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crankcase front cover (nosepiece) changes - Printable Version

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crankcase front cover (nosepiece) changes - JonE - 30-06-2020

I DO have the book of production changes and I HAVE looked at the index cards, but I'm scratching my head trying to resolve the differences in the nose piece... as a result of trying to match a starter shaft, a front bush, and nosepiece all of which are separate items to me.

The variables are:

nosepiece 1A 264 is 6.5" high
my starter shaft is 7 1/8"
My front bush has a coarse thread which doesnt match that of the nosepiece which is far more fine. The fact that the nosepiece has a thread suggests it thus had a bush...

Hedd has indicated on FB that there were two, one of which doesn't have a front bush. I was assuming the differences were just the 3/4" shaft length difference or so when the engines adopted the longer 4 speed gearbox. The index card shows Hedd is correct and its a little more complicated. But what caused the differences, and what is the simple story to what happen to the items through the course of production?[attachment=10657]


RE: crankcase front cover (nosepiece) changes - Mark R - 30-06-2020

Please others correct me if I'm wrong but

First comes mag starting handles, the shaft of which is larger in diameter than the later examples

Next comes the early coil nosecones which have a nut at the front, the shaft is still larger in diameter and the spring quite short pushing between a collar on the shaft and the nut (the shaft coming out through the front of the nosecone when dismantled). Having just measured the nut I believe it to be 1 1/4 thread outer diameter by 16 tpi. This is the type I think you have and it should have a nut at the front and larger diameter shaft with a collar on it.

Next the later 3 speed coil type, I seem to recall from some reading I did from circa engine number 130,000 onwards. I think part number 1A459 which has the later type shaft with pin through the end the shaft being of a smaller diameter,0when dismantled this comes out through the engine end of the nosecone.

4 speed nosecones are shorter and I think part number 1A559 as above but about 3/4 inch shorter

Ruby type are longer still but of the same basic design, some have a detachable handle on a square

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RE: crankcase front cover (nosepiece) changes - Hedd_Jones - 30-06-2020

The early coil nosecone with a threaded bush, and the later non threaded nosecone for 3 speed cars are different lengths. I couldnt remember which way, but I had thought the bushed one was shorter. I tried putting the chummy engine in the RL. Fundamentally it didn't work as a straight swap, due to the different lengths.

Similarly I had always believed the nosecone for the 4 speed cars were 3/4 inch shorter than the non bushed 3 speed nosecone. That is the nosecone on my daughters RP is 3/4 shorter than the nosecone on my RL. The RP one is also iron!.


RE: crankcase front cover (nosepiece) changes - JonE - 30-06-2020

so Mark's CA7C link gives nosecone heights:

my coil 3 speed 6 1/2" (+ bush) - shaft dismantles to front
RN Saloon 3 speed 7¼" (no bush) - shaft dismantles to rear
the later 4 speed RN/RP 6½" (no bush) - " " "

I think my shaft must be later as it won't come out through nosepiece. Should all shafts activate all dogs though?


RE: crankcase front cover (nosepiece) changes - Ruairidh Dunford - 30-06-2020

(30-06-2020, 09:28 PM)JonE Wrote: Should all shafts activate all dogs though?

No. Several different ones exist.


RE: crankcase front cover (nosepiece) changes - Hedd_Jones - 30-06-2020

So there you go. A RP nosecone, with the appropriate accoutrements will be the right length for a short rad coil car. Certainly for my AE chummy


RE: crankcase front cover (nosepiece) changes - AustinWood - 30-06-2020

The early coil shaft has a peg screwed in to the side of the shaft close to the inner end. This engages with the ledge on the casting to hold the handle horizontal. The peg has to be unscrewed before the shaft will come out through the nosepiece. It also has a dog mechanism to engage with the crank. Later shafts have a pin through the end like most conventional handles.


RE: crankcase front cover (nosepiece) changes - Ruairidh Dunford - 30-06-2020

Jon - to give us a starter for 10, post a photo of the starter dog you are using - more questions may then follow.


RE: crankcase front cover (nosepiece) changes - Mark R - 30-06-2020

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RE: crankcase front cover (nosepiece) changes - JonE - 02-07-2020

here are two other parts - bush seems far too coarse but perhaps is something that has been made up for something non-standard? And is it clear what this rod fits? Will photo the dog later... [attachment=10676][attachment=10677]