74's & 61's

[exeric]

I was helping a friend get his 46 OHV Harley started for the first time last night. It started on the first kick by the way, thanks to a good friend of ours who is in his 70's. Good old Marsh put the super tune on it.

In the coarse of eyeballing this bike from front to back, my friend pointed out something I was not aware of. On a 74 bottom end there are matching numbers on each side of the case. Single digit number, and they are located just behind the rear cylinder on the motor mount boss. Apparently a 61 will not have these matching numbers. I am curious to know if this followed on the Panhead as well. I'm not near my 51 FL right now so I can't look at it. I can see the logic of H-D stamping numbers there to facilitate in-house control. I've been around this stuff for a long time and I am always astounded by what I don't know.

[jwl]

I've noticed the numbers too and have done a little research but not much. I think all 74 inch engines had a 7 stamped in the case by the rear motor mount holes. This started in 41 and continued to the end of the 61 era in 1952. At some point after that I think an H was stamped in the same location to denote the FLH model. At some point in the assembly line process these stampings were made to make workers farther down the line aware that the cases were to be assembled as a 74 or FLH or whatever the case may be. I have no documentation to back these statements up but they are just some observations I have made over the years.

[VPH-D]

JWL,
I believe your observations are correct. After the motor was assembled, there had to be some way to identify whether it was a 61 or a 74. Same thing would be true for the FL/FLH series. I think the 6 or 7 number shows up in the confidential numbers on the case bottom.

As late as the 70s, the H number was stamped into the rear case area on FLHs and the Superglide family.

VPH-D

[bobdo]

74's & 61's

Happy Holidays All,
I'm also astounded by what i don't know. I've often wondered why the 7's were there. It makes sense to mark the cases in some way after the flywheel assembly is installed & prior to the VIN #'s being stamped. Can anyone see a reason for dealership replacement cases having the 7's ?
This new found knowledge has me bummed..
I have a '47 EL with title & it has the 7's.
Anyone out there with a scenario that makes sense of a 61" motor with the 7 stamps?
Bob

[jwl]

Bob, I'd have to assume it's a number job. Don't feel alone though, I have an FL without the 7's. I'm sure it's a number job also. Simple as that!

[exeric]

I looked at my '51 FL when I got home and it does have a 7 on each case half. Every time I learn something new, it pushes something old, out.

[partshunt]

Hi: Re the single digit stamping. Mine is a 54, need to look it over when I get close to it. Question is, after 61's were discontinued in 52, and with no FLH till 55, would they have bothered to stamp a 53 or 54 74FL/? I ask cuz that was the only option, a 74FL?? Was the 7 left out in thse two years?..Joe

[jwl]

52 74's, 53's and 54's were stamped 7. 55 and later were stamped 7 unless they were an FLH. Then they were stamped H. I don't when this ended because my 58 thru 66 have the voltage regulator bracket bolted over the area where it would be stamped so I can't see.

[VPH-D]

jwl
The H was stamped into the cases up through at least the 70s.
The Superglide family were all stamped with the H.
VPH-D

[Barry]

Hello, can anyone tell me why replacement cases do not have these numbers? I have a 1940 Knuckle that I bought from the original owners brother when he passed away. He worked for Harley untill the early 60s and rode this bike till 69. I was told that he had problems with the engine sometime in the 40s and got a new motor for it. The engine is a complete 47 fl with what apears to be factoy numbers that read 40el**** the same numbers that are on the original 1940 title that was with this bike. Was this a common practice or was it because he worked for Harley?

[jwl]

Barry, I suppose they didn't have the 7 stamped into them because when the replacement cases left the factory the factory had no way of knowing if the cases would be used on a 61 or a 74. The dealer stamped the serial number on the cases when he redid the old busted engine. They were supposed to have trashed the old cases then.

[exeric]

I've been thinking about this thread and there is one factor that bugs me. How often did Harley Davidson have to supply a replacement case ? I started riding in the early 70's when big twin knuckleheads and panheads were cheap and worn out and we still rode them hard. Among all the people I knew, no one ever deep sixed a bottom end. I know it can be done because I have seen blown out cases but I contend that it's rare. The blown engines I have seen have always had a good story behind them too ! Usually involving poorly set-up stroker wheels, bent con rods, dropped valves, or just amature engine building. I can understand blown up engines in the 60's and 70's because genuine H-D parts were the only game in town, but when you go back to the 30' through the 50's it seems like a stretch to imagine very many big problems with factory assembled engines. In another thread on this forum, Herbert Wagner mentioned that H-D used to maintain a card file on every engine they built. Unfortunately AMF filed all of that priceless information in the trash can so we will never know the answer to this question.

[VPH-D]

Your observation about replacement cases is correct. The average dealership in the 70s had very little call to request a set set of replacement cases.

There would have been two scenarios regarding case replacement; warranty or a customer's older machine

There were special forms required to order replacements, in a warranty situation, this was pretty straight forward.

In the case of a customer's older machine, there were more considerations. IIRC, about all that was available were late generator shovel cases. In other words, if you wanted a set of casesfor your 63 FL, you were out of luck. Keep in mind the old cases were required as part of the deal.
VPH-D

[Lonnie]

Speaking from experience, the short rib knuckle cases (on the number side of course) are weak along the curve where the ribs end and the case turns, as it makes the vertical flat to the deck. They can crack from the edge there were the cases meet all the way across, usually below the numbers from the ones I have seen. Though I have seen cracked cases that were always 61 inches, it would seem that the 74 really was the straw that broke the camel's back. H-D modified the cases with a thicker area then with the longer reinforcement ribs used on later knucks.

In Bruce Palmer's book, he states that the short ribs were used through 1940 and the long ribs began in 1941. I have seen quite a few '41's with the short rib cases, like mine, that have not had a number job.

FYI, my '41 cases were cracked from about 1-inch from the mating surface below the case bolt above the generator all the way to under the number boss. It has been repaired before and I hope this repair will do it! If this had occurred "back in the day", the case would have been replaced.

Lastly, I have seen a set of knuck cases with a Sept. 47 cast date and very high belly numbers stamped with '41 numbers. They were the correct stamp size and appearence and I firmly believe they were not victims of a number job. I did see that they had the "7" stamp on both cases as you note.

Lonnie

[Rub]

Lonnie, I have seen several sets of cases with late castings and early numbers. All were replacement cases. When I worked for a dealer in the 70's I even saw '66 to '69 cases with factory correct knucklehead numbers on them. The broken original cases had been sent to H-D and new cases were returned with the old numbers stamped in them. The entire transaction took place through a dealer. Anyone else know of this practice? Robbie