maximum valve insert size .....?
Turbo Mini Forums

Just wondering what is the maximum valve sizes you can have unleaded inserts for ?
on the 12G940 head.
Any one ?
THANKS
BENROSS:

I think that a 36 x 31 valve size head is about as big as you can go and still have unleaded seats? I have had a 36 x 31 head in the past with unleaded inserts, I think it was a Minisport head?

My avonbar turbo head (unleaded) has MG 1.4" (35.5) Inlet valves and std turbo (29mm I think?) Exhaust valves.

If you're using 31mm exhaust valves, I would NOT reccomend a bigger inlet than 35,6 without offsetting. It just gets too thin. Remember all the heat a turbo creates around the exhaust valve seats.

You can have unmleaded seats in any size you want. Just make them yourself in a lathe.

TOM & VEGARD.
Thanks:
I was wondering what the speed equipment shops produced ?
Anything?s possible but there are limits!, which I don?t want to fall into that trap.
Better to seek advice of someone who has been there, than make an expensive learning curve.
It?s the valve seat inserts I was wondering which sizes are currently available?
Could machine some but times precious at the moment.
Know one knows it all.


THANKS GUYS
BENROSS:

Minispares to them in 29,4 I guess you could use a 31 in them as well, at least 30mm (available from swifty, or do your own out of 31s), but the easiest would be do deliver the head to some of the specialists and have it all done including the seats.

thats the way iam going to go Vegard,
thanks for the advice guys.