Going to order some hypatech pistons +.120, does anyone know a part number?

Also can someone point me in the right direction for what kind of compression I should be aiming for for a +120 998 block with an SC12, and perhaps a copy of the stroke/bore table with the listed capacities.

While I'm at it, Ive got 7.5" disks single pot; How crazy would I be to not run a booster with this set up?

CR depends on what boost level you`re looking at using (in combination with what ignition advance you intend)

brake booster is not needed

_________________
No offence intended here but--> anyone writing a book about minis 30 years ago may not have experienced such worn or stuffed-with components as we are finding these days.

You should put your heart & soul into everything you do.

Where can I get gasket kits for a bmw head, I want a top end rebuild kit but not even bmw make them anymore, apparently.

Ask around at bike repair shops, or even cylinder head reconditioners, as they can usually supply gasket sets

How would one go about making valve stem seals and the like?

If you can't find any aftermarket seals then im sure you could find another make that will do the job. TheMiniMan or other people on here may know more. Otherwise ask a cylinder head shop.

i`m not sure what you mean about wanting a BMW top end gasket set,,, we use a modified mini head gasket (or have one made) & valve stem seals are available at BMW bike shops

there are no other "top-end" gaskets you need unless you`ve busted or lost the cam cover seal,,, but you can just buy them too

_________________
No offence intended here but--> anyone writing a book about minis 30 years ago may not have experienced such worn or stuffed-with components as we are finding these days.

You should put your heart & soul into everything you do.

Okay been learning a fair bit.

Ive decided to go with +94 hypatec pistons for my 1100s sourced 1275.

What stroking options do I have and which crank should be fitted to an 1100s
(haven't had time to pull it down yet)

Finally will standard conrods be up to the task in my proposed twin cam engine?, depending on what I work out the comp ratio to be I may be looking at up to 10psi.

Kirby, hipertechs will be fine up to 12 or 15psi

you can fit a stroker crank ,.. 84mm would be the max that i`d use, but be careful & work out the compression ratio first ,, as you may end up too high for turbo application as you can`t just happily take heaps off the top of the piston to lower the comp ratio, there is a only so much metal above the rings ,,, the safe limit there would be to leave about 5mm above the top ring... so removing metal from the combustion chamber would be (or rather "maybe) needed... do some homework with measuring things up first

& if you do choose to go the stroker crank route then "S" rods (narrowed to suit the stroker crank) will be fine

or you could opt for aftermarket "H"-beam rods if you like spending money & adding more confidence

_________________
No offence intended here but--> anyone writing a book about minis 30 years ago may not have experienced such worn or stuffed-with components as we are finding these days.

You should put your heart & soul into everything you do.

Hi Matt, I thought some of the Mini places in the UK selling K conversion stuff were selling custom made head gaskets of differing thicknesses to adjust the CR.

Is this a bodge (like fitting a decompression plate) or an effective way to adjust the CR if required.

Cheers.

_________________
1970 Mini Deluxe - 1275, Weber, Clive 346 cam, MS 4-pot slotted discs, Megajolt ignition Now with new improved Mambas... almost on the road
1966 Van with Traveller rear seat conversion
2008 Prado GXL
All in various states of repair...

that`s fine, (if you want/need to do something like that) we certainly havn`t needed to so far, , , we simply use a BK450 Payen 1275 mini head gasket, modify it a bit, & set the comp ratio by lopping some off the pistons for turbo applications

if you need more volume then some can be taken out of the chambers in the head

but why i said what i said earlier is that it`s best to work it all out before you do anything, that way you can make a plan of attack & you shouldn`t have any dramas

those English gaskets are VERY expensive

_________________
No offence intended here but--> anyone writing a book about minis 30 years ago may not have experienced such worn or stuffed-with components as we are finding these days.

You should put your heart & soul into everything you do.

You wouldn't happen to know the standard cc of an 8v bmw head would you there matt?

8v is 21cc

16v is 28cc

_________________
No offence intended here but--> anyone writing a book about minis 30 years ago may not have experienced such worn or stuffed-with components as we are finding these days.

You should put your heart & soul into everything you do.

Precision int is stuffing me around, what do people usually pay for a set of hypatec pistons?

http://www.minisport.com.au/category5_1.htm
Or try Lindsay at Minis Plus.

_________________
DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.