gt40p head junkyard questions

Discussion in 'Fox 5.0 Mustang Tech' started by fivespeedsteed, Feb 22, 2013.

  1. They are not related.
    The smog pump feeds clean air into your exhaust stream so that the cats have enough oxygen to run hot and burn off polution.
    If you don't have cats, your smog pump is running for no reason.
    If you do have cats, and remove the smog pump, it is possible that your cats clog up due to lack of oxygen/heat.

    The EGR is totally internal plumbing, except for the water lines going into the TB adapter. All you see is the lines, and the valve on the adapter (and wires of course). With the smog system, 99% of the system is external to the engine.
  2. Exactly.

    The plumbing of the EGR and smog system are not connected. The EGR is internally plumbed, the smog setup is external.

    I need to look again at my GT-40P heads. I'm starting to confuse myself. The EGR port and thermactor ports (for smog) on the heads are separate.
  3. So if I want to use the egr and delete the smog pump i could use p heads and the 96 explorer intakes?

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  4. NO NO NO, the EGR runs inside your stock heads (internal system). The GT-40 heads are internal and that's what you need in order to keep your EGR hooked up and functioning correctly.

    The smog pump and egr both run internally inside your factory heads in two different passages as I understand it. GT-40 has the internal EGR passages to keep your EGR functioning so you need to go find an 5.0 Explorer/Mountaineer year 1996-1997 1/2 (no later than mid 97) and go get all of the upper/lower intake including throttle body and the heads.

    GT-40P came on 1997 1/2 and later and was setup with an EXTERNAL style EGR system so for the easiest upgrade you want to stay away from this setup.
    ratio411 likes this.
  5. So p's just aren't the answer if I wanna keep egr stuff

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    ratio411 likes this.
  6. I spent a good 30 mins searching the NET since my GT-40Ps are currently 30 miles away from me to look at.

    There are no thermactor ports on the 40P's. These are the ports in the exhaust port of the head that the air pump pumps fresh air into during car warm-up.

    The regular GT-40's do have these , but from what I'm reading the Lightning GT-40 does not have them.

    The 40P's DO have the EGR passage.

    Sucks that this thread came up now. I literally have had a set of GT-40P's in my trunk for the last 2 months (I was moving and had nowhere to store them). Otherwise i could stroll outside and look.
  7. 5L5, how does somebody with GT-40P heads install them and retain a functioning EGR system?
  8. Same as any E7 head. The EGR passages are on the inside part of the head. Just need to bolt a lower intake manifold down that has the provision for an internal EGR and everything else is the same as a standard Mustang.

    basically in the center of the 4 intake port openings is a small opening. Thats the EGR port.
  9. So you're saying that we can take 1998 Explorer GT-40P heads and bolt a 1996 lower/upper intake to them and retain a functional internal style EGR system?
  10. That's what I'm getting at. I plan to pull the smog pump/ thermocater stuff but not egr. So p heads and 96 explorer/mountaineer intakes will pull that off?

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  11. I'm gonna hold off my answer til Sunday. I'll be taking a good look at my 40P heads to make sure the info i pass on is correct.

    As for the upper intake, if you are gonna go with an explorer intake, you want an early model with the internal EGR. Easy way to tell if looking under the hoods is the part number right behind where the distributor would be on the Mustang.

    F87E-9k461-BA has the internal EGR plumbing
    F87E-9k461-BB does not

    basically look for the last two letters. Grab a -BA upper and lower and leave the -BB intakes alone.
  12. I'd like to hear from people who have actually successfully mixed and matched newer P heads with older lower/upper intakes & TB. For insurance I would NOT mess with it until such a person surfaces or gives a write up. Other than that I think people normally find a single donor and make the swap because that typically is enough work and modifying already.

    We all know for fact the 1996-97.5 is a no brainer for retaining EGR functionality as it pertains to our mustangs. As far as I know, neither Explorer/Mount. GT-40 or GT-40P came with thermator ports unless they're from a Cobra or Lightening.
  13. im eager to see, i dont mind pulling two explorers apart. i could buy both intake sets and both head sets and use the p's and BA intakes (if the egr will work) and sell the bb intakes and non p heads for someone who doesent mind ditching the smog stuff.

    im definatly ditching the termocator stuff and going to get those magnaflow spun cats, but i do want to keep my egr
  14. Ok took a peek at my heads.

    EGR port is there. Connects to one of the two center cylinders. Tried to get pic of inside but can't do well on iPhone.

    Therm actor ports are not drilled, but the bumps are there. Just not machined through.

    Sent from my iPhone 4S using Tapatalk

    Attached Files:

  15. so im good to run a 96 intake setup and p heads and keep my egr stuff and ditch my smog
  16. pulled a p motor explorer apart today, got the upper and lower intake manifold, throttle body and heads. all looks well. there were no 96 explorers to get the intake manifolds off of, im still debating running an egr or not.

    so this tfs stage 1 cam advertises .499 lift with 1.6 roller rockers and .312 overall, are the stock roller rockers 1.5?

    my next move is to get the valve spring kit and take the heads to the machine shop. they said 285 to hot tank both heads, install the valve springs and seals, mill them flat, and do a 3 angle valve job. which isnt bad.

    im also going to research if i want to use the explorer rockers or get aftermarket ones, and catbacks, because i want to change my exhaust up. im geting shorty p headers, and an offroad h pipe, but im not sure the mufflers i want to use. i have a flowmaster force II catback, but i want some more volume. and my tail pipes are crimped over my mufflers really bad so i dont know if i can re use the pipes.
  17. just keep the intake thats on it, give it a good porting and slap it all back together with the new cam, no need in drilling the heads

    get you some new comp rrs

    if u hadnt already go back and snatch the ecu and wiring out of the explorer along with the obd2 port

    keep edis on it and leave it as it is

    you definitely need larger than 19lb injectors

    $200 will get you a custom tuned chip and no CEL

    this link will help u out with injector sizing
  18. You're saying the manifold will work without egr? Snatch the ecu and wiring why?

    19 lb injectors aren't enough?
  19. the only stock ford roller rockers came on the 93-95 cobra (maybe the lightning too, not too sure about that one), the stock explorer stuff is the same stamped rocker used on the regular and ho 302's for probably close to a decade before, and theyre 1.6 ratio (which is why most cam specs will give lift numbers at a 1.6 ratio). if you dont have the budget for a crane set (the o.e. rockers used in the cobras), the stock stampers will work fine, thats what i run, sure it may leave some on the table, but theyre easy enough to change out once you can afford them.