The Stovebolt Site Forums The Shop Area Engine Shop starter and flywheel teeth match?

Hi all,
I have a 1950 Chevy 3100, with a 1960 261cu-in engine, the starter and flywheel though are a bit of a mystery.
bought the truck after the engine conversion and I have no details other than what I've been able to determine by looking at engine codes, etc.. Right now I have not yet counted the number of teeth on the flywheel (will do that later today), but the starter engage gear has 9 teeth. My starter has gone out (stud is worn, button copper is worn, 1/2 of the brushes are worn). Looking to rebuild, but have also bought a NAPA 6v starter (Part #: RAY 2449651) and am trying to determine if it’s a correct match, it also has 9 teeth. A couple of questions then.

1) 1950 216 & 235 engines, and specifically 6v systems seem to have used 139 tooth flywheels (or is it that ALL 6v used 139 ?). By 1960 and the 261 all were using 12v and had 168 tooth flywheels... or so I've read. As the starters, for both seemingly have 9 teeth each... so how does one determine if the starter they have is for the right engine/flywheel ?

2) This is a particular issue with the NAPA remanufactured unit, since it is matched by year and not engine/flywheel. Both the existing and NAPA starters are essentially the same with mechanical type starter buttons (mechanically). Both the existing and NAPA starters measure 14mm, so I am assuming I should have a correct match ?

3) If then I assume I have a 139 tooth flywheel, that would mean the 1960 261 engine had its flywheel replaced with the older 1950 engine’s flywheel… correct ? In other words all 261 engines, especially in 1960 era were 12v based…. and so from the thread here means it should be 168 tooth version ?? And it that even possible to perform such a switch ?

4) I am also having trouble finding a correctly listed mechanical "solenoid" (as most are calling it). For the older 1950 era starters, they are all push-button mechanical and look like what I have. However for the 1960 era starters all seem to in fact be electrical solenoid type units and not a match for what I have. Are perhaps all these push-button type “solenoids” the same ?

I really love this forum for all the great help and knowledge/experience.... you folks are greatly appreciated.

Joe

How to tell 168 tooth flywheel from 139 tooth without counting all the teeth. This is a 168. [img]https://www.stovebolt.com/ubbthread...oad/Number/49654/filename/clipboard1.jpg[/img]

Distance between the 1st and 10th tooth is 2.363". 6volt distance is 2.86 inches.

Before someone asks which tooth is the 1st tooth, any tooth can be the 1st tooth, then count 2, 3, 4 etc. until you get to 10.

Thanks for the feedback guys. So i have 139 tooth flywheel (4 teeth per inch... whereas the 168 is 5 teeth per inch.... based on Deve's Inline-6 Engine book.

Still curious though, unless my research is wrong, all 261 engines were 12v based and SHOULD have had 168 teeth.... strange that mine has the 6v based 139 teeth.


Anyway, I'm back in business. Time to show it off at some Christmas events ;=)

1954 was the first year for the 261, so 1954 and 1955 first series are still 6 volt.

Ahh.. so that makes more sense. Someone found a 1960 261 engine as it had all the latest refinements, but they wanted the stomp starter so went with the 1950-ish starter. Assuming the flywheel was then the only change after 1955... the newer 1960 engine might could have taken a 1954/5 139 tooth flywheel to make it all work. Be cool if someone knew for sure this was possible (for someone else in the future)... but got mine going so thanks all for the feedback/tips.

Joe

Other than some minor differences in the position of the timing marks, virtually all 216, 235, and 261 flywheels will interchange. The bolt pattern and dowel pin spacing is the same on all of them. Just be sure to match up the ring gear tooth count with the appropriate starter.
Jerry

Aside from the number of teeth, the heavy-duty flywheels were drilled for a 9-bolt clutch up through 1953. 1954 and '55 1st had 139 teeth and a 6-bolt clutch. Thereafter, all had 168 teeth and 6-bolt clutches. 9-bolt clutches are NLA and you must have yours rebuilt, as with the disc. I went through this ad nauseum last summer. FWIW, bell-housing part numbers are unique for 54 and early 55 as they changed the motor mounts in 54. Why 55 2nd and later bell housings carry a different part number, I do not know. Perhaps I read the parts book wrong.