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View Full Version : BSA sidevalve valve bits?



Ginge09
11th March 2024, 17:36
Hi all,

Looking for collets and valve spring cups for a BSA sidevalve build.

Collets are 29-0410, same as OHV A7 or A10 but also common to M20,M21,C10

Valve spring cups are 66-0221 and are for a single spring. Same as M20,M21,C10. OD 1 1/4”, ID 7/16”, height 5/16”

Tried the usual local suppliers but no joy.

Grumph
11th March 2024, 18:32
Try Bland Bros in ChCh.

If all else fails, collets and retainers are not hard to machine up. Done it myself for odd shit.

Ginge09
11th March 2024, 19:42
Thanks Grumph,

Don’t have machining gear so was hoping someone has some bits in a box going begging.

Thanks for Bland Bros. They look old school enough to be worth a try.

Cheers

husaberg
11th March 2024, 20:13
Hi all,

Looking for collets and valve spring cups for a BSA sidevalve build.

Collets are 29-0410, same as OHV A7 or A10 but also common to M20,M21,C10

Valve spring cups are 66-0221 and are for a single spring. Same as M20,M21,C10. OD 1 1/4”, ID 7/16”, height 5/16”

Tried the usual local suppliers but no joy.

if you don't have any luck I seen quite a few A7/10 heads the other day.

pete376403
11th March 2024, 20:42
Nothing here? https://www.britishmotorcycleparts.co.nz/

Grumph
12th March 2024, 07:31
if you don't have any luck I seen quite a few A7/10 heads the other day.

Any twin carb ones in there ? Asking for Warwick.

Kickaha
12th March 2024, 16:43
Any twin carb ones in there ? Asking for Warwick.

They'd be more than I could afford, I have a Kawasaki one I can make fit anyway, the twin carb heads aren't well thought of by a lot of the BSA guys

husaberg
12th March 2024, 17:52
Any twin carb ones in there ? Asking for Warwick.

I don't think so, Not any pre unit twin carb threads any way ,I was looking for a 3t engine so I wasn't paying a lot of attention.
There was a cyclone unit head at one time but I think its gone.
You have seen that shed, God knows what's actually in there. I did see a small fin ZB33 head and Cylinder. And a lot of Ariel huntmaster A10ish cases etc
I do recall Hugh Anderson raced an Iron headed twin carb A10 at an early cust 83ish in a Norton frame.
But I think some early A10 iron heads had bolt on flanges that could be modified from twin carbs but with single carbs not just the super flash.
Years ago Warwick showed me some of the pics of Twin carb Alloy heads, I had never seen one
looking on Google it seem some early A7ss had Road rocket had bolt on manifolds with Alloy heads but not splayed out.

Ginge09
12th March 2024, 18:39
Ok, can someone PM me with the potential lead details?

I don’t need twin carb OHV stuff but it sounds like the right shed to look in.

Kickaha
13th March 2024, 05:54
https://mikesclassiccyclespares.com/product/29-0410-pair/ I've bought through there before and it was reasonably quick and easy

Flip
23rd January 2025, 21:07
Did you find what you were looking for?
I have a few M20 bits.