| Author |
Message |
Tony Bare
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, June 29, 2005 - 11:26 am: | |
Could someone explain the difference (besides the obvious) in air and electric starters,and the pros and conds of both. |
Chris
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, June 29, 2005 - 2:07 pm: | |
I see no pros to an air starter as a private owner. Obviously there is some benifit or the transits would not have used them. However, everyone I have spoken to has recommended swapping to an electric ASAP. Basically if you sit for too long and loose air pressure you are stuck. Finding someone to jump start with batteries is no problem, finding someone to provide air is more difficult at best. What's worse is that if the bus does not start on the first try, there may not be enough air for a second try, then you have a air up again, which can take a very long time, even with a fairly large compressor. And that is a bummer. If you loose prime, the air starter may not spin the engine enough to get primed again, another bummer.
Also for me personally, the air start was cool, but stressful. I had to air up first which took like 20 minutes, double check everything to be sure it would start, then start it. I have since switched to electric, and now it is no different than starting a car, varoom and it goes. I like electric start better. |
Brian Brown (Blue_velvet)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, June 29, 2005 - 2:10 pm: | |
Air starters require a HUGE air tank, usually taking up valuable bay space. No air/ no start, so leaks aren't allowed on the starter side. However, there's obviously less coach-side batt requirements... maybe two Grp. 31's for a 24v coach, maybe even a single batt. for a 12v one.
Only air starters I've seen were on the DART 102's at auction awhile back. Air tank took up most of the back bay.
Elec. starters generally need two 8Ds to start a DD below 50 deg, 12v or 24v... and BIG cables.
HTH,
Brian
PD4106-1175 |
James Maxwell (Jmaxwell)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, June 29, 2005 - 5:47 pm: | |
Brian: I agree on the air starter position, but 2000-2200 CCA will start any DD(that's not wore out) down into freezing weather and that only requires 2 good quality Grp 31 batteries, which occupy even less space than 1 8D. |
Brian Brown (Fishbowlbrian)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, June 29, 2005 - 6:42 pm: | |
JM, that's news to me. So, was the orig. 8D spec'd. to give the juice to run the mega-blowers that aren't present now in most of our conversions?
Thanks for the info. When/if my 8Ds wear out, I'd love to replace them with something smaller/ cheaper.
BB |
Jim Ashworth (Jimnh)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, June 29, 2005 - 7:08 pm: | |
Group 31 batteries come in two capacities-- 950 CCA and 625 CCA. Prevost uses 4 of the high capacity batteries instead of 2 8-D's. They take up more room than 2 8-D's and cost a bit more. You might just want to keep the 8-D's
Jim |
James Maxwell (Jmaxwell)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, June 29, 2005 - 7:48 pm: | |
Jimnh: Grp31 come in a variety of CCA ratings, not just 2. Trojan makes 1100 CCA models (I know, I have had them) and Trojan now has one rated at 1225 CCA. I'm sure there are others on a par. Interstate also has a 1100 CCA Grp31. I don't know how u can figure that 4 batteries, each at approx. 1/3 the size of an 8d, can occupy more space than 2 8d's. True, they are taller, but the square area doesn't compare. I currently have eight (8) Grp 31's in a case that would limit me to 2 8D's(can't use 3 for 24v and can't put 4 in it), and I can pick my batteries up all by myself w/o getting a hernia. In fact though, 2 spriral wound gel cells will start 8v71 and 6v92's in freezing weather, if u want to go smaller yet. |
BrianMCI
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, June 29, 2005 - 8:39 pm: | |
I currently have two Group 31's to start my 8v71...
In our fleet we have a large number of 10 wheeled trucks as well as transports, semi's, street sweepers, motor graders front end loaders and backhoes with all manner of engines and virtually every one has either two or three group 31's I can't think of any using 8D's ...that includes a truck running a Silver Series 8V92. For the past ten years or so, we haven't seen any new trucks come with 8D's.
Brian |
Buswarrior (Buswarrior)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, June 29, 2005 - 11:35 pm: | |
Hello Tony.
For a busnut, electric starter is the way to go.
Academically...
Air starters have an advantage in colder weather in that they will not lose cranking power as the temperature drops. Batteries start losing power as the temp drops. One of the principal problems in starting a cold diesel is getting good turning power out of the starter.
And, with the air start, there is the ongoing savings through the life of the bus, that you don't need the second 8D battery to power the starter.
BUT, you are stuck with the air supply limitations detailed above, which are a killer to a busnut. You have better things to do than worry about maintaining a squeaky tight air starter circuit.
My big transit company, after 30 years of air starters, has gone back to using electric starters for the new buses. You need the two batteries for the 24 volt AC equipped buses anyway.... Back in '75 when they went to air starters, they weren't spec'ing air conditioning, and they had 12 volt systems, so the battery savings was possible.
And, as noted, attaching an air line to fill that massive air start tank, or attaching a set of booster cables, which one gets the bus out into service quicker?
Go electric young man!
happy coaching!
buswarrior |
John Jewett (Jayjay)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, June 30, 2005 - 1:02 am: | |
For those of you who have never heard an air starter, take your high decibel hearing protection with you! They scream like a banshee, and on flat ground can be heard for almost a mile. The first time you used it in an RV park, would most likely also be your last. IIRC about 135 Db, A scale. Well past the point of pain.
Cheers...JJ |
Jack Conrad (Jackconrad)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, June 30, 2005 - 7:49 am: | |
Reference the 135 Db. I just had my hearing tested yesterday at the Fire Department, looks like I will be wearing hearing aids soon. I was told anything that produces a sound level of 85 Db or greater will cause hearing loss. When they tested our fire and ambulance apparatus as well as our equipment, they found that almost every tool we use produces more than 85 Db. Once hearing damage occurs it is permanent. Think ear protection. Jack |
DavidInWilmNC
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, June 30, 2005 - 8:07 am: | |
One of the best 'tools' I've purchased for doing my conversion is a couple sets of ear protectors. One is like old-style headphones and is good for intermittent use. The others are the disposable foam plugs that are good for extended wear. It's amazing how much better I feel after wearing these -- less fatigue and less ringing in the ears. They're especially good when using the air chisel to remove rivets in the interior. |
Richard Bowyer (Drivingmisslazy)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, June 30, 2005 - 11:24 am: | |
And high quality digital hearing aids are very expensive. Ny last ones were over $3000 each, so take care and protect your hearing. I worked around big equipment many years and now have about a 60% hearing loss.
Richard |
Jack Conrad (Jackconrad)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, June 30, 2005 - 12:03 pm: | |
They tested my hearing at 7 different frequency ranges. After 28 years of sirens, air horns, and other assorted loud equipment, our department only started providing ear protection in the last few years, my hearing loss ranges from mild in the lower frequency ranges to profound in the upper frequency ranges. Jack |
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