Author Topic: Conrod identification  (Read 1365 times)

Offline rustedshut

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Conrod identification
« 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

Online KiwiGF

  • Last had an A10 in 1976, in 2011 it was time for my 2nd one. It was the project from HELL (but I learned a lot....)
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Re: Conrod identification
« Reply #1 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
New Zealand

1956 A10 Golden Flash (1st finished project)

1949 B31 rigid “400cc hot rod” (2nd finished project, + favourite bike)

1949 C11 rigid, but why!!! (cos it was cheap)

1937 B21, project missing parts, mission impossible?

GL1800 Goldwing, well, the wife likes it

KTM 950 ADV, cos it’s 100% nuts

1952 Armstrong Siddeley Whitley for rainy days (with wife

Offline terryk

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Re: Conrod identification
« Reply #2 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.
1950-53 A10 rigid/plungers, 1958-61 A10 super rockets, 1947-50 A7 longstrokes, 1949 Star twin,
1951-54 A7 plungers, 1940s M21, WDM20s,
1948-50s B33s rigid/plunger/swingarm, 1948-50s b31s rigid/plunger/swingarm

Offline Goldy

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Re: Conrod identification
« Reply #3 on: 29.08. 2011 15:15 »
The main thing is to check the centres. A7 are 6" and A10 6.468".
56 A10 Golden Flash - Restore, ride, relive.                                          
56 C12 BSA project ongoing

Offline rustedshut

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Re: Conrod identification
« Reply #4 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.

Offline muskrat

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Re: Conrod identification
« Reply #5 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.
'51 A7 plunger, '57 A7SS now A10CR,  '83 CB1100F, 88 FXST .
Australia
Muskys Plunger A7