recommendations for torque wrench pls

[Bob Culver]

No, no, no!
One of the Club site recommendations is/was grossly wrong . Even 25 for original b.es. very high. Most original show stretched threads.
Refer any source for normal hardware carbon steel HT bolts. Original ones in car probably not much superior.
For other makes with far heavier pistons and 5/16 16 to 21 ib ft was recommended. What the racers care to do with exotic screws is another matter.
The saga of broken studs is considerable.
Excessive head stud tension distorts valve seats, contributes to block cracks.
Like valve compressors there must be myriads about from the days when everyone worked on cars and now very few.

[Chris KC]

I would suggest 20lbft (cold) for head nuts.
As a point of reference, the recommended torque for side-valve Reliant rods was 18lbft, though I use 22lbft on mine, which are slightly modified.
I use 30lbft on centre main bolts (modified a la Rolt/ Wheaton/ Hastings and others).
Both the latter with lightly oiled threads.

Jon, I'd say 50Nm is a good size, accuracy will be better than a larger wrench. Get a girt big spanner for your flywheel.

[andrew34ruby]

I have never used a torque wrench for any engine assembly, seven or otherwise. And I guess that very few garages did in the thirties, or even the fifties and sixties.

[Chris KC]

I have never used a torque wrench for any engine assembly, seven or otherwise. And I guess that very few garages did in the thirties, or even the fifties and sixties.

That may in part explain why bits were forever falling off cars before the 70's!