24 Volt Voltage Regs and 24V Magnetos

[redvettemike]

The '52 M38 we are working on came with some extra parts. There are three (3) 24 volt voltage regulators. One appears new. There are two (2) 24 volt magnetos. These are used but look ok. I have no idea on what would be a fair price for these items and would appreciate some guidance.
Tks,
Mike.

[wesk]

Hi Mike,

I had to move your post to auctions since you neglected to positively ID each item for sale and price it.

The voltage regulators depend a lot on their ID. Part# Model# right off their data plates. They came in a ton of flavors. amperages, and manufacturers. Some fit M38's / M38A1's and some don't.

Same goes with the magnetos. Of course there is a slim market here for magnetos which are usually found on farm tractors, airplanes and tank engines. Unless, of course, if they are actually battery powered distributors.

Core is all you can get for a proper M38/M38A1 voltage regulator no matter how pretty they look. Unless you bench check them and warranty them.

I'll help with proper model/part numbers:

M38:

Generator, 24V, 25A:
All M38 stock from Willys: Autolite or Prestolite GHA4802UT, ORD# 7374750.
The later M38A1 generators will work but were not original to the M38.

Voltage regulator:
Autolie or Prestolite, VBC4002UT, ORD# 7524309
The later M38A1 regulators will work but were not original to the M38.

Starter:
Early thru eng ser MC74419: Autolite or Prestolite MBP4301UT, ORD# 7762616

Late after eng ser MC74419: Autolite or Prestolite MCZ4001UT, ORD# 8328132
The later M38A1 Delco & AL/Presto can be used but were not original to the M38.

Distributor:

Early M38 thru chassis ser MC20599: Autolite or Prestolite IAU4004UT, ORD# 7375375

Late M38's after MC20599: Autolite or Prestolite IAU4006UT, ORD# 7355596

The M38A1 distibutor uses a different advance curve but can be adapted to work as a sub for IAU4006UT only.


M38A1/M170:
Generator, 24V, 25A:
All M38A1/M170 stock from Willys/Kaiser: Autolite or Prestolite GHA4802BUT, ORD# 8673350

The Army outsourced this unit to Delco for spares to their supply system. These can be used also. The Delco unit 1922304 or 1117495, ORD# 7355736 can be used with the Delco Regulator.

Voltage regulator:
All M38A1/M170 stock from Willys/Kaiser: Autolite or Prestolite VBC4002UT, ORD# 7524309

The Army outsourced this unit to Delco for spares to their supply system. These can be used also. The Delco unit X204SS can be used with the Delco Generator.

Starter:
All M38A1/M170 stock from Willys/Kaiser: MCZ4001UT, ORD# 8328132

The Army outsourced this unit to Delco for spares to their supply system. These can be used also: X10483, ORD# 8329740

Distributor:
All M38A1/M170 stock from Willys/Kaiser: Autolite or Prestolite IAU4006AUT, ORD# 7355869

The Army outsourced this unit to Delco for spares to their supply system. These can be used also: Delco 1118656, ORD# 8360020.

[redvettemike]

The mag's show the following:

#1 Spec # AXS1850 Order # C735_969 Mfg's # 1AU4006AUT

#2 Spec # AXS1850 Order # C7355596 Mfg's # 1AU4006UT

Voltage Regulators (3)

#1 Spec# MIL-R-10265 (Presto Lite) Order# 8712283 Pt# VBC4004UT

#2 Spec# Mil-R-10265 (Electric Autolite) Or# 8712283 Pt# VBC4004UT

#3 Spec# MIL-R-10265 (AutoLite) Order# 7524309 Pt# VBC4002UT

I'd appreciate some guidance on the value of these units. The #1 Voltage Reg seems perhaps to be new.

The owners also have 3 YS marked carbs (all used; opne may be sold).
Tks,
MIke

[radtech]

Prices all depend on condition.Without pictures they can not be valued unless they are new in the original unopened factory packaging.

[wesk]

Again, These are not mags or magnetos! The are distributors which is also their proper nomenclature in the Supply ORD's and the data plates.

The mag's show the following:

#1 Spec # AXS1850 Order # C735_969 Mfg's # 1AU4006AUT

#2 Spec # AXS1850 Order # C7355596 Mfg's # 1AU4006UT

The Regulators PN VBC4004UT are M151 & M35 series units. They are similar to the M38/M38A1 unit VBC4002UT but differ significantly in their internal wiring of the Current & Voltage regs and resistors.

As mentioned a couple of times they only have core value unless you can bench check them and provide warranty on their operation. Core value can be determined by canvassing the vendors for their core deposit amounts.

On the carbs you will need to ID them by their complete model # IE YS637S for the M38 and YS950S for the M38A1/M170. Again you are faced with core value only.

[redvettemike]

I have an old time generator rebuild guy. It might be an option to see if he can rebuild these magnetos. I have no idea if the voltage regulators can be rebuilt or not. There are two 24V generators that I may also ask him about rebuilding. Just a thought. Tks for the help.

[charlesfitton]

I have an old time generator rebuild guy. It might be an option to see if he can rebuild these magnetos. I have no idea if the voltage regulators can be rebuilt or not. There are two 24V generators that I may also ask him about rebuilding. Just a thought. Tks for the help.

OK - I'll ask - what magneto's are you refferring to?


f

[redvettemike]

I have an old time generator rebuild guy. It might be an option to see if he can rebuild these magnetos. I have no idea if the voltage regulators can be rebuilt or not. There are two 24V generators that I may also ask him about rebuilding. Just a thought. Tks for the help.

OK - I'll ask - what magneto's are you refferring to?


f

There are two used magnetos: AXS1850 both.

[wesk]

Magneto vs Distributor

An ignition magneto, or high tension magneto, is a magneto that provides current for the ignition system of a spark-ignition engine, such as a petrol engine. It produces pulses of high voltage for the spark plugs. The older term tension means voltage.[1]

The use of ignition magnetos is now confined mainly to engines where there is no other available electrical supply, for example in lawnmowers and chainsaws. It is also widely used in aviation piston engines even though an electrical supply is usually available. In this case the magneto's self-powered operation is considered to offer increased reliability; in theory the magneto should continue operation as long as the engine is turning.

In short the magneto produces it's own electrical power for the ignition system.


This is an automotive Magneto for a small block Chevy


This is a Magneto on an Allis Chalmers Tractor.

These have rotating magnets internally that generate the spark.
__________________________________________________________

Battery and coil-operated ignition system with distributors.
Main article: Inductive discharge ignition
With the universal adoption of electrical starting for automobiles, and the availability of a large battery to provide a constant source of electricity, magneto systems were abandoned for systems which interrupted current at battery voltage, using an ignition coil to step the voltage up to the needs of the ignition, and a distributor to route the ensuing pulse to the correct spark plug at the correct time.

An improved ignition system was developed by the Dayton Engineering Laboratories Co. (Delco) and introduced in the 1910 Cadillac. This ignition was developed by Charles Kettering and was a wonder in its day. It consisted of a single ignition coil, points (the switch), a capacitor (to prevent the points from arcing at break) and a distributor (to direct the spark from the ignition coil to the correct cylinder).

This is a battery powered distributor type auto ignition system.


Here you can see the automotive battery powered distibutor ignition system and the inside of the distributor. Note there are no internal magnets in a distributor.



This is the IAU4006AUT DISTRIBUTOR

This is NOT a magneto.

Finally for those that are still not convinced that black spark maker in the M38 is actually a distributor:



Even the Military admitted they were in fact DISTRIBUTORS