15 replies to this topic

[Jimmyarm]

Hi All,

Someone in the for sale section has a low mileage, cooper head for sale. Other details are unknown.

As its a 998 head, can I just bolt it on to my std 998 and expect a slight performance increase.

Probably a good idea to ask for the casting no. !

Oh and does £60 sound like fair dos ?


James

[Jammy]

If its a proper Cooper head it will need skimming (if it hasn't been done already) to get the compression right.

It will give a slight performance increase over a standard small bore head.

Check the head number.

[Jimmyarm]

Thanks Jammy, damn your quick !

Will probably get it reconditioned by my local chaps if I go ahead. Any ideas on how much needs skimming off ?

[Jammy]

Thanks Jammy, damn your quick !

Shhhhh, this isn't a reputation I want spread around!

Will probably get it reconditioned by my local chaps if I go ahead. Any ideas on how much needs skimming off ?

Not sure on how much to take it, it needs to be measured and calculated, and I don't have the formulas with me at the mo.

**Edit, found it, the fact that its unleaded might mean its either a late Cooper head (large bore and a lot of work to fit to your 998), or its had hardened valve seats put in it.

[Jimmyarm]

The ad starts with Weber 45 DCOE, it should be at the top as I just posted in there.

Not sure on how much to take it, it needs to be measured and calculated, and I don't have the formulas with me at the mo.

I knew you would say that ! I have the Vizard book at home somewhere so I will try and have a go.

[Jammy]

Sorry, yea, found it now, have edited my last post.

[Jimmyarm]

I guess the casting number will reveal all

[Wil_h]

Yes, you are looking for 12G295. With the right cam, there are better that nay modified closed chamber 998 head.

[Jimmyarm]

Yes, you are looking for 12G295. With the right cam, there are better that nay modified closed chamber 998 head.

Hi Wil, sorry I didnt mention that I am trying to avoid pocketing the block if possible which I believe you have to do with a 295 casting head.

Just want a little bolt on increase for cheapo pennies whilst my 1380 is under construction

Edit, I'm thinking about a 12g940 head arent I ? the 295 is the 998 cooper head..

Edited by Jimmyarm, 27 July 2006 - 10:02 AM.

[Jammy]

Yea, the 12G940 large bore head requires the block pocketing (in most cases). I believe the 12G205 (or was it the 202) is also pretty close to the 295.

[Jimmyarm]

Well after all this, lets hope its a 12G295, then I can get around to fitting the alloy inlet manifold and LCB/freelow manifold, been waiting until I found a new head to do it all at once.

Then its back up to Slarke to see what difference it makes

[Wil_h]

yep 202 is the other one.

[Jimmyarm]

Out of curiosity, does anyone have a rough idea of what bhp/torque gains are likely to be fitting a 12g295 head onto a stg 1 kitted 998 ?

Trying to figure out if its worth doing for the £££'s

Jimmy

[chunkyjh]

No but if you do find out let me know as thats what i'm about to do to mine. Just need the head rebuilding with new valve seats. best of luck with it!

[Wil_h]

I have 998 with a 12G295 and an MG metro cam and stage one(ish) puts out around 60bhp. So maybe 55 without the cam