Correct valve size???
Turbo Mini Forums

I have a 12G206, from what I gather after reading this site, they are very similar to the 12G295. I was going to order:

C-AEG587 Exhausts (1.040")
C-AEG588 Inlets (1.217”)

From Mini Spares…However, my current valves measure:

Exhaust 1.00”
Inlet 1.159”

The 1.159" inlet valve is way smaller than what all my books say should be in there. It appears the valves that are installed in this head are probably from a 12G202…. Is this even possible without changing the seat? Should I order the smaller inlet valve or the ones the books say should go into this head? ***I am hoping someone more familiar with mini heads can look at the pictures and tell me the inlets look undersized in relation to the exposed seat….

Also, these valve have a single long groove (~3/8”) for the retainer…the valves I was looking at buying have the triple collet…will I still be able to use the same spring caps with new keepers? ....they currently have double springs which I believe is what the 206 had....the 202 had single springs...I think

Edited by Mikes1098 on 23rd Jan, 2008.

you can use 33mm race inlets and 29.5mm race exhaust valves in this head,.... if new seats are cut and valve throats are opend
and the ports are modded as well
de shrouding of the new valves are done also.
head needs skimming to get the desired CR back

i have done a couple last year for peeps on here

theres a lot of work but they make storming heads
to convert you need triple groved caps valves collets

new guides & race springs

Edited by BENROSS on 23rd Jan, 2008.

Just to clarify...when I convert to the triple collet valves, I will not have to replace the spring caps (or "retainers"), I will just have to get triple collet valve caps (or "keepers").

You will have to use the 3collet retainers as well, as the angle is different.
That head looks the way it should in my book.
On my 202 head, I'm using std A+ inlets for exhausts ( These are hardened so can cope) and 31 or 32mm inlets. I get these from frinding down some AEG163 inlets. Fitting big bore valves in small more heads just makes a nightmare of rocker geometry. You need 2mm rocker post spacers and possibly longer pushrods. Don't go crazy on valve sizes, it's good to have something bigger optional next time