a beginners question
Turbo Mini Forums

Please be gentle i'm still new to this turbo game.
Ok i have a 1330 block with new aep21253 pistons recently re-bored from 1275 mg metro. Also have a stage 3 head. These pistons i believe are too high compression for a turbo mini. Is this correct? What would be the best thing to do given this setup. I suppose i could try and swap the pistons for somthing with a dish as they are new and never fitted.
Would anymore work need doing to the stage 3 head, which is also brand new.
All this was bought before i got the chance of an mg metro turbo engine to put in my project. I was going to do the normally aspirated upgrade. but now want to use the turbo option.
Would any of the parts i have be suitable?
cheers Paul

"I'll get there in the end"

the pistons can be machined to lower the compression and or the head can be ground out more for the same reason , alternative is a spacer plate with a head gasket either side ,using your pistons(type) and spacerplate limit the power to around 150 max whats the budget and how much power do you want?

150 BHP is the top end of what i want at the moment, so i could use the spacer plate you spoke of. I need to know, do i have to get a spacer plate machined or is it available off the shelf somewhere. We deal with a very good engineering company at work, but i would need some specs to instruct them what to do. Could you let me kow what to tell them.
Is there a down side to using a spacer.
cheers Paul

"I'll get there in the end"

Spacer plate will compromise the valve train geometry of course... I realised this after making a CAD data file of the block face ready for getting some laser cut. Little point in doing it unless we can come up with some cheap pushrods that are around 3-4mm longer than stock 1275 ones...

I get where your coming from with the longer push rods which would make sense if you put a spacer between the block and head.
How easy is the machining of the pistons for an engineering shop? And would this compromise the strength.

"I'll get there in the end"