Ariel single crankshafts

[Bill Mathison]

Good day from Canada. My first Ariel was a 1957 VH in 1967. In retirement I have built a VCH road racer, a VH rigid flat tracker, 1938 VH girder road racer, and a John Bartram framed HT. I am now endeavoring to build a VB 600 methanol sprint bike and recently acquired a W/NG 1944 engine. Now I am looking at the cranks from the VB, NH, and VCH. The crank pin location from the centre of the crank. Could someone please help me understand how the strokes can be different on these three cranks, with the pin location equal distant from the crank centre on all three. Thank you. Bill

[adrie.degraaff]

with the pin location equal distant from the crank centre on all three. Thank you. Bill

They should be differend stroke NH 85mm, VH 95mm and VB 10.5?

[Bill Mathison]

So Adrie, it is only the rod length that matters. The NH, VH, and VB rod lengths are different. Thanks. Bill

[Pete.Silson]

Bill

So Adrie, it is only the rod length that matters. The NH, VH, and VB rod lengths are different. Thanks. Bill
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From my limited knowledge of engine geometry, I would think that the distance from the crankpin to the centre of rotation is always half the stroke.

Pete

[adrie.degraaff]

So Adrie, it is only the rod length that matters.

No read it again, stroke and conrods are differend, in stroke NH, VH, and VB, in conrod shape there is NH, VH, VG and VB.
VH and VG have the same stroke but differend bigend size.

[Bill Mathison]

Thanks Adrie.

[Roger Gwynn]

Except from 1949 when the VG gained the 1" pin. and pre 1935....

[Bill Mathison]

Thanks Roger, Ardie and Pete. Tomorrow's job is about measuring and calculating with these orphan connecting rods that I have inherited.

Bill

[Pete.Silson]

Bill

Post-1935 I believe there were only three conrods used. These can be identified by the number on the conrod web i.e.

A7/339 (NH)
A7/473 (VH)
A7/524 (VB)

Post-1949 the rod numbers are the same but they are reinforced around the big-end eye.

Pete

[Bill Mathison]

Thanks Pete.Silson