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Mr.Sleepy
Dodge Dakota
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7/22/2004
15:27:48
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 Subject: Warning About Headers on 4.7
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Just to let you guys know that I have about 50k on my 4.7 and the bolts on the manifolds are so rusted that 3 local racing shops have declined to work on my truck out of fear they may snap a bolt. They commented that 50k was too many miles to work in my area due to the harsh climate. Michigan winters are bad and very salty so it doesnt surprise me. I have returned my headers and have bought speakers instead, if I can tbe fast, I'll be loud. If your going to put on header do it on a brand new truck or you might have to pay big dollars to get bolts replaced.
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Izzy
Dodge Dakota
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7/22/2004
17:22:17
| RE: Warning About Headers on 4.7
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Put some Marvels Mystery Oil (or some other penetrating oil) on each of the bolts one evening before chashing for the night and let it sit overnight. Pull the bolts yourself the next day and replace them with some new ones.
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Old Fool
Dodge Dakota
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7/23/2004
12:10:00
|  RE: Warning About Headers on 4.7
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No matter how many miles on the 4.7L or even the type of winters you have the bolts come out very easy due to the Alluminum heads. I have replaced the stocks with headers on several 4.7L Dakotas and a couple of them looked like the bolts were to rusty to get out, but with very little effort and no broken bolts replacement was fairly easy. I do suggest notching the flange on the drivers side for the back 2 bottom bolts since the pipe is only about 1" from the flange making them difficult to start. JBA sends 1.25 x 30mm grade 8.8 (8.8 metric = grade 5) bolts. These are to short and only about 1/2" of the bolt actually goes into the head risking a stripped hole if over tightened. Replace all of them with 1.25 x 35mm bolts and the notch on the 2 back bottom bolts will ease the install since you can put the bolts and gasket on and then slide the header down the notches. Sorry to here your techs in Michigan are bone heads.
Later,
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prple-gaseatr
Dodge Dakota
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7/23/2004
17:43:46
| RE: Warning About Headers on 4.7
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Message:
if you have a john deere shop near you, get this stuff. its called aero-kroil. (thats where they sell it around where i live).its in an orange can. this stuff will penetrate and remove anything. its awsome, pb blaster is ok too,but this stuff really works.
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actually
Dodge Dakota
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7/24/2004
22:00:47
| RE: Warning About Headers on 4.7
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Message:
this is even a better warning!
A few years ago an off-road magazine did a test on the 4.7 hooked up to a dyno, and compared hp and torque with and without headers, the rumor at the time was that the 4.7 exhaust manifolds did a really good job on none or slightly modified engines. Well the short story is that with headers they gained a whole 2 thats right 2 hp and only 3 lb-ft over the stock cast manifolds. BUT those figures only apply to the 4.7 and no other engine.
so the question is,
Do you really need to spend 300 or so for a trick looking set of tubes that improves less then 1.125% and most likely would, in real world use, show no difference?
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Old Fool
Dodge Dakota
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7/24/2004
22:53:36
| RE: Warning About Headers on 4.7
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Message:
Yep on a stock or 'Slightly' modified engine they have very little effect. But the more you do to your engine, the more they improve. And the sound difference from stock to the headers is incredible. They sound a bit sick, but good overall with the stock logs. Put the headers on and it's a different engine completely. And a suposedly built engine is real bare with the stock manifold on it.
Later,
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hey
Dodge Dakota
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7/26/2004
14:10:20
| RE: Warning About Headers on 4.7
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Message:
i see you are still an old fool and did not get the prevoius post,comparing to older style engines the 4.7 is already considered a "more then slightly modified engine" the engine that 4X4 offroad used had over 2000 bucks in aftermarket mods in it before they took it to the dyno. with that much change over stock you would figure that it would give 30 to 45 hp but it gave nothing that would have ever showed up on a time slip. it is also obvious that you have not looked under the hood of a 4.7 and seen the difference between the older style manifolds on the Magnums verses what comes stock on the 4.7
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Old Fool
Dodge Dakota
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7/27/2004
01:23:15
| RE: Warning About Headers on 4.7
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Message:
Nope I never look under the hood of a 4.7L, uh, I take that back, I do every day with mine.
Later,
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Old Fool
Dodge Dakota
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7/27/2004
01:50:09
| RE: Warning About Headers on 4.7
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Message:
And if you have ever been 'Under' a 4.7L and seen the stock 'Y' pipe, then you would understand why even the best headers in the world wouldn't make any difference on the 4.7L. No matter how good they will breath on the bench compared to stock logs, they will not be able to release past the stock 'Y'. Not an argueing kinda person really, but with proper mods they do OK, even better than KB or 4x4 World mag has published.
Later and have a good day,
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mrman
Dodge Dakota
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7/27/2004
07:43:39
|  RE: Warning About Headers on 4.7
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Old Fool,
Do the magnesium valve covers need a lot of prep work before painting??
Also, in the overhead shot of your 4.7, what is that small black connector with the silver colored angled bracket that is bolted to the passenger side fenderwell?
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CThomp
*GenIII*
7/27/2004
09:05:08
| RE: Warning About Headers on 4.7
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Message:
And not to mention...Nice Dak there old fool!! What mods do you have done to it? What did you run in the 1/4 that day?
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Old Fool
Dodge Dakota
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7/27/2004
09:45:33
| RE: Warning About Headers on 4.7
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Message:
MrMan,
The valve covers didn't need a lot of hard prep at all. I removed them and used BerryMans choke and carb cleaner to get the Oil and dirt off of them. Then I took them to the local quarter car wash and sprayed them down good. Then I used Auto Prep by Kleen Strip to prep them. The paint is 500 Degree High Heat paint w/Ceramic by Dupli-Color.
The black connector you are referring to seems to be a relay. Can't realy tell since it runs back into the wiring harness what it goes to, but I figure something todo with the A/C and heating.
C Thomp,
Thanks for the compliment on my truck. I feel better about all the work I have put into it when I get those.
The Performance Mods on my truck are:
Intense Performance Z-Tube CAI
KenneBell Optimizer II PCM Upgrade
F&B 70mm Throttle Body
H.O. Cams
JBA Shorty Headers
Custom True Dual Exhaust With 3rd Cat Removed
IAT Relocated to the Z-Tube
Clutch Fan Removed
As you can tell from the picture that was at Bandimere Speedway in Denver, CO., Elevation 5,800'.
The truck ran so-so that day, but these are my times for 2 runs:
R/T...... .065
60'......2.169
330'.....6.658
1/8th...10.366
MPH......66.95
1000'...13.532
1/4.....16.208
MPH......84.61
NHRA Altitude Correction factor =:
1/4.....15.034
MPH......91.15
R/T...... .037
60'......2.169
330'.....6.672
1/8th...10.412
MPH......66.40
1000'...13.595
1/4.....16.276
MPH......84.38
NHRA Altitude Correction factor =:
1/4.....15.097
MPH......90.90
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android287
Dodge Dakota
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7/27/2004
10:10:08
| RE: Warning About Headers on 4.7
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Message:
Awesome truck old fool. I just wish i could find a shop that has a sweet mendral bender so i could feel the benefits of the true duals with my mods.
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CThomp
*GenIII*
7/27/2004
10:19:19
| RE: Warning About Headers on 4.7
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Message:
Android: Thats the same problem i'm having down here in Ft. Myers. Noone does mandrel bends.
Old Fool: When you relocated your IAT, did you thread your z-tube? Also, where on the tube did you install the IAT? I'm running a 4" z-tube currently. I'm going to get the HO cams and intake installed before I redo my exhaust. I've also got a 70mm BBK Tb.
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Old Fool
Dodge Dakota
JOIN HERE
7/27/2004
11:04:29
| RE: Warning About Headers on 4.7
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Message:
If you use 2.5" pipe from the pre-cats back then using a standard bender and limiting how much bend is done is as good as using a mandrel bender. If you notice on that pick of mine the bends are slight and are done in sections. A shop in Louisiana did mine.
C Thomp, if you look at the pics of my underhood, you will see the blue hose. I bought an extra IAT sensor for the '02 (price = $9.56). It is 1/4 turn unit not threaded like the ones for the older Magnum engine. I drilled a hole in the Z-tube a tad bigger than the sensor, then cut the blue hose shaped like the connector and then pushed it through and done the 1/4 turn thing on it. It fit's well. Made enough difference to pick up 1/10th in the 1/4 mile.
Later,
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Deerridge
GenIII
7/27/2004
12:05:32
| RE: Warning About Headers on 4.7
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Message:
You guys know more about the race stuff than me. I really don't care about that anyway. Headers on my 03 4.7 made a noticable impact on low end torque for pulling (6 too 7k loads). It was very noticable when holding overdrive while pulling at about 2000rpm. Prior to the headers it was a constant in and out of fifth gear. Horsepower gains in the 5 to 6k rpm range for 15 seconds don't mean squat for a work truck. You guys leave the work powerband in 2 seconds or less. I believe the headers move at least 20 ft lbs or better into the range.
Real Horsepower
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CThomp
*GenIII*
7/27/2004
12:24:46
| RE: Warning About Headers on 4.7
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Message:
It really is too bad that header manufactures don't make more of an effort to post dyno charts for their headers. Charts being the key word. Not just a numbers claim. I also use my dak for a considerable amount of towing and would enjoy the low end torque. There are already plenty of ways to make horsepower and torque in the middle to upper power bands.
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deerridge
GenIII
7/28/2004
10:28:39
| RE: Warning About Headers on 4.7
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Message:
It all depends on the mission your on. I couldn't see any great improvement either in the upper ranges, but down low its really there for you. There is alot of dicussion here on the subject. Most indicates headers give extra low torque and adding the catback moves it back upthe curve somewhere. The same type of thing comes up with the bigger throttle bodies. Interesting for sure. The HO cams interest me for pulling torque too. I can't really make up my mind on them, bucks vs improvement wise.
Real Horsepower
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CThomp
*GenIII*
7/28/2004
11:08:06
| RE: Warning About Headers on 4.7
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Message:
The improvements with the cams have been pretty well documented. And with the ho cams the price is less than the headers if you can install them yourself. That is unless you get the krc 206's or higher. Then you're gonna be forkin it out. Thats just the way it goes. As far as headers go I think the tri-y design is supposed to be the best for torque. Thorley has headers now for the 4.7L though I don't think they are
tri-y's.
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