Close



Page 2 of 2 FirstFirst 12
Results 26 to 29 of 29

Thread: Aluminum heads

  1. #26
    FEP Super Member xctasy's Avatar
    Join Date
    Jun 2012
    Location
    Dunedin 9011, New Zealand, South Pacific
    Posts
    3,961

    Default

    Your Results May Vary.....mmb617 ran a T5 behind a 408W and 'PRC' Procomp heads...his deft mechanical empathy again! Didn't drop a valve, but I'll bet you had the heads and valve gear all set up after a full disassembly, reground seats and full check...


    Just remember, 86AscMclaren, the later 1996 model year to 2000 model year demise, the Explorer ran a split duration roller cam of very low lift, and short durations,

    F4TE-6250-BA Hydraulic Roller 256 intake, 266 exhaust, 422/448 lift profile.

    Almost exactly like the the lame old 153 to 178 hp 351M/400 engines hydraulic lifter cam of the 70's.

    It was a pure emissions cam, and you don't see any power increase with it in an Explorer block over , say, the 5.0 HO spec engine with E6 or E7 heads , even with its later GT40 spec lower and upper intake the Explorers had.

    Nice for maintaining low end torque and one of the best non performance cams around. If something like that cam was put on 2.8 and 2.9 Cologne engines, people wouldn't have found them lame, languishing from 2000 to 3500 rpm. It would make most short stroke engines stump pullers.


    On a 5.0, those golden factory GT roller cams, were the the right first point, but even they weren't as good as some of the old hydraulic cams in some applications. .


    The Cobra SVT cam. When the 93 Cobra came out, they had to use the reduced intake duration, but ever so slighly higher lift

    F3ZE-6250-CA 1993 Thunderbird 5.0 cam, 270/270 and 479 lift with 1.7's, or 450 with 1.6's as per the 93 T bird.

    It stayed with that 270/270 and 479 lift with 1.7's in the 1995 , now named the F4ZE-6250-EA.

    On the best 90's 5.8's, they never even got to the other stouter 5.0 roller cams for the 1995 Cobra 5.8 R SVT, and it used the Windsor version of the ancient Cobra Jet D1ZZ-6250-A and D2ZZ-6250-B cam, effectively the D2JE 6250-BA 351 W marine cam with 270/290 and 481/490 lift. Which rocks harder than even the 82 to 84.5 Mustang 5.0 Torino 351W cam.

    As an example of what the three and four bar GT40 heads can do, Ford then played around with the US 5.0 engines in Australia, with the factory E7, GT40 or GT40P heads, but in some cases, reowrked a little by CNC porting, blue printing, adding 1.7:1 rockers, better cams, headers, and , eventually, 347 stroker cranks to make a 335 hp 5.6 liter engine with a special Modular 5.4 upper intake manifold.


    Proof of the part of the boost possiable with the GT40P heads for the last 1998 to 2002 cars is this list:-


    5.0 liter ... 235 HP net ... 292 lb-ft ... Falcon Forte and Ghia. Stock 256/266 Explorer F4TE-6250-BA cam I think.
    5.0 liter ... 268 HP net ... 310 lb-ft ... XR8, up to May 2001. F1ZE-6250-AA cam, a very strong 276/266 duration 444 lift
    5.0 liter ... 295 HP net ... 321 lb-ft ... XR8, May 2001 and later, F3ZE-6250-CA 5.0 270/270 with 1.7 rockers, 0.479" lift .
    5.6 liter ... 335 HP net ... 369 lb-ft ... T series Tickford T3 TE50/TS50 sedans, Pursuit 250 pickup, Nov 01 or later. Custom cam.

    One thing though, a good AFR, TFS or Promaxx 175 will be worth its weight loss in hp and reliabity. Other lower tier heads, well its again your choice.


    Ther's never been a better time to buy aluminum heads, but after they been reworked, good 5.0 's are don't just happen, they are built. Its awfull easy to screw up (mess up/ruin) a good 5.0 with a dropped valve.

    This was brought to you from another detailed grocery list on GT40P's

    http://vb.foureyedpride.com/showthre...GT40p-question

  2. #27
    FEP Super Member erratic50's Avatar
    Join Date
    Dec 2016
    Location
    Nebraska
    Posts
    4,575

    Default

    GT40 heads had different springs depending upon what application they were installed on. 93 Lightning, 93 Cobra, and 96-98 Explorers were all different.

    The lightning heads were drilled for 351W head bolts. If memory serves me correctly, the lightning heads had bigger chambers to keep the compression on target on a 351. They had 1.7:1 roller tip rockers like the Cobra and springs to accommodate the Lightning cam - same seat pressure as the Cobra if I remember right. This matched the 351W GT40 lower and tubular long runner upper on the Lightning.

    The Cobra heads were drill as normal for 302 head bolts. They had 1.7:1 roller tip rockers and springs to accommodate the Cobra cam. Total lift was in the .478 range if I remember my Cobra trivia correctly. This matched the GT40 style lower and short runner "Cobra" upper. The only thing that was missing really was about 3-4 degrees of cam retard needed to make the Cobra 302 less of a torque monster down low but far more rev-happy

    The Explorer heads are very similar to the Cobras. They had crappy 1.6:1 rockers and poor valve springs matched to the wimpy Explorer cam and GT40 302 base with much longer runner upper. About 2" longer than the Cobra. (as this is what Tom Moss cut out of an upper then replicated the ETs of a ported Cobra upper on the same ported lower)

    P heads share a ton in common with the GT40 heads but have shown more swirl and demonstrate more power when 40's are swapped for 40P's. But headers can be a pain.

    Personally if budget were near zero and I needed to build a driver setup I would probably go with P's because they are more plentiful. I would look into different combinations of springs and retainers to see what works. ( starting with stock HO - haven't tried that one before myself or researched it). I would pay attention to seals. I would go to 1.7:1 rockers - especially on the exhaust side - as more lift and duration from a stock cam is a no brainer. I would run the cam up to 4 degrees advance on a daily driver street motor or up to 4 degrees retard on a motor I'm planning to rev past 6000 routinely.

    Keep your timing sane and hold your RPM down or you will run yourself dangerously lean on 19lb/hr injectors.

    I run a 65MM throttle body with a Typhoon EFI with 19's on E6SE heads a mild cam and BBK equal shorty headers. I converted to MAF with an A9L and 70MM MAF. With my combo I had to crank up the fuel pressure to keep it safe past 5500. My injectors were maxed out at 100% and A/F ratio was terrible. My cam is retarded from a worn timing set and my car sees full power shifts at 6100 every time I drive it. Fun.

  3. #28

    Default

    Quote Originally Posted by xctasy View Post
    Headbytes Porting cuA simple ASTM test that can be done for 50 bux. If the head is around 85-90 Brinell, it most likely won't hold the gasket without casting yield. Generally, although it varies, the minimum safe level of hardness is 95 Brinell. That's based on normal index testing the English use, and asside from Cosworth, the English generally don't do so well with aluminum castings as the US. Edelbrock I think rates as the best, heaviest bulk density aluminum heads on the market.
    Really? Edelbrock density better than Brodix. Brodix stuff is the heaviest stuff I have messed with. Very obvious when welding, machining and cutting on them.

  4. #29

    Default

    Gt40 3 bars for 180 a piece from gear head engines. I have a pair. Working well.
    1984.5 G.T.350 5.0 CFI AOD Convertible (TRX package, loaded)
    K&N filter in a stock dual snorkel, GT40 heads, Edelbrock 3721 intake, MSD 8456 Dist., MSD 8227 coil
    Comp cams XE254H, hypereutectic pistons
    Hooker Super Comp Shorty Equal Length Headers, catted BBK H-pipe, full custom duals
    Maximum Motorsports caster/camber plates and strut tower brace, 3.73 rear, dura grip (both Yukon)
    Ford Performance Springs, Firehawk A/S 225/55r16 on LMR TRX r390 wheels (street)
    Federal 595 rs-rr 245/40r17 and 255/40r17 on OE cobra r wheels (race)
    AOD rebuilt with a 6 clutch direct drum, Koline steels stacked with 8 clutches, Kevlar band, superior shift kit, new torque converter. --Everything else stock and fully functional.

Page 2 of 2 FirstFirst 12

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •