2 replies to this topic

[Mini118118]

Hi one and all, I have put a few posts on here over the last few weeks and have read through some topics, Can anyone tell me what i need to tell my local Machine shop to offset a 1275cc block up to 1380cc, Apparently bores 1+2 and 3+4 are bored as pairs. Can anyone advise thanks

[Guess-Works.com]

I use the following, with the block arranged with bore 4 on the left and bore 1 on the right

Bores 1 & 2, 0.015" to the right and 0.010" to the rear

Bores 3 & 4. 0.015" to the left and 0.010" to the rear

Actually the offsets for using old triumph 74.7mm pistons, but works well for the smaller 73mm pistons, in fact worth doing at + 60

[ACDodd]

I offset each pair outwards from the centre by between 0.010 and 0.015" depending on the original centres.

AC