Headers, whats the real gain?

[randy73]

do people really look for street cred while driving a 69 charger? you get about as much credit as you need just driving one compared to all the other rides on the road.  Noone really cares if its the fastest thing in town anymore.   About the only people that want street cred are the people that deserve none.  Sorry younger owners, some of us have outgrown that by now.  I build the car to suit me, not anyone else. 

If you have a non RT charger and you've put a big block in the car, by all means put a set of headers in it, it only makes sense.  Having a real R/T sometimes means we don't want to deviate from stock that much.  Maybe a cam, roller rockers, and an aftermarket carb as long as it can't be seen from the external view of the engine bay.  Almost every car i've seen headers on the headers are almost always rusted looking, they're never clean and nice looking.  I have to be willing to make concessions, I'm also not willing to swap out the rear 3.23 open rear in the car, whereas a 3.90 or 4.10 would easily make it quicker in the quarter, i'd much rather have a car that can be driven on the interstate at 75mph with rpms in the reasonable range.  Used to drive it long distances.

I also am more interested in real dyno numbers that show at the wheel hp and torque improvements than I am with just a motor.  I am sure they will add some power, as many tests in the 70s, 80s, and 90s proved that they do add hp, but they almost always tested cars with cams, intakes, and carb changes also which isn't a fair representation compared to the stock.  What do the stock class drag racers use on their cars? how do they get into the low 12s or 11s with an engine that appears stock on the outside? 

Unlike many here that have been driving their chargers, its been so long since my car has been on the street that I'll be happy just to be able to drive it to the store and back without something happening to it.  I certainly don't want to blow the motor up after having it survive 30 years of storage.  The engine only has 70k original miles on it when i stored it. 

while I agree with a lot you said, make no mistake. Dyno number do not tell the whole story about and engine or a car, I have seen many a car with great dyno numbers get blown off the track by cars with lesser numbers. Weight distribution, tire size and width and a lot more go into making a quick and or fast car.

[Lord Warlock]

for sure, my 300hp stealth would blitz the charger in the quarter, even before i upgraded the exhaust, bigger turbos or turned up the boost from 8psi to 16psi. It was no contest, awd makes a world of difference, as well as weight distribution.  Used to get challenged alot when i drove the stealth daily, and i used to race it often, never lost a race in it.  It surprised many car owners on the road who thought it was a heavy pig till they couldn't keep up with it.

Have no idea what the charger would actually run in the quarter, pretty sure it was in the 13s when I drove it regularly, and today it sits on 17x11 rear rims with 315 drag radials so it should launch a whole lot better than it used to.  If it ever gets driven hard again. 

[darkside]

imo when you pop the hood them big hp manifolds make the 440 look more massive so That's what i'll be running.I remember back in the day having to
unbold the drivers side engine mount  and jack the motor up to change header gaskets and starters and I ant doing that again.

[Ghoste]

while I agree with a lot you said, make no mistake. Dyno number do not tell the whole story about and engine or a car, I have seen many a car with great dyno numbers get blown off the track by cars with lesser numbers. Weight distribution, tire size and width and a lot more go into making a quick and or fast car.

All too true, what many fail to see is that the dyno is a tuning device and it is only looking at a portion of the overall package.

[myk]

imo when you pop the hood them big hp manifolds make the 440 look more massive so That's what i'll be running.I remember back in the day having to
unbold the drivers side engine mount  and jack the motor up to change header gaskets and starters and I ant doing that again.

How often were you having to change out gaskets and starters?

[1974dodgecharger]

imo when you pop the hood them big hp manifolds make the 440 look more massive so That's what i'll be running.I remember back in the day having to
unbold the drivers side engine mount  and jack the motor up to change header gaskets and starters and I ant doing that again.

How often were you having to change out gaskets and starters?

Gaskets can blow easy unless u use some kind of rtv on it.  I use Percy's alunmim with rtv nothing's blown now. Lol

[myk]

imo when you pop the hood them big hp manifolds make the 440 look more massive so That's what i'll be running.I remember back in the day having to
unbold the drivers side engine mount  and jack the motor up to change header gaskets and starters and I ant doing that again.

How often were you having to change out gaskets and starters?

Gaskets can blow easy unless u use some kind of rtv on it.  I use Percy's alunmim with rtv nothing's blown now. Lol

From what I gather from most here, it seems that leaking header gaskets is almost a common occurrence.  I don't like the sound of that; then again the Charger never gets more than 3K miles a year anyway, so....

[Ghoste]

If you ignore it yes.  Use a quality HEADER gasket with high temp sealant and then re-tighten the bolts once in awhile and you should not have any problems.

[tsmithae]

I know that Percy's is highly regarded around here and if mine fail, I intend to go that way.  However, I ran into Soupy's gaskets at a swap meet and I am very happy with them so far.  I haven't gotten a lot of run time with them, mostly just breaking in the engine on the test stand so far.  However, it is another alternative and I just thought I would pass it along.  High quality, thick, American made gaskets that are far better (so far) than the thin ones I have run across yet. 

http://www.ebay.com/itm/Chrysler-Big-Block-Exh-Gaskets-361-383-400-413-426-440-/120616430407?pt=Motors_Car_Truck_Parts_Accessories&vxp=mtr&hash=item1c154cab47

[darkside]

imo when you pop the hood them big hp manifolds make the 440 look more massive so That's what i'll be running.I remember back in the day having to
unbold the drivers side engine mount  and jack the motor up to change header gaskets and starters and I ant doing that again.

How often were you having to change out gaskets and starters?

It was my daily driver and back in early 80's  paper gaskets sucked. 

[cudaken]

Far as header leaks, my Hookers Super Comp's on my 68 Road Runner are God, 32 years old?  I have never had a header leak! 

Far as changing starters, yea that still sucks. But over time I have found a few tricks.

My first set of headers where cheap Castlers and what POS they where!

While my Charger was pretty much stock I was fine with the HP Manifolds. It was a driver and a extra 10 to 20 HP did not make a differences to me. Then the Go Fast Bug Bite and I built a new 440 with the GMC 6-71, I added headers. 

Cuda Ken 

[Kern Dog]

These "Are headers worth it?" threads crack me up.
On one side you have the sensible guys that understand the dynamics of an internal combustion engine. They realize that an engine is like an air pump: The faster air can pass through the engine, the more power it will make.
THEN you have the stubborn old timers on the other side that actually believe that their iron manifolds make either the same or almost the same power. THESE same guys have the mistaken belief that an engine needs backpressure to run right.  

Headers do many things, two of the most important are the following:
1) They are less restrictive, allowing the exhaust to flow from the engine faster.
2) They have a "scavanging" effect. This means that as each cylinder fires and pushes out the exhaust, when that tube merges into the collector, it creates a suction that actually draws the exhaust from the next cylinder to fire. In simpler terms, each pulse, each cycle of spent gases that enters the collector creates a path for the next pulse.
No manifold does that.
If you install headers and lose power, you didn't tune the engine to take advantage of the headers.
If you install headers and get leaks, you probably did something wrong.

[Cooter]

^ yep. It in fact, many new cars run some form of tubular exhaust header. Only time I see a cast iron manifold today, it's usually in a high heat, or towing vehicle.

[1974dodgecharger]

I like to go in threads to say the opposite i said in another thread to see who responds and I'm right on who responds only to go opposite what I say, always.  I once said headers give u hp/tq the same person in this thread said no its worthless this time i say its worthless and those people say its worth it 

These "Are headers worth it?" threads crack me up.
On one side you have the sensible guys that understand the dynamics of an internal combustion engine. They realize that an engine is like an air pump: The faster air can pass through the engine, the more power it will make.
THEN you have the stubborn old timers on the other side that actually believe that their iron manifolds make either the same or almost the same power. THESE same guys have the mistaken belief that an engine needs backpressure to run right.  

Headers do many things, two of the most important are the following:
1) They are less restrictive, allowing the exhaust to flow from the engine faster.
2) They have a "scavanging" effect. This means that as each cylinder fires and pushes out the exhaust, when that tube merges into the collector, it creates a suction that actually draws the exhaust from the next cylinder to fire. In simpler terms, each pulse, each cycle of spent gases that enters the collector creates a path for the next pulse.
No manifold does that.
If you install headers and lose power, you didn't tune the engine to take advantage of the headers.
If you install headers and get leaks, you probably did something wrong.

[Lord Warlock]

Don't think i've ever said they're worthless, they have their place and in some cars where power is the only concern I would go with a full exhaust upgrade.  The whole point of this thread was just to find out how much power they would add over the stock magnum manifolds which were considered a decent design which evidently gave a 3 to 5hp increase over the lesser manifolds of the day.  Much of the advertising of the old days said headers would add 30 to 40hp which I've always thought was a little on the high side on an otherwise stock motor.  I figure a good set of headers should add 20hp, which is enough to feel it in the butt dyno but may not equate to much in quarter mile times.

I am an Old Timer, and I believe the stock manifolds weren't bad as far as flow goes, I do however believe that headers SHOULD improve the flow provided the design was an effective one, but am not stupid enough to think that every header will outperform a well designed manifold, not without a port job on the exhaust ports. 

Never put a whole lot of stock in the backpressure necessity part of the argument.  engines flow air in, and they pump it out, the more air the more power.  I have personally seen folks go too large on an exhaust system and had the car get slower in the quarter.   

[1974dodgecharger]

I had a paper gasket aluminmum foil hybrid type gasket always blew at #7 area...

imo when you pop the hood them big hp manifolds make the 440 look more massive so That's what i'll be running.I remember back in the day having to
unbold the drivers side engine mount  and jack the motor up to change header gaskets and starters and I ant doing that again.

How often were you having to change out gaskets and starters?

It was my daily driver and back in early 80's  paper gaskets sucked. 

[BSB67]

These "Are headers worth it?" threads crack me up.
On one side you have the sensible guys that understand the dynamics of an internal combustion engine. They realize that an engine is like an air pump: The faster air can pass through the engine, the more power it will make.
THEN you have the stubborn old timers on the other side that actually believe that their iron manifolds make either the same or almost the same power. THESE same guys have the mistaken belief that an engine needs backpressure to run right.  

Headers do many things, two of the most important are the following:
1) They are less restrictive, allowing the exhaust to flow from the engine faster.
2) They have a "scavanging" effect. This means that as each cylinder fires and pushes out the exhaust, when that tube merges into the collector, it creates a suction that actually draws the exhaust from the next cylinder to fire. In simpler terms, each pulse, each cycle of spent gases that enters the collector creates a path for the next pulse.
No manifold does that.
If you install headers and lose power, you didn't tune the engine to take advantage of the headers.
If you install headers and get leaks, you probably did something wrong.

To think that the right headers don't add power to any engine is just silly.  But I don't think anyone on this thread is suggesting otherwise. 

The OP did not ask: "is it worth it?" And of course the answer to that question is completely personal and subjective and only the OP can answer that for himself.

The answer to his actual question, "what is the real gain?" , based on the information he has given, has been answered as good as it can be.  5 to 40 hp.   There are so many unknown details regarding the OPs specific case that the right answer would simply be a lucky guess.

Here is my guess.  If the engine is 325 hp-ish, the cam is stock or has an overlap of 48° or less, and the exhaust system after the manifold/header flanges is identical, 10 to 15 hp. that would result in a 0.10-0.15 et, and 1.0-1.5 mph improvement at the track.

[cdr]

BSB67 , YOUR car & engine combination is VERY interesting. 

[ACUDANUT]

Does nobody give real advice anymore.
It depends. How much of a fight do you want putting them in. How many times do you want to replace a starter. How many times do you want to replace leaky gaskets.

[BSB67]

Does nobody give real advice anymore.

Heck, generally speaking, I thought the OP got some pretty good feed back.

[RECHRGD]

These "Are headers worth it?" threads crack me up.
On one side you have the sensible guys that understand the dynamics of an internal combustion engine. They realize that an engine is like an air pump: The faster air can pass through the engine, the more power it will make.
THEN you have the stubborn old timers on the other side that actually believe that their iron manifolds make either the same or almost the same power. THESE same guys have the mistaken belief that an engine needs backpressure to run right.   

Headers do many things, two of the most important are the following:
1) They are less restrictive, allowing the exhaust to flow from the engine faster.
2) They have a "scavanging" effect. This means that as each cylinder fires and pushes out the exhaust, when that tube merges into the collector, it creates a suction that actually draws the exhaust from the next cylinder to fire. In simpler terms, each pulse, each cycle of spent gases that enters the collector creates a path for the next pulse.
No manifold does that.
If you install headers and lose power, you didn't tune the engine to take advantage of the headers.
If you install headers and get leaks, you probably did something wrong.

So it's the "stubborn old timers" that don't know that headers do offer some hp gain!  Who the hell do you think first designed them?

[Ghoste]

Whoohoo!  By that rationale it means Im neither stubborn nor old.  Good thing I love headers. 

[cdr]

for me i love headers,as said in previous post lots of variations on the answer to the OP question,headers help fill the cylinder with a fresh intake charge during the overlap cycle of the cam,the intake & ex valve are open at the same time & the exhaust pulse & flow help to draw the intake charge into the cylinder,also intake runner length plays a part in how well the header works ,they can compliment each other or hurt each other,its all about the combination of parts & if the engine was built for headers or built for stock exhaust manifolds, by putting headers on an engine that was specifically built to run manifolds the gain would not be as great as an engine built with headers in mind. there are more variables that i want get into,but bottom line is the camshaft specs are the biggest factor on the answer.

[Homerr]

Almost a 9% increase in HP for that low performing 440.  Not bad at all.

Hmmm, my calculator says 3-5%.

[c00nhunterjoe]

Whats the real gain over manifolds? My rough opinions:

Bone stock- 5 hp
mild (mild cam, intake etc)- 10-15
Drag- (choppy cam, heads etc) 15-25
Race- (full build, 12:1, big heads, big solid roller etc) 30+

There, thats my opinion