Starter Motor Internal Guts

[Gene M.]

There are numerous P/N's for high torque and regular starters that fit Chevy and Corvette applications. Aside from the nose to fit big or small block what are the differences in the armature and field coils that may or may not be different. This is discounting the differences in high torque vs regular starters. Only concerned with differences in high torque group separate from concerned with differences in regular starter group.

It would seem armature and field coils would be wound different. Maybe not............

[Joe L.]

Re: Starter Motor Internal Guts

There are numerous P/N's for high torque and regular starters that fit Chevy and Corvette applications. Aside from the nose to fit big or small block what are the differences in the armature and field coils that may or may not be different. This is discounting the differences in high torque vs regular starters. Only concerned with differences in high torque group separate from concerned with differences in regular starter group.

It would seem armature and field coils would be wound different. Maybe not............

Gene------

The field coils and armatures are the difference between standard and HD starters. In addition, the HD starter frame has the field coil contact hole in a different position that the standard starter frame.

The HD starter field coil assembly consists of 4 coils; the standard duty starter consists of 3 coils. The HD coils are also longer than the standard duty coils. The HD starter armature is longer than the standard duty armature and there are other differences.

Other than the above, the HD and standard duty starter components are the same. However, there may be other differences, usually minor, in either type starter depending on application.

Also, the HD starters are designated 10MT; the standard duty starters are 6MT or 8MT.

[Gene M.]

Re: Starter Motor Internal Guts

Gene------

The field coils and armatures are the difference between standard and HD starters. In addition, the HD starter frame has the field coil contact hole in a different position that the standard starter frame.

The HD starter field coil assembly consists of 4 coils; the standard duty starter consists of 3 coils. The HD coils are also longer than the standard duty coils. The HD starter armature is longer than the standard duty armature and there are other differences.

Other than the above, the HD and standard duty starter components are the same. However, there may be other differences, usually minor, in either type starter depending on application.

Also, the HD starters are designated 10MT; the standard duty starters are 6MT or 8MT.

Yes I understand and familiar with all that between HD & SD starters. But from your reply it sounds as if all SD starters have same armature and field (3) no matter the attention to p/n. And the HD starters all have same armature and field (4 poles), same deal.

So using parts from one HD to fix another HD is transparent. And same is true for SD to another SD unit. Armature and field speaking.

[Wayne M.]

Re: Starter Motor Internal Guts

Gene -- my P&A30B (Rev Jan'70) Gr 2.043 shows at least two of the long (11.0" shaft length) HD armatures; Delco D-4121 (#1965724), and D-4111 (#1940624). I have 2 NOS of the former (one in the pull-string box, never opened), and one NOS of the latter. Comparing side-by-side, offhand I can't see a difference, but I'm sure there is, or else there wouldn't be 2 part #s.


Applications, per the parts book: the D-4111 is for starters 1107352 (396), ...8351, ...8381. The D-4121 is for 1107365 (427), ...8385, ...8400.

[Gene M.]

Re: Starter Motor Internal Guts

Gene -- my P&A30B (Rev Jan'70) Gr 2.043 shows at least two of the long (11.0" shaft length) HD armatures; Delco D-4121 (#1965724), and D-4111 (#1940624). I have 2 NOS of the former (one in the pull-string box, never opened), and one NOS of the latter. Comparing side-by-side, offhand I can't see a difference, but I'm sure there is, or else there wouldn't be 2 part #s.


Applications, per the parts book: the D-4111 is for starters 1107352 (396), ...8351, ...8381. The D-4121 is for 1107365 (427), ...8385, ...8400.

Thank you Wayne that is the type of information I was looking for.

[Joe L.]

Re: Starter Motor Internal Guts

Yes I understand and familiar with all that between HD & SD starters. But from your reply it sounds as if all SD starters have same armature and field (3) no matter the attention to p/n. And the HD starters all have same armature and field (4 poles), same deal.

So using parts from one HD to fix another HD is transparent. And same is true for SD to another SD unit. Armature and field speaking.

Gene------

The field coil assemblies are the same for all HD (10MT) starters and the same for all standard torque starters (6MT, 8MT).

However, that's not the way it is for armatures. That's why I said the HD starter armature is longer than the standard duty armature and there are other differences. I didn't get into detail previously because I thought what you were interested in were the basic differences between the armatures. The basic difference between the armatures is the length of the wound section of the armature. As far as other differences are concerned and with respect to 63+ starters, there is a difference between the armatures used for starters used with aluminum noses (short bolt/long bolt type for 12-3/4" flywheels), those for cast iron nose starters (2 intermediate length bolt type for 14" flywheels), and those used for aluminum nose starters (2 long bolt type for 14" flexplates used with 1970+ automatic transmissions). So, there were SIX different armatures, as follows:

GM #1955937------standard torque (6MT, 8MT), aluminum nose (1 short, 1 long bolt type for 12-3/4" flywheels)

GM #1966228------standard torque (6MT, 8MT), cast iron nose (2 intermediate length bolts for 14" flywheels)

GM #1940624 -----high torque (10MT), aluminum nose (1 short, 1 long bolt type for 12-3/4" flywheels)

GM #1965724-----high torque (10MT), cast iron nose (2 intermediate length bolts for 14" flywheels).

GM #1971568-----standard torque (6MT, 8MT), aluminum nose (2 long bolt type for 1970+ 14" flexplates).

GM #1970548-----high torque (10MT), aluminum nose (2 long bolt type for 1970+ 14" flexplates).

As you can see from the above, it gets complicated when we get into all of the different armatures but the BASIC difference between the armatures remains as I described. I can also tell you than NONE of the above armatures is interchangeable with one another. I can say this for certain because "I've been down this road". So, what are the specific differences? I've forgotten but they're important.

[Joe L.]

Re: Starter Motor Internal Guts

Thank you Wayne that is the type of information I was looking for.

Gene------


I'm glad that Wayne was able to provide you with the information you were looking for while I, apparently, was not able to do so.

[Gene M.]

Re: Starter Motor Internal Guts

Gene------


I'm glad that Wayne was able to provide you with the information you were looking for while I, apparently, was not able to do so.

No not at all. Your last post was perfect. All the armatures that make up the different p/n. Wayne did show there was some kind of differences from his two armatures. thank you