The BSA A7-A10 Forum
Technical (Descriptive Topic Titles - Stay on Topic) => A7 & A10 Engine => Topic started by: Stephen Foster on 11.08. 2012 16:25
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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 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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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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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!