Fall/Winter 2019 Updates - Alternators, Exhaust, and More

The above pictures show the brush and regulator assembly from the 60A Plane-Power alternator.  The black carbon brush was the part that had broken.  The regulator and brushes fit together as a unit, and you can buy them as an assembly from Aircraft Spruce, to carry as a spare.  Since I had such a spare on-hand in the airplane, I gave it to the alternator shop so that they could use it when they rebuilt the alternator.  Yes, it's a standard Nippon Denso (or aftermarket such as Unipoint, in my case, part) but the issues is, to add over-voltage protection, Plane-Power actually somehow opens up this regulator and solders and hot-glues a jumper wire in place that you can see in the first picture above, to add OV protection to this regulator in the form of a crowbar type circut.  This will cut power to the alternator if an over voltage condition occurs. The 4th pic above is a friends pic of the diode assembly that fits in this alternator.  I had one go bad, and found we could order them on Amazon, so I had already ordered one of those as well.
Above you can see more pictures of my case half from the alternator.  The alternator shop looked at all the alternator parts and basically told me this:  The alternator I have is a Nippon Denso clone.  Not a TRUE Nippon Denso, but a clone made of aftermarket parts.  They said that it's still a good alternator, but if it were all true actual Nippon Denso OEM parts, it would be "bulletproof" according to them.   They said N.D. is very good, but N.D. makes parts better than many of the aftermarket makers.  So on the surface, at least in this case, this would tell me that Plane-Power (at least at the time of mine being produced) saves money by not buying real N.D. systems, instead going with cheaper aftermarket alternators. They then modify them, and sell them for our experimental aircraft use.  Below are pics of the bearing.  I've had another PP alternator user tell me that the bearing they had, had a nylon or some sort of plastic external ring in it, that they assumed was helpful in securing that bearing more tightly into the housing.  The alternator shop rebuilt the alternator, replacing the bad case half, and used some sort of bonding agent on the new bearing so that it would be tight in its bore and not be free to wobble or vibrate. Now, see below the pics of my external cover shell.  The vibration my alternator experienced was enough to put cracks into my tin cover.  That high-speed alternator can really shake, I guess.   The final pic below is the diode pack part number, in case someone wants to order spare diodes for their Plane-Power 60A alternator. I have been a Plane-Power supporter for years. Ever since I was building my RV-10 and they trial-fit their 70A alternator to my plane, and did a bracket adjustment to get the fit just right, so they could start selling that alternator for other builders who used my engine.  I had one alternator failure, I think around 400 hours or so, but, to be completely transparent and honest, it was before I really knew how to properly tension the alternator belt on these planes.  We have no tensioner, so the method is to measure the breakout force that it takes to slip the pulley on the belt, with a torque wrench.  A new belt uses 11-13 ft-lbs as the max, and a used belt uses 7-9 ft-lbs.  If you tighten it more than that, your alternator will probably suffer early bearing failure, which is exactly what happened to me on the 70A alternator that I used on the RV-10. Here's the kicker to the RV-14 alternator failures.  There seem to be 2 common failures that the 60A Plane-Power, specifically, suffer.  One is a stator coil winding breakage.  This one at least seems to me, from reading people's reports, to happen to many people early on.  It's like a design defect.  My first failure was like that.  Around 70 hours in, my coil fried in that alternator.  Nothing much you can do about that in the field.  The second common issue is that the connector plug vibrates a lot, and the wire terminals would vibrate against the plug pins and eventually wear, or arc, or dirty to the point that they would no longer work.  People solved that a couple of ways.  One was to inject RTV into the terminal area to support the wire better.  The other is a more proper way.  There is actually a rubber ring seal MADE for those connectors that will surround the wire and stuff into the connector to secure it from vibration.  I ordered a couple of spare connectors and pins and those round seals, while in the process of tearing into these alternators.    Now, when my first 60A alternator failed, I consider that a design issue, or assembly issue.  But, when I swapped that alternator out, I happened to be in Idaho, stranded on field at an airport, and replacing the alternator out on the ramp of the airport.  I didn't have a complete set of tools, especially a torque wrench, so, I doubt (I honestly don't remember) that I was able to properly get a precise belt tension.  What bothers me is that I don't remember if I ever got around to checking the belt tension when I got back home.  I would think so, but it's entirely possible that I didn't, and I myself caused this bearing to fail from it being too tight a tension setting.  I don't generally remove the safety wire and re-tension at annual, because looser is better than tighter and as it wears it will become looser and looser.  If it gets too loose, you will hear the screech as the alternator belt slips, and it will usually happen in humid weather.  So since this belt never gave me problems, I may have just left it and caused this all myself.  If so, I feel like goon. At any rate, there are a fairly large number of people over the past 5 years who've had issues with stator windings and plug terminals, and I guess I went from being a total supporter of Plane-Power, to believing that perhaps they needed to work harder on their 60A reliability.  My 70A reliability I consider to be very good.  But, what you don't hear a lot about is people complaining that their B&C brand alternator gives them issues.  So, with 2 failures on this 60A Plane-Power, I decided to consider jumping ship... Turns out that isn't necessarily all going to ensure you are trouble-free...  Keep reading.

Plane-Power vs. B&C

So after being fed up with reading reports of Plane-Power 60A failures, I decided to indeed bail out on Plane-Power, and go with B&C.  Right up front there are vast similarities, and also some differences.  First, you can see that both alternators are very very similar in case.  They both have many parts that could be swapped from alternator to alternator.  The Brushes themselves are the same.  The Plane-Power has a regulator, but even though the B&C is externally regulated, the regulator module still exists in the alternator as well.  The cases are very similar but if you look real close, you see that the ears and arms are not in the same alignment or distance from other components.  So, you cannot use the brackets for the Plane-Power on the B&C or vice versa.  The main bolt that holds them to the plane is also not the same size between the 2.  The Plane-Power, as you see more pics in this write-up, seems to have a heavier duty boss mount bracket, bolt, and tension adjuster arm, and also includes a cross-tie bracket that attaches to your starter for even more rigidity.  The B&C does not include that.  Hmmm, maybe I'm getting ahead of myself here. I'll save that for later as I have more pics coming.  But, for now, notice that the pulley on the Plane-Power is a nice machined aluminum pulley.  The B&C I'm not sure if it's steel or aluminum but I think it's steel. The pulley nuts are also not the same size. You'll need a 22mm socket for the B&C pulley.  Otherwise, there are more similarities than differences. One thing you will NOT see, that you DO see on my Plane-Power 70A alternator, is a blast tube mount.  My 70A alternator had a place to attach and air blast tube to cool the back of the alternator. And, I had it attached on my RV-10.  The Plane-Power 60A does not have this, and in my opinion, probably needs it just as much or more as the 70A does.  The B&C doesn't include it either. I should also note right now that I have one concern that came up AFTER I bought new B&C alternators.  Yes, that's plural...alternator(S).  When I decided to make the swap to the B&C primary alternator, I decided a good long-term strategy was to use the same primary and standby alternators on each plane. This would allow me to buy a 3rd alternator as a spare, and make it so on a big trip such as Alaska, I could carry a spare that would fit either plane.  I could also just plan to run each alternator for about 500 hours and then have it rebuilt, swapping in my spare, and that would allow me to try to eliminate unforeseen failures by treating the alternator as a preventative maintenance item.  Good theory, I think.  But the jury is still out on if I made the best decisions. I'll try to summarize that at the bottom of the alternator discussion. For now lets say that one thing I take a little issue with is that while the B&C has a great reputation among RV-10 and other RV people, I don't think that the current alternator, the BC460-H necessarily will have the same long-term reliability reputation and here's why.  B&C built it's great reputation on the L-60 alternator, which is not the same animal as this.  That alternator was larger, and had a different rear wire connector to it that is more robust. My 70A Plane-Power also has a more robust rear wire connector.  So the common failures of the Plane-Power being the rear connector and stator windings, I think we can say that the B&C may experience more connector failures down the road than they did in the past.  One thing that B&C does BETTER though, is that they include those round wire seals on their wires.  So that may eliminate or reduce that issue, too.  The stator windings I'm not sure on.  If it's a design issue, they may face similar issues.  If it's an assembly issue, they may end up better off.  Time will tell.  But, when comparing reliability, I'm just saying I don't know that just going by the company names "Plane-Power" or "B&C" is going to be enough.  The Plane-Power has a 60A version, and a 70A version. Both have significant differences.  I believe the 70A is superior to the 60A, for a few reasons.  The B&C has their 60A version, but it's not the same as their old version.  But, it does have one other probably Ace in the hole...   I took my 3rd alternator, the brand new B&C, into the alternator shop and had them look inside the back of it.  I wanted to see...was this a true Nippon Denso or an aftermarket clone.  From what he could tell, he said it did appear to be a true Nippon Denso alternator.  So perhaps even though they have some things in common with the Plane-Power 60A, it will be more bulletproof than the PP is.  I know the way he spoke of true ND that if I had my choice, that's what I'd want. Below is just a pic to show you my old Plane-Power connector plug.  The wires go in the back side, and that is where you need to secure the wire better.  The blob of RTV is unrelated...it was just there to prevent vibration to other engine components.  But, one important thing to note is that the red wire goes to 2 pins.  That provides redundancy for the connection for the field wire to the alternator.  More on that below too...

B&C Alternator Parts

First, right off the top, I wanted new brushes, so I pulled the brush holder out.  The brushes are a standard part that you can buy at any alternator shop for about $8-10.  On the B&C it's got no additional jumper wire like the Plane-Power does, so you don't have to carry the brush and regulator spares as a complete unit.  The regulator, in fact, doesn't likely even need a spare, unless you have an issue with the pins itself....because the regulator is bypassed on the B&C. I'm not sure the brush holder solder terminals are usually RTV covered, but on the B&C you can see the parts are covered with red RTV, probably to protect against shorting or something.  Otherwise, it's a standard part that you can easily get anywhere. The diode pack is where things get funky.  You'll have to look and identify this a little over a couple of rows of pictures.  For starters though, look at the 2nd picture above.  Notice you see a black glob of RTV, and a fiber pad curved under it...below that area is a screw hole.   Now keep that in mind and lets jump down a couple rows of pics.
Check out the 4trh pic, and the ones in the line below this text...you see a standard diode pack compared to the B&C one in the alternator.  The entire lug that holds that pack down and grounds that terminal to the case, is completely cut off.  So part of the process for B&C is to chop that lug off with a saw/dremel and then they take the cut portion and cover it with an insulating fiber pad, and glue it on with RTV.  That separates that diode pack connection.  Dig in a little further and you can see the back side of the regulator module.  Look closely and you see the black guts of the module have been previously cut and removed.  But, the part number is a standard part number and indicates its a true Nippon Denso part too.
Here are just some additional pics of the black brush holder and brushes that I bought from the shop, and the brown ones that came with the B&C.  They are functionally identical.  There is a silicone rubber ring attached to the B&C one that can be removed and put on the black ones if you ever swapped them.
So then after getting brushes, I wanted a spare for the "what if" scenario for "what if my connector pins go bad".  Luckily the fix for this is to just buy the spare regulator module, but, you can't just buy the module and stick it in...it takes a little modification because remember, this regulator doesn't regulate. It's a dumb, neutered module. As you can see from the pics above, there is a lug near the 3-pin connector that B&C also completely cuts off.  You can see if you look close enough the rough edge left, so it's a standard part, but hacked up for the B&C External regulation. Below you can also see one difference with the B&C's wiring connectors.  Notice the black wire seals around the wires.  That's better than Plane-Power. WHAT WAS NOT SO COOL, is that the pics below don't show what originally shipped with my first 2 B&C BC460-H alternators.  It seems that while a friend of mine who bought the BC460-H back in May, got the wiring connector WITH the jumper wire to the redundant 2nd pin, when MINE shipped, B&C had decided they didn't feel it was worth the added redundancy, so they shipped me their "newer" design connector where they only stick a single wire into the center pin.  I was NOT happy about that, and called them and had them ship me replacements with the redundant pin, and, I ordered a couple spares for myself as well.  So with MY installations, mine has the 2 pins connected, but if you order a BC460-H, you should insist you get a 2 pin wired plug as well.
Finally, it was time to dig in and modify and neuter my regulator module as well.  I cut off the lug that they cut off, and then used a razor to repeatedly slice and pull at the black module on the back of my new regulator (the Tan colored one) until I could flip it up.  It isn't very thick.  You can ohm out the 2 pins that are actually used on the connector, and find out which various lugs on the original regulator are connected to them.  Since the regulator is external, you should get about zero ohms between the pin and the lug when you have one that's attached, and you should get infinite ohms for ones that aren't used.  I was able to figure out what lugs were connected to the 2 pins on the connector, and then identify the guts of the regulator to see where both the 2 external pins were attached, and where the lugs were attached internally.  There are little solder lugs all around the perimeter of the regulator, and it wasn't hard to track them down.  Internally there were some hair thin wire jumpers and things that are useless going forward.  You can see my thick black wires that I soldered in place to jumper the terminals to the external lug terminal.   Once that was done, I once again compared my B&C modified regulator to the one I modified and verified that only the lugs that SHOULD connect to the connector pins had any continuity, and that the regulators ohmed out identically.  I then popped my back cover back on, and rtv sealed it up again.  I should really never have to use this home-modified module, if the pins never go bad.  But, at least I have a spare that I can carry on a trip if I ever need to.  I think it was about $28 for the replacement regulator module, at the alternator shop.

Alternator Bracket Issues

So I mentioned above that the brackets don't work between the 2 alternators, i.e. you can't use the Plane-Power brackets on the B&C Alternator and vice versa.  Here are some pics of the differences.

The cleaner looking bracket is the B&C bracket.  Notice how the bolt is smaller on the B&C, and the bracket itself is taller.  Otherwise they are fairly similar.  When I ordered, both my IO-540 engine and my IO-390 engine are Boss Mount engines, and the IO-540 is a narrow deck engine but the IO-390 is a wide deck engine.  Ordering the alternators right from B&C, they ask if you have a wide deck or narrow deck engine and then single or double groove pulley.  Well, I had to call them because in their definition, any narrow deck engine apparently uses case mount and not boss mount, which is incorrect in my case.  They told me over the phone that if I have a boss mount, then I want the wide deck version, either way.  Poor use of terminology on their part because there is too much variety.  So leave the wide and narrow deck out of it.  And, both of my engines being single groove pulleys, I ordered 2 of the same kit.  Also take note below that the Plane-Power alternator has an included joggled small arm that attaches to the alternator bracket and the starter, to give more rigidity.  The B&C dos not come with that piece.  They do sell them, but you would have to ask and make sure the measurement is right to fit your install, and then when you do install it, it's likely to require you to also replace the bolt with a longer bolt.
Below are pictures of the tension adjuster arm.  Notice that the Plane-Power is quite a bit thicker and stronger, ad it has a bent joggle in it.  This allowed the arm to fit perfectly on my install.  The arm was fairly short, the alternator was snugged up near the engine block, and all was well.  The B&C isn't such a good fit.  The tension adjust bracket is thinner, flexes a little, and comes too long for my install on the RV-14 so I had to cut it shorter and re-drill the hole in the end.  That is in the B&C manual.  It would be nice if it fit better, because even after cutting it, the arm was longer and at a different angle altogether and ran into my heater intake SCAT tube, so I had to RTV bond a silicone pad to the SCAT to protect it from chafing the bracket.   Additionally, there is too much of a gap on both of my installs, between the tension adjuster arm and the alternator face.  So they provide you with the tensioner bolt and a thick washer, but you end up needing 2 thick washers or more, to get the proper fit.  Had they joggled the arm like Plane-Power did, it would be much better, but, I think with their thinner arm, they would probably need to use thicker material if they were going to add a joggle.  If these were the only problems, the job would have been much better and my impression would have been left much higher, but it got worse. What ended up happening is that the B&C bracket for the Wide Desk, Boss Mount, Single Groove engine, didn't end up fitting properly on my RV-14's new IO-390, which is Boss Mount, Wide Deck, and Single Groove.  The U shaped boss mount bracket has one round hole in it, and one oblong hole.  I used the straight tensioner arm as a guide to ensure my alignment would be good.  I STRONGLY suggest all builders with B&C (and any other alternator for that matter) actually check your alignment of your main pulley and the alternator pulley.  If the alignment isn't good, you will wear, and risk breaking your belts.  If the belt breaks, and you have a crank sensor like I do, you could end up disabling the ignition system or anything else that is mounted up by the ring gear.  So always ensure you have good alignment.  Mine was off by something in the neighborhood of .093-.095" (EDIT: It's actually about .060-.062 off) or so.  If I lifted my alternator to it's highest position and slid the tensioner arm wrapped around the large pulley unit it contacted the alternator pulley, it did NOT line up in the groove on the alternator, but dug into the side of the pulley.  So, in order to get it to fit, I had to file not just the round hole in the bracket to make it oblong, but file the oblong hole even MORE oblong.  That will just be one more place that you could end up with bracket movement in the future, causing alternator belt issues.  So I called them and found out the difference between the bracket I got (single groove) and the other bracket they offer (dual groove).  Turns out they shift the alternator back about .130".  I then went on to try the install on my IO-540 as well.  I figured that if there were going to be an issue, it would be on that engine since technically that was a narrow deck engine.  Sure enough, the single groove bracket didn't fit that one either!!!!  It was off and it was worse than the IO-390!!  I decided to have them send me 2 of the dual groove brackets so that I could try those instead.   First the RV-10 with the IO-540.  That one was off almost perfectly the amount of .130", which is the same amount that the dual groove bracket adjusted, so swapping my SINGLE GROOVE engine to the DUAL GROOVE bracket fixed that install completely.  But what about my IO-390 that SHOULD have been perfectly matched?  Nope, that shifted it too far, as expected, and now it was out of alignment the other direction.  I did ask B&C to look into fixing this by coming out with a proper fitting bracket, but to date I have not heard of any progress on that front. EDIT 3/28/2020: B&C Finally sent me some parts to try to fix the alignment issues. They "fixed" the issue on the IO-390, but after I pondered it, I wasn't thrilled with the fix, because that would mean the same alternator would no longer fit the IO-540. It turns out I was right, because when I went to fit the RV-10, it was now NOT good. Remember that previously I had to use their "Dual Groove" pully boss mount to make it fit. Well, it keeps getting more interesting. The Dual Groove must really be a "Single Groove" bracket, because I installed these alternators on my RV-10 and they all fit perfectly: The Plane-Power 60A, the Plane-Power 70A, and the BC460-H with the Boss Mount Bracket 403-301-4 (Dual Groove type that comes with the FK5400-1_Special install kit). The Standard FK5400-1 alternator install kit coems with the 403-315-2 Boss Mount Bracket, which does NOT fit my IO-540 nor the IO-390 properly, with the BC460-H. So it was back to the drawing board. The real fix is to come up with a new Boss Mount bracket that moves the holes .060-.062" FORWARD on the Boss Mount Bracket from what the 403-315-2 bracket is. OR, move the holes AFT .068-.070" of what the 403-301-4 Boss Mount Bracket has. So the hands down winner of the bracket design here is the Plane-Power.  I'm not sure if it's just because they're a smaller company, or because they just don't know as much about the variety of Lycoming engine cases as Hartzell/Plane-Power does, but Plane-Power beats them badly on alternator bracketing as far as I'm concerned.  B&C's stuff looks nice, but until they have the proper fit, and the same strength, it's hard to walk away with warm fuzzies about the upgrade from a bracket perspective. EDIT 3/28/2020: Ok, so here I have to make another correction. If you read my update above, you see I tried all 3 alternators on the IO-540 and they all fit and aligned acceptably well. The Plane-Power alternators *appear* to align better, but that's because the bottom of the V-Groove is wider. In actuality, on the IO-540 it may have been off the width of a couple pieces of paper. Not 100% perfectly, but acceptably close. So I tried all 3 on the IO-390 and what I found there was that the Plane-Power 60A and the Plane-Power 70A both were off slightly on that plane, too. I estimate it would take maybe .036-.042 to get them to align properly on the IO-390. So that means that if everyone elses engines are the same exact form factor as mine, the Plane-Power alternators they're using are not aligned perfectly. The BC460-H remember is about .060-.062 off, so it's slightly worse...or .068-.070 with the other boss bracket. Either way, I think every builder should abosolutely verify perfect alignment on their IO-390 and even the IO-540, because an alternator belt breakage could cause them to be out of electricity, which would be a disaster on an electrically dependent engine. And, for Lightspeed Ignition users like myself who have a mini sensor or crank sensor up front, it could mean that the belt takes out the sensor, rendering their ignition immediately useless. NOT GOOD! I have a whole section below dedicated to this bracket issue, so if you keep reading you'll see exactly what's up.
More pics of the arm, the cut I had to do to the arm, and pics of the brackets I took before sending back my unused brackets.

Alternator Upgrades with Standby Installation

Some of these are out of order, so I'll walk through them.  Pic 1 above shows a completed install on the RV-14.  Notice the tensioner arm touches the SCAT tube.  I have it padded though so it won't be a problem.  Pic 2 is my old belt from the Plane Power install of the 60A alternator.  On the IO-390 that previously had a 60A, I was able to use the old belt.  On the IO-540 with my larger pulley 70A Plane Power alternator, I had to pull the prop and install a shorter belt that came with the B&C.   Pic 3 is just another shot of the alternator, and Pic 4 is my standby alternator's ANL fuse holder on the firewall. In the row below, Pic 1 shows the plug for the B&C after I told them I didn't want their single-wire, non-redundant cable.  The 2 pics in the middle are the way my alternators were initially delivered...single wire.  Not great for redundancy.    Pic 4 below is just a photo of one of my fuse blocks for a bus.  One thing that surprised me about my build is the amount of extra wiring involved.  The plane power has a single wire that goes from your breaker, through your alternator switch, and then to the alternator.  They include a 2nd white wire for an indicator light, that I didn't install.  So it's super simple.  The B&C requires:  1 Power wire to the regulator, fed by a 5A breaker, run through your alternator switch.   2 Ground wires, one to the regulator case, and one to a ground terminal. They are redundant but you need both.  Then, in order for the regulators to work, you also need to connect a wire from your bus, to the terminal on your regulator, and that wire needs to be fused or have a breaker as well.  That wire is used to sense the voltage so your regulator won't work without it.  You also need to hook the alternators field wire to the regulator.
Pic 1 above is just a panel pic.  Pic 2 shows where I shoehorned in my alternator switch for my standby alternator.  I wish I would have planned during the build to install a standby, but I didn't. On my RV-10 it was always part of the plan, so I had a switch there and everything.  The RV-14 ended up having to have it stuffed in.  I used a switch-breaker combination, because I also didn't have a panel breaker for a standby, like I did on the RV-10.  The 4th pic I have no idea why I included.  It was the replacement cable they shipped me. Below are pics of the connector from when I was disassembling it to see how it went together. I ordered a pile of pins and round seals and a couple of the connectors (pic 4 shows one in black) so that I could carry a spare connector plug with me.  Not sure I'll ever need it but now I have it.  To remove the terminals, you need a couple tiny flat screwdrivers.  There are 2 ears on the side of a pull-out tongue that you need to bend in and then you pull the tongue out of the connector.  The inside there are some catches that you need to pry up as you release the terminal contact.  It's not too hard. Once you do that it's easy to pull the terminals out and replace them if you needed to.
Pic 1 above is an in-process pic of mounting my primary and standby regulators. They're much larger than I expected them to be.  Real solid feeling, but they take up quite a bit of space.   Pic 2 is the belt I use with the 2 planes.  Pic 3 and 4 are just shots of the installed alternator. Note the added washers on the bolt that rides the tensioner arm. Below, Pics 1 and 2 are just install pics again, while Pic 3 shows the upper bolt head on the tensioner arm.  Pic 4...darn, looks like a duplicate.
And here are a couple final pics of my alternator and a quick one of the standby alternator install too.  One thing about the install on the RV-14... The oil cooler hoses pass right through that area.  I was able to get the alternator in, but felt it best if I RTV a silicone pad to the top of the alternator and protect the oil cooler hose from chafing against it.  By using a couple spots of RTV, I can prevent that hose from moving, and keep it from covering the alternators vent holes.

Alternator Misalignment on IO-390

The pictures above and below show that if you slide the alternator adjuster bracket along the big pulley on the engine, and lift the alternator, you can use it as a guide to show where the groove will line up by seeing where the bracket hits the alternator pulley.  It is very hard to get good pictures at the perfect angles because you have to make sure to align the camera lens with the pulleys to get the best view, but even though these aren't perfect, I've duplicated the picture and drawn in the pulley edge in yellow so you can see the misalignment better. Notice that the bracket hits the left side of the pulley about 1/4-1/3 of the way up from the bottom of the groove, rather than being centered. It was very hard to get an approximate measurement but I'm guessing something around .093"-.095" of a shift was what was required to center it.  The 403-301-4 I think moves it .130" which makes the adjustment bar dig into the other pulley face.
	This is just another view so you can see the edge of the bracket digging into the pulley.
	This is the oblonging of the holes that I had to do, to get the alignment proper.  I had to elongate not only the round hole, but the oval one as well.  The engine bolts, by default, center up in the middle of the oblong hole on the original bracket, when both bolts are in.  The extra space in the oblong hole is not enough after making the round hole also oblong, to fix the misalignment, so both had to be filed.
These 2 pictures above are a poor attempt to show the amount of shift.  I originally filed the holes a little too far, so the bracket could be slid too far in the necessary direction, so I needed to make a mark so that I could have a reference when torquing up the bolts to know that I was moving it the right amount.  In that process, I tried to take a couple of pictures of the mark so I could show how much the bracket needs to be moved.  But, since there are no references such as the thickness of the marker line, it's not really useful for precision measurement, only for illustrating approximate shift necessary to align.
The following 3 pictures show the adjuster arm in position after correcting the misalignment.  You can see that the arm fits nicely into the base of the V groove as well as can be expected.
One additional issue that I encountered is that the adjuster bracket should either be bent, such as Plane-Power does with their brackets (which are much thicker), or a second thick washer should be included.  The gap between the adjustment arm and the alternator on both of my planes, IO-540 Narrow Deck and IO-390 Wide Deck, was about double the thickness of the thick washer that you supply with the alternator.  I had to find washers with the same OD and drill them out for the same size center hole.  Since I didn't have thick washers, I had to use 2 standard washers in additon to the thick one supplied with the alternator.  This shows the gap and the stack.

Red Cube Fuel Transducer Replaced

Engine Dryers for the Planes