Giving new life to GT40X heads

[Casper393W]

In the Ford performance circles the GT40X cylinder head is viewed as a mediocre entry level head. The Ford aftermarket is in full swing. Trickflow, AFR, Edebrock,and Dart all offer superior castings to the GT40X from Ford Performance.

I'm not dogging out Ford's offering because on a bone stock engine they will provide a great gain! You can expect to see 40-60 Hp gain over a stock E7 head depending on the combo.

What if you are building an engine on a budget and you are looking at your local craigslist ad and you see a set of these heads for $500-600 dollars.... Can you make these heads perform like a set of Trickflow's or Edebrock heads? We are about to find out. I'm putting together a 393W and since I have these heads already. We (David Vizard) and myself are going to see how well these heads respond to a bowl blend and good valve job.

Here are the specs starting out
Intake port volume 180cc as measured
Exhaust port volume 65cc as measured

1.94" intake 1.54" exhaust valves. This is a X307 Casting

Flow measured @ 28"

.050. 30.8. 24
.100. 59. 50
.150. 92.2. 76.9
.200. 123. 98
.300. 179. 121
.400. 213. 131
.500. 218. 133
.600. 229. 135
.700. 232. 135

This is the baseline, I will post more data as we progress and hopefully we can deliever the goods without breaking the bank!

Andy

[F-BIRD'88]

The flow is low where you need it. Forget the very high lift flow numbers.
Get it to flow at .400" and .500". Get the ex up to 180cfm.
Kinda a small head for a 393 CID motor.

Does this head casting respond to larger valves, reliably.? (casting meat)

[Casper393W]

I forgot to add...we flowed the exhaust without a pipe.
Yeah the head is on the small side for a 393 build. Ford actually offered a 393 crate engine with these heads in a 64cc version vs these at 58cc. Those engines were rated at 430HP. When we are done my goal is atleast 500hp

I will post pics of the ports later on tonight

[Casper393W]

These heads are pretty meaty as far as porting. It has a decent chamber that needs some work to maximize port flow in the mid range...

On the internet people love to bash this head but while I realize this will never be a AFR head it will be respectable in the end!

[Walter R. Malik]

Way back in 2003 to 2005, "Ford Racing" offered that package as a crate motor.

The M-6007-A392E using the Ford "Sportsman" block with with 9.7/1 compression ratio, reverse rotation "production" water pump, UNPORTED "X" heads with "bolt down" roller rockers, CompCams #XE282HR hydraulic roller camshaft, Mallory billet distributor, Ford Victor intake manifold, SFi damper & billet flywheel and using a 750 cfm vacuum secondary carb, made 450 lb/ft of SAE torque @ 4,000 RPM and 430 SAE horsepower @ 5,500 RPM.
Be aware that SAE dyno numbers are considerably less than STANDARD dyno numbers.

ALL for $6,800.00, customer list price.

With porting those heads, more compression ratio and a better camshaft ... 500 horsepower; easy.

[Carnut1]

The flow #s are near a done up E7TE head to start with. The difference is the ported E7TE head is doing it with 150cc port. I would not hog that port out, I would Pitot and graph that port and remove only what you really need to hit your goals. David will be a big help with this. The exhaust will need a full workup but they should go 175cfm or more without issue. Thanks, Charlie

[Casper393W]

Way back in 2003 to 2005, "Ford Racing" offered that package as a crate motor.

The M-6007-A392E using the Ford "Sportsman" block with with 9.7/1 compression ratio, reverse rotation "production" water pump, UNPORTED "X" heads with "bolt down" roller rockers, CompCams #XE282HR hydraulic roller camshaft, Mallory billet distributor, Ford Victor intake manifold, SFi damper & billet flywheel and using a 750 cfm vacuum secondary carb, made 450 lb/ft of SAE torque @ 4,000 RPM and 430 SAE horsepower @ 5,500 RPM.
Be aware that SAE dyno numbers are considerably less than STANDARD dyno numbers.

ALL for $6,800.00, customer list price.

With porting those heads, more compression ratio and a better camshaft ... 500 horsepower; easy.

David said that you know these heads inside and out!

I can say that these heads have quality components. They come equipped with PAC beehive springs with 10 deg locks, even though the valves have Ford numbers etched on them they appear to be Top Quality.

The port has a good shape, but suffers from having a flat floor and a short turn radius that is flow challenged.

Walter: what is the most you have ever seen a set of these flow?

[ClassicComp]

I have a customer that runs these on a 302 fairmont with a best of 11.94@113.
I would really like to find out how good these can be with some work.

[F-BIRD'88]

If you want to end up with a real 500 BHP from your 393W once these heads
are fully ported, You're going to have to cam it up.
Don't bother with a Hyd roller on this one.
Get a solid flat tappet cam or go straight to a solid roller street roller cam setup.

Something around 255-264@.050 on a tight snotty 105-106-107 ish LSA.
EG: a custom grind version of a Comp XR street roller cams.
DV can help you with this. and all you got to do is pick up the phone to custom order it to your specs. You don't need $1K roller lifters for this.
The standard solid Rollers lifters are fine on these cams.
Use what every big single plane racey manifold is best.
Use a big 800++cfm carb and fair big headers to let it eat.
Expect to rev it up a bit.

[wyrmrider]

When do we get mod e6 into the mix?
how much low end do you loose e6 vs e7 and GT?

[Casper393W]

Here is the intake that is going to be used! With Pricemotorsports adapter plates

[Casper393W]

The carbs have been worked over by BLP and are killer!
One of the hurdles is this manifold has small cross section runners.... It is going to require alot of work in its own right!

[Carnut1]

I would be flow testing the heads, intake, carbs and air cleaners assembled on the bench. Much more work but better info as well. Thanks, Charlie

[F-BIRD'88]

Here is the intake that is going to be used! With Pricemotorsports adapter plates

Right On. You got it all goin' on...

Yup you probabily want to open it up a bit.
They're made for that. Thats why the top comes off. HA hA.
Let us know whats going on there. CSA etc...

[Walter R. Malik]

Way back in 2003 to 2005, "Ford Racing" offered that package as a crate motor.

The M-6007-A392E using the Ford "Sportsman" block with with 9.7/1 compression ratio, reverse rotation "production" water pump, UNPORTED "X" heads with "bolt down" roller rockers, CompCams #XE282HR hydraulic roller camshaft, Mallory billet distributor, Ford Victor intake manifold, SFi damper & billet flywheel and using a 750 cfm vacuum secondary carb, made 450 lb/ft of SAE torque @ 4,000 RPM and 430 SAE horsepower @ 5,500 RPM.
Be aware that SAE dyno numbers are considerably less than STANDARD dyno numbers.

ALL for $6,800.00, customer list price.

With porting those heads, more compression ratio and a better camshaft ... 500 horsepower; easy.

David said that you know these heads inside and out!

I can say that these heads have quality components. They come equipped with PAC beehive springs with 10 deg locks, even though the valves have Ford numbers etched on them they appear to be Top Quality.

The port has a good shape, but suffers from having a flat floor and a short turn radius that is flow challenged.

Walter: what is the most you have ever seen a set of these flow?

The O.D. of the actual inserted valve seats will not allow any larger valves to be used.

Without enlarging those ports to much and simply just reshaping their port contours, using back-cut intake valves and tulip shape exhaust valves I have seen 265/270 on the intake side and 160/165 on the exhaust. ALL before .600" valve lift. However, those max numbers won't tell the story.

I have not seen any numbers from these heads where somebody actually spent a lot of time to kinda MAX port them.

You are correct in stating that all the components used are top quality. You can get TI retainers for those springs if you want them but, after all, it is supposedly an entry level head meant for the "bang for the buck" crowd. The "cast-in" steel spring seats will only allow a single valve spring.

On that crate engine ... just changing to a 950 cfm mechanical carb with a 1" POWERCONE spacer and the camshaft to a larger LAZER grind #305B/319B-08HR+2 made 470 horsepower at 800 RPM higher.

EDIT: the numbers for that cam are 305/319 @.006" - 250/261 @.050" - 220/229 @.100" - 173/180 @.200" - 118/123 @.300" - .385"/.383" lobe lift - 108 separation; 106 intake centerline.
I believe that Bullet Cams now owns the LAZER profiles.