Z1OwnersClub GB

Bit confused over the 1100 cylinder heads? Most seem to think the unitrak head is the one to go for,hand finished ports and steeper valve angles.
How do they differ?B1,B2 and unitrak?What about the shaft drive heads ?
Did Kawasaki really make different heads for these models?

B1 and B2 are the same apart from the B1 having the injection inlet cast into the head.
The B2 has slightly more lift on the cams,same as the Z1000R2 Lawson.
The uni-trak is shim under bucket and has different shape combustion chambers to the 1000J/GPz1100B heads.
Think the valves are a touch bigger and the cams have more lift
Have a word with Big Green Brad Pitt for more kosher s.p.

the uni-trac head is the last in the line with the most developement and much better cams (ask anybody who has rode a B2 and a uni-trac) the uni-trac is much more "camier" (not sure if that is a real word) and a much quicker. there is a problem swopping heads, but i cannot remember which way the swop is. Ray or Steve Debben would be the one to ask. jack is right the uni-trac has bigger valves. None of the heads were hand finished, production requirements at the factory would not allow this.

Thanks for info,anymore always welcome.

Just fitting a Unitrak head to my J1.
See post lower down.
Have had it bored to 1170 and fitting the head involves machining back the valve cut-aways in the piston crowns because the exhaust valves are more 'stood-up'.

1100 unitrak valves are larger. Unitrak cams are higher lift and unitrak cams are longer duration than their forebears.

Unitrak cams in a J1 head... hit the tops of the bucket wells and the unitrak head is; factory milled out in this area to allow for the clearance of greater lift from the larger (taller) lobes.

Inlet and exhaust ports look identical to the J head but havent measured them so cant say for certain. Having said that the two halves of the casting are a great deal better matched in the later head than my early J1 and this is evident when you look inside the inlet ports.

What did confuse me was that the inlet ports have the letter 'A' stamped purposefully and deeply, just inside which suggests that something marks them out as being different but i dont know what yet.

Cams for the later Unitrak appear to be R1, R3, R5, and R7. I have R3 and R7 but i dont know what this refers to either. Possibly class of fit, concentricity, or accuracy or diametricity of opposition of lobage, goodness knows!

I did measure the CC of the combustion chambers of both the 1100 Unitrak and J1 heads recently but cant for the life of me remember what the shift was between the two.
My purpose was comparitive between volumetric values of chambers in the same head as opposed to comparisons between the two heads if you see what i mean.

Combustion chambers on the Unitrak 1100 have the bi-spherical hemispheres cast in from factory. These inclusions are designed to assist with the squish function of compression and combustion but for the explaination you need to speak to Ray Debben or Steve Debben. This is where it runs out for me i'm afraid.

The only other difference in this particular comparison is that the J1 is shim over and of course the Unitrak is shim under. Bugger that makes my shim tool redundant.

There is another matter that might be worth mentioning her. The J motor has a slightly different deck height to the Unitrak motor. At this tim i have not managed to work out whether this is a slightly longer throw on the crank or a shallower barrell.
When i work it out i will post it here also.
Its worth considering because if like me you are grafting an 1200 top end to a thou motor, compression ratio, piston to head clearance, and valve cut-aways all need to be given some thought.

If your doing it at home can i suggest that you place a sausage of blue-tack or plasticine across the crown of the pistons (fore and aft) and turn it over slowly by hand. If somethings going to hit you will have the cushion of the goo but more importantly you should be able to see if you are close enough for concerns when dialling in the cams.

As you say any further info would be appreciated here.



AL

Al,the difference in block height is due to the different piston wrist pin size.
Uni-trak/Z1100R have 18mm pins,the Z1000J/GPz1100B are 17mm.

Yeah. Unitrak barrels are about 1mm longer - allegedly.


AL, I have 1170 Unitrak barrels on the Lawson, & it runs...

As the Wiseco's are the hi-comp ones with big valve recesses, I should have loads of clearance & a slightly reduced comp ratio, so hopefully no pinking

If I want to up the comp ratio in future, I can get skimming

zorded wrote:Cams for the later Unitrak appear to be R1, R3, R5, and R7. I have R3 and R7 but i dont know what this refers to either. Possibly class of fit, concentricity, or accuracy or diametricity of opposition of lobage, goodness knows!

A similar question was asked on the 750turbo.com site as the turbo cams have similar markings but no difference in measurements were identified. It's possible that these markings are to identify the individual dies that the cams were cast/ forged (not sure which). So that if there was a manufacturing problem with a batch of cams the problem could be narrowed down to an individual production line. Don't take this as gospel though. It was only the conclusion of the members as the cams with differing numbers didn't have any differences in measurements.

Thanks chaps thats very interesting. What i did notice with mine are that they both appear to have the same manufacturing fault (if it is a fault) but have different numbers on them.
Thats got me thinking that they may be wrong for the head or that something else has been altered like the cam caps.
Details in thread lower down on Unitrak head and cams issues!


AL

"bloody good forum"Lots of responce and info,perhaps Mr Debben will
see this and add a bit? cheers to all.

There was a good article about this very subject by Steve Debben in Newzletter #41 August 2001. Unfortunately that original magazine file was lost so I can't do a pdf but I can scan it if anyone's interested.

I'd appreciate a copy Chris

I could make good use of a copy,ready when you are.
Thanks for your help,Keith

Here it is it should print out fairly clearly at A4

http://www.z1ownersclub.co.uk/uploads/debben002.jpg

Good stuff, cheers Chris...... (& Romeo )