Alternator Conversion For Aerovee

[lakespookie]

Has anyone considered switching over the current generator to an alternator?

The 20 Amps are minescule and there are several alternators in the 30-50 amp range, Even Greatplains has a 30Amp option. I am not to the point where engine assemble has begun if anyone can provide some pictures of their aerovee rear section in particular with and with out the turbo it would give me a better idea of what kind of space is available. I am thinking the easiest solution would be to add a suplemental mount to the rear mounting bracket with a geared pulley. and the alternator offset set off of that although i assume space is pretty tight back there. I know the VW generator traditionally sat in the middle but i dont think it would be possible to adapt a 30 am VW generator given the unique back plate used by the aerovee.

OF course the best solution would probably be a starter generator that could be adapted to the current starter mount but i dont think those are readily available much less in the low volume/low power production range that would be appropriate for the aerovee.

Open to thoughts options comparisons between greatplains solution and sonex solution etc. And pictures are always apreciated =)

[lakespookie]

I wonder how hard it would be to retrofit the aerovee turbo with something like this accessory kit.

https://a6141.americommerce.com/the-com ... ckage.aspx

35 Amp Alternator in this guy.

[lakespookie]

This would be a better solution actually since it places the started at the same 9oclock position but there is also a 6oclock option

https://a6141.americommerce.com/9-o-clo ... ckage.aspx

[sonex1566]

I've been thinking about your ideas regarding a larger capacity alternator. I reckon that if you were going to go down the Great Plains VW route for the accessory case you would need to use their engine as well. They do their ignition system differently than AeroVee. I think their secondary trigger mounts to the oil pump. As far as power output goes I'm using an MGL IEFIS and V16 radio. There's not much room for much else! I also used a Jabiru rectifier which worked better and I got it for nothing which helped my decision, but so far it works a treat. Good luck.

[lakespookie]

Yeah thats the issue with that back plane but i wonder if the aerovee back plane can be addapted to use the great plains stator and alternator otherwise the alternative would be to either use a direct drive setup or a gear driven pully to a traditional belt alternator.

[sonex1566]

Ooohh boy! This is where you get to decide on your level of courage! If I was forced to make a decision like that I would want to physically hold the bits in my hands and work out how much room was needed. My metal working skills are limited to a 'Harbour Freight' type milling machine and lathe. I can tell you I would have to be getting pretty desperate to want to tackle it. I'd recommend trying to have a look at the back of an engine to see how everything slots together. The ignition pickups and charging stator are a neat fit. I would imagine if the Great Plains alternator puts out more power it would have to be larger, either in depth or diameter. I suppose my main query would be as to how much stuff do you want to install? The modern glass screens are pretty efficient, maybe if you could work backwards and workout your total power needs and then decide whether to panic or not. The Jabiru engines put out about the same. The Camit, if there are any around put out more but they're not manufactured anymore. I haven't a foggiest about the Rotax engines. Good luck.

[GraemeSmith]

Attached is a PDF of my Excel file of my electrical load analysis which I used to "work backwards" and get a result that would work with the 20 amp alternator when I was having issues maintaining a charge in flight at high rpm's with full alternator output.

I used 13.8 volts as my maximum voltage as this was measured at full charge against the mags, contactor and battery internal resistance.

I assume at best the system will be 80% efficient and so any amperage over 80% of 20 amps that will flag a RED total (I use Conditional formatting in the spreadsheet to achieve this).

A principal and recent big change was getting rid of the Skybrite traditional strobes and their power supply and going all LED which got me much more comfortably in the ball park.

Can't attach Excel files in the forum. So if you would like the original XLXS - PM me an email address.

[lakespookie]

Yeah I have done a power budget and its not great its def in the critical range for what I want in the setup I am already planning for the alternate coils at a minimum but it just seems crazy how small this power budget is. I get that this is meant to be a VFR daytime platform for the most part but literally everyone else provides a 30 Amp alternator at a min. I am still up in the air for engine choice although part of my goals are documenting the full build on a live stream which is why i want to go the aerovee path for documenting the engine building but i want more than 85 HP so the turbo version is my current coice but that power output is pretty meager for anything with lights and some modern navigation equipment.

[lakespookie]

Ooohh boy! This is where you get to decide on your level of courage! If I was forced to make a decision like that I would want to physically hold the bits in my hands and work out how much room was needed. My metal working skills are limited to a 'Harbour Freight' type milling machine and lathe. I can tell you I would have to be getting pretty desperate to want to tackle it. I'd recommend trying to have a look at the back of an engine to see how everything slots together. The ignition pickups and charging stator are a neat fit. I would imagine if the Great Plains alternator puts out more power it would have to be larger, either in depth or diameter. I suppose my main query would be as to how much stuff do you want to install? The modern glass screens are pretty efficient, maybe if you could work backwards and workout your total power needs and then decide whether to panic or not. The Jabiru engines put out about the same. The Camit, if there are any around put out more but they're not manufactured anymore. I haven't a foggiest about the Rotax engines. Good luck.

And yeah this is obviously not going to start till i have everything layed out to see what kind of clearance/space there is and cooling might be a consideration. Doing a direct drive setup would be the easiest assuming i can fit it between all the piping and the turbo. alternatily a bearing shaft mated to the flywheel or a prop hub belt setup could also work although i worry about lateral loading on the prop shaft.

[jfuerst]

I've been reluctant to share because these sorts of mods are often frowned upon, but I did it. 40 Amps.

I considered direct drive, but ultimately you really need a slight rpm gain in order to get the best performance out of the alternator, hence the larger engine pulley to alternator ratio. Also direct drive would put the alternator right where the turbo goodies go.