Refurbish 67 273 Exhaust Manifolds
This is the mockup on the bench. I used all SS allen head fasteners and polished them. My intake and valve covers are all SS allen head fasteners as well, I like the look.
This is the right side before photo. 
This is the right side after photo. 
This is the left side after photo and I don't have to tell any A-body owners how difficult this was to R & R without removing any other parts. Band-Aids everywhere now. 
This is the finished project photo. I heat cured them on the car and the paint kept it's as sprayed lustre and finish. No flaking or peeling, I think it is solidly bonded to the cast iron. 
What I know: All liquid applied coatings (paint) require a "gassing-off" period. One must know when to move to the next step safely. This is why I did not use any primer under the color.
What I learned: Cast iron is very porous and absorbs all the wash, blast, solvent and paint much more than tube or plate steel. This increases the gas-off time exponentially. The on-car cure instructions are possibly suitable for plate or tube but not suitable for cast iron. The instructions call for an initial run in of 20 minutes-do this at your very great risk. I was watching mine closely and after 6 minutes I saw some bubbling and shut the car down. I let it cool to hand warm and started the car again and watching it closely let it run for about 18 minutes up to 140 on the water temperature gauge. I called it for the night and let it sit overnight. The next morning I inspected the manifolds and they looked really good, I started the car and let it run for 35 minutes and got the water temperature up to 190 degrees. Then I shut it down and called it good. This project is complete and I have 2 or 3 more little things to do to the car before the spring roll out. Cheers and thanks for reading----DR----
This is the mockup on the bench. I used all SS allen head fasteners and polished them. My intake and valve covers are all SS allen head fasteners as well, I like the look.
What I learned: Cast iron is very porous and absorbs all the wash, blast, solvent and paint much more than tube or plate steel. This increases the gas-off time exponentially. The on-car cure instructions are possibly suitable for plate or tube but not suitable for cast iron. The instructions call for an initial run in of 20 minutes-do this at your very great risk. I was watching mine closely and after 6 minutes I saw some bubbling and shut the car down. I let it cool to hand warm and started the car again and watching it closely let it run for about 18 minutes up to 140 on the water temperature gauge. I called it for the night and let it sit overnight. The next morning I inspected the manifolds and they looked really good, I started the car and let it run for 35 minutes and got the water temperature up to 190 degrees. Then I shut it down and called it good. This project is complete and I have 2 or 3 more little things to do to the car before the spring roll out. Cheers and thanks for reading----DR----
