Author Topic: Dural or steel pushrods for "Golden Flash" ?  (Read 892 times)

Offline Stephen Foster

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Dural or steel pushrods for "Golden Flash" ?
« on: 11.08. 2012 16:25 »
I have a set of each of the above & am wondering if the tappet settings are the same ?
Inclined to use the original steel pushrods ..what is the theoretical advantage of the dural ones please ?

Whilst on the subject of tappet settings what are the optimum settings using modern fuel , etc .
Iron head with 1955 camshaft (reprofiled) ?

Had both sets donkeys years .

Regards all ,
Steve ..
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I own a 1955/56 B.S.A Swinging Arm "Golden Flash" , had it since 1976 .

Offline Goldy

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Re: Dural or steel pushrods for "Golden Flash" ?
« Reply #1 on: 11.08. 2012 17:06 »
I had dural push rods and the problem with them was noise, I understand that they flex when under load. I took them out and replaced them with steel. I cannot see that there is any difference with the settings. There is a lot about settings on the forum if you do a search. I understand that the settings are based on the camshaft that is used.
All the best Goldy
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56 A10 Golden Flash - Restore, ride, relive.                                          
56 C12 BSA project ongoing

Offline Stephen Foster

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Re: Dural or steel pushrods for "Golden Flash" ?
« Reply #2 on: 11.08. 2012 17:22 »
Thank You "Goldy",
Trying to have a mechanically quiet motor so inclined to re-use the original steel ones .
When I first acquired the "Flash" it came with about 6-7 gearboxes (including RRT2) , alloy heads ,
carbs & tons of spares ..the dural pushrods were in the deal .
The bike is now slowly coming back to life ...aided substantially be forum members particularly "Brian", "Muscrat", "Chaterelea",and many more ..Thanks once again all .                                       

Really like to make contact with a fell.ow enthusiast in the North West area ?
P.M for My phone number ?

Regards,
Steve ..
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I own a 1955/56 B.S.A Swinging Arm "Golden Flash" , had it since 1976 .

Offline Rocket Racer

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Re: Dural or steel pushrods for "Golden Flash" ?
« Reply #3 on: 12.08. 2012 02:48 »
If you consider rates of expansion, you have an iron barrel and head, so minimal expansion, whereas alloy pushrods when heated will expand.
If you ran alloy pushrods with an iron head I suspect you would need to run bigger tappet clearances to compensate the different expansion rates.
Alloy ones are lighter however as alloy flexes are typically thicker so that gain is partially offset.
The steel ones being tube are strong and of comparable weight, so ideal for road use.

There is a lot of fashion in parts like these, people think the alloy is better when in practice unless matched to comparable expansion alloy barrels and heads may in fact be inferior. But they do look nice!
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A good rider periodically checks all nuts and bolts with a spanner to see that they are tight - Instruction Manual for BSA B series, p46, para 2.
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