Direct start ???

It would take a long time with a bicycle pump to charge the system up!

I think it was another option for those engines that MUST start no matter what. Actually I guess the pony motor becomes the emergency start system when you had air available.

back in the 60's a trucking company in my area had a fleet of rig up trucks and heavy haul trucks for the oil field. the parking area had a pipe rail that all truck would line up on when in the yard. all trucks had air start and the rail was pressurized with compressed air . the sound was horrid when they all started in the morning. when in the field no matter how long they were never shut down. i think this is why most people in my area to this day think it is hard on a diesel to turn it off.

Mack trucks in Australia were almost always air start and as a rule we have very problems even other brands of trucks sold in Australia would use Mack air start tanks etc
When looked after well maintained they will hold air for a month or more
I think compressed air is fairly common on real big motors as ships and emergency power supplys etc
I did own two Ruston drag lines that were both air start many years ago and the compressor was two cylinder one pistion the larger of the two was petrol and the other the compressor and like the pilot motor on a Cat this was the unreliable part of the show

I do recall someone on here some time ago had a boat with Cat motor fitted and there was some problem with have a petrol pilot motor fitted bellow deck, I do wonder if maybe a air start was a option in that situation ??

I have only seen Cat air starts when the motor is in a truck

I do think ccjersey may have the answer to why these were built, Im thinking allong the line of emergency power supply for a hospital were you cant afford time to get something running these would be up going in a matter of seconds

Also I need to bare in mind that if I was in north America up were it snows for 6 months of the year a direct start Cat motor of this era would never start unless a lot of giggle gas is used, so in a lot of situations a having a pilot motor is the only way to start these older style motors

Thanks for the replies everyone

Paul

I always like to refer to King of Obsolete in the Great White North who dumped all his pony motors years ago and went to direct electric start.

I always like to refer to King of Obsolete in the Great White North who dumped all his pony motors years ago and went to direct electric start.

So I gather they will start a ok even in sub zero temps then
I would have thought you would need some giggle gas (ether ) or something similar, but having said that you may well need help starting any diesel in sub zero conditions
You maybe be able to tell I have no experience starting diesels in these conditions


Paul

Direct electric starting Cat engines with pre combustion chambers (D8H/K) never posed a problem for me, just a good glow with the glow plugs and they would fire straight up in sub zero temperatures. It does take good batteries for a positive start.

The smallest Diesel Engine I have encountered with an Air Start is a CAT 3512 bound for a Ship. Big Diesel Engines (4000hp) take a lot of Horsepower to turn over so they typically have Air Starters on them.
Waukesha Natural Gas Engines bound for the Oil Field very often have Air Starters on them as they would pipe 50psi or higher Natural Gas into them instead of Air.
I've seen MACK's that when they don't start, a fellow trucker would pull up beside and attach an air hose between the trucks to fill the tank. I was young when I first saw it and thought it was rather ingenious!