The BSA A7-A10 Forum

Technical (Descriptive Topic Titles - Stay on Topic) => A7 & A10 Engine => Topic started by: rustedshut on 27.08. 2011 07:00

Title: Conrod identification
Post by: rustedshut on 27.08. 2011 07:00

Gday all,
            Been a while but ive got a question,I cant seem to find these con rod part numbers anywhere in my A model 49-53 parts book.
      They were fitted to my 51 aa7. I just want to check to see they are right ones. (see attached pics)
   Thanks for any help.
  Cheers Rusted

Title: Re: Conrod identification
Post by: KiwiGF on 27.08. 2011 11:06

Hi the numbers are casting numbers not part nos the part nos are generally "close" in sequence to the part nos tho.....

After much thought I recently bought some billet rods rather than refurb my old a10 rods at a cost of  550nzd delivered nz versus 200nzd to peen/size the old ones and

the new ones look great compared to the oem rods!

I'm not sure if a7 billet rods are available tho

Title: Re: Conrod identification
Post by: terryk on 29.08. 2011 04:20

Yes they are A7 rods by those numbers the A10 are 67-270 from memory Im not in my shed to confirm but I have a box full of A7 and A10 rods.

Title: Re: Conrod identification
Post by: Goldy on 29.08. 2011 15:15

The main thing is to check the centres. A7 are 6" and A10 6.468".

Title: Re: Conrod identification
Post by: rustedshut on 31.08. 2011 08:24

Hi Guys thanks for the help.
Im sure now that Ive got the right con rods.
  I can rule that out as a cause  of my problem,  "pistons touching valves".  Can now only be pistons.
 Thanks again ,
 Rusted.

Title: Re: Conrod identification
Post by: muskrat on 31.08. 2011 10:21

G'day Rusted,
                  could be that PO had skimmed a little too much of the head or barrels, or you have the wrong (different breed) pistons. A wild cam, weak valve springs & high revs, or sticky valves could also be to blame.
 I had to run two spark plug washers to stop the slugs closing the gap up on the racer  *eek*
Cheers.