Alfa Romeo & other alternative valve hats
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Author:  paso750 [ Sat Oct 22, 2016 3:57 pm ]
Post subject:  Alfa Romeo & other alternative valve hats

I doubt it but did anyone try to use 8mm valve hats for Alfa Twin Spark engines as opener shims for a Ducati?
After searching the internet a bit I found that a few Alfa & Citroen SM (Maserati) guys are using Duc shims on their engines so it must work also vice versa.
Lotus twin cam (Ford Cosworth YB) valve hats have an ID of 7.95mm and may fit as well.
They can be found for ca 4 $/GBP/€ ea. which is a third of Ducatis price.

Schrick cams in Germany also list 8mm valve hat shims.


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Author:  Derek [ Sun Oct 23, 2016 9:30 am ]
Post subject:  Re: Alfa valve hats

Great find G. I do a lot of shimming work on Ducati engines for other owners here in Scotland. Having an alternative source at better pricing is fantastic. I see on the Schrick list that shims for 7mm valve stems are also available. These may fit the 4V engines. It will depend on their outer diameter and the depth from the shim face downwards.

Author:  paso750 [ Tue Oct 25, 2016 9:22 am ]
Post subject:  Re: Alfa valve hats

Hey Derek,

I`m a bit surprised there`s no interest in this topic. I searched through different Duc forums and found not one topic about alternative valve shims. I did find a few on Alfa Romeo and other car forums.

I sent an enquiry to AVL-Schrick and to http://www.maxrpm.de/, one of the shops here in Germany which sell the Schrick shims. Got no reply from Schrick yet but the owner of the shop sent me an email yesterday.
He wrote that from the open side to the bottom it`s 3mm (hence total shim height would be 3mm + "s" the thickness). The outer diameter is always 2mm greater than the inner diameter. As the shims were developed for tuned and competition engines the surface is hardened.

I wasn`t sure about the latter because other than on the Duc engines in cars the shim sits between the valve and a cup. It`s not in contact with the camshaft which is why I asked.

The Duc opener shim I measured also has 3mm depth and the outer diameter is 11mm. It seems its skirt is 0,5mm thicker (unless the guy from the shop measured incorrectly). Don`t think that makes a real difference.

I might get some the next time I need shims. EMS in the US sell opener shims for $8.50 which is a good price but in my case it`s plus international shipping, import duties and the time for them to get here.
At Stein Dinse they cost €12 ea. The Schrick ones are sold at maxrpm for €5.50. Just considering one would buy one of each size (32pcs) that would be €384 vs €176.
Actually it`s strange that at SD the 8mm 2-valve shims cost €12 while they sell the 7mm 4-valve shims for €6.40.

Pity there's no alternative for the closer shims. Other than EMS of course.

Author:  paso750 [ Tue Oct 25, 2016 7:44 pm ]
Post subject:  Re: Alfa valve hats

last update: I had posted in an Alfa forum to ask about the dimensions of the original Alfa Romeo (Twinspark) shims and they are od 11.5mm and 2.5mm depth.
They come in 0.025mm increments.

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Author:  Derek [ Wed Oct 26, 2016 8:26 am ]
Post subject:  Re: Alfa valve hats

Yes, I'm surprised no one else appears to have looked into this. I found two sources in the UK -
At prices of £4.00 and £3.50, much cheaper than Ducati. I had to buy a few 2V opener shims earlier this year, Ducati quoted me £16 each, I got them from Lacey Ducati http://www.laceyducati.com/ducati-parts/twin-cylinder-head-valve-opening-shims-c-175_313_315.html at £9.80 each.
The Alfa ones are much cheaper still. Next time I need to buy shims I'll look into it. I usually get an exchange FOC with the dealer unless he doesn't have the size I need in stock.

Author:  stylianos62 [ Tue Nov 01, 2016 8:18 pm ]
Post subject:  Re: Alfa Romeo & other alternative valve hats

Really interest post and always we follow these reports. Just maybe some (most , like me) owners , prefer service engineer to do this adjustment from time to time where total cost with other maintenance jobs has not obvious big cost difference for 2 valves tappets.

Author:  higgy [ Tue Nov 01, 2016 9:49 pm ]
Post subject:  Re: Alfa Romeo & other alternative valve hats

Actually if you are in the US and you buy the big kit from EMSDUC its $7.67 a shim for 38 shims delivered with tax

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