Acorn Nuts for 250's

Stephanm · Post by **Stephanm** » Sat Nov 10, 2007 3:53 pm

Can anyone shed some light on a very boring subject?

I am pretty sure that 330/365 and later had zinc plated acorn nuts for the cam covers and the intake manifolds but what about the 250's? Were they plated in Silver cad or in Nickel?
I assumed they were done in silv cad but I have a very original GTE that look as though they have that pewter/goldish nickel finish not the bright silver coating.

Thanks guys.

Post by **tyang** » Sat Nov 10, 2007 8:10 pm

Hi Stephen,

I believe they were nickel plated.
Here's a part of something I wrote a couple of months ago:

Speaking of sorted engine compartments, François and I got into a discussion about acorn nuts. My car had a handful of nuts that looked like the one in the right side of this picture. François informed me that these were incorrect for any Ferrari as they were replacement nuts once sold the now defunct FAF in Georgia. It must have been a popular item, as I've seen dozens of these acorn nuts on other cars. The correct nut is the one in the center of the picture, and the finish is nickel plated. The FAF nuts were chrome or stainless. Mine were probably chromed as they are all now rusting! François said the left acorn nut is another reproduction, and is not quite correct as the shoulder is different. For cars manufactured in the early 70s, like the C/4 and Daytona, there is even another acorn nut that has a shallower hex head. I'll have to cover these in a future post. If anyone can shed more light on this topic, please e-mail me!

Tom

Post by **330GT** » Sat Nov 10, 2007 8:41 pm

The Ferrari acorn nuts are designed to have the top pop off if the stud is too long and the nut bottoms (or tops?) inside of the acorn. The one on the right on Tom's picture is one piece. If the stud is too long, that nut won't tighten down on whatever it's supposed to.

Post by **tyang** » Sat Nov 10, 2007 8:57 pm

The one on the right was the FAF replacement that is often incorreclty substituted for correct ones. Bottoming out one of these could strip the threads on the aluminum head when using them on valve covers.

Another interesting thing is on the 365 acorn nuts the insides have a nylock insert under the cap.

Tom

Chris Coios · Post by **Chris Coios** » Sat Nov 10, 2007 9:51 pm

The correct finish for the acorn nuts on most 250's is clear cadmium (silver). The Ferraris in the early 1950's typically had one piece acorns, black oxide. Most of the two-part acorns available today are unfortunately about .5 mm to 1 mm shorter compared to the originals, depending on the source, sometimes requiring an extra spring washer to space it off a bit. In addition the hex section tends to be lower in comparison, even the ones deemed 'tall'.

Michael Bayer · Post by **Michael Bayer** » Sun Nov 11, 2007 7:16 am

Tom Chuck Wray told me the same thing about the GTC4 nuts, and we could not find a source for the precise replacement so we redid the old ones which is not the best practice for nylocks. M

Stephanm · Post by **Stephanm** » Sun Nov 11, 2007 5:16 pm

I did not think that they were Nickel. I am quite sure that the repro's are zinc, just a very silvery finish while silver cad has more of a marbelized green/yellow in it. THanks Chris for helping with this.

Whenever I have seen a industrial dull nickel flash that it is a very even platinum/dull look without the marbelizing assosiated with zinc or cad.

Post by **tyang** » Sun Nov 11, 2007 6:23 pm

Trying to read the differences in Clear Cad plating and Nickel plating, I've been trying to figure out which pieces use what. Perhaps I'm losing something in translation speaking to Francois when he tells me pieces are universally nickel plated when they should be clear cad.

For instance, the coolant tubes on a 275GTB that come out of the heads are nickel plated, right? What about the Dunlop Brake calipers and frames. Nickel or clear cad?

An example of things lost in translation with the frenchman is when he tells me to use clear silicone RTV by calling it "white silicone." I've gotten so used to hearing this, I caught myself also calling it "white silicone" as well!

Tom