25 replies to this topic

[mk3 Cooper S]

Other than the obvious what is the difference between 1340 and 1380cc engines- bore or stroke?

thanks

[mini_mad69]

Bore

a 1380 = 73.5mm bore

a 1340 = 72.5mm bore

Both with a 81.3mm stroke

Edited by mini_mad69, 01 December 2012 - 05:33 PM.

[mk3 Cooper S]

Interesting,

It has 73.5 pistons but the block is marked 1340?
Do you know how to identify a turbo block?

[mini_mad69]

I think there might be a number or two different one them. But primarily turbo blocks are the same as any other 1275 block. It's the bits attatched to the turbo motors that are different.

i don't know why it's marked 1340. Possibly bored out to 1340, worn out and then bored again but the number remained?

[Tupers]

A turbo block should be the same as any other 1275 from the same year.

[Guess-Works.com]

A true 1340 is a 73.5mm bore with a short stroke 79mm crank...

What most people call a 1340 nowadays is actually a 1330 +0.060 bore on a standard crank.

Never heard of 72.5mm pistons ???

[mk3 Cooper S]

A true 1340 is a 73.5mm bore with a short stroke 79mm crank...

What most people call a 1340 nowadays is actually a 1330 +0.060 bore on a standard crank.

Never heard of 72.5mm pistons ???

Thats what i recallected about the old skool 1340, it rev'ed harder than a 1380.
Where/what can i get a 79mm crank from?

Yep typo 73.5 hepolite pistons

[Tupers]

Is a 79MM stroke crank not a standard one that's been offset on the big end to take S rods?

[Guess-Works.com]

Is a 79MM stroke crank not a standard one that's been offset on the big end to take S rods?

It is

[mk3 Cooper S]

So it's just a crank grind then? If the rods are on the pistons they must be S ? I shall get some numbers.

[mk3 Cooper S]

Rods are 12G 4114/5 so that does not help.

I am presuming that the block is decked for a 1340?

[The Matt]

It's an offset crank grind yeah. My old man used to run one in his GT back in the 90s and it was a revvy little thing..

[Guess-Works.com]

Rods are 1.75" big ends so not offset ground crank, it's a 1380.

[The Matt]

I meant that the 1340 is an offset ground crank....not this one.

[mk3 Cooper S]

Ther is no crank fitted,
Any ideas of the deck height for both blocks?