BMP Air Starter System

[boxamatches]

Hi All,

AWESOME SITE!! With very knowledgeable people, very cool.

I am working on bringing a BMP to life, and in the manual it says to use the air starter as the main starting mechanism and the electric as a back up. My question is, what if the air bottle is empty? Is there a way to fill through an auxiliary fitting? Or do you just rely on the electric circuit for the initial start, then fill the air system with the engine driven compressor?

Thanks for any help you can give.

 

[B3.3T]

There is a fitting that can be replaced with a Schrader valve. Once done, 90psi+ should turn it over just fine. We have started them directly off the shop's compressor, too. But the electric starter should work as well.

 

[boxamatches]

Thanks for the reply.

Do you plumb it directly into the tank, or is there a more convenient place (fitting) that you have mind?

Thanks again.

 

[msehring]

there should be a fitting in front of the right front drivers periscope.

 

[Darwin T]

i don't know if this applies or not. the barges that load and discharge at our docks have motors with air starter to discharge porduct. they get the air from the tugboat if the boat was available, however, i have seen the barge operators use a hand pump mounted on the side of the motor to build up the pressure to start when the boat was not around. i have never went and looked at how the hand pump was attached, it looked like theywere pumping up a hydrolic jack. about an 18 inch handle with a cylinder. then they would hit the button and if it did nort start they would have to pump it up again. i know one barge had john deere motors, but i don't know if that barge had a hand pump.

so basically i am no help.

 

[Augdog1964]

Bmp

I have two BMPs and neither of mine have an auxiliary port setting in front of a periscope.

However I do know for a fact that msehring knows what the heck he's talking about... we regularly ask him questions and for help (and lucky he's a good friend)

SO... while mine do not have the port, his BMP must... so it may be a year thing, or a country of origin difference.

Also on the pressure, I don't believe we're talking PSI here, but atmospheres. My BMP and T55 bottles charge through internal compressor to 140 atmospheres not PSI. I don't believe 90lbs will do anything to start a BMP. You need almost 1500 PSI to get the engine moving....

Frank helps me on the vehicles and has a much better understanding on the air start system... so please chime in.... but YES you want to start using air whenever you can.

We are working to add a coupler to charge bottles from a high pressure (3500 PSI) compressor as we speak.

 

[BiffJ]

I've got to go with needing more than 90 psi as well. If the gauges in the BMP or T55 don't read at least 50 bar or Kg/cm sq the engine won't turn over. The gauges in these vehicles read either in Bar, Atmospheres or Kilograms per square centimeter. In any case the gauge reading of 150 is where they all end up popping the overpressure/dump valve on the compressor and according to conversion of either BAR or Kg/cm sq that works out to 2190 psi. I know the volume required to turn over a 38 liter engine like the V55 is going to be huge and at 90psi there won't be enough volume in the little tank to crank it. I've looked over the deck on the BMP and haven't found a fitting other than the window (periscope) washer/blaster on either the drivers or commanders area. I'm looking at tapping into the lines somewhere near the bottle to fill with a compressor should the need arise. After using the airstart on these vehicles I don't use the electric start anymore. We're going to hydro test the bottles in the T34 and get it going with air too.



Frank

 

[NEIOWA]

I didn't know the commmies used air start on their diesels. Makes sense I suppose arctic temps/batteries.

Most liikely easy source for high pressure air is going to be your local fire dept. They will have either 2216psi or 4500psi SCBA cylinders on hand. May will have adapter fittings/hoses for use in filling air lifting bags etc. Most often in the US this will be a Schrader or Hansen fitting. Most FD in communities of over 1000pop will have a high pressure compressor for filling their SCBA cylinders. You can easily procure a couple old steel 2216psi SCBA cylinders (rated 45ft3). These are functional obsolete and largely replaced by aluminum or carbonfiber wrapped Al. Many FD will have some old steel sitting in the attic. Or even old 2216psi Al which are all but obsolete. You talk nice to the FD you may be additional help. Many FD hae a truck with a mobile cascade system on board (multiple large 5000 or 6000psi tank). Used to refill SCBA cylinder at the fire scene. Install appropriate fitting on your track and get them to hook up a remote fill line and you can do some serious cranking. They may want a check valve on your track. Any risk of backflow/containination of their breathing air equipment from you old ruski TRP will kill the deal.

As mentioned, do have any air cylinders hydro tested if possible. Many test facilities will have issues with non US/DOT cylinders. You may well be better off replacing with a new US cylinder. An ASME cylinder (heavy duty) does not require hydrotest. A DOT cylinder required every 5yr. High pressure air is nothing to fool around with.

 

[BiffJ]

Got straightened out by Marc a week or so back on the BMP filler port. Its inside the vehicle just behind the right hand periscope. We were looking outside....kind of silly of us looking back.
Thanks Marc.

Frank

 

[msehring]

Frank, you are welcome, happy to help. M

 

[blueleadermark]

I've got a T-55a and I modified a cap intended for attachment of an air sprayer at the drivers' position with a male air fitting. It has it's own shut-off. I charge the system with scuba air (3000 psi, the system is in atmospheres, not psi, 14.7 to 1) using an adapter intended for charging paintball air tanks from a scuba tank. As the pressure will only equalize between the tanks you'll only get a partial charge but it's enough for about 10 starts. As the air in the vehicle drops you can charge further from the scuba bottle.

 

[BiffJ]

I made an adapter that replaces the cap inside the BMP behind the periscope. It is just an extra thick cap that is drilled and tapped for a High pressure Schrader valve. We installed the valve which has its own shutoff and use a high pressure compressor to fill the tanks. The BMP's and the T55 we have here use KG/cm sq pressure guages with 150 kg/cm sq being the top of the green/safe zone. That is 2134psi. The T34 on the other hand is marked in atmospheres and 150 kg/cm sq is 147 atmospheres so its pretty close. We have started the T34 with the air system quite successfully by filling the internal bottles with the high pressure compressor and making sure we close them after starting. Air will leak out through the system and with no onboard compressor there is no way to fill unless you're at the shop. The BMP's have onboard compressors and so do the T55's and later. The T54 may or may not have one depending on when it was last updated.....The air system is the best way to start by far.


Frank