[cammin 4.6]

If this has been covered just tell me what page. I have read this enough to go blue over the past months.

From a tech standpoint, 03 heads outflow 01's in stock form. My question is what if you take a set of 01 or 03 castings and do a full port/valve/etc on them wouldn't they basically be able to flow the same? Is there really any casting difference between 01's and 03's that would prevent this?

I know this isn't a definitive answer but...I believe there is a good bit more material to be removed in the '03 heads then the '01 so theoretically I would think if they were both maxed out the '03 heads would flow more. How much more?...I don't know.

Ashley

 

[Fourcam330]

I know this isn't a definitive answer but...I believe there is a good bit more material to be removed in the '03 heads then the '01 so theoretically I would think if they were both maxed out the '03 heads would flow more. How much more?...I don't know.

Ashley

You can get the '01 heads to flow as well as the ported '03s, but it going to take a lot of $ spent in porting time.
If you already have ported '01s then I can see going this route, otherwise I'd start with the '03s.
The '03 exhaust port essentially begins where a ported '01 ends. Therefore, the porter can spend more time working in other areas. The short turns are also improved in stock '03 castings so they're going to be that much better in the end.
Bottom line, same porter, same $ spent, the '03 heads will win.

 

[Ayrton]

If this has been covered just tell me what page. I have read this enough to go blue over the past months.

From a tech standpoint, 03 heads outflow 01's in stock form. My question is what if you take a set of 01 or 03 castings and do a full port/valve/etc on them wouldn't they basically be able to flow the same? Is there really any casting difference between 01's and 03's that would prevent this?

The 03 / 04 heads are have a better exhaust port design and all things being equal, the newer heads will always make more power. You are simply starting with a better design.

 

[vrtical]

You can get the '01 heads to flow as well as the ported '03s, but it going to take a lot of $ spent in porting time.
If you already have ported '01s then I can see going this route, otherwise I'd start with the '03s.
The '03 exhaust port essentially begins where a ported '01 ends. Therefore, the porter can spend more time working in other areas. The short turns are also improved in stock '03 castings so they're going to be that much better in the end.
Bottom line, same porter, same $ spent, the '03 heads will win.

Thanks thats what I was looking for. I race I don't have any $$$ :biggrin:

 

[vrtical]

So far we have just over 300 cfm with stock valves on 01's and not done. Plan on using oversize valves. This stuff is gonna be interesting

 

[tmhutch]

So far we have just over 300 cfm with stock valves on 01's and not done. Plan on using oversize valves. This stuff is gonna be interesting

Sounds like some great numbers. Post pictures and flow chart if you can :biggrin:

 

[TurboSnakeNINE]

On my 32v turbo application I had a chance to compare the two. By "borrowing" the top end of my buddies motor. I saw an increase of 31rwhp by changing the heads. HOWEVER, the turbo came on faster. Which is a big plus. As for power, we are running in the high end of the spectrum. So if the improvment was there. I'd like to think it would have been signifigant. As it stands though. There is not a big enough improvment to warrant me ditching my navigator heads. And yes, they do require the use of a modified intake.This comparison was between Navi heads and my buddys 03 cobra heads. The cams were identical. Our motors are very similar.

 

[Fourcam330]

Were both sets of heads ported?

 

[NoRcAl CoBrA...]

here are some before and after pics of some heads i am workin on motor is a .060 over on a 03 block high comp n/a motor with all the goodies including a frr500 intake

 

[vrtical]

I saw an increase of 31rwhp by changing the heads. HOWEVER, the turbo came on faster. Which is a big plus. As for power, we are running in the high end of the spectrum. So if the improvment was there. I'd like to think it would have been signifigant. As it stands though. There is not a big enough improvment to warrant me ditching my navigator heads. And yes, they do require the use of a modified intake.This comparison was between Navi heads and my buddys 03 cobra heads. The cams were identical. Our motors are very similar.

.060 over mod block do you have any flow #'s from the 03's? so ported 03's showed gains over ported navi's but your not going to use them? What intake did you use when testing the 03's?

 

[PGreenSVT]

NorCalCobra That is nice looking port work. Do you have flow numbers on those heads?

 

[NoRcAl CoBrA...]

no i dont have any flow numbers yet they are gonna get 1mm bigger valve on the intake and 2 mm on the exhaust these are 01 heads on 03 not even sure if he is gonna get these flowbenched i know i dont have a bench lol i wish i did i do all my own port work and i do it for a real cheap price if the customer decides to flow bench them on there own and is not happy with the results i am more the happy to report if the i/e ratio is not in the 75-80% range i figure for 350-600 bucks is pretty cheap for the work that is done in my opinion...

i dont have any special shop or tools or a reputation even other then the fact the i do sub contract port work of h.c.i motorsports but that is very rare maybe like once an month i am graduating from sequoia institue of auto motive tech. in 3 weeks i hope to start a cylinder head and engine building shop one day wll see i am only 20 got a lot of life left lol ...

 

[TurboSnakeNINE]

Were both sets of heads ported?

Yes - by the same machinist. Port work is near identical.

 

[96CobraConvert]

Need tips and pics on 96 Cobra Intake Porting.

I am getting ready to begin porting the factory intake on my 96 Cobra Vert. I already have most of the bolt-ons other than LT headers. Currently 13.6's @ 103mph on street tires and stock 3.27 gears. I of course would like to see 12's which I don't think are at all out of the question and in fact could probably get there with a 4.10/4.30 gear and Nitto's. I would like the last bit of HP I can out of the car.

I have installed a BBK Twin 62mm Throttle Body but have not enlarged the opening on the intake and figured I would go ahead and port the entire intake while I am doing the enlarging. However I hear alot of talk how if improperly done I can hurt my low-end torque, so I want to do the best possible job and make the most HP/Torque as possible.

Anyone that has any written instructions and pictures available would be greatly appreciated.

Thanks,

Dan

 

[NX330MustangGT]

SHM 4.6L Ford Engines Head Flow.

 

[NX330MustangGT]

Since this is a sticky on head tech, I'll post this link to Fourcam330's ported navi heads along side some Ford GT DOHC heads. :beerchug:

http://www.modularfords.com/showthread.php?t=19500

 

[zooyork970]

So all this talk about heads and I'm wondering about purchasing a 98 Cobra. The 305 stock will not be enough for me so I'm thinking about beefing up the engine. One question: Heads...

I'm just looking for something on the high end of street performance. Nothing too crazy. I'm considering some stock 03 heads with blower cams if i should decide to go with forced induction somewhere on down the road. So is this a good decision. From what I've heard, using the 03 will be good for that all around type of setup, whereas the stock "B" heads are only good up high or in a race app.

Also, what about ported navi heads?? How much would porting be?

 

[Z06KILLR]

I have some flow information on Ford GT heads.

Enjoy

EXHUAST

.50 40
.100 89.6
.150 132.5
.200 168.5
.250 193
.300 212.5
.350 223.5
.400 231
.450 245.2
.500 240.5
.550 245

INTAKE

.50 43
.100 90.8
.150 131.3
.200 169.1
.250 203.5
.300 234.3
.350 257.7
.400 274.3
.450 284.4
.500 290.6
.550 294.6

 

[tmhutch]

Impressive. Are those numbers without port work and at 28"?

Todd

 

[Z06KILLR]

Impressive. Are those numbers without port work and at 28"?

Todd

Yes Sir