308 valve shim....need help

The thickest Ferrari make is 4.9, which we stock - I'm surprised that you need to go beyond that size

 

Sorry, I have no idea who manufactures them - we buy direct from Italy, maybe someone else out there can help.

 

Pat - you have mail

 

There is a hack-mechanic trick that I will state here (without any personal experience).

You can use an Alfa Romeo shim over the end of the valve stem to artificially make the stemp longer, and therefore the required valve shim will be thinner. Hopefully, it will fit within the available range.

That is a hack.

 

Try Volvo shims. I dont know what thicknesses are available but I do believe they will fit the F car.

 

The shims are very low tech. You can have a machine shop make them for you and the have them hardened. This will cost you more than finding the right size but you can look for a long time. I have ground my own shims before and it is really easy. What you have going sounds weird. Are you absolutely sure the mechanic did this right? The best way is to measure the valve lash bucket to base circle of cam. write all this down on a piece of paper. then remove the cams and the individual shim and add or subtract for the right size. If you car is stock Ferrari I do not see how what you say can happen. In fact if this car had head work the valves would read out of spec and have to be replaced to avoid this problem in the first place.

 

Yes they are Volvo shims. I get them from my local Volvo dealer. Just bring on of the shims with you and they should be able to match them up. There 3 bucks a shim here in Canada.

 

i got my shims from global metrics most of the ferrari dealers get shims from them.

 

To me it sounds funny that your mechanic has replaced 11 shims so far and needs to do 4 more. I don't know what year and how many miles you have on the car but I only needed to change 1 shim on a 45k miles engine. All other 15 shims were in spec. Also I cannot believe the "short valve" thing that you mentioned. The only the gap changes are from the valves pounding in the seats (smaller gap) or the cam wearing (larger gap). Also you don't need to remove the cams to put shims in. Just need to make a few tools. Simple job.

 

It is very strange that you need very thick shims, even outside the normal manufactured range.
What usually happens is the exact opposite, which is that the valve moves closer to the cam, as a result of wear on the valve or valve seat, or if the valve seats have been refaced. which means you need shims at the thin end of the scale. Dont ask how I know.
Some Volvo shims ( to suit the B20 engine ? ) are the same as the 2 valve Ferrari, are cheaper and are availabe
in some sizes that Ferrari does not have.
While it's impractical to get a 2nd opinion while the car is in someone's workshop, I would ask to see the shims that were pulled from the car and what the sizes they where.
I would be expecting that shims of a similar ( thicker ) size had been removed as the tendency over time is for the valve clearance to decrease rather than increase.
If this is not the case, warning bells would be ringing.
Whats the condition of the camshafts & cam followers ?
Has the car had the heads off ?

 

Putting 2 shims together might lead to problems, HUGE PROBLEMS.
the smallest amount of oil gets between them, the shims suddenly grow in thickness--the cam either locks and breaks a lobe--or the valve goes down far enough to hit the piston. DO NOT DO THIS!!!!!!

Remember --liquids are NOT compressible

SORRY TO SAY THIS, BUT IF YOU CAN NOT FIND SOME THICK SHIMS--OR HAVE SOME MADE--YOU WILL HAVE TO REMOVE YOUR VALVES AND REPLACE WITH CORRECT ONES.......

 

New seats will require the heads to come off and valves to be removed--If you replace the valves then a valve/seat job needs to be preformed anyway.
It may be possible to "lower" your seats enough for the valve to work--but that is not a proper of safe method for fixing the problem

 

The 2 shims method mention above was done by someone here, and was quite ingenous. Trying it or not is your choice.

The alfa shim is a valve lash cap and goes over the stem UNDER the bucket.
The regular Volvo shim goes OVER the bucket.

So the two shims are never in contact.

 

Going through a major over haul so I will be tackling the valve adjustment thing. If the valves are too tight you could grind the valve tips to get the proper clearance. This of course is assuming you have the heads off. This requires assembling the cams and buckets and leaving the valve springs off so you can push the valve to the seat and take your measurement. I have heard but never done it myself, you can shim under the hardened shim to a small degree without worrying about oil underneath or hammering of the shim problems. Make sure you keep each hardened shim in its original spot, because the shims have already mated to the cam. you wont have to worry about this with new shims. Remember when you renew the valves and seats this sinks the valve further into the head, reducing the clearances between cam and shim, sometimes it might be enough.

Gary