timing gear steady plate

tractorman414

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Yesterday a STEEL ET161 timing gear steady plate sold on ebay for £37.00, with a description claiming "I think they were meant for more highly stressed engines, and for racing units or sprinters". I had always thought that the only metal suitable for the steady plate was one with a similar coefficient of expansion to the crankcases, i.e. aluminium/alloy.
Steel would surely pull the spindle ends together,accelerating wear.

Any thoughts ?

Bernard
 

Len Matthews

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Yesterday a STEEL ET161 timing gear steady plate sold on ebay for £37.00, with a description claiming "I think they were meant for more highly stressed engines, and for racing units or sprinters". I had always thought that the only metal suitable for the steady plate was one with a similar coefficient of expansion to the crankcases, i.e. aluminium/alloy.
Steel would surely pull the spindle ends together,accelerating wear.

Any thoughts ?

Bernard

Absolutely right Bernard. The whole idea was that the expansion rate of the steady plate would match that of the crankcase. On the same subject, many years ago as a very inexperienced Vincent owner I ordered a new steady plate from Harper Engines. I sent it back complaining that the hole for the idler spindle had been drilled oversize. It was returned with a note explaining the reason why. So much to learn!
 

nkt267

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Interestingly I have never seen an alloy one on a Comet,nor does it seem to be listed in my parts list although it is pictured on MO64..Maybe half a twin does not expand as much:D or does not need lightening:;)..John
 

clevtrev

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Absolutely right Bernard. The whole idea was that the expansion rate of the steady plate would match that of the crankcase. On the same subject, many years ago as a very inexperienced Vincent owner I ordered a new steady plate from Harper Engines. I sent it back complaining that the hole for the idler spindle had been drilled oversize. It was returned with a note explaining the reason why. So much to learn!
Which Idler ?
 

Howard

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Come on Len, put me out of my misery - why is it oversize. The reason I'm worried, I haven't had the timing gear apart for a long time, but I can't remember any of the holes being oversize. Is this something that's slipped under my radar from a previous owner or is it just my memory?

H
 

john998

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Steady plate

Hello,
I think Len is refering to the hole for the large idler spindle thread.
It is over size to allow for adjustment of mesh to the cam wheels.

Regards John.
 

Howard

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Ah yes I remember it well. It's a memory thing not a mechanical problem - there's a releif.

H
 
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