| Author | Message | ||
| Mark R. Obtinario (Cowlitzcoach) (206.163.13.5)
Rating: N/A |
On one of the other threads someone was suggesting they wanted to switch over to an air starter. Personally, I have no idea why anyone would want to do that. In fact, I have no idea why anyone would even spec a vehicle from the factory that way. If someone out there knows why you would want an air starter, I would sure like to hear the explanation. What I don't like about air starters is if you run out of air you will have a real problem getting your vehicle started. Granted, most of the air tanks are large enough to do a lot of cranking but the fact remains, if you run out of air you are SOL. If you run a battery down, you can usually find someone with a set of jumper cables to help you out. If you run out of air, there aren't a lot of people out there with air compressors that can help you out. When it comes to air tanks, the starter air tank can take up a lot of space. The starter air tank in the A3's that DART just sold took up the majority of the space in the third bay. That wasn't a problem for DART since they never used the luggage bays. But if you are using the bus in route or charter service or if you are converting to an RV, the space the air tank takes up could sure be used to better purposes. In any case, if someone could tell me why anyone would want an air starter I would appreciate knowing the answer. Mark O. P.S. If you really want an air starter, A-Z and NW Bus Sales both purchased several of the DART A3's. I am sure if you really wanted an air starter you could purchase the whole works from either one of them since they were both planning to convert the air starters to electric starters. Randy Fulkerson also bought some of the DART A3's and may have the stuff to convert to air starters as well. MRO | ||
| Curious (68.243.26.238) Rating: N/A |
I have the air starter... Had a tough time starting during winter due to User error (low fuel). However the tank only provided you with three shots at starting.. Which was a 125psi. One shot about 3 revolutions.. Then another 3 and another 3. Then air was to low to turn over in the cold. I have seperate compressor and happened to be where I could plug in had I not I would have be SOL. I WANT ELECTRIC. Sams sales new batteries, walmart someone anyone has them... NO AIR NO START. NO ELECTRIC NO AIR. | ||
| TWO DOGS (63.185.81.18) Rating: N/A |
There is air all around you...don't ya' have a wife and a bicycle pump....  i know ...i know...the devil made me do it | ||
| Curious (68.243.28.147) Rating: N/A |
2d my wife read this... she warns your wife will. Just a heads up.. | ||
| Phil Dumpster (24.16.243.37) Rating: N/A |
I'm the one looking to convert to an air starter. First and foremost, my APU (auxiliary power unit, what you would call a generator but for my bus it's a bit more than that) is going to be equipped with an air compressor, which will be used to maintain air pressure while parked. It will also be used to assist the engine mounted air compressor in airing up the coach when started from prolonged storage. Naturally, this air compressor will also be available to charge up the starter tank, which renders the likelyhood of being stranded without air to start with moot. Why convert to an air starter? The 6V92TA air start setups I've seen really crank the engine at a high rate of speed, perhaps 700 to 800 RPM as opposed to the 150 RPM of the electric starter. Those of you without turbo engines probably don't realize how much you have to crank them in cold weather to get them hot enough to start, as they have a considerably lower compression ratio. Spin them fast enough and they start much more quickly. The other reason has to do with the environment in which I plan to use my bus. It's not going to be a summer only use vehicle, nor is it going to be used to head south for the winter to warmer climates. Quite the opposite, I plan to use it up in Alaska in wintertime. As the temperature drops, the ability of the batteries to supply power diminishes, and the electrical power needed to crank the engine increases. While you can put heating elements around the batteries and use a block heater, you eventually get to the point where there isn't much you can do to start the engine without waiting until warmer weather arrives. An air starter is more or less immune to temperature. True, moisture in the air can freeze when exhausting out of the starter, but there are simple ways to prevent that. Hit the button and you have something on the order of 30 to 35 horsepower available for a few seconds to start the engine, and when the tank runs low charge it up with the APU and try again. An air starter setup doesn't require big and expensive batteries to be replaced every five years or so. Just the small battery on the APU, which is about the size of a battery you'd find in the typical 4 cylinder econobox, is the only starting battery on the entire coach. I can't use an air starter motor from a T drive coach like an MCI, as I have a V drive coach and need a left hand starter. | ||
| Sean Welsh (Sean) (64.81.73.194)
Rating: N/A |
Mark, Phil makes several good points, and, though I would not do things his way for myself, clearly he has thought his situation through and decided an air starter is right for him. As to why air starters are specified in general on new coaches, the vast majority of these go to transit fleets. All transit fleets have service trucks that they send out when a coach is disabled, and it is just as cost effective to equip these trucks with air compressors as it is to equip them with 24-volt battery-jumping equipment (more so, actually: they need the compressors anyway to fill tires and run air tools). If you have 100 coaches that need a new pair of 8D's every three years or so, you're buying around 70 batteries a year, for around a $7K budget hit. If you have 500 coaches, thats $35K. By contrast, air start systems have no "expendables" in them. Sure, they require routine maintenance and parts do wear out and need to be replaced, but it's not anywhere close to the ongoing cost of (starting) batteries. Bottom line: Air starters make a lot of economic sense for large fleets that never wander far from a service truck with a compressor. Electric starters make more economic sense for operators of smaller numbers of coaches or coaches that run longer-distance routes where electric starting assistance may be easier to come by than compressed air. On this last point, by the way, your assertion that finding folks with jumper cables is relatively easy is small comfort to those of us with 24 volt coaches. Out on the road, I would bet money that I could get a mobile truck service with compressed air way faster than one with 24 volts from which to jump. The cables alone are no help. Once, when my whole coach was dead (all three banks), I had to jump the generator from a car, because it had a 12-volt starter. Then I could get juice into the start batteries from the house system, and _then_ I was able to start the coach. -Sean | ||
| Curious (68.243.239.197) Rating: N/A |
When my air starter ran down after a couple of tanks of air...batteries were down and had to be jumpered... They were 2mos old and fully charged according to the vom meter I tested them with. | ||
| Sam Sperbeck (204.248.119.254) Rating: N/A |
Hi Sean, I see a slight flaw in your reasoning regarding the elimination of battery replacement costs in a transit fleet. I think batteries will still need to be replaced at nearly the same rate whether the buses have an air or electric starter if they are A/C and heater equiped. I suspect that the blowers place a greater demand on the batteries than the starter, since transit buses are typically only started once a day, but the blowers run all day. Hi Phil, You may need just a small battery for your APU, but what are you going to use to supply the electrical needs of the bus? If you are planning to use your bus in Alaska in winter it would seem to me you would want the bus heater and defroster to work, wouldn't you? Thanks, Sam Sperbeck La Crescent, MN | ||
| Mark R. Obtinario (Cowlitzcoach) (204.245.228.200)
Rating: N/A |
I am thinking the cost of batteries would not be any different from an electric start coach. As I recall, the DART A3's had the same number and size of batteries every other A3 has. I think I would agree the coach batteries are so big not so much to start the bus but to keep all of the electrical systems running, even at slow engine speeds. I would imagine the electrical systems on the DART A3's took a real beating in stop and go traffic with the A/C on full blast. Perhaps in that case, having an air starter would hide the fact you had some weak batteries a little bit longer. I know most of the DART A3's that sold at the auction had dead or really weak batteries. I am also thinking your neighbors are not going to appreciate you starting your bus at dark thirty in the morning with an air starter. An air starter makes a fast idling DD 2-cycle sound quiet. One of the nice things about doing your own conversion is you can do things the way you want. With the upgraded gear reduction starters that are available I just don't think an air starter is worth the aggravation or the cost. But that is my humble opinion. Mark O. | ||
| Sean Welsh (Sean) (64.81.73.194)
Rating: N/A |
Sam & Mark, First, let me reiterate that I'm not advocating air starters for conversions... On the battery subject: Most of the transits that I have come across don't run their blowers, etc. when the engine's not running. Typically there is a blower relay that energizes from the "R" terminal on the alternator -- no charging, no blowers. This let's you get away with much smaller batteries, as they only have to run lights, door valves, and other legally required safety hardware. Starting is what kills starting batteries. In transit service, where a coach may be started 10-15 times each day, starting batteries live a hard and short life. By contrast, a set of batteries (especially beefy 8D's, if they are used in spite of no electric start) will last a long, long time running fairly light loads and acting as a buffer to allow blowers and the like to run when slow-idling. To Mark's observation that the batteries in coaches being retired are generally in poor condition, I suspect some of those batteries may have been original equipment, and that, even so, the agency was able to operate the coach with the batteries in that condition right up to retirement. Air starters let transit agencies get away with lousy batteries, and I stand by my guestimates about the budgetary costs of starting battery replacement. (Not sure what the pay-back is, though, because I don't know the capital cost difference of the air-start system.) -Sean | ||
| Sam Sperbeck (204.248.119.254) Rating: N/A |
Hi Sean, The transit agencies you are familiar with differ from our local transit agency. Here the buses are normally started once a day and they operate on a continually rotating schedule throughout the day. They often sit at transfer points with the engine idling for up to 15 minutes when it is cold out so passengers transfering to other routes don't have to stand out in the cold. That will probably change when the new intermodal transit terminal is built this summer. Greyhound, local transit, regeonal transit and sightseeing trollies will all use the new facility. My research indicates that all the buses in the transit agency here use electric starters. It will be interesting to learn why? All the buses are parked in the bus barn when not in service so cold starting is not an issue. I will ask my friend who is a transit agency mechanic what service life they get from their batteries. Thanks, Sam Sperbeck La Crescent, MN | ||
| Sean Welsh (Sean) (64.81.73.194)
Rating: N/A |
Sam, Clearly there are regional differences in how agenices operate (and also different maintenance philosophies, depreciation schedules, etc.). Many agencies do spec electric start for their coaches -- I'm not suggesting air is always the right answer. I was just trying to answer the question "if someone could tell me why anyone would want an air starter I would appreciate knowing the answer." In California, where I have spent the last 20 or so years of my life (east coast, though, before that), coaches are almost never idled between runs. I've even seen drivers shut down when they're a few minutes early for a "time stop" (a scheduled stop from which they must not depart any earlier than scheduled). Of course, CA also has the toughest air pollution standards and one of the biggest pollution problems in the nation... All that being said... if drivers intentionally idle for long periods of time to keep the heat running (and, of course, they do in cold climates), then they should be using fast idle (for a whole bunch of reasons) while doing so, and there should be plenty of juice coming off the alternator to run the blowers. Batteries should not have to be shouldering the brunt of this load. So I don't believe this challenges my assertion that ongoing battery replacement costs are generally higher for electric-start fleets. -Sean | ||
| Larry (208.18.102.42) Rating: N/A |
Reason for air starters on many new trucks, was because they were to be used as fuel tankers. Rather self explanatory. Most such equipped trucks have a glad hand on the tank so that another truck can connect their trailer hose, to air them up, if required. The air tank for the starter, is used only for the starter (not air horns, brakes, etc). Not much of a battery required on such a truck. | ||
| TWO DOGS (63.185.80.226) Rating: N/A |
I was walking back to my truck one night,after eating in the truckstop,....ya' kinda got to be cautious when you have over a million dollars worth of stuff in your trailer..about the time I reached for the door on my truck,the guy next to me fired off his air starter,very unusual...terrible noise...he's lucky to be alive |