Z1OwnersClub GB

Thanks to a sharp eyed ZORDED - I now know that my GPZ1100B1 has a Unitrak bottom end in it - KZ10BE engine number.
So now I need to be sure which head it has with it. The bike had the engine assembled in the frame - but I do not know if it was run. So apart from measuring the valve diameters, is there a way to determine which head I have? (Apart from a thick one!)

The Unitrack head has a twin swirl combustion chamber (also known as "Bathtub" ) and the others are plain hemispherical.
If the head is still on then the only other way is to look for the letter "A" stamped in the inlet tracts.
They also have a 13mm under bucket shim set up as std but any head can be converted to that so best to go by the combustion chamber and the letter "A".

Looking at your project thread which shows Unitrack pistons would indicate you also have the head as using an earlier J or B head will cause valve to piston contact due to the differing valve and valve pocket angles.

Thanks Z1015, I can now say that I have a Unitrak cylinderhead to go with my Unitrak bottome end!
I went into the garage and saw that the cylinderhead had the Twin Swirl Combustion chambers and after a bit of further examination found the A stamped into the right hand two inlet tracts - could not see anything in the other two?
But due to your information I am a bit better informed. Thanks.

I have a unitrac bottom end in my B2 with a B2 head on it and it runs fine.
It does have B2 cams in it not unitrac ones.

It is good to know that the B head can be used with a A bottom end without any clearance issues, provided that the correct combination of parts.