Misc: Everything Else Series 'D' Case History

[LoneStar]

Hello all,

My Rapide basket case came with two primary cases. One is cast with part number T5/3 and has a mating number matching the Series C crankcases I have. The other has part number T5/6. This is listed in the Series D spares list.

Looking at the two, I notice only that the inspection port on the later version faces more upwards than in the earlier. Is anyone aware of other differences? Why a new part for Series D? It seems odd that Vincent, never flush with extra cash, would invest in creating a new version of the case if it were not necessary.

Series D case is on the left:

 

[chankly bore]

There was a remark made by P.E.I. at some stage that the front bulge over the E.S.A. was modeled on a female breast. It was suggested that the change in curvature was because the pattern maker at John Dale foundry had acquired a new totty. Perhaps there is a difference here to accommodate the series "D" ESA. Try a silicone implant in there and see if there's a difference in volume, before this Forum goes tits up.

 

[Robert Watson]

Use the one that has the mating number the same as your crank cases, (If one of them does?)

 

[ClassicBiker]

D crankcases were die cast weren't they? I imagine, I could be wrong of course, but that would include all the covers and not just the crankcase proper would it not? That would mean a casting die would need to be made rather than using a sand casting pattern. Depending on the draw line of the die it might have been necessary to alter the angle of the inspection port. If a casting die was being made anyway, may be the more vertical angle was thought better for filling the primary. As I say I don't know if the covers on the D are also die cast. But if they are then that is a whole new set of tools Vincents had to invest in, then that is the time to make changes.
Steven

 

[LoneStar]

There was a remark made by P.E.I. at some stage that the front bulge over the E.S.A. was modeled on a female breast.

Maybe that explains it; Series C cup vs. Series D cup...

 

[flashvin]

The Crankcases on late Series C and D twins were die cast. I’ve heard the term “gravity“ used as to the method of casting process used. The covers timing, primary , kickstart, and primary changed on the twins to die cast much earlier say some time 1948/49. There are at least 3 patterns of timing covers. The very last of the HRD embossed timing covers are the same lighter spec. as the Vincent embossed pattern. The HRD is a much cleaner rendition as compared to the cruder Sandcast versions.

 

[davidd]

All the die-cast cases and covers were designed in late 1948 through early1949 as the order for the dies was placed with John Dale around June of 1949. Eric Baily had to ratify the order and the payments when he took over the finances at Vincent in September of 1949 according to Phil Irving.

David

 

[clevtrev]

The Crankcases on late Series C and D twins were die cast. I’ve heard the term “gravity“ used as to the method of casting process used. The covers timing, primary , kickstart, and primary changed on the twins to die cast much earlier say some time 1948/49. There are at least 3 patterns of timing covers. The very last of the HRD embossed timing covers are the same lighter spec. as the Vincent embossed pattern. The HRD is a much cleaner rendition as compared to the cruder Sandcast versions.

There are Gravity and Pressure die casting methods.

 

[erik]

And vacuum and pressure casting method ! Erik