Frequently Asked Questions


Why do I need Adapter Flanges?
Adapter Flanges were created to allow the use of larger tube sizes with cylinder head bolt patterns that restricted the tube size.  An adapter flange is drilled for both the original bolt pattern and a new bolt pattern.  The adapter flange first bolts to the cylinder head and then the header is bolted to the adapter flange.  (demo video)

Adapter Flanges DO NOT allow you to go from one cylinder head configuration to another.  For example, you cannot adapt a header built for a 23° Chevy head to fit an 18° Chevy head, or to go from a standard port spacing to a spread port design.  This is not the purpose of an adapter flange.

Notes: Upon receiving adapter flanges, they must be port matched to the cylinder head prior to installation.  Normally made from 5/16" steel, adapter flanges can be special ordered in 3/8" thick steel.  In the case of small block Chevrolet 23° cylinder heads, the head manufacturer may have already drilled them with the Stahl 23° 7-bolt pattern.  In this case, adapter flanges are not required.  

Most spread port small block cylinder heads normally come with the Stahl 23° 7-bolt pattern.  Please do not confuse a cylinder head with spread ports and a Stahl 23° bolt pattern with an 18° head with the Stahl 23° bolt pattern, or a conventional 23° port location head that may have been drilled with the Stahl 23° 7-bolt pattern.  Feel free to contact us with any questions about your application.  

To see a short video about adapter flanges click here
For adapter flange dimensions click here.
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Does Stahl Headers offer ceramic or flame spray coating?
Stahl Headers does not provide ceramic or flame spray coating.  Instead, we use an 1800° silver paint, which if properly cured is very durable.  

If you are considering having your headers coated, you can request we build them without paint when ordering.  However, we very strongly suggest that you install your new unpainted headers prior to having them coated.  By running the engine for at least 20 minutes you will bake out most all of the lubricants and chemicals used during the process of making steel, forming it into tubing and finally bending the tubing.

IMPORTANT:  Always fit check a header before it is sent out for coating.  Headers coated with ceramic or flame spray coatings are no longer weldable.  Coated headers are NOT RETURNABLE under any circumstances.  Any header that has been modified by the customer in any way is NOT RETURNABLE.
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How do I cure the paint on my new Stahl Headers?
Ideally when removing them from the box and plastic bag you handle them very carefully as the paint easily rubs off until it has been heated to over 500 degrees.  If you have access to an acetylene torch hang the headers and aim the torch up into the collector so the heat comes out the tubes at the header flange.  Otherwise you can use a heat lamp or heat gun. This procedure bakes the paint on the header and assures longer paint life.
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Should I use a Header Wrap? 
NO! ABSOLUTELY NOT. There is nothing that will damage a header faster than the use of a header wrap, other than attacking it with a hammer or shot gun.  As advertised, these wraps do keep the majority of exhaust gas temperatures within the header.  The result is the wraps will prohibit the header tubing from cooling properly.  If you reduce the ability for headers to dissipate adequate heat properly, the result will  be premature failure of the metal.   Depending upon the application use and temperatures involved, the life can be reduced to only a few hours.  We consider exhaust wraps to be the header manufacturer's best friend. 

If engine compartment temperatures are an issue, the best solution is to use insulation materials on the sheet metal.  One alternative in some applications is to build a box around the headers and actually duct outside air into the box.  In some applications ceramic coatings have been known to help (see notes on coatings above).  Insulating any components that may be sensitive to heat, such as wiring, fuel & oil lines, etc., are a better option.

IMPORTANT: Use of header wraps will void any warranty.
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Are stainless steel headers an option?
Not at this time.  Our headers are constructed from mild steel.  Due to the increased cost of material and labor to assemble stainless headers, we find there to be a cost multiplier of 4.

If properly cared for, our headers are very durable.  It is not uncommon to find Stahl Headers that are 20 or more years old that are still in use today. 
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I don't see my application listed.  Do you build custom headers?
Yes, Stahl Headers can possibly build you a header for your custom application.  In our world the word "custom" means headers built on the vehicle. Timing as to the date may also be an issue as we normally do custom work from July thru December.  Finally, it should be understood that costs for a custom design and build can run between $2500 and $3000 for a V-8 application.  Feel free to contact us with any questions about your special application.  We may be able to offer you alternative solutions.
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Do you keep headers in stock?
Due to the many differences between cylinder head and block designs, Stahl Headers builds each header to order.  With so many after market cylinder heads being used, and those heads having measurable differences in port heights, locations and shape, it becomes necessary if you want optimum flow and power from your headers.  This allows us to build your header for your specific engine, ensuring the optimal fit and performance.  We frequently request a port template due to all the port shapes and locations that result from custom ported cylinder heads.  Average production time for a header order is usually between 10 and 14 business days.  Rush orders may be possible, depending on the current workload.  Feel free to contact us with any questions about your application.
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What is a port template?
Exhaust Port / Header Flange mismatch is one of the quickest ways to rob horsepower, yet is often overlooked.  Therefore, we take port alignment very seriously.  You may be requested to provide us with a port template prior to us building your header.  For instructions on how to do this properly click here
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Removable or Weld-On Collectors... Which is right for my vehicle?
When comparing Removable and Weld-on collectors of the same dimensions, there is no difference in performance.  However, there are other factors to be considered before choosing which style you need.

For example, removable collectors may simply make it it easier to install a header on certain vehicles.  More importantly, removable collectors also allow for the serious racer to "tune" their exhaust to specific race conditions through the use of adjustable primary pieces, or by changing the collector outlet size.  If your headers are damaged, removable collectors significantly reduce the cost of repairs.

However, on certain applications, such as a street driven vehicle, removable collectors are not your best choice because they will leak and there is no practical way to stop the leaks.  Thus, we always advise using fixed or weld on type collectors for a street driven vehicle.  Feel free to contact us with any questions about your application.
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I just bought a weld-up kit and some of the tubes appear to be bent incorrectly.
Before assembling your kit, please read the instruction sheet and other documentation included with your kit carefully.  Some kits may contain certain pre-bent tubes that require a "cut and weld".  This is simply because of the physical limitations of the bending machine itself and cannot be avoided.

There are some occasions where you may need to make a cut, remove some length and/or rotate a section of the tube to make it fit properly.  All of these modifications are carefully documented in the instructions included with your kit.  If you use care, take your time and follow these instructions, assembly of your kit should go smoothly.  

If you have lost or are unable to find your enclosed kit instructions, copies can be downloaded here.
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How do I fit a round tube into a square hole?
To form the tube to fit in the flange, we lay the end of the pipe on a vise, hammer and rotate in 90° increments until it fits into the flange.  We then tack weld the pipe to the flange.  After all 4 pipes are tack welded to the flange, we put the header in a vise on #1 pipe with the gasket site of the flanges facing up.

We use a large rosebud tip to heat the part of the tubing that is sticking through the flange, or any other part of the tubing we want to form, to a dull red color.  We then use a long punch, about 10" long, and lightly hammer on the side of the punch to form the tube.  Great care must be taken to not overheat the tubing.  It may takes as many as 15 or 20 cycles of heating and forming to finish one cylinder.

When the pipe is formed on one side of the flange, we tack weld the pipe to the flange to hold it in place with either MIG or TIG.  Then reposition the header to hold it by another cylinder pipe, for example #3 cylinder.  When finished forming all the pipes, we braze the pipe to the flange on the outside.

A printable copy of these instructions can be downloaded here.
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Why do Stahl Headers cost more?
That's a fair question.  We'd much rather explain the price than apologize for quality like other manufacturers are forced to do when their product is compared side by side with a Stahl Header.  Stahl Headers cost more because they take much longer to build.  Each header is is built one set at a time.  The processes we use result in headers that frequently last up to 10 years on a oval track car, and 20 to 25 years on a drag race vehicle.  We use a flange that is selected to match your port shape and location.  Our expertise in selecting the right tube / collector size combination is un-paralleled in the industry.

We were the pioneers of many technical components that are used today by the racing world in general.  Stahl Headers dedication to quality has resulted in a product that is the standard by which others are judged.

For additional information on why you should purchase a Stahl Header click here.
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