First service

[jhg1958]

Finally I have started the first service on my S/A A10.  I have done about 300 miles.  I put a cartridge filter on and on removal and cutting open there was nothing of note. So I am happy with that.  I have a lot of niggles to sort out and that is probably why I have been concentrating on my Triumph rather than the A10.

I was wondering if I need to retighten the cylinder heads?  If I do I assume I need to take off the rocker box.

John

[limeyrob]

Iron or ally head?  I do tend to re-torque heads after a few 100 miles but it is a right faff.  Still its only once and it does give you peace of mind that the gasket is clamped.

[Billybream]

It's one of those jobs that's recommended but is it really necessary on the iron head, if there,s no visible signs of leakage around the gasket and the tappet settings are unaltered I would not bother. To retorque its the tank off, rocker box off etc, then the delight of reassembly.
I have always torqued the head bolts, left 24hrs then checked before assembly of rocker box

[Rex]

I've done this irritating check and tighten-down twice on my iron-headed A7 (once after the head gasket blew, then again after the replacement head gasket had been fitted for a while) and it was needed too. The head bolts were relatively slack so well-worth doing.

[rocker21]

i fitted a carbon fiber head gasket , no need to torque it again,  fit it torque it down, leave overnight and recheck, it probably wont need doing, checked after 1000 miles should not have bothered , it had not moved, been like that for the last 3 years and no leaks.

[Black Sheep]

Glad your carbon head gasket is holding fine. Mine failed after 8 gentle miles. The replacement copper one is doing just fine.

[jhg1958]

Well after reading the advice here I took the plunge and decided to tighten down the head even though there was sign of leaking.  I have an oil leak on one of the rocker spindle feeds.  The thread is dodgy as some ham fisted PO has over tightened it and damage the thread. I bought a spare rocker cover C/W spindles when I realised this, but too late to change it over so I just tightened it as much as possible - it leaked. Not sure I was too tempted to buy one form SRM at £70 each.

Anyway, I was looking for torque setting for the head bolts and of course BSA did not provide any (bless em). A quick internet search suggested 30 to 35 ft/lbs.  I paid someone I could rely on for the engine block to be refurbished and assembled, so I do not know what he used.  I decided to check the torque on one bolt raising the torque wrench settings until I got some movement.  This was at 22 ft/lbs.  I set to work on the rest tightening them down to 22ft/lbs. Three of the bolts were already at or higher than this torque, the rest moved no more than 1/8 turn.

Should I go back and tighten them down to a higher torque?  I am always concerned about stripping the bolts out of the block and what a disaster that would be.

Just waiting on a pushrod comb to help return the rocker box in the right place.

Would it be possible to helicoil the rocker box spindle? It is into steel so not an easy task.  If so any recommendations?  I was unhappy about the replacement spindle it has obviously been standing somewhere damp.

John
     

[limeyrob]

I would (will soon be!) torque to the SRM figure of 32 lb ft.  That's not unreasonable for the tread size.  The slightly larger head bolts on my Perkins are 80 lb ft.
Take a close look at at where the leak is on the spindle as these don't need to be very tight.  There may be a poor fit or burr.  For some situations I've replaced the fibre washer with an o ring.  Sometimes works.  Heli-coiling steel is no problem, but this will be an imperial thread so you may have to search a bit for the right kit.

[Rex]

Yes, I used that figure too, though it was nerve-wracking cranking it up to that figure.
Luckily the headbolts were BSA originals so good metallurgy, unlike unknown Taiwan/Indian repro crap.