a set of 03/04 cobra heads will outflow the 3V's all day long.
This article, especially the Fox Lake guy's comments at the last paragraph of page one, continuing onto page two, would make a nice addition to your short and sweet reply. If the guy from Fox Lake is wrong, please let us know.
That's impressive for such a small displacement. I'm shooting for 350 RWH on my 2007 with bolt on mods. If you can hit 400 I'm sure I should be able to hit my goal.
This article, especially the Fox Lake guy's comments at the last paragraph of page one, continuing onto page two, would make a nice addition to your short and sweet reply. If the guy from Fox Lake is wrong, please let us know.
I think you're looking into it a little too much. I know Ron very well (he is the owner of Fox Lake).
Anyways, he is right about the 3V heads being very efficient, and it's quite evident on the power output these cars are making. Now, let's not read too much into either. As I have always stated on here, flow #'s only tell a partial story about cylinder heads, and the design of the chamber and valve angle tells a greater part. While the 3V heads are efficient, and are more favorable than the B series 4V heads, and relatively equal to the C (tumbleport) heads, there are certain 4V heads that will always make more power. STL's car is making ~408rwhp N/A and according to him it is maxxed out. Now, I've told him that I could get him another 20-25rwhp out of his car, and that is very true.
We have P/S 4V cars with stock intake manifolds and cams that are making 400rwhp, but they feature the 03/04 4V designed heads.
When people talk about 4V's, they tend to lump all the head designs together. Over the years, there have have MANY different designs, so it's unfair to argue against all of them together. The B heads were a unintelligent, quick thrown together design. Infact, Ford designed those heads in 6 months, because they were disgusted with the results of their original A heads that never went into design. The GT/GT500 heads, and the 03/04 cobra heads are the castings that made the 4V what it is, and those heads will always make more power. We have 480-500rwhp N/A cars running around with those heads. The 3V is efficient and a big step above the 2V, but let's not get carried away either....
This article, especially the Fox Lake guy's comments at the last paragraph of page one, continuing onto page two, would make a nice addition to your short and sweet reply. If the guy from Fox Lake is wrong, please let us know.
That's impressive for such a small displacement. I'm shooting for 350 RWH on my 2007 with bolt on mods. If you can hit 400 I'm sure I should be able to hit my goal.
350 is easily within reach... I was at 347 with a CAI, tune, pullies, eH2O pump, LT headers, o/r x, stage 1 cams and a 62mm TB.
Actually, I wasn't looking into the subject very much at all. You pretty much covered the flow-numbers-aren't-everything point, which is important, because many seem to only look at the numbers.
I get the impression you didn't want to get too involved at the beginning of this thread, but some readers could misinterpret your short and sweet post as saying the 3V heads aren't good (and should be replaced by 4V heads immediately). Having the "resident engine idiot" say the 3V heads can make good power will undoubtedly put some at ease.
Actually, I wasn't looking into the subject very much at all. You pretty much covered the flow-numbers-aren't-everything point, which is important, because many seem to only look at the numbers.
I get the impression you didn't want to get too involved at the beginning of this thread, but some readers could misinterpret your short and sweet post as saying the 3V heads aren't good (and should be replaced by 4V heads immediately). Having the "resident engine idiot" say the 3V heads can make good power will undoubtedly put some at ease.
I have nothing against the 3V's at all, they make power just fine. I've actually been impressed a few times by them. I only made that post to clarify that there are 4V heads that will outflow/outpower the 3V's unlike what STL stated.
The GT/GT500 heads, and the 03/04 cobra heads are the castings that made the 4V what it is, and those heads will always make more power.
While we're still not getting too carried away, is there any argument to the contrary of your statement? The reason for my question is that I've read/heard some discussions of some engine builders preferring the 3V to the 4V head -- of course we still have the question of which of the 4V heads.
While we're still not getting too carried away, is there any argument to the contrary of your statement? The reason for my question is that I've read/heard some discussions of some engine builders preferring the 3V to the 4V head -- of course we still have the question of which of the 4V heads.
The GT/GT500 heads are the best OHC head made to date. They are the offspring of the 2000 Cobra R heads, with the only difference being a 0.100" raised port roof to run a smaller lash adjuster. I have extensive labor in my set of Cobra R heads, and have them flowing ~390/280 @ 28" with VERY good port velocity.
The 03/04 Cobra heads are very good, and will still make more power than the 3V's (obviously stock vs. stock, ported vs. ported). As for the previous gen heads, I hate the B heads, as most will see when I talk about them, so yes a 3v head would be preferable over these.
What I like about the 3V's is the fact that they make rather good torque for an OHC engine, while having the ability to make good top end power. This is obviously ideal for a street car, since nobody will be winding their car out to 7k rpm on every shift. A lot of what turns people off to the 4V's is the fact that they are what I refer to as "torqueless wonders" They just lack that low end punch that we all like from the stoplight.
Regardless, the two 4V designed heads will stil make more power (and quicker ET's). That's why we run them on our 1200+hp engines
The 03/04 Cobra heads are very good, and will still make more power than the 3V's (obviously stock vs. stock, ported vs. ported).
What I like about the 3V's is the fact that they make rather good torque for an OHC engine, while having the ability to make good top end power. This is obviously ideal for a street car, since nobody will be winding their car out to 7k rpm on every shift. A lot of what turns people off to the 4V's is the fact that they are what I refer to as "torqueless wonders" They just lack that low end punch that we all like from the stoplight.
Regardless, the two 4V designed heads will stil make more power (and quicker ET's). That's why we run them on our 1200+hp engines
Thanks for the insight. The reason for my interest is the fact that I'm looking an engine rebuild in the face, so I want to know if going with a 4V setup will be worthwhile. Note, I am aware that a few 3V cars have gone into the 9s with a power adder (good enough for most of us with street cars). In addition, my car is a street car, so I don't want to have to rev it to the moon.
Everybody's talking about the head and external parts swap.
But what about the pistons? I don't know for sure, but the valve cutouts should be different for the 3V vs. 4V. Am I wrong or is there enough clearance with flat top pistons that have no cutouts?
Frank
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2008 GT Premium, Vapor Metallic, 5-speed stick w/MGW, GT500 front end, spoiler and replica wheels. Sequentials, GTA's, FRPP M6066M463V8 Whipple - can't wipe the smile off my face.
Everybody's talking about the head and external parts swap.
But what about the pistons? I don't know for sure, but the valve cutouts should be different for the 3V vs. 4V. Am I wrong or is there enough clearance with flat top pistons that have no cutouts?
Frank
there is plenty of PTV clearance, that valve reliefs are not needed (even with flattops).
Thanks for the insight. The reason for my interest is the fact that I'm looking an engine rebuild in the face, so I want to know if going with a 4V setup will be worthwhile. Note, I am aware that a few 3V cars have gone into the 9s with a power adder (good enough for most of us with street cars). In addition, my car is a street car, so I don't want to have to rev it to the moon.
Stick with what you have (ie. 3V heads). I would not suggest hte switch since it will be a street car only.
I drove a Marauder for 3 years- and there's a LOT more to this equation than just 3v vs 4v.
These new 3v engines are also VVT, guys!
I've got no doubt at all, if you're staying NA, that unless you plan on coming on strong at 120 MPH, the torque these VVT heads gain at low RPM's MORE than make up for whatever tiny HP they lose at 6,000 revs.
Geez... Until a low compression, small block 4v hits 4,000 revs, you might as well get out and push it
You pretty much covered the flow-numbers-aren't-everything point, which is important, because many seem to only look at the numbers.
, is there any argument to the contrary of your statement? The reason for my question is that I've read/heard some discussions of some engine builders preferring the 3V to the 4V head -- of course we still have the question of which of the 4V heads.
