| From | Message |
WipLash
R/T
2/29/2004
22:33:11
|
 Subject: RE: 4.7L Under Powered!?
IP: Logged
Message:
Also, the only technological advantage the 4.7L OHC engine has over the 5.2L is the OHC. This drastically cuts down on valve float. Take away valve float and there is no other advantage. In fact there is one severe disadvantage the 4.7L has. The aluminum heads dissipate too much energy/heat. In order for Aluminum heads to make the same HP as cast iron heads the compression ratio has to be bumped up almost 1 (10:1 instead of 9:1).
The 5.7L hemi isn't an OHC engine. What do you say about that? The last I checked the Hemi is making .99hp per cubic inch. Do they have valve float problems? NOOOOO!!! Why? Because they incorporated a shroud just above the lifter that keeps it from floating off the cam lobes. It is real simple. The Chevy guys were doing this 15 years ago on the 350 Chevy circle track engines. I couldn't afford it when I was racing. It accomplishes the same thing as the OHC. The only advantage the OHC has is that it is CHEAPER to manufacture. How does it feel to be the proud owner something that was cheaper to manufacture? It was cheaper to build, but did they lower the price of the truck? NOO! They raised the price of the vehicle because they have everyone convinced it cost more to make an OHC engine? It's the same fraudulent BS they ran for years on FWD. Every FWD car that came out and replaced a RWD car cost more at the dealer, but they cost half as much to manufacture. Go Figure! If you really believe all this BS about the technological superiority of the OHC engine then you will always be sucking the exhaust fumes of that HEMI that just blew your doors off.
|
Trukguy
Dodge Dakota
JOIN HERE
2/29/2004
23:01:07
| RE: 4.7L Under Powered!?
IP: Logged
Message:
Perfect. More misinformation. Give it a rest already. Nobody cares what YOU think. Your whole reason for being here is to ARGUE. Go argue somewhere else.
|
WipLash
R/T
2/29/2004
23:24:20
| RE: 4.7L Under Powered!?
IP: Logged
Message:
I'm just stating facts. I can back up all my infromation with engineering data. If you don't like it go to another thread.
The fact still remains that the 4.7L OHC was developed to cut manufacturing cost. It will eventually share components with the 4cyl. That will further reduce the manufacturing cost. Do you think they will lower the cost of the vehicle? Nope.
|
GraphiteDak
GenIII
2/29/2004
23:42:28
|  RE: 4.7L Under Powered!?
IP: Logged
Message:
I personally LOVED the 5.2/ 5.9
But the 4.7 has many things way more advanced stock to stock.
The HEADS are WAY more advanced. The INTAKE (being plastic and all) is WAY better for power. There is NO heated water or exhaust gases running through our intakes!!! The exhaust manifolds are even better.
The CAMS are A LOT easier to change than on the 318. The T-STAT is a 10 min job on the 4.7 with a reusable gasket that you NEVER have to scrape off. Actually, it looks to me that a LOT of parts are easier to dis assemble on the 4.7 than the older 318 engine.
Face it, those who are now buying new Dakota's are going to get a 4.7 as long as they get a V8. So there's no reason to say it isn't as good. And there's allready people running over 400 HP on these engines. They even have aftermarket internals for them. Is it as cheap as the 318's? No. But you CAN build these engines up and the more demand we get, the more aftermarket support we will start to see. I hope!
|
Trukguy
Dodge Dakota
JOIN HERE
3/01/2004
00:11:25
| RE: 4.7L Under Powered!?
IP: Logged
Message:
DodgeDakota.com used to be a pretty good source of information. Now it's populated with people that spread disinformation and only come here to argue.
Ray, if you want to argue with somebody then go to this site:
http://www.eng-tips.com
There are hundreds of "my knowledge is greater than yours" type of a-holes on that site for you to argue with. You should fit right in. I'm sure they'll really be interested in listening to you brag about the 30 year old engine design you worship. Feel free to tell them about your theory about aluminum heads and how pushrods make more torque. They might enjoy some of your rants about manufacturing costs and the evils of FWD.
No, really. Just go away.
|
WipLash
R/T
3/01/2004
00:51:30
| RE: 4.7L Under Powered!?
IP: Logged
Message:
Trukguy,
It takes an @sshole to know one. You seem to be an expert on @ssholes. Being a Mechanical Engineer, I tend to be more familiar with engines than @ssholes. Since you think I'm an @sshole, I'll take your word for it because you’re the expert on @ssholes......
Since you like to argue about the post people make on this forum, how about reading the first one I made on this thread? It reads like this:
"The thing I like the most about the 4.7L Auto is its responsiveness. It makes up for the lack in torque with extra response, quick shifting auto, lower 1st gear ratio, and a wider torque band. I was really impressed with how the RC Auto ran empty. I was very disappointed when I hooked a light 2000lb trailer to it. If I were to hook my trailer behind my 93 and the same trailer behind my 2002 4.7L, my 93 would blow its doors off. The thing that bothered me the most was that I could not set the cruise on the interstate doing 75mph with it in O.D. pulling a 2000lb load of furniture. It was constantly shifting out of O.D. I know you are not supposed to do that anyway, but I had no problem pulling that same trailer with 4000lbs on it at 75mph with the O.D. and the cruise on in my 93. The 93 supposedly only had 5 more ft-lbs of torque. Something’s not right there."
Nowhere in that statement did I insult anyone or make any derogatory comments. It's people like you that need to read between the lines and go to another forum.
I do like to argue, and if someone like you keeps pushing my buttons I will keep firing back. So, now the ball is in your court. If you don't like reading my post then quit posting derogatory post yourself. Otherwise, I will make a post everytime you do just because I'm an @sshole. You said it yourself, I'm an @sshole. I don't won't to proove you wrong now, do I?
|
Trukguy
Dodge Dakota
JOIN HERE
3/01/2004
01:02:21
| RE: 4.7L Under Powered!?
IP: Logged
Message:
Perfect. Your journey of self discovery is complete. Now that you understand your problem and how you are perceived, maybe you can help yourself?
|
WipLash
R/T
3/01/2004
01:06:43
| RE: 4.7L Under Powered!?
IP: Logged
Message:
You mean I was right? You really are the expert on @ssholes? I knew you were a pretty fart smeller.
|
Trukguy
Dodge Dakota
JOIN HERE
3/01/2004
01:12:16
| RE: 4.7L Under Powered!?
IP: Logged
Message:
ROTFLMAO.
Now that was the first post you've made in this whole thread that I can respect and appreciate.
|
WipLash
R/T
3/01/2004
01:25:20
| RE: 4.7L Under Powered!?
IP: Logged
Message:
Never mind then. I can't even get a good insult contest going. Those Chevy guys really get going when I mess with their heads. You just can't get a true MOPAR man worked up.
I did get way out there on the 4.7L. It is a better engine overall. I just wish it had another 50CI.
|
TexasTodd
Dodge Dakota
JOIN HERE
3/01/2004
12:53:54
| RE: 4.7L Under Powered!?
IP: Logged
Message:
Whiplash,
Did You READ my post, about the price of the HO cams I got?
IT WAS FROM A DODGE DEALER, IN RHODE ISLAND!!!!
Not used from a swap meet!!!
|
JES
Dodge Dakota
JOIN HERE
3/01/2004
15:30:58
| RE: 4.7L Under Powered!?
IP: Logged
Message:
WipLash -- I too am a Mechanical Engineer (Penn State - '95 - w/ tech focus on Vehicle Dynamics and IC Engines) ... and I too have gotten beaten to a bloody pulp on these boards a couple of times for approaching a topic from an engineering point of view. I know it's not worth much at this point ... but I do agree with you (from an engineer's point of view). I see where you're coming from, but I've learned to agree with the mechanics and keep 92% of my engineering thoughts to myself (they sound so much better in my own head anyway). :o)
Eric -- http://photos.yahoo.com/jes_96
|
GraphiteDak
GenIII
3/01/2004
19:28:01
| RE: 4.7L Under Powered!?
IP: Logged
Message:
As far as CHEAPER engines go, I think I once read that the 4.7 was actually MORE expensive for them to build. The HEMI was cheaper. Probably because I believe the HEMI is assembled in Mexico!
|
WipLash
R/T
3/01/2004
20:31:58
| RE: 4.7L Under Powered!?
IP: Logged
Message:
There are some interesting new features in the 4.7L's design. The one that intrigues me the most is the powdered metal connecting rods. I understand the concept because a studied it briefly during my Properties Of Materials class and my 1st cousin is also an Engineer/Metallurgist and his specialty happens to be powdered metal. I plan to get his opinion on powdered metal and how applicable it is for connecting rods.
Once again, powdered metal forgings are CHEAPER than steel or cast iron forgings. Very seldom does something cost less that is also stronger/better.
Martin Gear makes a line of powdered metal gears. I've used them in my manufacturing design work. The problem with using these instead of steel is the shock load the powdered metal gears can handle is half of what the steel gear can handle. They deflect less than steel and they wear less than steel, but if you submit them to high shock loads they will break the teeth off. Unless DC has reinvented/reformulated the powdered metal forging process, I'm afraid the rods in the 4.7L won't hold up under severe shock loads (DETONATION).
This is new technology being used..... I haven't checked, but this maybe the first time powdered metal has ever been used to make connecting rods. There maybe a reason for that.......
|
Kowalski
Dodge Dakota
JOIN HERE
3/02/2004
16:46:28
| RE: 4.7L Under Powered!?
IP: Logged
Message:
Rods in the 4.7 should not be seeing severe shock loads - these motors are quite resistant to detonation. Before jumping to conclusions as you usually do, please realize this is not the first time powdered metal has been used in this aplication. Perhaps the nicest detail takes advantage of that shearing - they shear the rod ends off to come up with perfectly mating rod ends when bolted back up. Please do look into it before you go off on another of your rants - and expect to learn they are well suited to the aplication...
|
GraphiteDak
GenIII
3/02/2004
16:58:06
| RE: 4.7L Under Powered!?
IP: Logged
Message:
He should talk to Duner.
It took a Turbo with a completely stuck closed waste gate to bend his 4.7 rods. It was detonation city and he got on it during a race several times while it happened. He must have had over 600 HP when that happened. He still drove the truck home from what I read from him.
I think he said the pressure even blew out the seal on the intake gasket!
I may be slightly off from memory, but his post is at the DodgeTrucks site.
People seem to be thinking these are one tough enegine. I guess everyone has their own opinion.
|
STS
Dodge Dakota
JOIN HERE
3/02/2004
17:25:08
| RE: 4.7L Under Powered!?
IP: Logged
Message:
Actrully its cheeper to build a OHV engine than a OHC or DOHC because of less parts to install.
The Hemi thats under the hood of you Dodge truck does indeed rev to high to get its toruqe peak. But I remember the older version 330 or 5.4 Triton reaching its toruqe peak at just 2500 revs with a very flat curve. Thats one think I like about the OHC design is that they do produce flatter toruqe bands. Now just imagine if Ford was to dish out 45 More HP on there current Triton motor engine.
Also You can kiss there sloppy V10 good by. It will be replaced by a new big block V8. Its rummord to be a OHC 429.
|
Kowalski
Dodge Dakota
JOIN HERE
3/02/2004
17:38:20
| RE: 4.7L Under Powered!?
IP: Logged
Message:
Where do people come up with some of this nonsense ? Where the cam resides in the motor has NOTHING to do with the torque curve ! Please take the rest of your Ford nonsense to a Ford board, where it should be better received by people who don't like to think too hard...
|
WipLash
R/T
3/02/2004
19:19:45
| RE: 4.7L Under Powered!?
IP: Logged
Message:
Kowalski,
You just explained it without even realizing why the rods are weaker. You can't CRACK the caps of a steel or cast iron forging. The reason they are able to crack the caps off the powdered metal forgings is because they are BRITTLE. You don't use powdered metal or aluminum in high shock load applications for that reason. I made reference to DETONATION as a warning to all the enthusiast that want to run out and jack the timing up on these engines. The 17 degrees full advance that you referenced a few weeks ago is there for a reason. They want to make sure that there is never any chance for detonation. Detonation will destroy this engine faster than any engine Chrysler has ever built.
These pistons are also brittle. They are the Hypertech high silicone castings. They are extremely brittle. I have raced these pistons. They do not hold up under high shock load conditions. They make fine cheap passenger car engine pistons. To make matters worse, they raised the top compression ring to within 1/8" from the top of the piston. Any detonation will cause the piston land on the top ring to CRACK. This has all been documented. I don't have to make anything up. All these fine attributes are what helped me make my decision to sell my 2002 4.7L.
DC doesn't even sell new pistons for future rebuilds. You have to replace the Piston and the Rod as one complete assembly. That is because they know both are WEAK! If one needs replaced then you better replace both.
These are facts.
|
WipLash
R/T
3/02/2004
19:48:22
| RE: 4.7L Under Powered!?
IP: Logged
Message:
STS,
Have you counted the parts? Lets add them up....
4.7L valve train parts:
timing chain sprockets................4
timing chains.........................2
lifters...............................0
pushrods..............................0
lifter retainers/aligners.............0
distributor/oil-pump drive............0
valves................................16
retainers.............................16
springs...............................16
cams..................................2
cam bearings..........................8?
total................................64
5.2/5.9L valve train parts:
Cam..................................1
timing chain.........................1
timing sprockets.....................2
lifters..............................16
lifter retainers/anti-rotation.......16
pushrods.............................16
rockers..............................16
springs..............................16
distributor/oil-pump drive...........1
spring retainers.....................16
cam bearings.........................5
total................................106
There are almost twice as many parts to assemble and manufacture on the 5.2L as there are the 4.7L valve train. To top it off, even the cam lobes on the 4.7L are powdered metal instead of flame hardened cast steel/iron. That is OK. The lobes on the cam are not subjected to any real shock loads. There should be no problem there. The reason the lobes are powdered metal instead of cast iron is because when you do a powdered metal forging the final product needs almost no maching (reduces cost).
What makes a powdered metal forging such a lucrative proposition over castings is the speed in which you can retool. A die shop can crank you out a new forging die in days and it is reusable for several thousand forgings. Cast iron dies are much more expensive to build and maintain and have very short lifespans. You can completely retool a shop in less than a week using powdered metal. It's an Engineers dream metal. Trust me, I know. Anytime I can make an application that can use powdered metals instead of steel stampings or cast iron I get a "pat-on-the-back". Why? Because I just saved the company money.
|
| | <<Previous Page P 3 Next Page>> |
