Sprint/1850 jackshafts different?

[cleverusername]

I have always seen these listed as being the same for TR7, Sprint and 1850 but I just put the 1850 jackshaft next to the Sprint one and they are different. The lobe which drives the fuel pump is much wider on the Sprint shaft compare to the 1850. I can't tell by eye if they have a different profile but it did surprise me.

is this a difference between the models or did they change the design of the jackshaft between early and late cars for all models?

[MIG Wielder]

I have 2 samples, both used, here in my spares box.
One is from a Sprint, the other was in a box of bits I was given.

The 1973 1850 parts book and the 1976 Sprint / 1850 parts book both list 215207 as the jackshaft part number, as does Rimmer's web-site for the TR7.

Both samples I have are stamped with an I.D. One is 0294W and has a 14,91 mm wide fuel pump cam.
The other is stamped 0216W and has a 15.2 mm wide cam.

The only difference between them I've just noticed is the 0294W specimin has a polished raised plain cylindrical section behind the water pump skew gear, as if something has been running on it. Like a very wide fuel pump cam. So may not be Sprint. This section on the 0216W specimin is present but is natural black.

HTH,
Tony.

[xvivalve]

They did widen the fuel pump cam as even with the added width it can be difficult to locate the pump arm on the cam

[cleverusername]

They did widen the fuel pump cam as even with the added width it can be difficult to locate the pump arm on the cam

So one is an early jackshaft and the other is a later one?

[xvivalve]

I believe so, yes...