Author Topic: Engine case number  (Read 1912 times)

Offline magicflem

  • A's Best Friend
  • ***
  • Join Date: Jun 2010
  • Posts: 63
  • Karma: 0
  • Sydney NSW Australia
Engine case number
« on: 22.04. 2011 00:32 »
I have come across a right side case with the number 67-1088 cast in it. Can't seem to find it in my parts catalogues. Any help would be appreciated regards year, model etc.
1930 BSA B30-3 Side Valve Girder (being restored)
1955 BSA A10 Road Rocket
1955 BSA A10 Golden Flash
1956 BSA A10 Road Rocket
1951 BSA A10 Golden Flash
1956 BSA DB32 Gold Star Clubman
1958 BSA A10 Super Rocket
1961 BSA C15 (being restored)
1961 BSA C15 Star "America" (being restored)
1961 BSA A10 "Big Valve" Super Rocket (being restored)
1963 BSA A10 Rocket Gold Star

Online trevinoz

  • Newcastle, N.S.W. Australia.
  • Wise & Enlightened
  • *
  • Join Date: Jul 2006
  • Posts: 2877
  • Karma: 67
Re: Engine case number
« Reply #1 on: 22.04. 2011 02:14 »
The casting number is not a part number.
The closest is A7 RH case, 67-1087.

  Trev.

Online trevinoz

  • Newcastle, N.S.W. Australia.
  • Wise & Enlightened
  • *
  • Join Date: Jul 2006
  • Posts: 2877
  • Karma: 67
Re: Engine case number
« Reply #2 on: 22.04. 2011 07:38 »
Further to this, after looking at several sets of cases, the RH side is numbered 67-1088 and the LH is 67-1086.
Same cases for A7 & A10.

                   Trev.


Online bsa-bill

  • Wise & Enlightened
  • *
  • Join Date: Mar 2006
  • Posts: 5413
  • Karma: 61
Re: Engine case number
« Reply #3 on: 22.04. 2011 08:31 »
As has been stated here before the part number is one less than the cast number, don't know if this holds true every time or not
All the best - Bill
1961 Flash - stock, reliable, steady, fantastic for shopping
1959 Rocket Gold Flash - blinged and tarted up  would have seizure if taken to  Tesco

Offline magicflem

  • A's Best Friend
  • ***
  • Join Date: Jun 2010
  • Posts: 63
  • Karma: 0
  • Sydney NSW Australia
Re: Engine case number
« Reply #4 on: 22.04. 2011 08:34 »
Thanks guys.
So I could use this rhs case with the A10 1962 left case that I have.
What are the thoughts on line boring etc to match un-matched cases? worth doing?
1930 BSA B30-3 Side Valve Girder (being restored)
1955 BSA A10 Road Rocket
1955 BSA A10 Golden Flash
1956 BSA A10 Road Rocket
1951 BSA A10 Golden Flash
1956 BSA DB32 Gold Star Clubman
1958 BSA A10 Super Rocket
1961 BSA C15 (being restored)
1961 BSA C15 Star "America" (being restored)
1961 BSA A10 "Big Valve" Super Rocket (being restored)
1963 BSA A10 Rocket Gold Star

Offline Goldy

  • Warwickshire, England
  • Resident Legend
  • *****
  • Join Date: Dec 2008
  • Posts: 619
  • Karma: 9
Re: Engine case number
« Reply #5 on: 22.04. 2011 11:13 »
The problem with unmatched cases is that as you say the bores need to be re aligned but you also have to match the cylinder base and the sump plate. A small amount taken of the face for the sump plate  would not cause any problems but machining the cylinder base would lower the barrels so I don,t know if it,s possible. Need to see if anyone has done this.
56 A10 Golden Flash - Restore, ride, relive.                                          
56 C12 BSA project ongoing

Online muskrat

  • Global Moderator
  • Wise & Enlightened
  • **
  • Join Date: Jul 2009
  • Posts: 8165
  • Karma: 106
  • Lake Conjola NSW Oz
    • Shoalhaven Classic Motorcycle Club Inc
Re: Engine case number
« Reply #6 on: 22.04. 2011 15:28 »
It is possible, if a bit time consuming. I would use the RH case as the reference and machine the LH to suit. A horizontal borer would be my tool of choice. I don't think you would have to take more than 20 thou off the barrel base for even the worst mismatched cases. A thicker gasket or compression plate will take care of that.
On the other hand a set of cases went for $50 US on ebay the other day plus $150 postage to Oz would be cheaper than the machining bill.
Cheers
'51 A7 plunger, '57 A7SS now A10CR,  '83 CB1100F, 88 FXST .
Australia
Muskys Plunger A7

Online muskrat

  • Global Moderator
  • Wise & Enlightened
  • **
  • Join Date: Jul 2009
  • Posts: 8165
  • Karma: 106
  • Lake Conjola NSW Oz
    • Shoalhaven Classic Motorcycle Club Inc
'51 A7 plunger, '57 A7SS now A10CR,  '83 CB1100F, 88 FXST .
Australia
Muskys Plunger A7

Offline magicflem

  • A's Best Friend
  • ***
  • Join Date: Jun 2010
  • Posts: 63
  • Karma: 0
  • Sydney NSW Australia
Re: Engine case number
« Reply #8 on: 27.04. 2011 08:31 »
In the "line bore" exercise would they add a weld inside the LH bearing and bush housing to reduce the id then line bore to match the RH case?
1930 BSA B30-3 Side Valve Girder (being restored)
1955 BSA A10 Road Rocket
1955 BSA A10 Golden Flash
1956 BSA A10 Road Rocket
1951 BSA A10 Golden Flash
1956 BSA DB32 Gold Star Clubman
1958 BSA A10 Super Rocket
1961 BSA C15 (being restored)
1961 BSA C15 Star "America" (being restored)
1961 BSA A10 "Big Valve" Super Rocket (being restored)
1963 BSA A10 Rocket Gold Star

Online muskrat

  • Global Moderator
  • Wise & Enlightened
  • **
  • Join Date: Jul 2009
  • Posts: 8165
  • Karma: 106
  • Lake Conjola NSW Oz
    • Shoalhaven Classic Motorcycle Club Inc
Re: Engine case number
« Reply #9 on: 27.04. 2011 10:43 »
With the cam bush housing a new bush could be made with an undersize ID and line reamed to size. With the main it could be tig welded or bored oversize and a bush made to shrink in then rebored. The reason I would do it all this way is to keep the relationship between the crank, idler and cam pinions. It's been a LONG time since I was a machinist making gearboxes for elevators.
Cheers
'51 A7 plunger, '57 A7SS now A10CR,  '83 CB1100F, 88 FXST .
Australia
Muskys Plunger A7

Offline magicflem

  • A's Best Friend
  • ***
  • Join Date: Jun 2010
  • Posts: 63
  • Karma: 0
  • Sydney NSW Australia
Re: Engine case number
« Reply #10 on: 28.04. 2011 04:39 »
Thankyou to you all.... I will let you know how I get on.
1930 BSA B30-3 Side Valve Girder (being restored)
1955 BSA A10 Road Rocket
1955 BSA A10 Golden Flash
1956 BSA A10 Road Rocket
1951 BSA A10 Golden Flash
1956 BSA DB32 Gold Star Clubman
1958 BSA A10 Super Rocket
1961 BSA C15 (being restored)
1961 BSA C15 Star "America" (being restored)
1961 BSA A10 "Big Valve" Super Rocket (being restored)
1963 BSA A10 Rocket Gold Star