The BSA A7-A10 Forum

Technical => A7 & A10 Engine => Topic started by: Marc12 on 20.11. 2014 21:37

Title: A10 RGS alloy cilinderhead
Post by: Marc12 on 20.11. 2014 21:37
Can somebody help me with the following: I have an aluminium cilinder head with dual ports (2 carb.). and the following numbers 671106 and J54- AM and RR. Is this a cilinder head of a RGS goldstar replica??
Title: Re: A10 RGS alloy cilinderhead
Post by: chaterlea25 on 20.11. 2014 21:56
Hi Marc
Welcome to the forum ,
This link may help http://atlanticgreen.com/a10dph.htm

John
Title: Re: A10 RGS alloy cilinderhead
Post by: muskrat on 21.11. 2014 08:58
Please correct me if I'm wrong but the heads with the bolt on manifold were called twin carb heads when you used the twin carb manifolds. The unit A50/65's had bolt on manifolds for single carb and splayed ports for twin carbs.
Cheers.
Title: Re: A10 RGS alloy cilinderhead
Post by: Marc12 on 21.11. 2014 18:01
It is still not clear for me. I added a picture Marc
Title: Re: A10 RGS alloy cilinderhead
Post by: Marc12 on 21.11. 2014 18:18
another picture, Marc
Title: Re: A10 RGS alloy cilinderhead
Post by: muskrat on 21.11. 2014 18:44
OK Marc you have a standard (don't think many would call them standard) bolt on manifold/twin carb head. The bottom picture on the atlanticgreen site. Someone has made their own adapter/manifold to take the twin concentrics.
Cheers
Title: Re: A10 RGS alloy cilinderhead
Post by: Marc12 on 21.11. 2014 18:52
Thanks, so it is not a a10 rgs cilinderhead. Does it have any value??
Title: Re: A10 RGS alloy cilinderhead
Post by: muskrat on 21.11. 2014 19:01
The RGS had a normal cast (single carb) manifold head. Your head would be of the batch that was made for the American racing market.
No it's worth nothing, I'll take it  >:D.  ;). The last one I saw on Ebay went for $500 US I think.
If you are building an RGS replica/lookalike, that head would give it that bit more bling.
Cheers
Title: Re: A10 RGS alloy cilinderhead
Post by: Marc12 on 21.11. 2014 19:27
Thanks, the head was on a engine with the following number DA1010863 RGS see picture. I cannot place this number. Is this RGS or??  Marc
Title: Re: A10 RGS alloy cilinderhead
Post by: chaterlea25 on 21.11. 2014 20:11
Hi Marc,
Those cases have been re stamped by someone  *sad2* *sad2*
BSA did not put "RGS" on the engine, someones "flight of fancy"  ??

RGS models are identified by  the frame  and used Super Rocket engines.
These have a D A10 R ***** numbers with usually a smaller HHC nearby

John
Title: Re: A10 RGS alloy cilinderhead
Post by: muskrat on 21.11. 2014 20:15
The plot thickens! Looks like a re-stamp by a previous owner. To my knowledge no motor was stamped RGS at the factory. The 10863 should be stamped where the RGS is. To the unknowing that would seem like the find of the century.
Cheers
John beat me.
Title: Re: A10 RGS alloy cilinderhead
Post by: Beeza on 21.11. 2014 23:03
Sorry about this being my first post, but I couldn't help to add this, it is mine and I have taken the GPs and head off and gone for the single mono.
Hope the photo posting works fingers crossed
Cheers Thomas
Title: Re: A10 RGS alloy cilinderhead
Post by: muskrat on 22.11. 2014 01:41
G'day Beeza  *welcome*.
Very nice looking bike mate. The single mono would be a lit easier to live with on the road. You could have just got a manifold to bolt on instead of changing heads.
Now get over to Bikes, Pictures & Members and give us an intro. We're an inquisitive bunch.
Cheers
Title: Re: A10 RGS alloy cilinderhead
Post by: trevinoz on 28.11. 2014 05:27
Marc,
                 The head is a 1954 Road Rocket type, the date is J54, not sure which month the "J" denotes.
Would have originally have had a manifold 67-1112 on it.

Trev.
Title: Re: A10 RGS alloy cilinderhead
Post by: Beeza on 30.11. 2014 10:55
Marc,
some more pics of the carbs and manifolds. The carbs are what was used on the first of the a65 spitfires and was an option to be sold with the a10 twin carb accessory kit by, I believe some US dealers. Anyhow jetting and timing requires some patience and finding a good set is a miracle.
Title: Re: A10 RGS alloy cilinderhead
Post by: Beeza on 30.11. 2014 11:07
Marc there are two types of manifolds available, there is a billet set you can buy (left manifold) fits the head port and carb inlet size very well and also has a sort of swirl machined in it to aid fuel air flow. Or the cast type (right manifold) which doesn't match either very well, the GP is a bit bigger diameter than the manifold and quite a bit more pricey.
Also a pic of the business side of it all.
Good luck

Thomas
Title: Re: A10 RGS alloy cilinderhead
Post by: lillygunny on 11.01. 2015 01:48
Mike Duckworth writes in "Classic Bike" March 1989, that the RGS had a single Amal Monobloc with optional air filter. The engine numbers have the DA10R prefix, with HHC stamped below the number designating the 8.75:1 high compression engine.
Title: Re: A10 RGS alloy cilinderhead
Post by: Rgs-Bill on 11.01. 2015 20:01
The RGS had a normal cast (single carb) manifold head. Your head would be of the batch that was made for the American racing market.
No it's worth nothing, I'll take it  >:D.  ;). The last one I saw on Ebay went for $500 US I think.
If you are building an RGS replica/lookalike, that head would give it that bit more bling.
Cheers

   The twin carb heads must have come down if you say you saw an e-bay one for $500. U S,    U sure that was not  some other currency, I saw one in U S on Flea Bay it went for $1400.00 U S funds   been several years ago though  ??
Title: Re: A10 RGS alloy cilinderhead
Post by: duTch on 11.01. 2015 21:38

  I would call a head with removable manifold(s) a' twin-port' until the addition of the desired inlet tract(s)/carbie configuration, then it can be a single or twin carb jobbie.....?
Title: Re: A10 RGS alloy cilinderhead
Post by: muskrat on 12.01. 2015 01:12
G'day duTch, you are technically correct. I may be wrong but I think they only left the factory on a bike in '54. From then on only sold to the racers and go fast crew, mainly in the US.
Cheers
Title: Re: A10 RGS alloy cilinderhead
Post by: duTch on 12.01. 2015 11:31

 Yo Musky, I guess I was thinking generically as other makes (weird jappo stuff that my youngster turns up with)have singles with twin-port heads and two carbs, and non-bonny Trihards have bolt ons with splayed in-tracts (Daytona)..all can get a bit confusing unless we have some kind of standard terminology
Title: Re: A10 RGS alloy cilinderhead
Post by: muskrat on 13.01. 2015 04:20
Dreaming *ex*. Their getting dearer though.
http://www.ebay.com.au/itm/BSA-A10-SUPER-ROCKET-FACTORY-RACE-DUAL-CARBURETOR-ALLOY-HEAD-/171639850593?pt=Motorcycles_Parts_Accessories&hash=item27f6884661
Cheers