4v Head Comparison

[CobraSwappedV6]

In case anyone was interested in a graph of flow data for the B, C, and 03 4v heads I graphed the data from an article on mustangandfords.com that compares the three heads.

 

[CobraBob]

Thanks for doing that!

 

[shurur]

In case anyone was interested in a graph of flow data for the B, C, and 03 4v heads I graphed the data from an article on mustangandfords.com that compares the three heads.

I would like to see that article.
This is showing b heads out-flowing non-03 c heads....hmmm.

I think the only big difference between the c heads was for better coolant flow.

 

[CobraSwappedV6]

I would like to see that article.
This is showing b heads out-flowing non-03 c heads....hmmm.

I think the only big difference between the c heads was for better coolant flow.

Ford Four-Valve Head Information Guide - 5.0 Mustang & Super Fords

Here is the link to that article, the c heads are much different than the B heads in design. I know many performance shops and builders use B and 03 heads instead of the C heads.

As for the flow I think this quote might explain it, "A design downfall of C heads, and their larger (5.4 Navigator) cousins, is the relatively flat floor and utter lack of a short-turn radius in the throat of the intake port. As such, the incoming air tends to overshoot the valves, making the port "think" the valves are smaller than they actually are."

 

[shurur]

Ford Four-Valve Head Information Guide - 5.0 Mustang & Super Fords

Here is the link to that article, the c heads are much different than the B heads in design. I know many performance shops and builders use B and 03 heads instead of the C heads.

As for the flow I think this quote might explain it, "A design downfall of C heads, and their larger (5.4 Navigator) cousins, is the relatively flat floor and utter lack of a short-turn radius in the throat of the intake port. As such, the incoming air tends to overshoot the valves, making the port "think" the valves are smaller than they actually are."

They were designed for a particular intake design; so I will be looking at that particularly or whether the heads were all tested on the same test-bed.

Thanks

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The increased midrange torque pro-duction and greater overall area under the power curve (when compared to swirl-port heads) will enhance the performance of a street/strip modular regardless of application.

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Fox Lake's worked B heads flowed nearly as much as the newest tumble-port heads, relying mainly on sheer volume, as opposed to velocity as in the newer single-intake-runner tumble port casting.
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I realize that the c heads are not the newest tumble port heads, but I thought that c heads flowed better than all b heads. Maybe it is more about the velocity.

This is an old test, 2004.
I may toss this up to the nasvt FB page for more clarification.

I am just not buying this at this point.
Todd Warren, na svt, has said that the c head will make more power na or fi than the b head.

Maybe it is a velocity vs flow issue though.

 

[shurur]

Ok...found this.
It is a velocity issue.


B heads vs. C heads


Post #3 na svt quote.
Smaller intake ports which equals higher velocity (resulting in more low end over B heads). The overall flow difference of the B and C port isn't that much (@28hg), but the gains are due to the better velocity and the a/f mixing. Oh, and the C heads use a better intake also. C heads will give you 20 or more hp at peak and more torque on the bottom end.

 

[CobraSwappedV6]

Ok...found this.
It is a velocity issue.


B heads vs. C heads


Post #3 na svt quote.
Smaller intake ports which equals higher velocity (resulting in more low end over B heads). The overall flow difference of the B and C port isn't that much (@28hg), but the gains are due to the better velocity and the a/f mixing. Oh, and the C heads use a better intake also. C heads will give you 20 or more hp at peak and more torque on the bottom end.

Very interesting, I have both sets of heads and intakes laying around but it looks like ill be using the C heads.

 

[xblitzkriegx]

The B heads would be great in a street engine if it were around 400ci. The ports are just way too big for a 4.6 and even a 5.4 if you're keeping it under 7500rpm.

I think the b head port volume is something like 235-230cc, I don't remember exactly. It's far greater than what a streetable small bore, small displacement engine needs. For comparison, a LS1 241 head has around 200cc port size and that engine is 65ci larger. It's not a direct comparison because it's 2v ohv vs 4v dohc but you can get an idea of port size vs engine size based on rpm. The LS1 is a far better match for a streetable engine and the b head would work great on the 4.6 at 9000rpm or with 30psi boost.