19 replies to this topic

[9FDXEH4]

Hi all!

Can any one give a help?

I´d like to buy a Hillman Imp pistons to convert one 1098 mini engine to a 1250cc's with this pistons +0.030" i think.

Where I can get one set of these pistons (online shop) as I´m from Portugal

Cheers for all mini lovers

[MRA]

And I have just seen that yo umention 1250, this would be 0.040" Imp pistons

[Tupers]

There's a NOS set on eBay USA at the moment, no rings though. Clicky

[Rosslin Racing]

Hi all!

Can any one give a help?

I´d like to buy a Hillman Imp pistons to convert one 1098 mini engine to a 1250cc's with this pistons +0.030" i think.

Where I can get one set of these pistons (online shop) as I´m from Portugal

Cheers for all mini lovers

I just watched Ebay until a set came up they do very often. good luck.

[Spitz]

what do you need to oversize bore the block to to use these pistons? ( I know it says +40...but is that for the IMP or MINI? )

[MRA]

It is +0.040" oversize for the IMP pistons and yes we have them...... brand new not old stock

[Spitz]

Just curious though....what the mini block needs for an overbore to fit these. ( not sure if I'm being clear.....is the stock imp bore the same as stock mini bore? )

[MRA]

I understand......

A 1098 +0.040" Mini pistons = 1132cc
A 1098 +0.040" Imp Pistons = 1251cc

[Spitz]

I understand......

A 1098 +0.040" Mini pistons = 1132cc
A 1098 +0.040" Imp Pistons = 1251cc

Understood ( I have a +40 1098 myself )

...but...again....what would you need to overbore a 1098 to fit +40 IMP pistons to attain 1251cc ?

( my head hurts now )

Edited by Spitz, 07 April 2011 - 05:08 PM.

[JustSteve]

I understand......

A 1098 +0.040" Mini pistons = 1132cc
A 1098 +0.040" Imp Pistons = 1251cc

Understood ( I have a +40 1098 myself )

...but...again....what would you need to overbore a 1098 to fit +40 IMP pistons to attain 1251cc ?

( my head hurts now )

+0.040"!!!

If yours is already over bored to the correct size, that's fine.

What do you not get?

[MRA]

You mean bore size ? well it would have to be approximately 68.966mm, I say approximately because you always bore to the pistons not the percieved size or that which is written on the box.

[Rosslin Racing]

If i remember it works out at +135 using the imp pistons i had.

[Spitz]

If i remember it works out at +135 using the imp pistons i had.

Now that's what I meant.

[MRA]

That would be a 1215cc on std Imp Pistons.... on +0.040" it would be 0.1727"

1215cc = +0.132 ish...

Edited by mra-minis.co.uk, 07 April 2011 - 06:38 PM.

[Spitz]

So to clarify.
To fit the +.040 IMP pistons to a MINI block....the MINI block needs to be bored ~+.135

meaning the IMP bore is larger to begin with...which was my original query.

( I took an Aspirin )