6 replies to this topic

[Dylan garbett]

Hi just joined the forum
I’ve bought myself a 1275 gt block which has previously been bored to 1330
The block is now worn but can be saved if bored to 1340
Does anyone know which pistons I need as I have +060 at the moment
Any help would be greatly appreciated
I’m 17 and don’t know so much about these
Thanks Dylan

[DavieW]

The engineering shop that bores your block should be able to tell you what pistons you need and be able to supply them.

[Dusky]

Never seen 1340 pistons.

[MrBounce]

1340 is not a standard engine size but one that was "adopted" by the engine tuning companies. a standard +60 bore gives 1330cc, which is the largest non-offset bore you can do. Really you should be looking to get that block sleeved instead back to 1275cc. You won't notice any difference in power. "More power" for an overbore is more pub talk than anything else. You might get an extra 1bhp on a bigger bore but I bet you wouldn't realise it.

[drydavel7]

Keith Calver has 72.5mm pistons on his site which give something like 1342cc. If your bores aren’t badly worn they’re a good shout. I’ve used them in a race engine and they’ve stood up ok.

 

Dave

[mini13]

Yeah, generally 1330 us referred to as 1340, a true 1340 has a stroked crank.

I would think that you'd likely need to bore to 73mm to get a clean bore

[Pigeonto]

Exactly what I did Dylan, went from 1330 to 1342 using Keith Calver's pistons but beware, they don't have much dish volume so you may need to increase the chamber volumes