Dakota Durango Forum banner
1 - 20 of 22 Posts

·
Registered
Joined
·
55 Posts
Discussion Starter · #1 ·
So I hear this is an option on these motors. I'm doing some research on these motors but can't find upgraded heads for them. Any info on this? So far I've found AirRam.com's info but didn't see anything about heads.
 

·
I hate you people.
Joined
·
2,409 Posts
There are no aftermarket heads available for the 4.7. However, there is an option but very few have done: the 2008+ 4.7's had a redesigned heads with a higher compression and revised cam profiles on the cams.
 

·
Condoms prevent minivans
Joined
·
537 Posts
4.7 HO heads are an upgrade, just tough to find.
 

·
Premium Member
Joined
·
2,111 Posts
The only difference between the standard 4.7L heads and the H.O. 4.7L heads are the fact that the H/O heads have "H.O." cast into them... otherwise they are identical and flow just alike. They offer nothing as far as performance gains over the standard 4.7L heads.... they both have the same potential when it comes to porting.

SPEED SAFE, NICK
 

·
Premium Member
Joined
·
2,111 Posts
Yeah, I read a lot too... But our head porter tells us they both flow IDENTICALY... We sent him both sets and he reported back that there is no difference in flow between the two heads. I have also spoken to others who have found them to flow the same.

IF there where any gains to be had between the two it would barely be measureable if at all... Definitely not worth the time and money to swap.


SPEED SAFE, NICK
 

·
110 HP, 11.1 MPG. FML
Joined
·
3,720 Posts
the way i read that, the actual "face" of the head inside the combustion chamber is shaped different to increase turbulence probably. might not flow air faster, but it might clear exhaust more throughly and resist detonation better
 

·
Condoms prevent minivans
Joined
·
537 Posts
There is more to cylinder head design then just flow. The chambers are shaped differently, could be to promote swirl, or flame-front travel, or quench, or even to avoid shrouding the valves (not a problem on canted valve heads like 4.7s, Hemis, 351Cs)... Like 318 heads have a better chamber design then the same era 360 heads. The 360s flowed better, but the chamber design (and a lot of meat for porting) makes the 318 heads better. I believe the same applies here to 4.7 HO heads.
 

·
Registered
Joined
·
411 Posts
There is more to cylinder head design then just flow. The chambers are shaped differently, could be to promote swirl, or flame-front travel, or quench, or even to avoid shrouding the valves (not a problem on canted valve heads like 4.7s, Hemis, 351Cs)... Like 318 heads have a better chamber design then the same era 360 heads. The 360s flowed better, but the chamber design (and a lot of meat for porting) makes the 318 heads better. I believe the same applies here to 4.7 HO heads.
I have had both sets of heads side by side and there is no distibuishable difference to the chambers, valves, or runners. Just better springs on the H/O heads. The 2008+ heads are MUCH, MUCH different though.
 

·
Premium Member
Joined
·
786 Posts
I have had both sets of heads side by side and there is no distibuishable difference to the chambers, valves, or runners. Just better springs on the H/O heads. The 2008+ heads are MUCH, MUCH different though.
According to this article, there are a few differences between normal and HO heads, but nothing that's too earth-shatteringly different. The main differences are the "HO" cast on the side of the HO heads, and the intake valves are deshrouded a bit from the normal heads.
 
  • Like
Reactions: V8Cowboy

·
Premium Member
Joined
·
2,111 Posts
I have had both sets of heads side by side and there is no distibuishable difference to the chambers, valves, or runners. Just better springs on the H/O heads. The 2008+ heads are MUCH, MUCH different though.
Same here... but there are those who have never seen the two side by side and all they have to go on is what they read.

I have had them side by side and flowed with the intention to confirm what has been written... There was no difference what so ever, the only real difference between the two heads are the valve springs and the H.O. cast into the H.O. heads.

But I’m not going to argue with those who have never had the two heads side by side.

For what its worth, if anyone thinks swapping your standard 4.7L heads for H/O heads will give a gain of any sort, you will be disapointed to learn there will be absolutley no difference in performance what so ever between the two heads... and your investment would have been made in vain.

SPEED SAFE, NICK
 

·
Premium Member
Joined
·
786 Posts
Same here... but there are those who have never seen the two side by side and all they have to go on is what they read.

I have had them side by side and flowed with the intention to confirm what has been written... There was no difference what so ever, the only real difference between the two heads are the valve springs and the H.O. cast into the H.O. heads.

But I’m not going to argue with those who have never had the two heads side by side.

For what its worth, if anyone thinks swapping your standard 4.7L heads for H/O heads will give a gain of any sort, you will be disapointed to learn there will be absolutley no difference in performance what so ever between the two heads... and your investment would have been made in vain.

SPEED SAFE, NICK
So go now and buy his $1500 race-ported cylinder heads! Even though he doesn't have any dyno sheets showing what gains he enjoyed from his head modifications! Just go by his flow numbers! Go buy one of his Power Wires, while you're at it!
 

·
Premium Member
Joined
·
2,111 Posts
So go now and buy his $1500 race-ported cylinder heads! Even though he doesn't have any dyno sheets showing what gains he enjoyed from his head modifications! Just go by his flow numbers! Go buy one of his Power Wires, while you're at it!
Really... thats not what this is about. My post where not aimed at selling my heads... They where aimed at informing other 4.7L owners of the differences between the two heads. Mthandt made a comment and I replied to it... but had no intention about saying anything until he brought it up.

So you found an artical on the internet... :clap2: I guess you have all the answers now. Im sure that artical has armed you with all the first hand experience you will ever need to know about the 4.7L engine. :bow:

Again, bottom line... there is absolutely ZERO performance to be had going from the standard 4.7L head to the H/O head. The only thing you will gain is the H/O casting on the head which can not even be seen when installed. So you dont even get a cosmetic gain.


Im just saying.....

SPEED SAFE, NICK
 

·
Premium Member
Joined
·
786 Posts
So you found an artical on the internet... :clap2: I guess you have all the answers now. Im sure that artical has armed you with all the first hand experience you will ever need to know about the 4.7L engine. :bow:
I know enough to question what you did. Maximum airflow alone does not determine how well a head will perform on a given engine. It's well and fine and dandy that you were able to squeeze out an estimated 70 more HP out of your truck's engine, but at what cost? And how much of that performance gain was due to your race-prepped heads? And can you tell me what sort of mean air velocity we could expect with your heads?

If you can't answer these questions, then your advice given here is effectively worth about as much as mine.

Again, bottom line... there is absolutely ZERO performance to be had going from the standard 4.7L head to the H/O head. The only thing you will gain is the H/O casting on the head which can not even be seen when installed. So you dont even get a cosmetic gain.
How do you know this? Did you actually perform flow testing on both types of head? Did you get dyno results that tested the effects of each of the heads? What? Are we supposed to go by just an external visual inspection of the heads? Or the proclamations of some speed shop owner who charges $50 for a cleverly packaged eBay-style resistor mod?

Im just saying.....
So am I...
 
1 - 20 of 22 Posts
Top