16 replies to this topic

[cornflakes5210]

hi im wondering if a cooper s carb 3/4 will fit on a 998 amd would it be beneficial?

[The Matt]

I think the Cooper S came with twin HS4's (1.5") not HS6 (1.75"). Unless you mean a later Cooper (mainstream) from the '90s?

Either way, it's a bit overkill for a 998 unless it's gome some other mods to go with it (BIG valve head, wild cam etc). I'd think you'd be better with a decent HIF38 jetted to suit your application. A carb itself doesn't really improve performanve that much on a car, it just allows the engine to suck in enough fuel and air for it to operate to its potential.

[cornflakes5210]

ok thanks will go looking for a HIF38 now would i be able to put that on and go? or will it require mods im not very technical minded.

[Big_Adam]

why not modify the carb for more flow. get bloody good flow rates with a bit of tweaking.

[cornflakes5210]

OOOHHH THERES A 12G195 head on ebay might watch that and may make a bid dont know yet ill see if the bank allows.

[cornflakes5210]

12g295

[The Matt]

haaaaaaaaaaaang on a sec.

Before you go spending your hard earned moolar. You may already have a decent carb on there???? What model is it your Min and what age?

Dunno much about the 12G295 heads, but I believe they are not just a bolt on mod, I think they have a failry big combustion chamber in them to allow for different pistons. Again, this is totally from memory of what I think I have read, but I think you'd have compression ratio issues if you just bolted a 12G295 straight on a normal 998 bottom end.

[cornflakes5210]

UM THE MODEL NOT HUNDRED PERCENT SURE THINK ITS A CITY OOPS CAPS. 1982 um will have to look at the log book to find out the proper model. i thought the 12G295 was on 998 coopers so i thought would be a good investment. oh well im not an expert.

[The Matt]

UM THE MODEL NOT HUNDRED PERCENT SURE THINK ITS A CITY OOPS CAPS. 1982 um will have to look at the log book to find out the proper model. i thought the 12G295 was on 998 coopers so i thought would be a good investment. oh well im not an expert.

Nor me, not by any means, I just think that one of the Cooper heads had mahooosive chambers in it to allow for different pistons (raised crown, rather than dished), which would mean that putting it straight onto a normal 998 would give you really low compression ratio. I think that head is the 12G295, but again, I aint certain. Just didn't want you to go spending yer money on something that wouldn't suit your engine.

Alot of people say to go with the 12G940 (1275) head and a pocketed block on 998s, this seems like a good option!

[cornflakes5210]

im not sure getting more confused by the second lol where are those geniuses when you need them i will keep the money in my pocket for now.

[Big_Adam]

CF man,

If you send your carb my way I can half the spindle and put some stubby screws in the spindle. Gets a nice chunk of airflow then. Means you would have to get a different needle but does work really well.

[Jimmyarm]

Fitting a 12g295 is a hell of a lot easier than fitting a 12g940, it needs skimming to get the CR right but thats it compared to having the block pocketed, messing about with the heater fee and possibly grinding down the water pump with the 12g940 conversion.

If your fitting a second hand head its good practice to have it skimmed anyway to make sure its flat

[cornflakes5210]

right then so the 12G295 would be better for me cool how much do they go for as i dont want to go bidding to much plus i have to drive to north england to fetch it boohoo.

[Big_Adam]

on flebay they norally go for anywere between £40 to £150 (had the words cooper in the title = lots of money) as I tryed to get one from there. Getting one from a nice chap here for £200 ish as its already unleaded.

If you want a little more speed clean your current head of C**p. Makes a hell of a difference.

[cornflakes5210]

i just want a nice tuned up mini not crazy technical C**p as the missus uses it everyday and she just wants some oomph!! hmm.. is it easy to take the head off? as ive never ventured further than taking the radiator out lol.