Refurbing Cooper Head
Turbo Mini Forums

Hi, i have a rolling road session on weds, and want to get my cooper (12G295) head on before it so the custom needle i get will be configured for the head as well as the stage 1 kit.

However its not in amazing condition to say the least. ive taken to it with a wire brush etc, but the inside of the ports looks rusty and covered in black soot, and i cant get to it.

Will this make much difference to the running of the engine if i get all the dust out but leave the rust?

If it will, what do you suggest doing? getting a professional refurb? i hear there are some people on here who know what they're doing with this sort of thing.

Cheers,

Mike

http://www.turbominis.co.uk/forums/index.p...tid=469104&fr=0

Get some flap wheels, you should be able to clean most of the crud out.

Something like this

http://www.google.co.uk/products/catalog?h...ed=0CGsQ8gIwAA#

I'd be more worried about the condition of the valves & seats. Unless you're very lucky, oversize valves have been fitted or hardened ex seats, then you'll probably find the seats are shot. Nearly every head of this type I've come accross has had this problem.
You'll also need to consider the chamber size. Depending on what pistons you're using & if the head's been skimmed or not you may find the compression ratio is far to low.

Phil.

WWW.TURBO-MINI.COM

so how would i tell what condition the valves/seats are? and the 12G295 had standard oversize inlet valves?

Would it be best to wait until i get the rest of the turbo parts and do it then because of the compression ratio?

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Take the valves out and look at the valve and seat. Damage is obvious.

Like Andy said, strip it & have a proper look, chances are the guides could be shot to.

Phil.

WWW.TURBO-MINI.COM

I'm not 100% sure on this, but if you bung an unskimmed 295 on an n/a 998 it may drive like shit due to the lack of compression. 998's aren't that good at keeping up with traffic even when they are okay imo.

Okay, valve guides and seats look suprisingly solid, only the 'o' ring seals are shot, and I have a new set of them.

I think that is going to be the issue, as it is an unskimmed one because it is for my turbo build.

Looks like I might just wait until i have the rest of the bits for the turbo build before I fit it? As it doesn't sound like it will be beneficial...

Cheers for the help

http://www.turbominis.co.uk/forums/index.p...tid=469104&fr=0

I thought the 12G295 was the cooper head off a 998? So surely it would be fine on a 998 block?

http://www.turbominis.co.uk/forums/index.p...tid=469104&fr=0

The chambers are too big, if i remember rightly the cooper 998 had pistons which have a raised crown.
'the standard head has a capacity of 24.2cc, the Cooper heads 28.4cc'

Edited by Carlzilla on 4th Feb, 2012.

It is. Different pistons though

It will be fine at 9:1 compression ratio with the 12G295 head on. Just a little less torque.

I drove mine like that for a year before fitting the turbo.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Ahh fair enough, so what would you reccomend in terms of performance/economy?
-fit the head and get a needle to suit head a stage 1
-fit the head with the rest of the turbo upgrades

Cheers

http://www.turbominis.co.uk/forums/index.p...tid=469104&fr=0

Rusty by nature

Well i've just fitted a stage 1 kit, and was told that it wont run perfectly until i get a proper needle for it (I have a BDL at present i believe).

And i was going to get it set up now, as i expected it to be a while until i had all the parts for the build. Just got word that i get a schollarship bursary from uni for £1000 though, so i think i am going to wait until i have the turbo on to get it set up, it's not too bad at the moment, just a little thirsty.

Surely changing the head will mean i'll need to get another needle? which would be my best bet until i get the rest of the turbo stuff on?

Thanks for the help by the way, slowly getting my head around all this turbo lark..

http://www.turbominis.co.uk/forums/index.p...tid=469104&fr=0

Get yourself a wideband lambda system and some small files. Tune it yourself and learn loads. All ready for the Turbo.

http://www.twin-turbo.co.uk
http://www.hillclimbandsprint.co.uk/default.asp

A man without a project is like a like a woman without a shopping list.

Hadn't thought about doing it myself, forgot that you dont need a rolling road.

Just had a look at the prices though, and its pretty dear, the proper ones look to be about 160-200. The gauges are a bit cheaper. What would i need to get started?

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The AEM wideband seems to be about the best for the money.

WWW.TURBO-MINI.COM

Thanks for that phil, looks like a much better idea than the £200 ones from trigger wheels. I think i'll invest in one.

How easy is it to use to profile needles? surely it involves a lot of stopping and starting?

http://www.turbominis.co.uk/forums/index.p...tid=469104&fr=0

There's a thread with detailed explanation on here.

I cant remember the title, Have a search.

In the 13's at last!.. Just

Is this the one you mean?
http://www.turbominis.co.uk/forums/index.php?p=vt&tid=159683

I just don't get how you can see the piston damper indicator position while driving? unless you drive around with the bonnet off?

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