Z1OwnersClub GB

Posted: **Sat Jan 07, 2012 10:59 pm**

hi all
i am doing a project on my 1170 and have read and heard of cylinder head swapping
what head is going to give me the most power ?
a gpz 1100 B1 or B2 or
unitrak gpz 1100 A1,A2 or A3

what is the best head to go for
as far as i know it is a gpz1100 motor A2 but not sure as is a Z1000 mk II i have

but want to get most power i can out of the motor.
many thanks

Posted: **Sun Jan 08, 2012 1:22 am**

You have 1170 then it is a 'j' style motor ?.
Gpz unitrac head with twin swirl combustion chamber (widely known as bathtub) is deemed to be the best. (And most sought after in racing circles)
These have a steeper valve angle to accomodate the fittment of bigger valves as std.
You will need to play with pistons etc to get correct compression ration as the combustion chambers have greater volume.
I would go for a 'J' head and have work done to that.
You will hardly tell the difference on the street.

Posted: **Sun Jan 08, 2012 1:40 am**

hi i all ready have the head but not sure what model it is off i will take some pictures Monday see if any one can help just wanted to know what was best one ie the A1, A2 or A3 if there was any advantage as thought would get head work done on the best head i can get hold of

Posted: **Sun Jan 08, 2012 1:51 am**

Post pic's of the combustion chambers.
Will know instantly what head it is,
Apart from the unitrac (bathtub) all other 'J' style heads are more or less the same.

Z1OwnersClub GB

Cylinder Head Help

Cylinder Head Help