Spring Bolt for Header to Cat on F430

As a new F430 owner I built a smoke machine and promptly tested my exhaust system. The headers were fine but the header to cat connection leaked on one side. Looking at the spring bolts the springs seemed way to small. I looked at several posts on Fchat and could not get a definitive size on the bolt assembly. I checked McMaster Carr and did not find what I thought would work. Ultimately I bought a full set (6 bolts) from the local Ferrari dealer. Before I put them in I measured everything and thought I would post it here if anyone wants to try and source them elsewhere.

Spring-
1.010" long
0.740" OD
4.420" ID
0.158" wire diameter
Ends ground flat
Material was strongly attracted by a magnet so I suspect it was not stainless
Sorry I forgot to count the number of coils.

Spacer-
0.400" OD
0.320" ID
0.905" Long
Not stainless

Bolt-
M8
65 mm long
25 mm of threads
8.8 strength
Coated with silver finish but it was not stainless

Washer-
Mildly attracted to magnet - Could be stainless
0.33" ID
0.79" OD
0.078" thick

Hope this helps someone. I ended up using a dremel to cut out the old bolts. Both the bolts and springs were junk. With new bolts the system is now very tight.

 

Image Unavailable, Please Login

 

The way it went together I think the spacer is there to limit how much you compress the spring. With the spacer you can only compress the spring about a tenth of an inch. You could tube to the right length. As long as it fits between the bolt and the spring you are good to go.

 

There are several part supplier sites that have exploded views of the many systems in the car and they have part numbers and quantities listed. It is worth putting one in your bookmarks.

Bolt 16044524
Spacer 114749
Spring 111743
Washer 12646778
Nut 212191