centre main strap

[Dean]

Hello

i am rebuilding a 1071 S engine and was thinking of fitting a centre main strap, but the 1275 straps say not for cooper s
and the others are only for 850/998/1098

so a few questions

is it worth fitting one?
who sells centre main straps for cooper s blocks
how have others do it.

i don't want to go down the 4 bolt route due to having to have the cap line bored ,just to much expense when its not a race engine

thanks Dean

[ivor badger 2]

Not worth fitting as the S has a decent quality bearing cap from new and you are highly unlikely to break it, especially as a road engine.

[John Bull]

I agree with Ivor B 2 to a point. The S centre cap is pretty strong. Having said that, some 35 years ago when I built the 1480 engine I am still running today, I did put a solid centre bearing cap, and believe it or not, I didn't even line bore the block ..... and 35 years down the road, hours of hill climbs and circuit racing later, it has still to show signs of centre main shell wear.

The way I did it was to machine the bearing cap to be tight, and shim it when assembling so that the crank turns smoothly without being too tight or too lose. It has worked faultlessly. In fact I pulled the caps out when dismantling yesterday, and after 4 circuit meetings I won't even be changing shells.

[mk1]

I would never bother putting a centre main strap on a 1071.

It is totally unnecessary.