headers or stock exhaust manifolds

[DAVID A HILL]

71 roadrunner 383 automatic. both original exhaust manifolds are broken. should I replace them with manifolds or headers?

 

[Car Nut]

I like the stock manifolds, but if you like more noise and more heat in your engine bay go with headers. On a stock 383, headers will not add that much HP.

 

[Kern Dog]

?????
More heat? Logic tells me that a less restrictive exhaust system would run cooler.
Headers for a stock 383 make about a 18-22 HP difference. Cars with headers do not have to be louder than a car with manifolds either...Manifolds often give a deeper sound with more interior resonance than headers. Thin wall headers do sound more "tinny" and hollow. I still like the sound. Good headers seal well. My TTI headers only get new gaskets when I have pulled the engine.
I have had headers on several cars that had manifolds when I first bought them. The only bad experiences I've had were with CHEAP headers.

 

[PurpleBeeper]

Stock motor stay with stock manifolds because headers are a PIA to put on.

If you want to go fast, then they're a good performance upgrade & also help mileage a little. Your engine bay does not get hotter BUT they do seem to make your feet a little hotter since the collectors end up under your feet and closer to the floorboard in my experience. And if you drive on bumpy roads, some headers can have ground clearance problems (mainly big tube 2"+)

 

[Cornpatch MO]

Seems to me that headers have more square inches of surface area, and that headers will throw off heat quicker. therefore making more heat under the hood. Cast iron exhaust manifolds contain the heat with-in them and more heat goes out the exhaust pipe. I believe headers are mostly beneficial at higher RPM. ...Anyway, that's my story and I am sticking to it ! ........................MO

 

[Car Nut]

The last car I had with headers was a 68 442, made the car hot inside too.

 

[Steve009]

Just put long tubes in my 383. A real b*tch to install but engine bay is cooler, quieter, and car idled smoother. Ceramic coating helps with heat in engine bay a surprising amount.

 

[Kern Dog]

Seems to me that headers have more square inches of surface area, and that headers will throw off heat quicker. therefore making more heat under the hood. Cast iron exhaust manifolds contain the heat with-in them and more heat goes out the exhaust pipe. I believe headers are mostly beneficial at higher RPM. ...Anyway, that's my story and I am sticking to it ! ........................MO

See, this is an example of how several people can have the same information yet still come to opposite conclusions.
Theoretically, What do you think retains more heat: A solid block of iron or thin sheet metal?
Restrictive exhaust systems RETAIN more heat because the exhaust faces more backpressure on the way to the tailpipe exit. Did you know that exhaust pipes are hottest at the points where they have the most restriction?
Hey, have all of the opinions that you want....Dyno tests prove that headers add power and not just at high RPM. First, they flow better, allowing an engine to get even MORE fuel and air in. Secondly, they scavenge the cylinders, in other words, one exhaust pulse sucks the next one out.

 

[MoparLeo]

To keep going on that, the reason that you get some of that mileage increase is because with the lower exhaust restriction the engine will run leaner. So to take advantage of the lower back pressure you would readjust/jet the carb to take advantage of that and get more hp.. The reason you will get opinions all over the place is because everyone's life experience is all over the place. Stock manifolds are heavy and have very thick walls. This keeps noise down under the hood as well as radiant heat. Early headers ( except quality custom made headers) were made from thinner gauge tubing and flange thickness, had no thermal barriers, ceramic coatings, header wraps etc... They tended to get leaks easier, since they had thinner flanges and distorted more when hot. The gasket materials were cruder. The earlier cars didn't have sound/heat deadening shields under the car between the exhaust and the floor boards. Enter catalytic convertors. The early ones would overheat often due to out of tune engines, prolonged idling in traffic and so on. This caused fires and the industry made adjustments to the entire car. Now depending on the construction and quality of your exhaust system, you may still experience some of the old problems. If you purchase high quality (and more expensive) exhaust systems, they tend to have the thicker flanges, thicker gauge and better quality tubing, ceramic/thermal barriers (they help cut down on radiant under hood heat and noise). Depending on your cars setup( engine mods, driveline mods ) and your driving style you may or may not notice any significant power/mileage increases. Don't throw your old manifolds out. They can be repaired and reused and are pretty much maintenance free. Look at how old they are and were still working. That is well past the service life of most header systems and when they wear out you must replace them. I have in the last 40+ years I have used most all of them or worked on them for others. I am now reliving my earlier life with more money and sense than before and run the stock system on my late model Magnum R/T 5.7 Hemi and use the TTI complete system on my 73 Challenger 5.9 Magnum crate. An old saying goes " the quality is remembered long after the price is forgotten" Let that guide you through all areas of your life.

 

[1967coronet440]

I just bought TTI headers with "thermal barrier" coating, supposedly reduces under hood temps by 50* who knows though. I put headers on everything

 

[DAVID A HILL]

?????
More heat? Logic tells me that a less restrictive exhaust system would run cooler.
Headers for a stock 383 make about a 18-22 HP difference. Cars with headers do not have to be louder than a car with manifolds either...Manifolds often give a deeper sound with more interior resonance than headers. Thin wall headers do sound more "tinny" and hollow. I still like the sound. Good headers seal well. My TTI headers only get new gaskets when I have pulled the engine.
I have had headers on several cars that had manifolds when I first bought them. The only bad experiences I've had were with CHEAP headers.

Do the TTI headers fit well or are they a pain to install?

 

[Kern Dog]

I have found that if you go into a header installation trying to take as few obstructions out of the way, you will find trouble. In other words, sometimes I think that I am saving time by NOT removing stuff. Often times those things pose an obstacle and it makes the header installation really difficult.
It also helps to have the car high enough in the air so that whether the header is slid in from the top or the bottom, the collector never has to touch the ground/floor.
TTIs are great, Dougs headers are of similar fitment for about 3/4 the price. The headers on my 70 Charger are the ones with thermal coatings inside and out. I've had them since 2004.

 

[Cornpatch MO]

See, this is an example of how several people can have the same information yet still come to opposite conclusions.
Theoretically, What do you think retains more heat: A solid block of iron or thin sheet metal?
Restrictive exhaust systems RETAIN more heat because the exhaust faces more backpressure on the way to the tailpipe exit. Did you know that exhaust pipes are hottest at the points where they have the most restriction?
Hey, have all of the opinions that you want....Dyno tests prove that headers add power and not just at high RPM. First, they flow better, allowing an engine to get even MORE fuel and air in. Secondly, they scavenge the cylinders, in other words, one exhaust pulse sucks the next one out.

Kern Dog , you are wrong because Mark Worman ( Graveyard Cars ) says so. And he knows more than anyone. ..................(a little sarcasm in case you didn't know) I didn't put headers on my 440 because good ones are very expensive , especially ceramic coated. My past experience was loose header bolts, and leaking gaskets. And I don't like the sound. And, I am a rebel among my peers. Only thing I like is that on well designed headers, the spark plugs may be easier to get to. The 68-69 magnum exhaust manifolds are a bugger to get to the plugs.........................MO

 

[Cornpatch MO]

See, this is an example of how several people can have the same information yet still come to opposite conclusions.
Theoretically, What do you think retains more heat: A solid block of iron or thin sheet metal?
Restrictive exhaust systems RETAIN more heat because the exhaust faces more backpressure on the way to the tailpipe exit. Did you know that exhaust pipes are hottest at the points where they have the most restriction?
Hey, have all of the opinions that you want....Dyno tests prove that headers add power and not just at high RPM. First, they flow better, allowing an engine to get even MORE fuel and air in. Secondly, they scavenge the cylinders, in other words, one exhaust pulse sucks the next one out.

Thicker metal verses sheet metal. Just for sake of argument, thicker metal will retain heat for a longer period of time, but may not throw off as much heat as thinner metal. I can't speak from experience, but a lot of people that do have the experience, claim headers do make more engine compartment heat. I think I will go with the most prevalent opinion.....................MO

 

[Ron H]

Well reading these posts sounds like everyone is in complete agreement. Yeah some irresistible sarcasm as I'm enjoying my Saturday afternoon beer...ok two beers...ok...

 

[rumblefish360]

This is what I have found personally on my rides.

Exhaust manifolds are rock sold super long lasting chunks of heavy iron. There performance level is limited but can be overcome. They get hot but I can not light a cigarette off of them. I tried when I smoked. No good. Won't like a cig.

Headers! Oh big! He we go.....

"UNCOATED HEADERS"

They will, without a doubt, add heat to the engine compartment.

"COATED HEADERS"

Will have a reduced amount of heat over unciated headers by far!

Run coated headers if headers are your choice. Well worth the money IMO.

Headers add power to the old rides with no other work done BECAUSE the OE carb setting is rich from the factory. Once the headers are added, the extra efficient exhaust means the engine out and also helps in cylinder filling.

In general, not perfectly, the engine is running leaner and filling more air and fuel into the cylinders.

THAT! Is how engines make more power with headers alone.

Kerndog mentioned power increase amounts. I'll shy away from this due to 1 thing alone, to many variables!
To many varieties of engine, bike specs & where you live in what ever condition the day is.

 

[MoparLeo]

David, the TTI exhaust systems are the most well thought out design wise, installation is very easy and if you use their complete system and install it properly, you will get many years of good, trouble free service. My complete system, engine to tail pipes ran about $1400. about 8 years ago. There are a few suppliers that offer discounts on the TTI's and I am sure that someone will chime in with that info. Depending again on your cars setup, engine/driveline mods you will see some improvement in performance. TTI normally use Dynomax mufflers which can be a little loud. You can also install resonators that will quiet it down pretty good. Talk to the people down at TTI. They only talk Mopar and don't do any other make.

 

[drobertson]

In my experience, headers have increased mpg on my cars by 2-3 mpg. Not bad, and the extra power is a bonus.

 

[TetanusShot]

My two cents.

I switched from stock manifolds to TTI's this year, they fit like a glove, but not nearly as easy to install as the manifolds. To me, the car sounds exactly the same inside and out. The engine temp went up 10 degrees with no other changes. No special coating on the headers. Mileage has not changed.

 

[relam]

Perfect timing on this subject for me. I am planning on getting the TTI Ceramic coated for my 66 Charger. Not sure what i will do with manifolds they are in very good condition , not stock with vehicle.
thanks for the feed back folks

I will be selling these most likely, were originally for a 440 magnum I was told by Mopar mechanic, my engine is 383 transplant, from a donor. i am third owner