Exhausts - where are they ??
- Thread starter Roaring Forties Defunct
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Ron Earp
Admin
Well,
To tell you the truth I think it is rather unacceptable. You've waited a long time, and now you've got to get the set coated yourself, which is going to probably cost more than the $200 built into the price.
My opinion - George needs to honor the original contracts and get the parts done correctly ASAP.
I hope he can or has corrected all the issues with delivery and parts to this point. After I'm finished and done with the parts I'll post my experiences and lock the topic. It appears I'm the last one left.
Ron
[ April 18, 2002: Message edited by: Ron Earp - Administrator ]
To tell you the truth I think it is rather unacceptable. You've waited a long time, and now you've got to get the set coated yourself, which is going to probably cost more than the $200 built into the price.
My opinion - George needs to honor the original contracts and get the parts done correctly ASAP.
I hope he can or has corrected all the issues with delivery and parts to this point. After I'm finished and done with the parts I'll post my experiences and lock the topic. It appears I'm the last one left.
Ron
[ April 18, 2002: Message edited by: Ron Earp - Administrator ]
With the ever increasing interest in building a GT40, and RF's low cost entry as well, it would be in all our best interests to find another source. Having a sole source is not good. Additional sources would spur competition, and make it a win-win situation for everyone.
What about the major header companies like Hooker, Headman, or Doug Thorley? They already have the talent and equipment.
Bill D
What about the major header companies like Hooker, Headman, or Doug Thorley? They already have the talent and equipment.
Bill D
Another source for headers is ERA. I am getting a custom set made up for a 351 which is going to run $2800 for stainless. $2400 for mild steel. I've seen the work that is done for them on these headers and it is first class. It's the true 180 crossover design and it is made to resemble the original GT40 system. This may be important for some. They are having a number of sets made up and should have a few extra.
As an aside for those coating your headers: I've been told the coating will discolor at the header hot spots. Nothing much can be done to fix this but recoating them. This person recommends leaving them as uncoated stainless because if they get discolored you can polish them to regain the original look. This is second hand info. Your's to do with what you wish.
Mark
As an aside for those coating your headers: I've been told the coating will discolor at the header hot spots. Nothing much can be done to fix this but recoating them. This person recommends leaving them as uncoated stainless because if they get discolored you can polish them to regain the original look. This is second hand info. Your's to do with what you wish.
Mark
G
Guest
Guest
Mark, It is true that a number of things can cause discoloration. You want to be very careful about greasy hands until they have been up to full heat a number of times for instance (afterwards also but especially until they are fully cured.) If aesthetics is the only reason for coating, then I'd probably agree with your source. But, that is n't the only reason. Stainless will take care of the corrosion issue, but it won't help much at all with the heat transfer aspect. A good ceramic coating can cut down the heat transfer out of the exhaust into the header, and then into the engine bay, by approx. 30%.
This is not an insignificant amount of heat.
This is not an insignificant amount of heat.
Not all stainless steels are the same. Starting in 1985 on the Mustang they made short little stainless steel exhaust manifolds on the 5.0 L 4V engines. These manifolds should not rust through, but they do develop a rusty colored surface. It is not until you get above the 300 series stainless steels (like a 400 or 500 series) will you avoid this surface rust issue. Due to costs, most stainless steel exhaust system products are of some form of 300 series stainless steel. If you think a set of stainless steel headers will shine like a set of nickle (chrome) plated headers you should reconsider your thinking. I'm not knocking stainless steel, but you should understand the phyics involved and what you will be getting. Also, just because the tubes are stainless it does not mean the welding material to weld them together was stainless.
Jim Seisser
Jim Seisser
Surface rusting is not really a matter of which series of stainless is used. In fact, type 409 (not a 300 series) is typically used in automotive exhaust systems.
From The Home Machinist's Handbook by Doug Briney:
<BLOCKQUOTE><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><HR> Stainless steels do not require any special coating to protect them, but unless stainless steel is passivated after machining, it is subject to corrosion and rust. The passivation process simply removes all of the ferrous material from the surface, leaving only the chrome and nickel exposed. <HR></BLOCKQUOTE>
From http://www.stebro.net/stwc.htm:
Why 409 type Stainless Steel pipes and shells?
<UL TYPE=SQUARE><LI>409 type Stainless Steel is specially designed for automotive exhaust systems.
<LI>409 type Stainless Steel resists atmospheric and automotive exhaust gas corrosion.
<LI>409 type Stainless Steel developes a light surface discoloring which will retard progressive corrosion. [/list]
Here is a link that will tell you more than you ever wanted to know about the common grades of stainless steel.
From The Home Machinist's Handbook by Doug Briney:
<BLOCKQUOTE><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><HR> Stainless steels do not require any special coating to protect them, but unless stainless steel is passivated after machining, it is subject to corrosion and rust. The passivation process simply removes all of the ferrous material from the surface, leaving only the chrome and nickel exposed. <HR></BLOCKQUOTE>
From http://www.stebro.net/stwc.htm:
Why 409 type Stainless Steel pipes and shells?
<UL TYPE=SQUARE><LI>409 type Stainless Steel is specially designed for automotive exhaust systems.
<LI>409 type Stainless Steel resists atmospheric and automotive exhaust gas corrosion.
<LI>409 type Stainless Steel developes a light surface discoloring which will retard progressive corrosion. [/list]
Here is a link that will tell you more than you ever wanted to know about the common grades of stainless steel.
