anyone think of a backup alternator?

[lostforawhile]

ok going out in a bit to bolt on the plate so i can see how far the pulley has to move to line up. i have a pulley but it's from a different car, the grooves line up but the center is totally different. the auto electric place here had a drum full of different pulleys. thinking of making a center with the correct size hole, pressing it into this pulley center, then welding it to the existing pulley. the grooves are right,but not the center. the 91 pulley will fit,but i couldn't find just a pulley. i used one of these for the alternator arm,
i cut it off just behind the slot, rounded the end,then drilled a 29/64 hole in the end behind the slot. the adjusting slot on the ac bracket won't line up with the alternator,so the hole on the arm had a bolt that goes through it,this bolt bolts through the ac adjuster slot. the alternator adjuster bolt goes through the slot in the arm,then when it's tensioned correctly,both bolts will get tightened. this allows the use of the existing adjuster slot on the ac bracket. looks to be plenty of clearance back there. i believe the alternator will be able to be removed or installed by removing one fan from the radiator.i'm taking out the PS pump during the install,just because it's much eaisier to install the brackets.

[lostforawhile]

[Ichiban]

I remember seeing the B20A5 with the alternator up top and front. I wonder how similar the bracket would be from that?

[lostforawhile]

Ok a long awaited update, I ended up with a civic Obd 2 alternator, it's smaller, lighter, and puts out more amps, I'm using the 70 amp one right now, but later it's an easy switch to an SI 90 amp, I'm still going to do the backup, but run 2 civic ones. I'll use a simple single pole double throw relay to switch the fields, at the moment I have a gutted factor alternator with just the case, bearings and pulley, to act as an idler pulley for the water pump, I wanted to put the belt on to check the alignment, but after turning the house upside down, I just can't find the new one, hence my signature. it's possible it may have to move slightly away from the engine, which will require some machining on the ac bracket. I built the harness, mocked it up, hung the alternator, then discovered I was sent the wrong alternator plug. It never ends.







fail!

[lostforawhile]

I still don't think you can run both at one time, in my setup it's one or the other, the problem with both running, is you end up in a feedback loop with two voltage regulators, if you were to use an external regulator and wire it to slave both alternators together, it would work fine, like using two batteries in parallel, but with two independently operating regulators it won't work. with the field shut off on the backup alternator the amount of drag on the engine should be very little, there were some of those gas saving forums that tested the amount of drag, and with the alternator disconnected the fuel mileage went way up, even with it free wheeling. it's a little weight penalty, but with the smaller odyssey battery, and the nearest town 40 miles from here, I'm out of comfortable reserve range. With this setup, it's flip a switch and the backup is online

[Ichiban]

I stuck the alternator up front on my b20a

[A18A]

If I was you instead of an alternator....I would put a belt driven compressor on there. then you could pump up tires, use tools, etc, etc. Lots of jeeps and lifted trucks with em but not many cars if any.

ha that's a pretty cool idea!! i really like it lol

i would consider that but it sucks horsepower.

That wouldn't be a problem unless it doesn't have a clutch or you like using tools while driving?

[w261w261]

OK Lost, when you get done with this it's time to consider a project where you can really wring out your skills........a HYBRID 3G! Out with the rear seat, in with a bunch of Li-I batteries, and (ahem) a bit of mod to the drivetrain. Or even better, skip the batteries as you're more of a mechanical guy, and set up a flywheel energy storage.

[lostforawhile]

OK Lost, when you get done with this it's time to consider a project where you can really wring out your skills........a HYBRID 3G! Out with the rear seat, in with a bunch of Li-I batteries, and (ahem) a bit of mod to the drivetrain. Or even better, skip the batteries as you're more of a mechanical guy, and set up a flywheel energy storage.

no hybrids for me, just a 25 year old car with no emissions, it's going to destroy the entire world with it's horrible pollution lol. I don't like electric cars, i'm an engine guy.

[w261w261]

no hybrids for me, just a 25 year old car with no emissions, it's going to destroy the entire world with it's horrible pollution lol. I don't like electric cars, i'm an engine guy.

Well then its time for the energy flywheel. Porsche is taking orders for an $800k race car with one.

[dieselgus]

Personally I do like the alt up front like that for cooling purposes. Only thing I would add is a heatshield on the manifold side to keep heat down to a dull roar on it. From a maintenence standpoint it would be a helluva lot easier to change as well.

As to a second one in the Oem location to be switched to, I dunno. Lotta work for a low failure item to make sure there is a redundant in place. Like one poster suggested, stick a compressor back there and use an AC clutch on the pulley end. On demand air would be a nifty addition to have on board, and you could probably get some decent CFM happening. Put an "M" coupler in the engine bay and plumb one to the rear just for shits and giggles.

[lostforawhile]

Personally I do like the alt up front like that for cooling purposes. Only thing I would add is a heatshield on the manifold side to keep heat down to a dull roar on it. From a maintenence standpoint it would be a helluva lot easier to change as well.

As to a second one in the Oem location to be switched to, I dunno. Lotta work for a low failure item to make sure there is a redundant in place. Like one poster suggested, stick a compressor back there and use an AC clutch on the pulley end. On demand air would be a nifty addition to have on board, and you could probably get some decent CFM happening. Put an "M" coupler in the engine bay and plumb one to the rear just for shits and giggles.

the main reason I want the backup, is location specific, it's on average 40 miles to any decent size town here, on back country roads, mostly unlit, I have 27 minutes reserve on the Odyssey battery, that's not enough of a reserve to be comfortable with, the only places to go in the event of a breakdown are tiny towns that are pretty much shut up at night, for example, if you were to leave Valdosta heading home, and not have enough gas, the nearest station open after 10 pm is 38 miles away. Thats how much SOL you would be if your alternator quit at night, as they usually quit at the most inconvenient time, the engineering on it is simple, you bolt the pulley from a stock alternator on to the civic one, and it takes the place of the factory one, with the OBD2 alternators, you just have to hook up the small black and yellow wire and it charges, disconnect it, and it shuts off and free wheels, remember something has to be in place where the factory unit is, so it acts as an idler for the water pump belt, switching the two alternators is very simple with a single relay

[lostforawhile]

Ok the ac belt won't fit, too big, i've swaped in several belts and it looks like i'm going to need a 3338K4 thats an autozone part number but will cross reference, i'll try to get some pictures, it looks like the belt is misaligned slightly, so i'm going to machine off apx 1/8 on one side of the AC bracket, so the alternator can move slightly towards the fender

[lostforawhile]

ok the alternator needs to move over slightly to line up the belt, the issue is the arm is hitting the alternator adjuster arm, I thought about machining the bracket, but it looks to be easier to machine the case itself, you can probably do this yourself with a grinder if you had to, I already found enough shims to line up the top bracket, I'll measure the shims and make a single piece adapter

[lostforawhile]

Ok a lot more is finished,

first is the spacer, this is the spacer next to the shims I used to get the measurement



center drilling the raw material making the spacer





this is what I machined to make the arm fit, I used a plastic bag to keep chips out of the alternator



you can also put the arm on the other side and use a spacer







this is the fuse block for both alternators, I have to swap the fuses with 70 amp fuses



still have to finish polishing

[1813mdw]

lookin good, lost. do you have an exact length on your belt? i can prob find it at my work tomorrow

[lostforawhile]

lookin good, lost. do you have an exact length on your belt? i can prob find it at my work tomorrow

i've got one that fits I'm just using a duralast 338K4 right now, later I'll swap it to a good belt, but this one should work, I think it's the right length, tomorrow i'll weld a heavy washer on the adjuster bracket where the arm bolt goes through, so the only adjustment is at the bottom like the AC, and I still need to make the tensioner

[1813mdw]

do you happen to know how much the new alt weighs w/bracket compared to the oem alt/bracket?

[lostforawhile]

do you happen to know how much the new alt weighs w/bracket compared to the oem alt/bracket?

I need to weigh it again, but I think it's two pounds less, it also has a higher output, I can also swap in an SI alternator, I'll have to swap the front case now, but it's 90 something amps, I didn't want the weight penalty of the second one, but with the situations i'm likely to drive in, it's pretty much a necessity. You do not want to get stranded in the middle of nowhere here, or you'll be spending the night in the car, i'm not counting the weight of the AC bracket, The original brackets don't weigh much, I wish I could get that AC bracket cast in aluminum, eventually I might, I have friends who pour aluminum

[1813mdw]

I need to weigh it again, but I think it's two pounds less, it also has a higher output, I can also swap in an SI alternator, I'll have to swap the front case now, but it's 90 something amps, I didn't want the weight penalty of the second one, but with the situations i'm likely to drive in, it's pretty much a necessity. You do not want to get stranded in the middle of nowhere here, or you'll be spending the night in the car

this seems like alot better option than the legend alt which weighs a ton more than our stockers. i may need to buy a bracket from you in the future

[lostforawhile]

this seems like alot better option than the legend alt which weighs a ton more than our stockers. i may need to buy a bracket from you in the future

I didn't modify the stock bracket at all, I just modified the arm on the alternator, I wish I knew someone who laser cut, as I could make these adjuster arms, since both ends will be fixed, it doesn't need the slot, it uses the adjuster slot on the AC bracket. I can make the spacer bushing very easy, takes about ten minutes. for the arm now, it's a cut off Mr. Gasket universal arm.

[lostforawhile]

Alternator is in!!

upper pivot bracket

belt tensioner washer, you tighten the 7/16 bolt up from underneath,and it pushes on the washer and tightens the belt,then you tighten the tension bolt

back of tensioner washer




terminal block passenger side inner fender

alternator cable end,cable is run in firebraid

I'm working on a heat shield it will get covered in that mica based insulating sheet

distribution block on firewall


I'm probably going to put a functioning alternator back where the factory one was,just electrically disconnected except for emergencies, I've found out from the high milers that an alternator with no field operating has almost no effect on performance and an almost negligible effect on the engine, I don't like one working there mainly because the fuel bowl is directly above it. It's pretty simple to use a contacter and a relay to switch between one or the other. If it's electrically dead and gets fuel in it there is no ignition source. It would be nice to have the backup at the flip of a switch if the primary one fails, if you were in the city it would be no big deal,but out here it can be a long way home if you are stranded. It's a little weight penalty but worth the safety factor

[2oodoor]

I don't understand it but it is pretty cool stuff all the same!
You have a 4 in 1 header? that thing looks wicked

[lostforawhile]

I don't understand it but it is pretty cool stuff all the same!
You have a 4 in 1 header? that thing looks wicked

cliffs:
well basically I used a 98-2000 civic OBD2 alternator,because I had to move the alternator, and the pulley is an exact match for the AC compressor groove in the crank pulley,the original one sat directly below the fuel bowl on one of the carbs, since they are a bottom outlet fuel bowl with a rubber hose, that didn't look very good, one leak into the alternator and you have a fire. I took a burned out alternator and gutted it, except for the case, bearing and pulley, and that's my idler pulley where the original alternator was. Since I know that a disconnected alternator isn't much more drag then the idler pulley itself, I may use a functioning one there,but disconnected,except for emergencies, EG. slight weight penalty vs 40 mile walk home in the dark.

[lostforawhile]

interesting, I found out that in order to shut off the civic alternator while running, you not only have to disconnect the field wire,but the warning light indicator wire, I'm assuming the indicator bulb is feeding voltage back across the bulb filament to the regulator, since the factory alternator has two wires supplying power to the regulator both of them plus the warning light wire will need disconnecting. it's pretty simple with some basic relays.