9 replies to this topic

[Dave_ravation JB]

i have a 998cc engine in a 1988 mini, i was thinking about getting a stage 3 head for it
and was just wondering first what the power increase would be. would like any help with this as soon as!

Attached Files

•  IMG_11081.jpg   208.68K   4 downloads

[smudger]

depends what you class as a stage 3.

are you going hands dirty or just bolt on?

Think if i remember rightly, Mini Sprocket saying how to fit a 1275 head without pocketing the block.

KC has also said this in a mag feature. Maybe thats something to look at.

[mini93]

i think its all about valve clearances, but i wouldnt trust it, at high revs valve bounce can occur unless strong springs are fitted

[alexcrosse]

usually get double valves springs tho on stage 3. Id always try n get bronze guides and doubles.

[smudger]

its just that so many people have different ideas of what they call stage3 too.

if hands dirty, then cam change would be better(?)

and for bang for pounds, thats better isnt it.

[mini93]

valve bounce can still occur, due to inertia and all that
if you trust enough to not cut away the block dry build it, using moddling clay or somthign similar then turn the engine so the rockers push down the valves, this will squeez the moddling clay then measure how much clearance there is add about 1mm to that to give for valve bounce if its found to touch the block after the 1mm is added i would recess the block (well i would do anyway)

[Car Nation]

ive got a stage 3 head but on a 1293 have 2 really get better rockers etc 2 make more difference i think.
on a 998cc i had put a stage 1 kit from minisport just made it a bit nippier so say bore it out or get a 1275cc engine because a stage 3 aint cheap i think

[Big_Adam]

Dave,

Before you go going for quick go faster think about the bottom end of the engine.

[smudger]

I always sort brakes, suspension and stage1 before looking for power.

better safe than sorry!

[Senile Old Git]

well when I did 998`s I bought two heads from Minispeed, a stage 3 and a stage 4 for each of the cars, the stage 4 did pep the old girl up quite nicely.

I still have them both if you are interested