes to air one up. You starter will require more volume than can pass through a valve stem quickly. Id vote for the little electric deal or one powered be a small gas engine.

[ThaddeusW]

I may be proven wrong, but I dont think the tire idea would work. Valve stems are very small and dont pass much air. Think how long it takes to air one up. You starter will require more volume than can pass through a valve stem quickly. Id vote for the little electric deal or one powered be a small gas engine.

Yes that is true but your not directly running the starter from the tires. You use the tires to fill the air surge tank for the starter and then let er rip. Just like jumping with batteries, your not starting the dead vehicle from the jump vehicles battery. Rather recharging the dead vehicles battery from the good one.

[RowdyRebel]

Worst case scenario, put a valve stem on the air tank and carry a bicycle pump. Might take a little work to air it up, but you'd never have to worry about the pump running the batteries dead, running out of gas or not having the gas motor be able to start to run a compressor, flattening all of your tires and still not having enough air, etc...

[ThaddeusW]

Worst case scenario, put a valve stem on the air tank and carry a bicycle pump. Might take a little work to air it up, but you'd never have to worry about the pump running the batteries dead, running out of gas or not having the gas motor be able to start to run a compressor, flattening all of your tires and still not having enough air, etc...

LOL that sounds like a good workout! I wonder how long it would take to fill a 60gallon tank to 100+ psi

[Kav]

LOL that sounds like a good workout! I wonder how long it would take to fill a 60gallon tank to 100+ psi

Hi everybody, over the years I have always carried and used an air hose to pump up the start tank. I have found that you always have to use two tyres with about 100psi in them to get enough pressure in the tank to start the truck. The problem is not always getting enough air to work the starter but enough pressure to open the dump valve on the start tank. There are at least 4 different types of dump valves, and some dump valves will open at 70 psi whereas most of them need closer to 90 psi to activate them. Years ago I tried unsuccessfully to pump up the tanks with the 12 volt compressors that were around then. After about 15 minutes they used to melt - never to go again. The modern 4wd compressors should be much better- the only way is to try them. Supercheap and Repco both have 12 volt compressors which they claim will do the job, but the duty-cycle beats a lot of them once they get to about 50psi, and this is not enough to start them. Certainly the small petrol powered compressor mounted in a tool-box is the ideal thing if you remember to carry petrol all the time. It is essential to have a guage on the start tank as you can top up the tank if the pressure is a bit low, rather than waste that pressure that is already there. We were fortunate over the years as we mostly left the trucks at the Quarry and used the End loader to pump them up if they ran out of air, but if they were left at the other end, we used the tyres. Best regards - Michael.

[Ironman]

Years ago I tried unsuccessfully to pump up the tanks with the 12 volt compressors that were around then. After about 15 minutes they used to melt - never to go again. The modern 4wd compressors should be much better- the only way is to try them. Supercheap and Repco both have 12 volt compressors which they claim will do the job, but the duty-cycle beats a lot of them once they get to about 50psi, and this is not enough to start them. Best regards - Michael.

That would be another perfect example of "You get what you paid for"

We have a few places around here (Canadian Tire) (Princess Auto) that sells the 12v compressors for under $20 and you'll be luck to get 20 minutes out of them.

If anybody was to go this route and have a 12v compressor behind your seat for emergencies? Don't cheap out, get a good one.

[peterj]

Years ago... there used to be an air hose you screwed into your spark plug hole.. take 1 plug out and put the hose in.. your engine works as a 1 cyl air compressor.. down side - your filling tire/truck with air/fuel mix!! it might ignite, but i have no reports of this. another option for emg use.. a small bottle of nittrigen, or co2..can be refilled at a welding shop...third option.. bottle of air, dive bottle.. these are just air but at 750-1000psi (i think) very high pressure, and can be refilled at a dive shop...

just wild ideas.. think outside the box

peterj

[ThaddeusW]

Years ago... there used to be an air hose you screwed into your spark plug hole.. take 1 plug out and put the hose in.. your engine works as a 1 cyl air compressor.. down side - your filling tire/truck with air/fuel mix!! it might ignite, but i have no reports of this. another option for emg use.. a small bottle of nittrigen, or co2..can be refilled at a welding shop...third option.. bottle of air, dive bottle.. these are just air but at 750-1000psi (i think) very high pressure, and can be refilled at a dive shop...

just wild ideas.. think outside the box

peterj

Good idea on the nitrogen cylinder. Gas expansion is constant for a given temperature. Boyle's law states P*V=k or Pressure times volume equals a constant as long as the temperature is the same. As long as you use the same units for P and V the formula works. So you can mix PSI and Liters but you cannot mix two different volume or pressure measurements like gallons and liters or PSI and kPa.

So lets use a standard 23.3x7 inch HP-60 industrial gas cylinder with an 11 Liter capacity filled with nitrogen at 2000 PSI. It has a constant of 11*2000 = 22000. Now most air starters have a 60 gallon surge tank which in liters in 227.12L. So we to divide 22000 by 227.12+11 (we add the 11 liters on the fill bottle because the pressure will balance out between the two) to get the pressure for the new volume which is a little over 92 PSI. Barely enough for a shot or two. So to fill a 60 gallon (227.12L) tank to 125 PSI you need to get the constant which is 28390 and divide it by the pressure of your fill tank (lets again use 2000 since its the standard pressure of an industrial high pressure cylinder). So that becomes 28390/2000 = 14.195 liters. So two cylinders could do the job but only for a few shots.

Now lets try this with a 3000PSI dive cylinder filled with nitrogen. I don't know the exact capacity of diving cylinders but I did a quick search and turned up 12 liters. So lets do the math:

3000*12 = 36000

36000/(227.12+12) = 150.5 PSI (you would use a pressure regulator to regulate the gas from the fill cylinder!)

So yes a 12L 3000 PSI Diving cylinder can fill a 60 gallon(227.12L) starter tank up to 150 PSI! And dont worry that I am using Nitrogen as an example, air is 78% Nitrogen, 21% Oxygen, 0.9% Argon and 0.1% for the rest. A mix of gas follows Boyle's law as well including air.