Author Topic: 1925 douglas TS valve cap pins  (Read 4649 times)

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Offline tck

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1925 douglas TS valve cap pins
« on: 29 Apr 2015 at 14:08 »
What material should I use for these pins that hold the valve spring retainers? my pins are mangled but it looks like they were a push fit in the round hole in the valve and then reduced to a D section both sides and bent out slightly to prevent them falling out is that a correct reconstruction?

Offline tck

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Re: 1925 douglas TS valve cap pins
« Reply #1 on: 29 Apr 2015 at 16:10 »
Looking at one pin that is marginally better it looks like they are simply a length of round rod but still unsure what material would be suitable..

Offline midman

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Re: 1925 douglas TS valve cap pins
« Reply #2 on: 29 Apr 2015 at 23:53 »
I've been told that a proper size drill bit cut off works fine.

Offline eddie

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Re: 1925 douglas TS valve cap pins
« Reply #3 on: 30 Apr 2015 at 06:37 »
I have been using needle rollers for the last 10 years and have never had any problems with either bending or breakage. I have also heard of others making use of offcuts of old spokes as they are made of a high tensile steel.

  Eddie.

Offline Chris

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Re: 1925 douglas TS valve cap pins
« Reply #4 on: 30 Apr 2015 at 06:54 »
Hi all
It is essential that good quality steel is used for the pins. Most valves have a hole of 1/8" diameter but over the years some valves have been made with other diameter holes and as the result of wear some may have their holes oversize from the original. The pin ideally should be a good sliding fit in the hole and for this reason I have for many years recommended the shanks of twist drills which in good quality drill bits is soft enough to cut with a junior hacksaw. These are of course available in all sizes to suit taking into account number drills as well as standard 1/8" drills for new valves. As Eddie mentions, spoke material is also good quality high tensile steel but is only available in Standard Wire Gauge (SWG) sizes the nearest to the most common holes size being 10 gauge at 0.128" which may be OK for used valves with some wear in the holes. These or larger diameter spokes can be used with a bit of turning to fit any size valve hole. Chris.
 

Offline cardan

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Re: 1925 douglas TS valve cap pins
« Reply #5 on: 30 Apr 2015 at 10:07 »
Drilling holes in valve stems is a tricky but satisfying job. I buy a new drill bit each time (1/8 for smaller stems, 5/32 for larger), then use a piece cut off the plain (chuck) end as the pin. No problems for veteran-strength valve springs. I mark the length I want, put the drill bit in the lathe on a very low speed, then use a thin cut-off wheel in the Dremel to cut it off.

Leon

 

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