| Author | Message | ||
| shawn bennear (Lilneoplan)
Rating: N/A |
In my efforts to "change a few things" on my little neoplan, I am going to add new gauges and a tach that are readable. (backlit through the face) I have no clue where to hook up the tach on the 8.2 diesel. i hear alot about alternators, so where on the alternator should it go. it is a electrodyne alternator. dont know much about this stuff yet, but i will learn. sorry for all the dumb questions...lol shawn | ||
| TWODOGS (Twodogs)
Rating: N/A |
don't let these guys kid you shawn...a tach will not help anything or fix any problem.the engine will go up to where the gov. is set & go no faster..spend your money on fixing up the inside ,buy a couple of futons,an inverter & a refrigerator,porta potty to start..& enjoy useing your bus... | ||
| Sean Welsh (Sean)
Rating: N/A |
Sheesh, TwoDogs, I can't believe you continue to post here. Do you really think that people buy and use tachometers to make their engines or coaches go faster? I use my tach all the time, especially when climbing grades -- to keep my engine in the power band and reduce the load on the cooling system. Shawn -- a diesel engine has, by itself, no electrical signal suitable for running an electric-impulse style tachometer. You basically have two options: If your alternator has a terminal marked "R" or "Relay," you can use that. This is essentially a tap into one of the three windings ahead of the diode bridge, providing a half-wave signal with an average amplitude about half that of the DC output voltage for the unit. Often, the coach builder has connected the coil of a relay to this terminal, using the output of the relay to provide an "engine running" signal, typically for purposes such as powering up the HVAC blowers. Not all alternators have this output (though it would surprise me if Lamar had chosen one without it, since Neoplan typically runs the blowers through such a relay), and, if yours does not, then your other option is to buy a "tach generator," which is basically a small pulse generator that you must mechanically connect to the engine someplace to provide the tach signal. I would start by looking at the alternator, and/or trace the blower wiring back to a 12-volt relay someplace, and trace the relay input back to the alternator. HTH, -Sean ('85 Neoplan) | ||
| jimmci9 #2 Rating: N/A |
i agree with 2d..... buy stuff for the interior... and start using your coach....take it somehere that can check and set (if necessary ) the hi idle....it had the same type of governor that the 2 strokes have... a tach isn't that important....i admit it's handy to have, but not as necessary as some of these ppl will lead you to belive.... | ||
| R. Steve Nichol (N4rsn)
Rating: N/A |
For 10 years, my 4106, has never had a tach.. How ever, now I am somewhat hard of hearing, and can see I am eventually going to need one, as I can't hear the engine as well. However, If I could hear the engine, I wouldn't put my money on a tach, but, into something to enhance the interior, of exterior. However, "TO EACH HIS OWN" If you feel you need a tach, put it in, and enjoy it. Just My 2 cents Steve | ||
| John MC9 Rating: N/A |
Dunno... no bus I ever drove had a tach. When it was full of passengers, all yakkin' and making noise, the engine never could be heard over the noise... We'd "feel" the engine speed (vibration) through the shifter... Rule "A": Know what maximum speed you can go in each gear. Watch the speedometer and shift at the governor limits. (usually 1st=15, 2nd=35, 3rd=55, and 4th to the max. mileage will vary) Once you know what the maximum speed is in each gear, you'll know where to shift up or down.. And hell, when you're climbing a grade, shift as soon as your speed drops to what the maximum is for the gear lower than the one you're in. You don't need a tach for that. I don't know about anyone else, but when I'm driving, I have enough to do watching traffic, checking mirrors (and glancing at the gauges), to be bothered with focusing on a tach to be able to shift.. That's -my- opinion, anyhow.. | ||
| TWODOGS (Twodogs)
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looks like ol' seen is over-ruled....kids ....sheeeechhh | ||
| TWODOGS (Twodogs)
Rating: N/A |
anybody that needs a tach to know when to shift...needs to have somebody to tell him to look both ways before crossing the street  | ||
| david anderson (Davidanderson)
Rating: N/A |
Shawn, I bought a VDO tach for my Eagle (6v92). I tried hooking it to the R terminal and could never get the dip switches on the back of the tach set to correctly match the R pulse output. I had great difficulty getting the correct paperwork from VDO to hook this up as it was a closeout purchase from Ron the Busnut. I ended up buying a VDO matching tach sending unit that screwed into the bottom of the flywheel housing on the 6v92 that counts the teeth on the flywheel. I had the paperwork to set the dip switches for flywheel tooth counts. I use the tach a lot when climbing and descending mountains. David Anderson | ||
| Pete/RTS Daytona (Pete_rtsdaytona)
Rating: N/A |
David The popular Detroit Diesel / Delco gear driven oil cooled generator's "R"terminal puts out: (2.93 gears x 3 pole stator x 2 (full wave rectified) = 17.58 pulses/rev) @ approx 12 volt Pete RTS/Daytona | ||
| Sean Welsh (Sean)
Rating: N/A |
Pete, I would point out that Shawn has an Electrodyne, not a Delco, so your math will not help him. (Although I'm glad you posted it -- I've got a Delco). 2D and John -- I never said I used the tach to shift. I have an Allison -- the ATEC knows damn well when to shift. I bet Shawn has an automatic too. I *still* find the tach to be a useful gauge, especially on the grades. I also use my oil pressure gauge and voltmeter, even though, by some folks' reasoning here, gauges are just unnecessary distractions. Oh, and I also find myself looking at all four brake gauges routinely -- two tank pressures and two application pressures. Did I mention the tire pressure/temperature monitor? How about the DDEC readout display? Call it information overload if you like, but I like to have it available whenever I want it. All of which is irrelevant in this thread. The man asked how to hook up a tach, not whether or not he should have a tach. I would point out, by the way, that, according to his web site, Shawn has more than passing experience with commercial buses, so speaking to him as if he's never driven one before is just a tad condescending, don't you think? -Sean | ||
| Jack Conrad (Jackconrad)
Rating: N/A |
I agree with Sean, I like to know what is going on mechanically all the time. My new dash has 14 gauges, in addition to the 5 leveling system gauges and the generator gauges. Hopefully the additional gauges can help prevent a problem or find it while it is still minor (left and right water temp gauges, pyrometer, transmission temp) and can help me diagnose problems from the drivers seat (ie. fuel pressure gauge, brake application pressure). Perhaps this is information overload, but as FASTFRED says "Do it your way" and this is my way. YMMV Jack | ||
| niles steckbauer (Niles500)
Rating: N/A |
Jack and Sean - its always been apparent to the readers of this board, IMHO, that you both take the time to be well informed with regards to your rigs construction, maintenance and operation, and this hobby in general, while generously passing your informed knowledge on to the rest of us - Niles | ||
| John MC9 Rating: N/A |
Sean- You're right. He didn't ask "if", he asked "how". And right again, that some of us assumed (wrongly?) that his personal choice for a conversion must be different than an automatic he probably drives for the company. And it was with that leap of logic, compounded by your own remark: "I use my tach all the time, especially when climbing grades " that it was assumed that the tachometer would be used for knowing when to shift. And so it was asked: Since commercial buses do not usually come equipped with a tach, why would one be necessary expense? Those of us that questioned that, certainly aren't saying that it's wrong to do it "your way". Feel free to do it anyway you desire! I'm doing things my way. It might be the wrong way, but that usually is, my way.. And everyone else can do whatever they please as well! No biggie. But without dissenting views, what good would a forum be? Shawn- You didn't ask a dumb question!! If you want to know what a "dumb question" is, wait until the next time I post a question. The "boat diesel forum" may have some info regarding the 8.2 tach. It's probably safe to assume that any boat shop could be of assistance, if the answer to "how" or "where" to connect it, isn't here. My 6V92 has a fitting for a mechanical tach. I'd been under the impression that all diesels need some way to connect a tach, for setting the idle and max limits, etc. I have very little experience or knowledge of diesels engines, but most others here do have. I find it surprising that the location of a mechanical or electrical tach fitting for each engine type, hasn't been mentioned thus far. It does seem to me (and others) as an unnecessary expense of time and cash to be burdened with, when you're going to be spending a lot more than planned just on the conversion process alone. When it comes to that, we're all in that same boat.. err...bus. (Nice web site, btw!!) | ||
| B"H"M (Dragon)
Rating: N/A |
I have an 8.2 and when I had to have a new alternator we tried to go to a 1 wire with the internal voltage reg. We never got the tach to work 1 wire but the shop changed to a 3 wire plug(the alt already had a bayonet labled tach) we hooked to that and bingo So the easiest way to get a tach is to removew the alt and see if it does have 3 bayonets. 1 will be the tach, mine was the single not the double. If you dont have the bayonets or the right plug it's a simple thing for a good alt shop to rebuild and not very expensive. | ||
| John Jewett (Jayjay)
Rating: N/A |
Shawn...there is no such thing as a dumb question, although you will frequently get many dumb answers! (See previous posts) Cheers...JJ | ||
| mel 4104 Rating: N/A |
too gauge or not to gauge is that the question?? well i had a fellow bus nut here in the yard about 2 months ago that puts about 50,000 to 60,000 miles per year on his bus going from west coast to east coast, Alaska to Costa R. in the south and any where inbetwwen that he can drive to as to back country logging or minning roads and swamps in the south and tundra in the north. yes he says that he has to o be pulled some times and puts more paint on to cover the scratches at times as he enjoys his bus more than anyone i know and gets more use out of it. BUT he has NO gauges, none- no oil ,fuel,air, temp., None and and only an off and on light switch.when i asked him why the answer was --keep it simple stupid--- so i figured for me the answer was do it my way and for the other fellows to do it their way and let them enjoy their way as we do doing it our way. but yes i have a tack. and i look at it some times but not always and getting hard of hearing i hang on to the stick more for shifting it seems but which ever way i use to go i still seem to get there. just rember do it your way. mel 4104 | ||
| JR
Rating: N/A |
I've already bought a tach so the debate is over on that part, however, I was looking at the rear junction box on my 87 NJT and there's a label that states the "R" alt terminal is permanently grounded. Does this mean that my tach won't read off the alternator "R" terminal? Got a 50DN alternator. Does this sound like something that needs to be altered? I don't use the bus AC...been gone. I've got the engine out doing a rear seal, and this seems to be an ideal time to hook up the tach. Got several blank wires going to the front junction box from the rear junction box. Anyone ever seen this before? Am I confusing some other "R" terminal? I could probably spend several days perusing this thing and figure it out, but if someone is familiar with this...it'd save my 3 remaining brain cells a lot of trouble! Put me down as a guage lover. They allow baseline assesments. If your water temp or oil pressure or whatever, varies significantly, I want to know about it before something quit$. Thanks | ||
| Sean Welsh (Sean)
Rating: N/A |
JR, It is unlikely that the actual "R" terminal on the alternator itself has been grounded. It *is* possible, though, that the corresponding terminal in the J-box has been grounded (and also disconnected from the alternator itself). It's almost impossible to know what wiring changes may have been made to your J-boxes along the way, so the best bet is to trace each circuit out. In the case of the R terminal, I would find the actual terminal on the alternator itself, and trace the wire (if any) to see where it ends up. HTH, -Sean |