12g202
Turbo Mini Forums

yesterday i got a 12g202 head in good nick off a friend of mine.

it is unskimmed and i would like to use it for a project.
I would like to install it on a na 1.0l innocenti engine with powermax pistons


as you can see the exhaust ports on both heads are the same
the only difference is the inlet port and total chamber size

12G202
1 5/32"
29,53mm
1"
25.4mm
26,1cc

12G295
1 7/32"
30.95mm
1"
25.4mm
28,3cc

does anyone have any experience with this?
and will 12g295 valves fit on the 12g202 head when i adjust the inlet ports?

In Short! ................

the 295 head is the one what has nearly! all the work done for you in the factory casting but needs a little more port work etc.... to make a superb head.

the 202 head is simlar but does not have as much work compleated in the factory casting process but....... it can make a storming great head with a little extra work!

the inlet valves wont interchange without machining new seats for the extra valve size you are after .... but thats not it,

you need to alter the combustion chamber to remove the extra material around the valve which is shrouding the oversized valve you plan to fit inorder so it flows correctley and takes advantage of that larger valve

you may need to skim the head also to get the desired CR you are after ?
hope this helps

thanks for the help, i was able to source already some of this info in the yellow bible.

so i am planning to widen the inlet valve and enlarge the chamber according to vizard probably, also skim the head whilst i am at it to get cr down even further. taking into account my pistons are already elevated

There is some knowledge on what to do the 202 on this forum, in fact I think some people rate it above the 295 when worked.

It might be Vegard.

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

www.twin-turbo.co.uk

Rusty by nature

What I've found is that the 202 has a potential to be just as good as a 295. There is material in the right places but it takes a lot of work/time/money. If you're confident in doing it yourself, a 202 will be very good. If you're paying someone to do it, the 295 makes more sense. I've had to do some 202s as three 295s cracked on me and they are becoming scarce.

Have a look here:

http://home.online.no/~lyngset/enginestuff...t=25&pDispType=

Nice link.

Why the smart turbo picture ?

Anything under the blanket ?

Rusty by nature

@advantage, i'm gonna use it on a n/a engine

these are all parts i collected over the years and i want to make something out of it, for street purpouses and on a budget

that's why i want to try to do all the work myself, it would be a great experience and save me a couple of euros

But do you do the machining yourself ?

Enlarging ports and chambers is all I can do so as I said, I'd rather spend 100 quid on a camshaft than on valves and valves seat cuts ...

I think it's more HP per £ spent ...

There is also an issue if using 1275 valves in a 202 head, they are too long (or short, can't remember), you can piss off Vegard !

Rusty by nature