RE-SHIMMING AFTER HEAD RE-FURB

[PAULJAC47]

Hi All re-fitted the head to my Z1B today and got cam timing right after half dozen attempts!.As I thought may be the case after cleaning out all carbon and having new valve guides fitted my shim to cam clearances which were all about 2 thou before strip down have now been reduced to zero!. i guess i need a much smaller shim 2.0? and check each one in turn and work out size i need,trouble is i reckon i will need to change all eight, i know that the club does an exchange but i dont fancy taking cams off to send all eight for exchange after the game me and my mate had getting it timed right.Is there ant other way round this????........Thanks in anticipation p.s anyone got a small shim 2.0? i can beg steal or borrow.........PAULJAC47

[tlc]

Oh fcuk. 2.0mm shim ?

Time for new stuff in the head

[Steve Cooke]

You don't need to remove the cams but you will need a shim removal tool, you will probably find that you can move some of your existing shims around and lessen the amount you need to replace. the minimum shim size is 2.00 so if you need smaller than that you will have to look at lopping a little of your valve stems 'within the recommended maximum' and if that doesn't give you enough you'll have to stretch the wallet.

[PAULJAC47]

Hi Guys all my shims i know are 265 or 270.now the head has been re-furbed it has caused the shim gap to close.i am guessing i need a small shim 2.0? to work out what sizes i need.

[tlc]

Just make a guess and ask the club (Jerry) to send the shims you need.
If you need more then ask after sending the others back.

[Pigford]

I got a 2.00 even a 180 somewhere.....

PM you address matey

[grumpuszed1]

there is a page in the genuine manual that will tell you how to work out shims you need, it states the distance from the top of the vavle stems to the face of the vavle spring lower seat, this is only a rough guide but it will anable you to set them up roughly to start. if you have had new guides put in then i hope you have had the vavle seats re-cut as if they are not perfectly aligned then you could have a vavle pick up which will cause it to stick and you know what happens after that "ouch" you didnt state whether you had replaced the vavles as well but you can grind up to 0.3mm off the standard vavle lenth without removing all the hard material,this will get you some adjustment in the shims back. you must grind the vavles on a surface grinder as this will make sure the vavle stem face is still square to the head.
hope this is of help!

[Al]

Paul all of the above plus been faced with a similar problem in the past myself. Not suggesting that you do this but i modified a copper two pence piece on some 800 paper and used it to calculate out the correct clearance from there.
Needless to say you have to have a valve shim removal tool to do this even half arsed.
There is a recent drawing on the site for the shim tool if you can make one or if you prefer, pm me and i'll send you mine.
Chrisu has also posted an easy guide to the operation with really high quality photos so no mistaking.

False economy ultimately because two years later needed to re-set shims and had to take the head off needlessly and have the valve stem ends ground as was correctly mentioned above to bring it back within the range of available shims sizes.

Good luck with your decision.


AL

[Rich]

Get yourself a 200 shim them start measuring all clearances, work out what you need and if you are a club member ask Jerry if he has those he can swap. Then when you have changed them send the others back to Jerry.
The only problem you will have is if you don't get clearance at 200 you will need the stem tips ground.

[bigmac103]

Hi Paul,

What problems did you enounter when setting up the cam chain? I´m just about to do mine. Any advice greatly appreciated.

Bill

[PAULJAC47]

Hi Mac,A few points....Make sure you keep T mark at 1-4 still( i used a 17mm ring spanner tye wrapped to brake pedal)...when you line up ex cam make sure small arrow is lined up with surface of head,then pull chain tight up at front of block.remove cam auto tensioner at rear of block,push plunger into itself as far as it will go and lock off,aftet this torque ex cam caps to 8ft Ibs.now fit in cam 28 marking lining up 28th pin on chain counting anti clock after ex cam arrow lined up with head,fit in cam and torque down same as ex cam.you should now have slack between cams,fit top tension pulley assembly,now check all marks line up as per diagram on forum noting arrows show engine going backwards,Fit auto tensioner and release plunger it should shoot in and take up slack.remove tye wrap and rotate engine clockwise till it comes back to 1-4 T and make sure all marks still line up.it took me few attempts to get bang on,it seemed i had to go anti clock first then clock for tension to be taken up!.Take it slowly with 17mm spanner on crank bolt you should not feel much resistance(plugs out),if you have carbs and exhaust off you can watch valves with penlight torch to double check.only when you are sure all is ok ease over with kickstart.You can then check shim gaps as per the excellent pics on forum......Good Luck PaulJ...

[Al]

Dont believe the numbers etched on the shims at least half of mine mic up differently. Not significantly, but enough to make a difference when you are working between highest and lowest tolerance and having to make decisions about whether to go big or small.



AL

[bigmac103]

Thanks Paul, appreciated.

The shims i've mic'ed up are not exactly as marked, so well noted Zorded.

Bill

[Pigford]

CHECK TO CAM CAP TORQUE FIGURES..... I THINK IT MAY BE ib/in NOT lb/ft...... THEY ARE TOO EASY TO STRIP.... BY HAND/FEEL IS BEST

[bigmac103]

Pigford, would you use thread lock on the cam caps?

Bill