Valve clearance

Carlos

Member
Hello, I'm with a dilemma, maybe you can help me.
I've found a good workshop who made a nice job with the cylinder head of my 2000TC engine.
After the job, I reassembled the camshaft, with the original shims.
Now I find that there is no clearance, as expected because all the valve seats where machined slightly.
I don't know how to start : if I grind the existing shims , I don´t know how far to go.
I was trying to get shims from Kawasaki ( 13mm ) but they are too short ( max 3.2 mm and mine are between 10,37 / 10,48 mm ).

Am I wrong if I ask the workshop to cut a a 13mm rod in different sizes and to try them until I got the right gap ? Then I grind the original
shims to each size ?
I don't know if it´s clear the question.

Thanks
 
This is only a suggestion as I presume you don't have access to a selection of shims. Measure all the shims you have. Subtract the clearance you want from the size of the shim. Grind down the shim to that new size. (Accurately). Measure for clearance again. If you still have no clearance repeat the process. If you do have a clearance work out what you need to do to the shim to make it correct. Then once you have a figure for the size of shim you require, buy the shims you need.

The alternative is use all the shims you have to find one shim that will fit and stand above the valve retaining cap. Then measure the clearance, (which will be massive) then add the figure you need to the size of the shim you have in there to bring it to the correct clearance, and buy shims to make up that required size.
 
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It is worth pointing out that tappet shims are usually case hardened, that is they have a hardened coating. This means as Harvey has said when you know the size you will need the buy a shim to suit. If you use a ground down shim it may wear quickly giving lots of lash.
 
I would add that J R Wadham has shims at £7.50+VAT+Shipping EACH. (Presumably used)

I have a good selection of used shims, (although a lot of the common ones are gone, but this may not be a problem here as the valves have been cut into the head) and I'd be prepared to help with the calculations (In Imperial) and measure and sell shims as required. (Once again, in Imperial)
 
It is worth pointing out that tappet shims are usually case hardened,

They still wear where thay sit on the top of the valve stem, but then you just turn them over. They don't wear anywhere near as much as they will on a ground surface though.
 
This is only a suggestion as I presume you don't have access to a selection of shims. Measure all the shims you have. Subtract the clearance you want from the size of the shim. Grind down the shim to that new size. (Accurately). Measure for clearance again. If you still have no clearance repeat the process. If you do have a clearance work out what you need to do to the shim to make it correct. Then once you have a figure for the size of shim you require, buy the shims you need.
Sounds quite useful, Thanks ! Its a good starting point.
 
I would add that J R Wadham has shims at £7.50+VAT+Shipping EACH. (Presumably used)
I know, but I need a starting point to order the right ones. Thanks !
I have a good selection of used shims, (although a lot of the common ones are gone, but this may not be a problem here as the valves have been cut into the head) and I'd be prepared to help with the calculations (In Imperial) and measure and sell shims as required. (Once again, in Imperial)
Good ! As soon I have an idea of the size, I´ll tell you. Thanks for your offer !
 
They still wear where thay sit on the top of the valve stem, but then you just turn them over. They don't wear anywhere near as much as they will on a ground surface though.
Regarding your background I will take your comment very seriously ! Thanks
 
Shims are cheaper from Wins International, as I have recently discovered. Geoff had all the ones I needed, which were between .390 and .399in – at the bottom of his span of available sizes.
 
Earlier P6 engines used two shims per valve, the thinner one under the thicker one so that both would stay in place within the valve retaining cap. The ranges of factory shims were .074in to .083in in .001in increments, then .092in to .142in in .010in increments, then .262in to .352in again in .010in increments. The idea was that with the right combination of shim pairs, any required overall shim thickness was possible.
 
Aha! And wasn't there something about circlips with the earliest shims? I'm just plagiarising the manual… the only P6 shims I've actually seen are the later, single, long ones which seem to be accumulating in my garage.
 
The two shim setup seems to have a much wider adjustment range than the single shim sets. Two shim runs from .336 to .435, the single shims are .390 to .422. Not sure why they went from stocking 20 sizes of shim to stocking 32 sizes.

Yours
Vern
 
I've finished grinding a little bit the old shims, in order to have some clearance to start to calculate the right one.
The metod I use is as follows ( please correct me for any mistake in the process ).
I mount the camshaft with everything ( new valves with springs, tappets and old shims ), in the head ( but not in the block ).
I use the 10 long bolts, putting the old gasket ( to avoid damage in the new flat head face ), large washers and 10 nuts ( from the wheels, a tip from a member ).

Now the question (having in mind that all the setup is only for a matter of measurement):
Do I have to use the high torque rated in the manual ( 55lb/ft )? or
Can I use a lower torque in order of not to stress the long bolts ?

Thanks
 
I think I read a recommendation somewhere that should only torque to 10 ftlbs or so doing it that way so as you might damage the head. However I have not been able to find that in a manual, so it might have been an opinion I read elsewhere.
 
I think I read a recommendation somewhere that should only torque to 10 ftlbs or so doing it that way so as you might damage the head. However I have not been able to find that in a manual, so it might have been an opinion I read elsewhere.
Thanks, I will wait for more opinions, but I think that is a matter of torquing enough to have an accurate reading of the clearance.
 
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