Re: Headers vs HP Manifold
[Re: ramman5600]
#1106833
11/04/11 12:25 PM
11/04/11 12:25 PM
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Joined: Apr 2005
Posts: 15,134 Kelowna, B.C. Canada
DPelletier
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Ahhhh, the old headers vs. manifolds discussion. OK, why not? - yes headers will usually show a gain over manifolds. how much depends on the motor/build. Expect maybe 10-15 on a street RB. BUT - most people fail to consider that the exhaust system is a SYSTEM and the motor doesn't really care WHERE the restriction is. I am positive that my HP manifold/2 1/2 " mandrel bent TTI/Dynomax Ultraflow system flows better than a set of cheapie headers mated to the stock exhaust system. - People tend to look at this two ways; one person will say why give up the hp using manifolds and another will say that you can get whatever hp you are after using manifolds with the right build. Both are usually correct: it depends on your perspective. Headers vs. Manifolds pros - flow better, usually pick up some hp, lighter cons - most leak, higher underhood temps, full headers can drag, doesn't look stock. As was said; 500hp can easily be had with manifolds....how much power are you looking for? Dave
1970 Super Bee 440 Six Pack
1974 'Cuda
2008 Ram 3500 Diesel
2006 Ram 3500 Diesel
2004.5 Ram 2500 Diesel
2003 Ram 3500 Diesel
2006 Durango Limited
[url] http://1970superbee.piczo.com [/url]
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Re: Headers vs HP Manifold
[Re: dogdays]
#1106835
11/04/11 02:50 PM
11/04/11 02:50 PM
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Joined: Apr 2005
Posts: 15,134 Kelowna, B.C. Canada
DPelletier
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A common misconception is that headers only influence the top end. Another common misconception is that headers only reduce power by reducing restrictions in the exhaust system.
Dyno tests have shown that shorty headers make more power than manifolds and long tube headers make more power than shorties. It has to do with the length of time the exhaust pulse travels in its own tube. A good long tube header will not only increase power above the torque peak, but it also increases torque below the torque peak. This low rpm increase clearly has little to do with flow restriction.
The oldsmobile head is an example. The center two exhaust ports are run together in the head and come out as one wider port which should lower restriction for those two ports. However, it is always advantageous to divide the ports. There is significant cross-talk between the two which interrupts something, probably scavenging during overlap. Flathead fords also had the center two exhast ports run together. In the flathead crowd it was a well-known modification to run a piece of sheet metal up that center port to divide the sides and increase performance.
There's more to an exhaust system than restriction.
R.
I am aware of all that, yet my observations are still correct. I presume that you meant to say "increase power by reducing restrictions". Restriction isn't the ONLY part of the equation.....but it is the most important part, esp. when comparing relatively restrictive stock exhaust systems.
Dave
Last edited by DPelletier; 11/04/11 02:56 PM.
1970 Super Bee 440 Six Pack
1974 'Cuda
2008 Ram 3500 Diesel
2006 Ram 3500 Diesel
2004.5 Ram 2500 Diesel
2003 Ram 3500 Diesel
2006 Durango Limited
[url] http://1970superbee.piczo.com [/url]
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Re: Headers vs HP Manifold
[Re: DPelletier]
#1106836
11/04/11 02:56 PM
11/04/11 02:56 PM
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Joined: Jan 2003
Posts: 16,376
dogdays
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Re: Headers vs HP Manifold
[Re: DPelletier]
#1106842
11/04/11 03:31 PM
11/04/11 03:31 PM
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Joined: Nov 2004
Posts: 2,825 Sk. Canada
RemCharger
master
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master
Joined: Nov 2004
Posts: 2,825
Sk. Canada
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Whats even scarier is a f.a.s.t car with real headers.
Yeah, you're right; a 383 with headers is the shiznit!
Dave
Sorry wasn't talking about my car. Reread the quote.
fastest I've gone with my motor is 130 ,, so I'm hardly in the same ranks
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Re: Headers vs HP Manifold
[Re: DPelletier]
#1106844
11/04/11 04:22 PM
11/04/11 04:22 PM
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Joined: Nov 2004
Posts: 2,825 Sk. Canada
RemCharger
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master
Joined: Nov 2004
Posts: 2,825
Sk. Canada
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Quote:
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Whats even scarier is a f.a.s.t car with real headers.
Yeah, you're right; a 383 with headers is the shiznit!
Dave
Sorry wasn't talking about my car. Reread the quote.
fastest I've gone with my motor is 130 ,, so I'm hardly in the same ranks
I did reread your quote; you changed it from "fast" to "f.a.s.t." which changes the meaning......and of course there AREN'T any F.A.S.T. cars with headers......against the rules and all that.
anyway, have a good day.
Dave
Well I agree, when you have lemons, you make lemonade. Here's to hoping your day is as good as mine
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Re: Headers vs HP Manifold
[Re: DPelletier]
#1106847
11/04/11 05:27 PM
11/04/11 05:27 PM
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Joined: Nov 2004
Posts: 2,825 Sk. Canada
RemCharger
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Here's to hoping your day is as good as mine
Thanks!
Where in Sask. do you live?; I was just in Regina and Moosejaw for meetings and to visit some friends not too long ago......nice place.
Dave
Saskatoon (saskaboom ? ). Yes very nice city , more importantly, the one with the race track. Last time I was in Kelowna was in the mid 80s. Now theres a nice city. Just curious, do you know if your 'Bee was from here? A friend of mine sold one some time ago... he had 2 6 packs one auto, one 4 spd. Not sure which one he sold. He also has a concours pink 383 with white paint roof.
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Re: Headers vs HP Manifold
[Re: RemCharger]
#1106848
11/04/11 07:50 PM
11/04/11 07:50 PM
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Joined: Apr 2005
Posts: 15,134 Kelowna, B.C. Canada
DPelletier
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Here's to hoping your day is as good as mine
Thanks!
Where in Sask. do you live?; I was just in Regina and Moosejaw for meetings and to visit some friends not too long ago......nice place.
Dave
Saskatoon (saskaboom ? ). Yes very nice city , more importantly, the one with the race track. Last time I was in Kelowna was in the mid 80s. Now theres a nice city. Just curious, do you know if your 'Bee was from here? A friend of mine sold one some time ago... he had 2 6 packs one auto, one 4 spd. Not sure which one he sold. He also has a concours pink 383 with white paint roof.
Anythings possible; I was only able to track my car back 4 owners to about the early '90's. All I know is that it crossed the border into Canada in 2004 from Clovis Ca. and the last time the car appeared to have been driven was 1981 and that it had a California plate on it. My theory is that the car was crashed in 1981 (body damage pass quarter, wheelhouse, bent axle, broken K frame). At some point in time it sat outside but not somewhere really wet as the body was solid.....then somebody tried a very poor attempt at an amature restoration (brazed up many of the underhood holes, hacked and brazed trunk floor replacment, spraybombed dash and gauges, 3 cast pistons and 5 forged ones......well you get the idea). Car then passed through several hands in the US and 2 more in Canada before I bought it and started throwing money at it like a drunken sailor!
Anyhow, if I get up your way, I'd love to and maybe see your buddy's bee's.
sorry to everyone else for the
Dave
1970 Super Bee 440 Six Pack
1974 'Cuda
2008 Ram 3500 Diesel
2006 Ram 3500 Diesel
2004.5 Ram 2500 Diesel
2003 Ram 3500 Diesel
2006 Durango Limited
[url] http://1970superbee.piczo.com [/url]
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Re: Headers vs HP Manifold
[Re: DPelletier]
#1106849
11/06/11 05:05 AM
11/06/11 05:05 AM
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Joined: Dec 2007
Posts: 646 VA.
mosweethemi
mopar
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mopar
Joined: Dec 2007
Posts: 646
VA.
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Hello We have two 1970 Road Runners six pack car, Engines is the same, one has TTI headers ($835.00)and the other has stock manifolds,Both have 3" with 40s flowmaster all the way , one with chrome tips,one with turn downs,Both have 410 gears, one auto trans other 4 speed. The Stock manifolds car sound better and has more power then the header car! both cars have a H pipe also. Is it the stock manifolds ?All but one of the last 10 cars have stock exhaust and 3" pipes. MY Is headers is for drag racing ,manifolds stock street cars 450-550 HP , no engine heat under the hood. no gasket troubles.no floor board heat, again
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Re: Headers vs HP Manifold
[Re: mosweethemi]
#1106850
11/06/11 11:00 AM
11/06/11 11:00 AM
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Joined: Mar 2004
Posts: 3,287 Dalton, MA
Slipknot440
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Posts: 3,287
Dalton, MA
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my stock bore, stroke, iron block, iron head, single 4bbl, 9.1 compression hemi was dynoed with and without headers. 498 hp with manifolds, 511 with 3" headers. Already had 2.5" TTI exhaust from the former 440, so cutting up a new exhaust and dropping a $1000 on good coated headers just wasn't justifiable for 13 more hp. I also didn't mess with my starter or beat up my inner fenders like I have in the past with headers. Also, all the manifold cars i've ever had have never ran hot. All my header cars get a little warm for my taste and have ended up some type of leak.
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Re: Headers vs HP Manifold
[Re: Slipknot440]
#1106851
11/06/11 11:33 AM
11/06/11 11:33 AM
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Joined: Jan 2003
Posts: 24,562 Brookeville, Md
Mr.Yuck
Not enough dumb comments...yet
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Not enough dumb comments...yet
Joined: Jan 2003
Posts: 24,562
Brookeville, Md
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Quote:
my stock bore, stroke, iron block, iron head, single 4bbl, 9.1 compression hemi was dynoed with and without headers. 498 hp with manifolds, 511 with 3" headers. Already had 2.5" TTI exhaust from the former 440, so cutting up a new exhaust and dropping a $1000 on good coated headers just wasn't justifiable for 13 more hp. I also didn't mess with my starter or beat up my inner fenders like I have in the past with headers. Also, all the manifold cars i've ever had have never ran hot. All my header cars get a little warm for my taste and have ended up some type of leak.
I would hazzard a guess as the HP is restricted by the iron intake, carb, low compression and cam selection. Not the header or not to header. Also one doesn't need to spend $1000 on a set of headers. As mentioned before if you already have the mani's and exhaust use it, if you are statrting from scratch and you want the most out of your engine get a set of headers. Some people here think they are the most complicated thing in the world for some reason. If you take your time even cheap sets can be installed w/o issues. ALL headers will be harder to install than mani's so keep that in mind.
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Re: Headers vs HP Manifold
[Re: Mr.Yuck]
#1106853
11/06/11 02:20 PM
11/06/11 02:20 PM
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Joined: Apr 2005
Posts: 15,134 Kelowna, B.C. Canada
DPelletier
I Live Here
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I Live Here
Joined: Apr 2005
Posts: 15,134
Kelowna, B.C. Canada
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Quote:
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my stock bore, stroke, iron block, iron head, single 4bbl, 9.1 compression hemi was dynoed with and without headers. 498 hp with manifolds, 511 with 3" headers. Already had 2.5" TTI exhaust from the former 440, so cutting up a new exhaust and dropping a $1000 on good coated headers just wasn't justifiable for 13 more hp. I also didn't mess with my starter or beat up my inner fenders like I have in the past with headers. Also, all the manifold cars i've ever had have never ran hot. All my header cars get a little warm for my taste and have ended up some type of leak.
I would hazzard a guess as the HP is restricted by the iron intake, carb, low compression and cam selection. Not the header or not to header. Also one doesn't need to spend $1000 on a set of headers. As mentioned before if you already have the mani's and exhaust use it, if you are statrting from scratch and you want the most out of your engine get a set of headers. Some people here think they are the most complicated thing in the world for some reason. If you take your time even cheap sets can be installed w/o issues. ALL headers will be harder to install than mani's so keep that in mind.
Who says the horsepower is restricted? 500hp out of a pump gas, non stroker doesn't sound restricted to me! As far as the intake comment; you know this is a Hemi, right?
anyhow, even though the Hemi manifolds are better than the RB HP ones, this is a good example of a motor that obviously didn't benefit much from installing headers (even the good, expensive ones!)
Dave
1970 Super Bee 440 Six Pack
1974 'Cuda
2008 Ram 3500 Diesel
2006 Ram 3500 Diesel
2004.5 Ram 2500 Diesel
2003 Ram 3500 Diesel
2006 Durango Limited
[url] http://1970superbee.piczo.com [/url]
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Re: Headers vs HP Manifold
[Re: Mr.Yuck]
#1106854
11/06/11 02:57 PM
11/06/11 02:57 PM
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Joined: Feb 2003
Posts: 21,318 Manitoba, Canada
DaytonaTurbo
Too Many Posts
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Too Many Posts
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Posts: 21,318
Manitoba, Canada
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Quote:
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my stock bore, stroke, iron block, iron head, single 4bbl, 9.1 compression hemi was dynoed with and without headers. 498 hp with manifolds, 511 with 3" headers. Already had 2.5" TTI exhaust from the former 440, so cutting up a new exhaust and dropping a $1000 on good coated headers just wasn't justifiable for 13 more hp. I also didn't mess with my starter or beat up my inner fenders like I have in the past with headers. Also, all the manifold cars i've ever had have never ran hot. All my header cars get a little warm for my taste and have ended up some type of leak.
I would hazzard a guess as the HP is restricted by the iron intake, carb, low compression and cam selection. Not the header or not to header. Also one doesn't need to spend $1000 on a set of headers. As mentioned before if you already have the mani's and exhaust use it, if you are statrting from scratch and you want the most out of your engine get a set of headers. Some people here think they are the most complicated thing in the world for some reason. If you take your time even cheap sets can be installed w/o issues. ALL headers will be harder to install than mani's so keep that in mind.
You missed the part where he said this is a HEMI. There's no comparing 440hp manifolds to Hemi manifolds.
versus
Hmmm
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Re: Headers vs HP Manifold
[Re: DPelletier]
#1106858
11/06/11 08:23 PM
11/06/11 08:23 PM
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Joined: Jan 2003
Posts: 24,562 Brookeville, Md
Mr.Yuck
Not enough dumb comments...yet
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Not enough dumb comments...yet
Joined: Jan 2003
Posts: 24,562
Brookeville, Md
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Quote:
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my stock bore, stroke, iron block, iron head, single 4bbl, 9.1 compression hemi was dynoed with and without headers. 498 hp with manifolds, 511 with 3" headers. Already had 2.5" TTI exhaust from the former 440, so cutting up a new exhaust and dropping a $1000 on good coated headers just wasn't justifiable for 13 more hp. I also didn't mess with my starter or beat up my inner fenders like I have in the past with headers. Also, all the manifold cars i've ever had have never ran hot. All my header cars get a little warm for my taste and have ended up some type of leak.
I would hazzard a guess as the HP is restricted by the iron intake, carb, low compression and cam selection. Not the header or not to header. Also one doesn't need to spend $1000 on a set of headers. As mentioned before if you already have the mani's and exhaust use it, if you are statrting from scratch and you want the most out of your engine get a set of headers. Some people here think they are the most complicated thing in the world for some reason. If you take your time even cheap sets can be installed w/o issues. ALL headers will be harder to install than mani's so keep that in mind.
Who says the horsepower is restricted? 500hp out of a pump gas, non stroker doesn't sound restricted to me! As far as the intake comment; you know this is a Hemi, right?
anyhow, even though the Hemi manifolds are better than the RB HP ones, this is a good example of a motor that obviously didn't benefit much from installing headers (even the good, expensive ones!)
Dave
ok...low output hemi and hemi manis. Ask the FAST guys if they'd like to run even small tube headers vs the manis. His motor doesn't need headers because of the low numbers, however if he had some cam a decent carb (or carbs) and intake the headers would add well more than 13hp. You can gain up to 38 more HP going from 1 3/4" to 2" in a semi-mild 440.
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Re: Headers vs HP Manifold
[Re: Mr.Yuck]
#1106859
11/06/11 09:32 PM
11/06/11 09:32 PM
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Joined: Nov 2004
Posts: 2,825 Sk. Canada
RemCharger
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Sk. Canada
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Quote:
You can gain up to 38 more HP going from 1 3/4" to 2" in a semi-mild 440.
Nothing wrong with manifolding-down a 550hp motor to 500. Its still nothing to laugh at. Me being the extremist that I am,,, would prefer the free- flowing version. Again* nothing wrong with restrictive exhaust.
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Re: Headers vs HP Manifold
[Re: RemCharger]
#1106860
11/07/11 02:03 AM
11/07/11 02:03 AM
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Joined: Jan 2003
Posts: 27,421 Balt. Md
383man
Too Many Posts
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Posts: 27,421
Balt. Md
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You can gain up to 38 more HP going from 1 3/4" to 2" in a semi-mild 440
I would be surprised to see that much gain. I know CPPA had a test done years ago on a mild 440 and it was just as fast with the smaller 1-3/4 tubes as the 2" because it lost low end on the 2". To me the stronger engines will benifit more going with the larger tubes. I could be wrong but I didn't think it would make that much difference on a mild 440. Ron
Last edited by 383man; 11/07/11 02:03 AM.
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Re: Headers vs HP Manifold
[Re: Mr.Yuck]
#1106861
11/07/11 10:00 AM
11/07/11 10:00 AM
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Joined: Jan 2003
Posts: 4,664 Newfoundland
mopar_man
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master
Joined: Jan 2003
Posts: 4,664
Newfoundland
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My , I wouldn't put headers on an outhouse. Absolute trash with no measurable gain on a street motor. If your drag racing and need to get every scrap of hp available , sure go for it and they will increase hp but be prepared for leaks , excess heat , fried wires , etc etc
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Re: Headers vs HP Manifold
[Re: mopar_man]
#1106863
11/07/11 11:54 AM
11/07/11 11:54 AM
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Joined: Jan 2003
Posts: 27,421 Balt. Md
383man
Too Many Posts
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Balt. Md
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Quote:
My , I wouldn't put headers on an outhouse. Absolute trash with no measurable gain on a street motor. If your drag racing and need to get every scrap of hp available , sure go for it and they will increase hp but be prepared for leaks , excess heat , fried wires , etc etc
I dont know what headers you use but I have never had any of them problems. In fact the headers on my sons Dart have been on the car since 1997 and have never leaked or blew a gasket or burnt a wire. The same with my 63 as I have no problems at all using headers. They make much better headers now with thick flanges then the junk back in the 70's with paper thin flanges. I will take headers any day over manifolds on a performance car. Unless I ran a class where the rules make you run manifolds I will take the hp and use headers. Ron
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Re: Headers vs HP Manifold
[Re: 383man]
#1106864
11/07/11 12:32 PM
11/07/11 12:32 PM
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Joined: Jan 2003
Posts: 24,562 Brookeville, Md
Mr.Yuck
Not enough dumb comments...yet
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Not enough dumb comments...yet
Joined: Jan 2003
Posts: 24,562
Brookeville, Md
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Quote:
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My , I wouldn't put headers on an outhouse. Absolute trash with no measurable gain on a street motor. If your drag racing and need to get every scrap of hp available , sure go for it and they will increase hp but be prepared for leaks , excess heat , fried wires , etc etc
I dont know what headers you use but I have never had any of them problems. In fact the headers on my sons Dart have been on the car since 1997 and have never leaked or blew a gasket or burnt a wire. The same with my 63 as I have no problems at all using headers. They make much better headers now with thick flanges then the junk back in the 70's with paper thin flanges. I will take headers any day over manifolds on a performance car. Unless I ran a class where the rules make you run manifolds I will take the hp and use headers. Ron
like I said Ron some folks here think they are the hardest thing next to rocket science. Actually headers are a good cheap alternative to Hi-Po manis. Hi-Po manis can cost twice what a set of headers cost. If you go w/ headers you get the added benefit of MEASURABLE HP and MPG's if you care about that.
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Re: Headers vs HP Manifold
[Re: DPelletier]
#1106866
11/07/11 03:15 PM
11/07/11 03:15 PM
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Joined: Jan 2003
Posts: 5,888 Athens, Greece
Pyper70
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Joined: Jan 2003
Posts: 5,888
Athens, Greece
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Anyone who says HP manifolds don't leak hasn't experienced an HP manifold leaking. I had one leak. Now place yourself in the middle of nowhere without a reputable machine shop. Now bust out the hand files and emery cloth and sit there for 10hours sanding down the entire flange of a 40 yr old cast iron manifold (happened 2 years ago). I have purchased since then a set of plain jane hedman shorties which I sent out to get blasted and then Jet Hot coated. I do plan on installing them on my 440 I just haven't allocated the time yet. My 440..Nothing crazy..480 lift Isky, 10:1, Dual Quads, 727 with a gear vendors. I will say though that the 906s are coming off along with the HP manifolds and I am installing the Eddy heads that have been sitting on my shelf for 2 years. Down the road, these Hedmans are going to get bolted with the same induction (dual quads, CH28, Eddy heads) to my 505 stroker. 4.15 crank, .540 Comp roller, H beam rods, 11:1 motor. I fear the only thing at that point weak in the system will be the trans but I do not lay into it at street lights, I don't do burnouts....I run down the line and chirp tires between gears. Hoping for 475hp on my 440 now and 575hp on my 505.
Family owned 1969 Charger R/T DualQuad 440/727/GVO/3.55s
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Re: Headers vs HP Manifold
[Re: DPelletier]
#1106868
11/07/11 05:40 PM
11/07/11 05:40 PM
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Joined: Jan 2003
Posts: 27,421 Balt. Md
383man
Too Many Posts
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Ron I didn't belive it either until I read t he Car Craft artical that somebody posted here. As a matter of fact I think it was 39. I don't have the link but I'm sure it can be googled w/o much effort.
39 on one particular motor; sure. The reality is that you could gain anywhere between nothing and 100hp: it depends on the build.
It really isn't rocket science; the amount of power gained by switching to tube headers from manifolds depends on a number of things;
- the manifolds in question. Our HP manifolds are decent - better than GM BB manifolds and worse than Hemi or MW manifolds.
- where the other bottlenecks are; there isn't as much point in increasing exhaust flow on a motor that has a crappy flowing intake, heads, etc.
The best example of a motor that needs headers that I can think of is a 427 L88 BBC which due to it's restrictive factory manifolds, good flowing heads and a radical solid lifter cam can gain somewhere around 80 - 100hp with the swap. My guess is a stock street hemi or Max Wedge falls on the other side of the spectrum; the stock manifolds flow much better than their GM counterparts. An RB with HP manifolds falls somewhere in between......depending on how it's built. I would guess that a bone stock 375hp 440 Magnum would see a slight increase along the lines of 10-20hp......is that worth it? that depends on how you weigh the pros and cons; there is no right or wrong answer.
+ Dave
Actually I may have misled some as I thought Mr Yuck meant 39 hp going from 1-3/4 headers to 2" headers not from manifolds. And he may well be right as it just seemed like alot for the header upgrade. Sorry if I misled anyone. Ron
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Re: Headers vs HP Manifold
[Re: DPelletier]
#1106870
11/07/11 08:40 PM
11/07/11 08:40 PM
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Joined: Jan 2003
Posts: 24,562 Brookeville, Md
Mr.Yuck
Not enough dumb comments...yet
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Not enough dumb comments...yet
Joined: Jan 2003
Posts: 24,562
Brookeville, Md
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Quote:
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Actually I may have misled some as I thought Mr Yuck meant 39 hp going from 1-3/4 headers to 2" headers not from manifolds. And he may well be right as it just seemed like alot for the header upgrade. Sorry if I misled anyone. Ron
Perhaps not; rereading the posts, maybe you were right and they meant 39hp between 1 3/4" and 2" headers. All I know is that is way more that I would think is possible on a stockish/street style 400 -450hp build. On a 500-600hp motor, maybe.
Dave
it was header vs header. and it was here maybe a week ago. I'll see if I can find it.
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