Daytona Valve Shim Info

After having our cams re-surfaced, straightened, and re-ground, enough material had been removed from the base circle that we need slightly thicker shims. A couple of questions: Is there any reason to set the clearances other than what the service manual says - .25mm intake and .50mm exhaust? That's where they were before, but the cam grinder was recommending .30mm on both, which seems wrong.
Also, it appears that through a few supersessions the Daytona is using the same 33mm diameter shim kit as things like the 2 valve 308, 246, 400, etc? Finally, we have two intake valves that want to have shims that are 5.0 and 4.95mm, just above the readily available thicknesses of 4.9mm. I couldn't find any oversize options - are there?

Thanks

 

There are literally dozens of different vehicle manufacturers that use this same type of shim. You might have to do some digging but if memory serves me VW and Volvo are just a few. Suppliers in the States will not know how to help but the Europeans will.

 

Fiat has the same shims
when I remember right they have up to 5,25 mm, but not sure. too long ago
lancia has the same

here is a 5,05 shim:
https://www.ebay.at/itm/193530952317?fits=Make%3AFiat&hash=item2d0f57fa7d:g:AnoAAOSwCWte8MSU&amdata=enc%3AAQAIAAAA8BMgUoj0kTmCQmngL32a77a9S8JwwswykqWIhX4eV%2FmQMy6nhAIDqOzWu160MSZye0XAjSNjor4NjZFvqijEHcs7GwZm11deVKLqR0SNGwRiFD1zXWOuxQygy9QDob9smPbH%2B4ZRI6a%2F8L%2BTu3uiQzTurK5YdSbWsfdnuOxkWwxIq33a%2FiYzAjbAuYmcB7x%2FrLlVjtiaDLch8FMZWrwzrJHvJGpf4apYRUfOW8fRD%2BxzGwP%2BVurjT1TceS0Euciq6poYfQMdXwW%2FGCpc6QF6qUThEk6rm4ikPoeWdGU%2FB5ZWUcldxq4ZnGMU%2F%2BHhCZ44CQ%3D%3D%7Ctkp%3ABk9SR-zOs4eOYg

 

The optimum valve lash is a function of the cam grind. If you set the valve lash to 0 and measure the lift versus crank degrees you will find there is a gentle take up ramp that is designed to take up the valve lash at the beginning and end of the cam profile. The valve lift rate is much faster once you are on the primary lift ramp. Set the valve lash so that you are 2/3rds to 3/4s of the way up the gentle take up ramp before the cam contacts the bucket. You don’t want to spend a lot of time on the gentle take up ramp but you need to be on it before the aggressive ramp starts. The 2/3 to 3/4 setting allows for variation and some wear.

cheers Jim

 

Daytona shims same as 308

 

2-valve 308…

 

To the OP.
All correct and if the cams were properly reground there is no good reason to deviate from the Ferrari specification.

I am a little surprised a good quality cam grinding service would have left you with cams with such a reduction in base circle standard range shims are no longer usable. It could have been avoided.

 

Thanks for all the input, everyone. Indeed, it looks these 33mm shims were used in a number of Italian cars and the folks at Midwest Bayliss have shims that are available in the 5.0 thickness that I need for a 124 FIAT. They claim that they are the same properly case hardened and stamped parts that most Italian OEMs have been using for years.

I was a bit surprised at first, too. But we were already very near the thickest shims on the intakes, so it took almost no material removal to require a shim barely over the common Ferrari range. We didn't have it done, but the head work was fresh and done by a shop that Patrick Otis described as "the best head guy out there". I believe that some shops set new valves and seats in "shallow" so that as they wear and get reground at some point, you have the entire range of thinner shims available to you. Of course, I don't know if that's how we ended up here.

Finally, does anyone have a good experience with one of the tools that wedges against the cam and holds the tappet down such that you can slip the shim out with the cam in place? I found someone on the forum who was using the Ferrari style service tool on a 365 GTC but he had to grind it quite a bit to get it to work. The one that the FIAT guys use on what should be the same tappet might work, but I don't know if it will foul part of the head casting on the Daytona.

Rory

 

I know Pat very well and I am sure he sent you to someone good. I used a guy right there in SLO for years but I do not think he is still in operation. Lots of tools can perform that job. For many years we used to grind down a thrust washer to hold the follower down once compressed. I have a set or 2 of the Ferrari tools. Ricambi offers reproductions of them.

https://www.ricambiamerica.com/95979560-tool.html

 

I never adjusted at a daytona teh valve clearance. but at a 308 you may modify the FIAT tool a little ( they have several tools ). it is only to keep the valve open during you change the shim. to press down you can use the original FIAT tool

 

Thanks for the tips. I've seen two very different looking FIAT tools - a single hook end with a long handle and a short forked tool that would bear on both sides of the tappet at once. But if the Ferrari knock off from Ricambi works without modifying, I may go that route.

Although he hasn't gotten a dime from us yet, Patrick has been very gracious with his advice to us and set us up with his dyne guy to do the break in run - he just seems like a great guy. Sadly, there are very few shops still around that do that kind of machine work in SLO or anywhere else, for that matter.