Onan Stator Upgrade

[bmsgaffer 2,045]

The onan parts manuals (and service manual) lists both a 20amp and a 35amp stator for the P216/P218/P220.

Does anyone know if this can be put in without switching out the flywheel? (Obviously with the 35A regulator)

They list two flywheels for different specs, but I cant correlate that to stator size.

@boomers_influence or anyone else?

[boomers_influence 106]

bm
P 216,218,220 spec B and beyond,
lists the same flywheel for 20 and 35 amp.
the original 20 amp stators used on some B
and some T 260 engines are now called 35 amp.
thank you. boomer

[bmsgaffer 2,045]

Thanks boomer!

Looks like the project will be getting an electrical upgrade!

[Save Old Iron 1,566]

Thanks boomer!

Looks like the project will be getting an electrical upgrade!

So you are turning your WH into a MIG welder?

Don't forget the entire negative half of the stator output goes unused. If you can keep the additional powered devices ISOLATED from your system negative ground on the tractor, you can power additional accessories off the rectified NEGATIVE side of the stator.

[bmsgaffer 2,045]

Shhh, you never know! I like having LOTS of electricity available.

I have always wondered if they ditched the negative wave so the coils didn't heat up too much with a constant current draw. I've been too afraid to try it on a working engine since its hard to get in to change the stator if I burn it up.

If I were to do it I would just build my own rectifier/regulator so that I would be using the whole wave instead of having two isolated ground systems. I have some pretty radical ideas for electronics on this C-205HD project if I get it that far along.

[Save Old Iron 1,566]

. I have some pretty radical ideas for electronics on this C-205HD project if I get it that far along.

I'm still trying to keep simple dripping bathroom and kitchen faucets from turning into two whole room remodeling projects. Then we do fly by wire throttle and choke mods and the SMD version of the indicator pcb.

[Save Old Iron 1,566]

 I've been too afraid to try it on a working engine since its hard to get in to change the stator if I burn it up.

 

I have always been under the impression the style of stator used in our applications are mostly "self protecting" by the dc resistance in the coil wire and the inductive reactance of the stator as a whole (remember, it is an AC generator). Make one of your mods the installation of a thermistor (or RTD temp sensor) in the stator cavity..

Edited July 28, 2015 by Save Old Iron

[bmsgaffer 2,045]

Haha, i know what you mean about the house projects. Between the house projects and two boys 2 and under, my tractor project time is limited... But it is still on the list! (someday it may get knocked off, but im working hard to keep it there)

I was thinking about that self-regulating thing with the coils, but just couldnt figure out why they never went to a full-wave rectified... easier and cheaper I suppose?

That's a good idea. Shouldn't be too hard to stick a sensor in there.

[Save Old Iron 1,566]

 couldn't figure out why they never went to a full-wave rectified... easier and cheaper I suppose?

 

The SCR in the RR acts as both the means of half wave rectification and battery charge control - very elegant in my opinion.

Full wave rectification is unnecessary as the lead acid battery is a very effective capacitor and filters out AC ripple produced by the half wave SCR rectifier.

[Save Old Iron 1,566]

I'll let you know how my experimentation works out. I am just now beginning my training on negative side power.

[RED-Z06 2,221]

How did this turn out?