Exhaust System

The original exhaust systems for PF coupes (and other early Ferraris) was made by Abarth and no longer available.  Ferrari changed to using Ansa exhaust systems with the GTE model.

My coupe came with a NOS GTE exhaust system as that is the closest approximation to what is needed.  I'm not ready to work on that, but started thinking about the parts I'll be needing.

The early Ferraris used center pull exhaust strap hangers.  From the middle of the GTE production, they went to the side pull hangers.  Of course, I have a number of side pull ones left over from my 330 GT along with the 4mm aluminum spacers that match that I won't be able to use.  Parker Hall does sell reproduction versions of the center pull hangers, both is black (50's models) and cad for later cars like mine.  These take a thicker 6mm spacer.  I talked to Parker about the spacers, but he no longer has a source and just a few in stock (I need 24).  So I looked at a few websites before trying McMaster-Carr (I should always start there).  They have a 1/2" diameter, 1/4" thick with a 1/4" hole round aluminum spacer.  The originals are 12mm x 6mm with a 6mm hole.  So these will just be a little larger, but I don’t think that a Concours judge will risk grass stained knees using a micrometer to measure them at a show.

The other pieces of the exhaust that is missing are the collectors (between the headers and front muffler).  These are a single pipe, with a triangular flange at the front and a slip connection on the other end.  So they shouldn't be too difficult to fabricate and get bent correctly.

I was talking to Tom Shaughnessy last fall about the exhaust system.  He mentioned that David Carte makes them periodically.  So I contacted David and found that he was going to make some fairly soon.  So I ordered a complete set for my coupe.  David created a set of plans based on an original Abarth system off an inside plug PF coupe.

The completed system arrived the other day.  David included a set of instructions since these aren't just bolt on.  This isn't so much of an exhaust system, but an exhaust kit.  It includes original type clamps and flanges w/gaskets and hangers to be welded on in the correct places.  He even included the black oxide bolts and brass nuts for the flanges.

For now, it just gets hung on the wall as the engine has to be installed in the car to fit everything properly.

I checked with Carte to see how these are finished.  They just get painted with a semi-gloss black.  I need to find some that is heat resistant, perhaps paint used on barbecues?

I've been doing some part collecting and figuring out what else I need for the exhaust.

First, a perusal of Parker Hall's catalog showed that I'll need a set of Abarth stickers (5 per side, 10 total).

Until the middle of the GTE production, Ferrari used center pull exhaust hangers rather than the side pull (left) as on my 330 GT.

This means the set of side pull ones that came with the car are surplus.  Parker sells center pull ones, both in cad plate and black paint.  The painted ones are for early 50s cars, so mine takes the plated ones. 

The side pull hangers use 4mm thick spacers on both sides of the chassis bracket to separate the pair.  With the center pull hangers, you need 6mm spacers instead.  I found a source of 1/4" spacers (6.13mm) that are slightly larger in diameter (1/2" or 12.7mm) than the original 12mm.  These are available from McMaster-Carr at a very reasonable price.  Since you need 48 (12 locations times 4), it was a nice find.

In addition, my headers have 2" triangular flanges on the ends, while the collectors David made are for a slip connection.  The slip connection was used on the inside plug engines and early outside plug ones.  So I will get matching flanges, gaskets and reducers to go to the 1 7/8" pipe used on the collectors.  They will have to be welded to fit onto the collectors.  These are available at most auto parts stores.

As I working on the collectors on the 330 GT, I found out that Ferrari changed the exhaust studs to 8mm from 7mm on the 250 model.  This meant that I needed 7mm brass nuts for the coupe.  The fine thread 8mm ones are hard to find, but the 7mm ones can be ordered from McMaster-Carr.  However, getting 7mm lock washers isn't as easy.  It turns out that Ace Hardware carries these, but my local store doesn't stock that size.  They did make a special order for me, though I ended up buying a box of 100.

After the engine was put back in the car a Dennison International, Butch mentioned an issue they had found with Carte's reproduction exhausts.  David doesn't connect the inlet and outlet pipes in the front can.

As you can see, the inlet (top) just terminates with an open pipe and some holes.  The outlet pipes just have a series of holes with the open end close to the end of the car.  Butch says that this costs ~20 horsepower and makes a tinny sound.  His fix is to modify the internal pipes and make an Y pipe to connect the inlet and outlets.  Then pack around the Y pipe with some muffler packing to eliminate the tinny sound.