Author Topic: A7 alloy head on A10 barrels?  (Read 5489 times)

Offline Jim

  • A's Best Friend
  • ***
  • Join Date: Oct 2009
  • Posts: 35
  • Karma: 2
A7 alloy head on A10 barrels?
« on: 14.10. 2009 17:07 »
Hi I'm Jim and am new to this forum.

I recently bought a 1961 Gold Flash and am slowly trying to sort her out and tidy her up.

For purely cosmetic reasons I would prefer to have an alloy head on her. As A10 alloy heads tend to be considerably more expensive than A7 ones, is it possible to use the A7 head. I appreciate that the valves may possibly be a bit smaller (although maybe no smaller than the Gold Flash ones) and the bores will be larger than the design of the head but as I am not using high compression pistons does this matter. Am I being stupid even considering going down this route?

Any words of wisdom gratefully received.
Wimbledon, England.
BSA A10 x2
BSA B44 x2
BSA B40
BSA A65
TriBSA 500
Buell XB12R

Offline rocket man

  • Valued Contributor
  • ****
  • Join Date: Mar 2009
  • Posts: 466
  • Karma: 2
Re: A7 alloy head on A10 barrels?
« Reply #1 on: 14.10. 2009 18:06 »
i dont think your being stupid it will look great i dont know about the
A7 shooting star head fitting thou i would try to go for the a10 alloy head
because you might get a bit more performance out of it and also the push rods might be different
size in length  and the bolts might be in a different place its worth the extra cost also they keep a lot cooler
than cast iron ones
 


dave

Online muskrat

  • Global Moderator
  • Wise & Enlightened
  • **
  • Join Date: Jul 2009
  • Posts: 8168
  • Karma: 106
  • Lake Conjola NSW Oz
    • Shoalhaven Classic Motorcycle Club Inc
Re: A7 alloy head on A10 barrels?
« Reply #2 on: 14.10. 2009 19:20 »
G'day Jim,
             Fits no worries. have a look at http://www.a7a10.net/forum/index.php/topic,1806.0.html it's a A7 head on a A10. The breathing may be a bit restricted so I put A10 valves & seats in and ported to suit. Also relieved the edge to match the larger barrels. They are a big macarno set, most bits are interchangeable. I also have a '57 top end on '51 plunger cases. Mix & match, make it how you want it.
Cheers
'51 A7 plunger, '57 A7SS now A10CR,  '83 CB1100F, 88 FXST .
Australia
Muskys Plunger A7

Offline A10Boy

  • Wise & Enlightened
  • *
  • Join Date: Jun 2008
  • Posts: 1075
  • Karma: 11
  • Solihull, Near Birmingham England.
Re: A7 alloy head on A10 barrels?
« Reply #3 on: 14.10. 2009 20:52 »
Hi Jim and welcome.

Cant help wondering, if you wanted a alloy headed A10, why didn't you buy one?

Golden Flashes are supposed to have iron heads, and they are better for it. Rockets are supposed to have alloy heads and they to are better for that.

Is your Flash nice and original or already "Modified", if it is, I guess it wont matter too much.

Regards

Andy
Regards

Andy

1960 A10 - Black Golden Flash
Plus
1974 Kawasaki Z1a
Yam XJR 1300

Offline rocket man

  • Valued Contributor
  • ****
  • Join Date: Mar 2009
  • Posts: 466
  • Karma: 2
Re: A7 alloy head on A10 barrels?
« Reply #4 on: 14.10. 2009 21:02 »
one good reason is they dont rust a lot like cast iron ones do
i wouldn't mind getting some alloy barrels if only they did them

Offline A10Boy

  • Wise & Enlightened
  • *
  • Join Date: Jun 2008
  • Posts: 1075
  • Karma: 11
  • Solihull, Near Birmingham England.
Re: A7 alloy head on A10 barrels?
« Reply #5 on: 14.10. 2009 21:09 »
They don't rust if properly looked after, painted or whatever.
Regards

Andy

1960 A10 - Black Golden Flash
Plus
1974 Kawasaki Z1a
Yam XJR 1300

Offline rocket man

  • Valued Contributor
  • ****
  • Join Date: Mar 2009
  • Posts: 466
  • Karma: 2
Re: A7 alloy head on A10 barrels?
« Reply #6 on: 14.10. 2009 21:21 »
your right as long as there looked after

Offline Rocket Racer

  • Wise & Enlightened
  • *
  • Join Date: Jun 2009
  • Posts: 1415
  • Karma: 16
  • A kiwi with a racing A10 rig and too many projects
    • NZ Classic Sidecar Racing
Re: A7 alloy head on A10 barrels?
« Reply #7 on: 14.10. 2009 21:28 »
Nothing wrong with alloy or iron, if the bikes fairly stock becomes more an issue whether you value originality. Is your existing head stuffed? I dont see why you shouldnt be able to source a fresh head, theres a lot of stuff available on places like ebay.
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.
New Zealand

Offline LJ.

  • Peterborough UK.
  • Wise & Enlightened
  • *
  • Join Date: Jun 2006
  • Posts: 1403
  • Karma: 15
  • The Red A10!
    • LJ's Website!
Re: A7 alloy head on A10 barrels?
« Reply #8 on: 14.10. 2009 22:04 »
Even A7 Alloy heads are expensive. Why not get some silver paint and coat the Iron head? Can look very nice, see picture! Talk about mixing and matching... This is an A7 with A10 barrels, goodness knows what else is in there!
Ride Safely Lads! LJ.
**********************
1940 BSA M20 500cc Girder/Rigid- (SOLD)
1947 BSA M21 600cc Girder/Rigid-Green
1949 BSA A7   500cc Girder/Plunger Star Twin-(SOLD)
1953 BSA B33  500cc Teles/Plunger-Maroon
1961 BSA A10  650cc Golden Flash-Blue
1961 BSA A10  650cc Golden Flash-Red

Offline mike667

  • A's Best Friend
  • ***
  • Join Date: Nov 2008
  • Posts: 213
  • Karma: 0
Re: A7 alloy head on A10 barrels?
« Reply #9 on: 14.10. 2009 22:51 »
They don't rust if properly looked after, painted or whatever.

I like 'em rusty - give's e'm that i actually ride look
 - and remember as Mr. Young says "rust never sleeps"

Offline rocket man

  • Valued Contributor
  • ****
  • Join Date: Mar 2009
  • Posts: 466
  • Karma: 2
Re: A7 alloy head on A10 barrels?
« Reply #10 on: 14.10. 2009 22:59 »
it just needs water to grow *smile*

Offline BSA_54A10

  • Wise & Enlightened
  • *
  • Join Date: May 2008
  • Posts: 1981
  • Karma: 32
    • BSA National
Re: A7 alloy head on A10 barrels?
« Reply #11 on: 15.10. 2009 11:14 »
Hey all you catalogue Nazi's, it is his bike and if he want to put an alloy head on it he is entitled to do so with our blessings.
Bike Beesa
Trevor

Offline Jim

  • A's Best Friend
  • ***
  • Join Date: Oct 2009
  • Posts: 35
  • Karma: 2
Re: A7 alloy head on A10 barrels?
« Reply #12 on: 15.10. 2009 11:28 »
Thank you all for your help.

To answer some of your questions:

I'm not about to mess up an original Gold Flash, the bike was bought as a mongrel (e.g. conical hub front end, non standard seat and rear mudguard) and I'm not intending to put her back to standard. The alloy head is for purely cosmetic reasons and A7SS heads seem to be far cheaper on eBay than A10 ones, one recentluy sold for £111 whereas I think you would be hard pushed to get an A10 head for much less than £250.

I'm toying with the idea of putting high level spitfire pipes on her and may put on an old Fleetstar tank that I have lying around.

I'll try an upload a picture of the bike as it is at present but I'm not sure if I have permissions to do so yet.

Wimbledon, England.
BSA A10 x2
BSA B44 x2
BSA B40
BSA A65
TriBSA 500
Buell XB12R

Offline LJ.

  • Peterborough UK.
  • Wise & Enlightened
  • *
  • Join Date: Jun 2006
  • Posts: 1403
  • Karma: 15
  • The Red A10!
    • LJ's Website!
Re: A7 alloy head on A10 barrels?
« Reply #13 on: 15.10. 2009 11:55 »
That indeed is a nice looking bike Jim... The springs on the upper forks give it a real mean look. I can see why you are wanting an alloy head, with most of the bike being black the alloy would stand out rather nicely. Good luck for your search for one!
Ride Safely Lads! LJ.
**********************
1940 BSA M20 500cc Girder/Rigid- (SOLD)
1947 BSA M21 600cc Girder/Rigid-Green
1949 BSA A7   500cc Girder/Plunger Star Twin-(SOLD)
1953 BSA B33  500cc Teles/Plunger-Maroon
1961 BSA A10  650cc Golden Flash-Blue
1961 BSA A10  650cc Golden Flash-Red

Online muskrat

  • Global Moderator
  • Wise & Enlightened
  • **
  • Join Date: Jul 2009
  • Posts: 8168
  • Karma: 106
  • Lake Conjola NSW Oz
    • Shoalhaven Classic Motorcycle Club Inc
Re: A7 alloy head on A10 barrels?
« Reply #14 on: 15.10. 2009 12:02 »
Looks great the way it is. New gaiters and paint or alloy head. The springs between the triple clamps are a little odd, but so am I. Better stopping up front. Good one Jim.
Cheers
'51 A7 plunger, '57 A7SS now A10CR,  '83 CB1100F, 88 FXST .
Australia
Muskys Plunger A7