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Author Topic: early A10 rod and head bolts  (Read 1101 times)
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pooch
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« on: 01.08. 2006 22:45 »

 Gday,
About to reassemble engine.

51 small journal/small fin thin flange barrel.

From BSA service sheet 208, I see that it has 2 torque settings depending on whether 22 or 26 TPI of 10 and 8.5 ft lbs.

It says later bolts can be fitted to early rods.

Also says after 1956 it is 22 ft lbs.

I am presuming that it means after 1956, this is the big journal rod , does it have larger bolts?

Haynes says after 1953.

Both service sheet and haynes have no headbolt torque setting.

Bsa 208 even goes to say "make them really tight".

Mewonders how tight is really tight?

Can anyone enlighten me as to the diameter of a post 53 or 56 rod, just so I am sure it can or cannot fit the earlier rod, so all I have to,  do is check whether 22 or 26, and the headbolt settings.
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« Reply #1 on: 09.08. 2006 23:18 »

Hello, have gone for 32lb\ft with no problems, suppose this equals "really tight", tightening in the correct sequence, fingertight first then max 5 lb\ft at the time. Retighten is good after  "some" miles to compensate for compression of the copper gasket. No idea of my bolts' tpi. Some info here http://www.audioworld.net/BSA/head.htm

Hope this helps
Regards

Erling
A10gf 53
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...making things complicated is simple, making them simple is complicated
dpaddock
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« Reply #2 on: 29.09. 2006 02:23 »

Head bolts are 22 TPI (BSF). Go for 40 ft lb in 3 ft lb increments, using thread lube and thick (1/16 inch) hardened flat washers.  I suggest you chase the bolt holes beforehand and blow them out. You do have the factory bolt tightening pattern, yes?
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David
'57 Spitfire

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