C3 1969 427 Ceramic headers - what are best?

[Blondie69]

Hi all
Pick your brains time. I am looking at Ceramic headers for my Big Block and wondering where to purchase them from? What make are the best fit without alteration required?
Has anyone changed theirs recently and what challenges did you come across? As nothing always goes to plan.
Thank you

 

[Roscobbc]

Hi Barb. I've used both Hedman and Hooker headers. I ran the black painted Hedmans for about 10 years with no issues - no ground clearance issues.......however the collectors were very close to the floor, especially on the drivers side.....and yes ones feet would get very warm in summer. The collector are relatively short and are fairly easy to link-up to existing system. I suspect that if you have cut-outs it might require some 'surgery'?
Ceramic coated Hedman headers for a '69 BB are 1 7/8" tube item 66891 currently @ $938.96
I currently have Hooker Super Competition Ceramic coated 2 1/8" i.d. headers. Universally recognised as being the very best on the market. They have been on the car for perhaps 12 years - they are starting to show tiny rust spots (much like chrome ones tend to). I simply use TCut to polish the surface and they shine-up really well. They performed significantly better than the Hedmans (especially over 4000 rpm with the specific 'tune' and capacity of my engine). But' (and this is a very big 'but') my Hookers (no longer available) have primary tubes that are 1/4" larger in diameter than the current 2123-HKR @ $1299.95 and 'hang' very low and far back in the chassis creating ground clearance issues. If considering these best check out dimensions before buying.
If your budget allows Hayward and Scott at Basildon will fabricate stainless headers and perhaps link-up to your existing system.

 

[Blondie69]

Thank you Ross for your experience with ceramic headers. I will look into them.
Yes clearance is a must as have only just had a new exhaust system put on and it tucks very nicely away.
The transmission is having to come out again ( leaking oil at the engine) so thought it would be a good time to make more changes and try to keep the engine cooler....if possible with a BB.
What's your thoughts about Doug ceramic headers? Having read many articles ( sometimes not a good idea as I get more confused ) Dougs have been mentioned.
Thank you

 

[Roscobbc]

Doug's are great for side pipes - they seem to have taken over where Hooker have left-off after Hooker discontinuing many variants. Hooker were 'the name' for headers once. Not sure if Doug's do a suitable header for your car (side exit header....yes, underfloor I'm not too sure) ..I'll take a look for you later.
Be careful relating to options like power steering and specifically a/c. Some headers won't fit with these options. My Hookers wouldn't fit an a/c car.

 

[teamzr1]

Here is some interesting exhaust systems that have chambered mufflers

Classic Chambered Exhaust Inc. - Home Page

www.classicchambered.com

 

[Blondie69]

Doug's are great for side pipes - they seem to have taken over where Hooker have left-off after Hooker discontinuing many variants. Hooker were 'the name' for headers once. Not sure if Doug's do a suitable header for your car (side exit header....yes, underfloor I'm not too sure) ..I'll take a look for you later.
Be careful relating to options like power steering and specifically a/c. Some headers won't fit with these options. My Hookers wouldn't fit an a/c car.

Thank you. Yes have read that clearing the spark plugs is also an issue. I need to be sure on the correct ones as they are not cheap. Thank you for your help.

 

[Roscobbc]

Doug's (a division of Pertronics) only appear to offer side exhaust systems for C3 Vettes.

 

[Blondie69]

Great workmanship for the work already done. Definitely don't want to convert to side pipes.

 

[Roscobbc]

Thank you. Yes have read that clearing the spark plugs is also an issue. I need to be sure on the correct ones as they are not cheap. Thank you for your help.

 

[Roscobbc]

Off-the shelf-underfloor headers will obliviate the use of your electronic cut-outs in their current position. The header collectors will sit much further towards the rear of the car and probably under the footwells. Shorty generic non-specific headers may allow the use of your cut-outs in a similar position but will possibly create clearance issues with the clutch linkage or other parts. Someone will need to fabricate some piping and bends between the collector reducers and exhaust pipes, hopefully incorporating your cut-outs. What diameter are your rather nicely fabricated exhaust pipes?

 

[Blondie69]

Off-the shelf-underfloor headers will obliviate the use of your electronic cut-outs in their current position. The header collectors will sit much further towards the rear of the car and probably under the footwells. Shorty generic non-specific headers may allow the use of your cut-outs in a similar position but will possibly create clearance issues with the clutch linkage or other parts. Someone will need to fabricate some piping and bends between the collector reducers and exhaust pipes, hopefully incorporating your cut-outs. What diameter are your rather nicely fabricated exhaust pipes?

2.5 inches diameter. I think shorty are the only option due to clearance issues. Been looking at these tonight but don't have any reviews

 

[teamzr1]

Great workmanship for the work already done. Definitely don't want to convert to side pipes.

Shop used good grade of pipe and made the X-pipe to correct size for good flow but to create best exhaust pulses should be close to the engine and then for rest of length did not use Mandrel bends so final exhaust system is limited to the smaller diameter of bends
Not sure why on the left head had to do so many bends but in the end the exhaust flow is less volume as confined to the bends they did and adds some back pressure

This is a waste as example if using 2 1/2" pipe but bends reduced flow to like 2 inches

Overview of Mandrel Bending​

Mandrel bending is a specialized tube bending technique that utilizes a solid rod, known as a mandrel, inserted inside the tube. This method is essential for maintaining the tube's structural integrity during the bending process.

Key Features of Mandrel Bending​

• Structural Support: The mandrel prevents the tube from collapsing under pressure, ensuring that the final product retains its shape.
• Quality of Bends: This technique produces high-quality bends with smooth curves, avoiding creases or kinks that can occur with other bending methods.
• Material Distribution: During the bending process, the material is evenly distributed, which helps maintain the tube's wall thickness and overall strength.

Advantages of Mandrel Bending​

Advantage	Description
Prevents Structural Deformation	The mandrel supports the tube, preventing any deformation during bending.
Cleaner Bends	Results in aesthetically pleasing bends without visible imperfections.
Versatility	Suitable for various materials and wall thicknesses, accommodating different applications.

Applications of Mandrel Bending​

Mandrel bending is widely used in various industries, including:

• Automotive: For exhaust pipes and other components requiring precise bends.
• Aerospace: In manufacturing parts that need to withstand high stress and maintain structural integrity.
• Furniture: For creating tubular frames and supports.

This technique is crucial for projects that demand high precision and quality in bent tubing.

 

[Roscobbc]

2.5 inches diameter. I think shorty are the only option due to clearance issues. Been looking at these tonight but don't have any reviews View attachment 33233

Unless someone has personal experience using these on a Vette I'd be dubious about laying out good money only to have chop them up.....and then ruin any ceramic coating.
Header flanges often need 'trimming' to clear head bolts, perhaps other items?.
Should have sorted headers first ideally - then all items behind afterwards. A set of stainless headers fabricated on the car to work with current set-up will cost the best part of £1800 - £2000

 

[Blondie69]

Shop used good grade of pipe and made the X-pipe to correct size for good flow but to create best exhaust pulses should be close to the engine and then for rest of length did not use Mandrel bends so final exhaust system is limited to the smaller diameter of bends
Not sure why on the left head had to do so many bends but in the end the exhaust flow is less volume as confined to the bends they did and adds some back pressure

This is a waste as example if using 2 1/2" pipe but bends reduced flow to like 2 inches

View attachment 33234

Overview of Mandrel Bending​

Mandrel bending is a specialized tube bending technique that utilizes a solid rod, known as a mandrel, inserted inside the tube. This method is essential for maintaining the tube's structural integrity during the bending process.

Key Features of Mandrel Bending​

• Structural Support: The mandrel prevents the tube from collapsing under pressure, ensuring that the final product retains its shape.
• Quality of Bends: This technique produces high-quality bends with smooth curves, avoiding creases or kinks that can occur with other bending methods.
• Material Distribution: During the bending process, the material is evenly distributed, which helps maintain the tube's wall thickness and overall strength.

Advantages of Mandrel Bending​

Advantage	Description
Prevents Structural Deformation	The mandrel supports the tube, preventing any deformation during bending.
Cleaner Bends	Results in aesthetically pleasing bends without visible imperfections.
Versatility	Suitable for various materials and wall thicknesses, accommodating different applications.

Applications of Mandrel Bending​

Mandrel bending is widely used in various industries, including:

• Automotive: For exhaust pipes and other components requiring precise bends.
• Aerospace: In manufacturing parts that need to withstand high stress and maintain structural integrity.
• Furniture: For creating tubular frames and supports.

This technique is crucial for projects that demand high precision and quality in bent tubing.

Thank you for this information. I am definitely learning a great deal about exhaust systems. I did ask at the time why a bend at the front and my guy said i would not have been able to get the oil filter out to change it at a later date. The spec i gave him was clearance underneath as the previous system was too low.
I am unable to see where the x pipe would fit if nearer to the engine. I am a complete beginner. But understand what you are saying. Thank you

 

[Blondie69]

Unless someone has personal experience using these on a Vette I'd be dubious about laying out good money only to have chop them up.....and then ruin any ceramic coating.
Header flanges often need 'trimming' to clear head bolts, perhaps other items?.
Should have sorted headers first ideally - then all items behind afterwards. A set of stainless headers fabricated on the car to work with current set-up will cost the best part of £1800 - £2000

Yes timing of work is a hot topic with me at the moment. I have done it the wrong way round but I thought as the transmission is coming out again it would be a good time.
I have been in contact with a guy Macjacks Corvettes in USA so waiting for a quote to ship over and more information. Financial suicide I no. Jury is still out as to whether I get them done.

 

[Roscobbc]

I looked on Hedmans website yesterday - and couldn't see these..............

Hedman 68216 Chevy Corvette 396-502 CID (Without A.I.R.) HTC Ceramic Coated Long Tube Street Headers - John Woolfe Racing

Hedman 68216 HTC Street Headers Ceramic Coated Long Tube Style Application: Chevrolet Corvette 396 - 502 CID (Without A.I.R.) 1963 - 1982 Click here for ful ...

www.woolfe.uk

Collectors appear to point downwards - might be adaptable for your current set-up
Perhaps worthwhile having a word with Woolferace - see if these are actually in stock - perhaps ask if they have a returns policy for goods returned (in original condition) - at £600 its a fair price.

If you can only source mild steel headers there are companies in the UK that can spray ceramic coating - but it must be both internally and externally to achieve proper corrosion protection and reduced surface heat.

 

[teamzr1]

Thank you for this information. I am definitely learning a great deal about exhaust systems. I did ask at the time why a bend at the front and my guy said i would not have been able to get the oil filter out to change it at a later date. The spec i gave him was clearance underneath as the previous system was too low.
I am unable to see where the x pipe would fit if nearer to the engine. I am a complete beginner. But understand what you are saying. Thank you

Granted, I go for best performance, so I see things differently

Being you have a big block it is even more important to assure when on exhaust stroke all gases are pulled out so that the cylinder for next firing of that cylinder has clean air/fuel (AFR) charge

An X-pipe closet to the heads, creates more stronger exhaust pulses
Those pulses increase/pull extracting the gases out, the further the X-pipe is the weaker the pulses are

Also -pipe closer to heads increases torque
As example, here is recorded data from my C5 that has a custom 373 CI engine with long tube headers
with 3 inch collectors and total exhaust is also 3 inch, no reductions at all
As you see with blue line with X-pipe how quicker the torque increases then with no X-pipe installed

.

Any reduction of the exhaust, such as in your case of no Mandrel bends causes flow reduction
Just an example of perfect design for my C5, all 3 inch and lucky I was able to make the X-pipe right off the collectors of headers

At the least require Mandrel bends and X-pipe fitted as close as design will allow
Of course if you're just a waxer
Stock exhaust will do OK with mufflers sound you prefer

If interested in all the testing and design I did for my C5, lots of detail at :

Team ZR-1 X-Pipe project

We decided to make our own exhaust X-pipe to replace where the CATs go for when racing. To me the X pipe should be close to where the bends are that trap gases and not further back where pipes are straight. We also made slip flanges for the CATS so they can be easy swapped with X-Pipe ...

www.teamzr1.com

 

[teamzr1]

As to that snake exhaust pipe section on left head there is a workaround I do

You can buy an oil filter adapter plate, and it replaces the filter and has two oil hose adapters
Oil filter then can be moved anywhere in the engine bay you want and now no filter to be in way of
exhaust pipe

In my case it than allowed me to use a much larger truck oil filter, and add more oil volume as the
oil in those hoses and larger filter