Author Topic: early A10 rod and head bolts  (Read 2221 times)


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early A10 rod and head bolts
« on: 01.08. 2006 21:45 »
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.

Offline dpaddock

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Re: early A10 rod and head bolts
« Reply #1 on: 29.09. 2006 01:23 »
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?
'57 Spitfire