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  #1  
Old 05-19-2008, 10:37 PM
dodger1 dodger1 is offline
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Default 4.7 hop-ups?

Ever since the 4.7 SOHC engine was released I sort of expected to hear of people hot-rodding the motor, but haven't. Any particular reason for that? (Might be the wrong forum for this question) Have any of you modified this engine?
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Old 05-19-2008, 11:42 PM
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ehostler ehostler is offline
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Too much money for too little gain in power. Unless you are building a race engine or a pull engine, it just isn't worth the expense.
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Old 05-22-2008, 08:07 PM
Walkercolt Walkercolt is offline
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Well Ed, you did put it short and sweet. I'd like to see some four vavle heads for the 4.7. That would improve the breathing of the motor, but they probably couldn't be built for less than $5000 a pair. Then a bigger thottle body, a new program for the ECU, headers, and you might get 50-70HP...maybe, at normal RPM's. The same money will give you 100 HP on a 5.2 or 5.9 easy. I think when Diamler had Chrysler, they had other plans for the 4.7 engine. Maybe stuff it into a mini-van, or another sedan platform(like the Intrepid). Something less than the Hemi, but more than a V-6.
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Old 05-22-2008, 08:38 PM
dodger1 dodger1 is offline
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Walkercolt, that comment makes me wonder what Chrysler had in mind for the engine's developement future - as mentioned, an OHC must be more expensive to build than a pushrod motor. Although it's still a base V-8 in trucks and Jeeps.
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Old 05-22-2008, 09:24 PM
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ehostler ehostler is offline
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It was simply a replacement for the tired 318. It had close to the same amount of power, but with better fuel economy. With CAFE hitting Chrysler, they had to do something.
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Old 05-23-2008, 12:26 AM
Walkercolt Walkercolt is offline
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Ed, it was emissions and weight, not fuel economy. The "LA/Magnum" heads had reached their limit on development for HC emissions, and Magnum engines are short-stroke engines which don't emission test as well as the long stroke 4.7L. The HO versions of the 4.7 are much more "car-like" than "truck-like", higher RPM powerband and less low-end power and torque. The Hemi has been TOO successful. High output, clean running enough for cars, and not too exspensive to build. The price of a Hemi was always a problem for the "elephant".There are tons of room for more development of the new Hemi. More displacement, then four(or 5,or 6) valve heads for more power and even cleaner emissions. Very Diamler-Benz-ish, without being an OHC engine(yet). I don't believe during development of the new Hemi D/C thought it would make emissions standards for cars...just a truck/van/SUV engine. The Charger was probably designed around the 4.7L(as crowded under the hood as the Charger is). The magazines(C&D, R&T, Mopar Muscle, etc.) said when Diamler sold Chrysler, several cars under development were cancelled. Some of them could have been platforms with the 4.7 as an option.
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Old 05-23-2008, 09:56 AM
peg leg peg leg is offline
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Default Isn't there...

A 270 HP version in some early 2000 era Jeeps? Maybe the ECU for that engine could retrofit. Then too, the cost for 35 HP could be preventative.
Great little engine, though.
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Old 05-23-2008, 04:23 PM
Walkercolt Walkercolt is offline
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Yeah, they made a HO 270 HP version last year. Cams and a ECU flash, headers, bigger thottle body, exhaust system, about 3-5 grand for maybe 50HP. Not that effective bang for the buck. Not gonna spend that on my Dakota for that return. KRC Performance is about the only performance parts source for the 4.7, and they don't offer that much, and it's all exspensive compared to Magnums or Hemi add-ons.
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Old 05-23-2008, 11:37 PM
dodger1 dodger1 is offline
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Same old story - smaller the market, bigger the price. Thanks for the info, guys - always wondered why the 4.7 seemed to be an orphan - aftermarket-wise.
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