The BSA A7-A10 Forum
Technical (Descriptive Topic Titles - Stay on Topic) => A7 & A10 Engine => Topic started by: Peter in Aus on 27.04. 2021 04:01
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Dose anyone know what the varies engine pushrod lengths are for the A7/A10.
Peter
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42-3108 /56-62 / 6 spring clutch = 11.530" ( not SR )
42-3860 / 54-55 / = 11.450"
67-3183 / 47-54 / rigid & plunger = 11.220
42-3272 / 53-63 / SR & RR = 21.000"
These came off a little give away from BSA
Push rod gauge which was a 12.5" steel rule with the push rods for all pre unit models drawn on it
We were going to try & reproduce it as a rally give away but the costs were too high .
Sorry, that was clutch push rods
Will dig up the valve push rods latter on as there is a customer at the gate right now
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Only got the lengths for the short stroke
A 7 ;- 8.0625" & 9.000"
A 10 ;- 8.500" & 9.500"
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Thank Trevor, I should have said " engine VALVE pushrods" that I was enquiring about, never mind that other info might be helpful to some one.
I'm doing up a motor that is a bitsa, A10 casings A7 barrel A10 head, lots of fun.
I have 2 sets of valve pushrods that I don't know what they are out of measuring:- 2 @ 8 3/32, 2 @ 8 3/16, 2 @ 8 19/32, 2 @ 9 3/32.
Ges I will have to just put it together (that a long way of yet) and see what fits *beer*
Thank you for your input,
Peter
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peter all I can say is check the rocker arm geometry with the push rod different lengths, dry build. I found out that what I thought were the correct spare set of push rods for my A7 were only a little bit longer and found the tappet adjusters were screwed nearly fully out.
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quit shure, but remember the pushrods are all the same lenghth, and the rockerarm geomety too. Except the camfollowers often reground and shorter than originals.
That make the difference.
cheers Klaus
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hi Klaus I am referring to a problem I found with mine when I had pushrods that were a bit longer than another set I had, both sets were supposed to be A7. I am no good at navigating things but on the 9 4 2020 I put two photos on with the before and after change of pushrods. these are REPLY 20 and REPLY 28 on cylinder head thread
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peter all I can say is check the rocker arm geometry with the push rod different lengths, dry build. I found out that what I thought were the correct spare set of push rods for my A7 were only a little bit longer and found the tappet adjusters were screwed nearly fully out.
Thanks Berger, that is what I intend to do but as I said that is a long way of yet.
Thanks Klaus for your input. *good3*
Peter
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New set of push rods for my 51, A10 Plunger are- Exhaust 9-7/16, Inlet 8-1/2 inches.
The mixed set that came with the bike,(project) are-Exhaust 9-1/2 inches, which appear to be A10 as per my new ones, and inlet 8 inches, which I believe to be A7.
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Thanks Russ, the pushrod lengths see to be all over the place, I will find out when I eventually put it together.
Thanks for your input *beer*
Peter