Exhaust Manifold 2013
April 02, 2017


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I decided to purchase a used late model exhaust manifold to add to my spares collection and one thing led to another
and I decided to make it a direct replacement for my header, in the event that I ever decide to remove it.  This one was
really rusted, but flat and straight, so I decided to do a full restoration, including ceramic chrome coating and an O2 Sensor bung.

**** Viewers are warned that if they attempt any mechanical repairs or modifications,
or follow procedures referred to here, they do so at their own risk, and no liability will attach to me.****

This is the condition of the manifold as it arrived from the eBay seller.  Not that bad, but the rust
came off ever time that I touched it or set it down to work on it, so I took it for an initial sandblasting. 


This is the manifold after a quick $30 blasting at a shop in CT.  Not required, but I hate making a mess while I work. 
Time to start knocking out the emission tubes, as they won't be needed for my purposes.  They usually drive right out.

(it was really rust free, but I let it sit in the open air for three weeks before I got around to working on it)

This is the flange and and the old gasket , which the sand blaster did a number on.

The thread size for the injector rail plugs is 1/2" X 20.  I'm using socket set screws to fill the holes.

I wanted to re-tap all of the threaded areas to make sure there was no problem before the final blast and ceramic coating.

I deal with the flange studs later, as two were frozen in and needed heat to get them out when it went for the milling work.

These actually thread very easily, despite how they look.

This wonderful milling machine is going to do some nice work to allow an oxygen sensor to go between the two side of the manifold.

This is part of the equipment at the new shop of Her Majesty's Service, in Cranston, RI.  Erik Nygaard is the owner and a great friend.

This shows the milling of the manifold upper flange surface as well as the hole for the O2 sensor bung.

The bung is now set in place and ready to be brazed in.

All set into place and test fit to insure the threads are all OK.

This is what the tip of the sensor looks like between the left and right side of the manifold for the stock twin exhaust pipes.

I had another bead blast done, because I thought that would be good for the coating.  For powder coating it is fine,
but for ceramic chrome coating, there is a steel media used that actually cuts into the metal to give the ceramic a place to grip.

Here is another view, after the bead blasting, showing the nice through hole from the milling machine.

Just a side view for another perspective.

Now that the frozen studs are gone, I can now re-tap the threads in the stud holes in the flange.

These are 3/8" X 16 or 3/8 UNC.

Time to test fit the socket set screws from Fastenal.  These are black oxide and I may go to stainless or chrome, but they are fine for now.

Remember, these are 1/2" -20 thread X 1/2" length in Black Oxide.  Fastenal P/N (SKU) 1125702.

I also ordered the 1/2"-20 thread X 5/8" length in 18-8 Stainless Steel.  Fastenal P/N (SKU) 0171616. 

These will fill the threads completely to the top.

These socket screws are also 1/2" long, which fills the threads pretty well. 

Freshly back from HTC Racing / Disk Brakes R Us in Rockland, MA.  These guys do great work and also do all of the exhaust side pipes and headers
for factory Five Cobra kit cars.  They have the in house capability of doing the blasting, as well as the ceramic chrome and powder coating.

Another look down inside and they blasted the entire inside of the manifold for me, without my asking.  Very professional, indeed.

These are the studs and brass nuts, along with the steel exhaust pipe gasket from The Roadster Factory,
but I need to get some SS or Grade 8 lock washers to have a complete setup.

Nice and clean and a good deal of coating down in there.

This is the rear of the manifold as it sits on the car.  Erik's welding looks very strong and good now that the ceramic chrome is on.

The last view, all ready to go, with the socket screws in place and the studs and nuts on for storage.

The new stainless socket set screws arrived today from Fastenal.  Part # 0171616.

You can see the difference between the 1/2" and 5/8" lengths.

The 1/2" sit down in the threads and the 5/8" are a thread and a half above, which I prefer, along with them being stainless.

Six of one, half dozen of the other, I suppose.  They both will still block off the exhaust and that's what matters most.

The last of the lasts view, all ready to go with the new stainless 5/8" length socket set screws.

Thanks to Tom at HTC Racing / Disk Brakes R Us in Rockland, MA   (781) 447-6652


Erik at

40 Industrial Road
Cranston  RI 02920 
(401) 352-0888


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This site was last updated 04/02/17