10 replies to this topic

[MaryQuant88]

Reading 'Hands on tech' Mini Magazine Febuary, they are modifying a 998.
They bolt on a 1275 head and there is no mention of pocketing the block

So will a 1275 head fit straight on? Mini World says otherwise

Mini mag says there will be a 0.042 inch clearence with gasket

Rocker Ratio of 1.22, Is that a standard Rocker?

Very Confusing for me :saywhat:

:wales:

[Bluemini]

All depends, some people say it is possible and other say not. One of the mags did this article last year and pocketed the block.

If you are thinking of doing it yourself then do a trial run first, fitting the head without the gasket then turn the engine by hand and see if you have any issues.

[Dan]

Read the article properly. Calver went to very great lengths to set up the valve clearances in that head including use of a low lift camshaft. Even after measuring carefully and calculating everything he still turned the engine several times by hand with the head simply resting on and used a DTI to check there was enough room left for the gasket to compress. You can't even be sure that every gasket will compress the same amount unless you spend an absolute fortune on formula 1 quality gaskets. You certainly can't just chuck a 1275 head on a small block and hope it'll work 'because you can almost guarantee it won't. With careful, methodical and skilled engine assembly it can be done but the inexperienced shouldn't really try this without proper research and measuring everything 6 or 7 times first (unless you have a very large and heavy wallet).

Edited by Dan, 05 February 2006 - 07:18 PM.

[MaryQuant88]

:gasp: A very large & heavy wallet is something that I havent got at the moment!

So if you say this is no DIY job for the begineer, Can you suggest a cheap engine builder?

:wales:

[Dan]

Cheap and good don't generally go together in engine building. Simon at Morspeed is good and while he's not cheap he won't rip you off. His prices are a lot lower than some others.

[liam_italian]

Build a short stroek engine i say, get it revvin to 10k and u talkin wicked torque, ideal for rallyin!

[Dan]

It's not possible to short stroke any A series block without a 1071 or 970 Cooper S crankshaft which are very very non available. Reproduction ones are really expensive and cut from billet so not as good as a forging. Even at the maximum re-bore and maximum de-stroke of a standard crank a large bore block is still over-square.

Edited by Dan, 06 February 2006 - 02:46 PM.

[MaryQuant88]

Anybody got an idea of how much that 998 rebuild would cost?(The one in the Mini Mag)

Simon at Morspeed is good and while he's not cheap he won't rip you off.

Have you got some contact details? Where is he located?

[Dan]

You're almost talking about a full on race spec for that engine and a very high quality build. I'd say a couple of thousand easily.

Morspeed Performance Tuning, near Leicester.

[liam_italian]

Anybody got an idea of how much that 998 rebuild would cost?(The one in the Mini Mag)

Simon at Morspeed is good and while he's not cheap he won't rip you off.

Have you got some contact details? Where is he located?

Rebuild it yourself, if you get stuck in sure iceman/ woody and the rest of the lads down at Peblic will help you if ya get stuck!

[sirmarky]

I actually fitted a 1275 head on a 998 block in the early 90's !
at the time i did not want to raise my insurance policy costs with a larger engine & decided to carry out this mod after my mate gave me the idea....
i got hold of 2 old 1275 valves , one inlet & one exhaust...
i then fitted the new head onto my 998 block & painted the valve faces on the head (i did not tighten the head down) , i then fitted the pushrods & rockers & rotated the engine 2 turns..
note that i did not fit a head gasket so that the valves actually touched the block face & left a nice paint outline onto it...
once the head was removed i managed to use the old valves in a drill & a tub of valve grinding paste to cut out pockets on the block face.
it took me all day to do this though as i was carfull as not to slip !
anyway , after all that i fitted a 1275 headgasket & built it all up & fitted a 1.75 su carb off of a mg metro.
the result was fairly good , not much more in acceleration power but sheds load more torque , especially low down where as before it was always flat & needed a lower gear change....
i do have pics of this job i did , these are at my parents house ... i will dig them out next time im there & post them up here.
be warned that unless you pocket the block , you will end up with bent valves !

mark