Overbore a 1.1 litre 0.060"?

[peugeotbill]

i'm boring my 1.1 and the machine shop has bored my block, it finally cleaned at .040 before the hone, they're suggesting i go .060. will the block bore that far and what about compression! and will i need to go to a 1.2 headgasket?
bill

[JackJ]

Did you take the new pistons in with you when the block was bored? If not then take a measurement of the bore then see what the measurement is.Then see what the measurement of .040 oversize pistons are.If they are = or close then they should be honed by the machine shop to fit that piston.Usually when they bore a hone should be included.I have not ever seen .060 pistons for a 1.1.The clearance for the piston is usually .005-.008but check the number given with the new pistons.If they think a hone would be more than that I would hone it lightly myself ..I just had a 1.1 block done .010 over with nos Mahle Pistons my dad got in Germanyand thy bored and honed $25 a hole..If they went a hair over that standard- .040 bore size to fix deep scores make them pay for "Total Seal" piston rings which can be custom made for your .040 pistons .oo1 larger outer diameter.They should have stopped right at that critical.040 diameter and then called you if there were any imperfections.Basically sounds like they screwed up.Make them check into the above, or get you another block.pm me if you need more info.

[GTJIM]

Opel list the maximum oversize as .5mm (0.020") and note:

"When honing or boring cylinders, obtain pistons first. Determine piston diameter and rework cylinder bore to size."

"When installing new Opel pistons clearance should be 0.0004" - 0.0008" in bore."

This is VERY tight as the Opel 'Mahle' pistons are hypereutectic and expand very little. Less than one thousandth of an inch!

That being said; several people have bored the 1.1L block to considerably larger oversizes - some as much as 3.2mm (0.125") - and used Vauxhall Viva 1159cc pistons. You may even be able to find some 1.2L pistons in Europe ...

You really have to cut your coat to the cloth available - get pistons first and bore or sleeve the block to suit the pistons you can get.

HTH

[Jinx]

1.1 and 1.2 block are basically the same except for the bore. some people even go for 1.3 displacement but thats the absolute limit.
1.2s pistons are for sale on the german aftermarket (i'm very happy they used the same block until 92 )
here's the most known shop: Krause Rennsporttechnik
(they also have sportpistons which make for 1257cc displacement and 1:9,6 CR)