Quick GT40P Question

Discussion in 'Fox 5.0 Mustang Tech' started by mrswivlepants, Sep 20, 2005.


  1. v8only

    v8only Active Member

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    i've seen those specs here and on the corral before, should be a fairly easy search. I never tried looking them up specifically.
    #21
  2. mrswivlepants

    mrswivlepants New Member

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    So no on the explorer springs? Can I reuse the HO springs? I'm not looking to sink a ton of money into them. I'd like to get some info on what I should DEFINITELY change.
    #22
  3. Allforspeed

    Allforspeed New Member

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    i would get some used valve springs off somebody who has swapped their old trick flow or afr springs off, afr and tfs said the springs that come on their heads work fine on a E7TE head as long as they are set up fine, i got some for 30$ for my ported stocker budget motor from a guy on heres trick flow heads, but new crane ones are only 80$ and all the stock retainers and stuff are fine as long as they arn't broken, i'm having someone else set them up though since i dont know how to do that, besides the springs i bet you'll be fine!
    #23
  4. v8only

    v8only Active Member

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    good idea.

    Ho springs will be ok, but it's advised to have them tested first.

    essentials to swap:

    -obd 2 electrical stuff for eec4 stuff
    -fuel rails
    -timing cover/accessories
    -oil pan
    -pickup tube


    highly recommended, cam/springs/new oil pump
    #24
  5. thumper460

    thumper460 Founding Member

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    Springs are important!! everything you do will turn to crap, with out the correct pressure!! tired and worn springs are ok.. but you know your are going to push it, so not counting the HP loss from weak seat pressure, or valve float.. get good springs! the heads are off.. the machine shop will do it and make al the pressures correct, there are some things you can skimp on, and then some you cant!! cool??

    Just me.................................

    Thumper
    #25
  6. crazypete

    crazypete All my crevices are greased.

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    I just removed some AFR doubles. Theyre 120 pounder double springs. PM me if you want em. They have about 1000 miles in them.
    #26
  7. v8only

    v8only Active Member

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    it's not just you. My buddies harped on me so bad on this subject, thats why I ponied up for the tfs springs.
    #27
  8. jwzg

    jwzg Member

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    No times yet, since I only get home about once a year these days. Got the gears in over the summer and it felt like a different car. Current setup is probably good for low 14's or so. The stockish AOD really holds it back.
    #28
  9. mrswivlepants

    mrswivlepants New Member

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    Wow, that sucks that you only get to visit your pretty Strawberry lady once a year. I hope I get some decent power out of the heads. Right now I'm pushing mid 14s with a tired 152k engine. My mods include a cobra intake, 73mm C&L TB, 70mm MAF (too big IMHO), 24 lb injectors (waste of $ IMHO), BBK catted H pipe, some kind of high flow cats, and Sportlines.
    #29
  10. jwzg

    jwzg Member

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    Yeah, it's rough not being able to get home often. Our second kid is on the way and travelling is just plain hard. However, if I was working at home, I wouldn't be able to afford all of the goodies ;) Anyway, you'll need the FRPP headers to go with the p heads. MAC sells a set of p specific shorties, but I'm not conviced about their quality. That package, even with a 70mm TB, ought to work very well. Unless you are having issues with the C&L meter, leave yourself room to grow a bit with the 24lb injectors. If you are getting the heads worked a little bit, send that lower off to Tmoss and you might be amazed at what this combo will do.
    #30
  11. jaymac

    jaymac New Member

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    Slightly ported and polished P's, milled 0.030", Explorer unpper and lower, 4.10's and 2800 stall.
    13.61 @ 98.98 (no top end for some reason I can't figure out)
    BTW I run BBK shorties. I had a problem w/ plug 7, and had to remove the header to change the plug :(
    I idn't have to bash the primaries, but I'm running an old motorcraft wire backwards on #7; 90* end on the plug, and 135* end on the cap. heat sleeve on #7, and bend and zip-tie #5 to the valve cover :)
    #31
  12. mrswivlepants

    mrswivlepants New Member

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    Maybe you know, or someone else....will AFR springs work on these heads? Does it matter if they came off of a stud mount setup rather than a pedestal like the gt40ps? Someone educate me on springs and the valve train please.
    #32
  13. mrswivlepants

    mrswivlepants New Member

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    bump on the last question
    #33
  14. crazypete

    crazypete All my crevices are greased.

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    Hey, if you have the old springs out, measure the diameter and uncompressed height. If they match, you can use my afr springs without worry.
    #34
  15. tmoss

    tmoss Gettin Wired Founding Member

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    You have to find the spring diameter, installed height and seat/open pressures to know if they will work or not.
    #35
  16. thumper460

    thumper460 Founding Member

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    You buy a cam... you buy some heads.... gaskets... timing chain.... the hours to put it all together. Fire it up.. sounds good!! Make a few runs around the block.. feels good!! then the first run, you stack the valve springs... or lose the race 'cause the valve is bouncing on the seat and not holding power.. or worse.. you float the valve and hit the pistons and take out the whole freaking engine... why?? Cause you put in "should work springs" Make sure.!!. there are things you can skimp on... and things you cant!!

    Just me...............................

    Thumper

    Hi Tom!
    #36
  17. crazypete

    crazypete All my crevices are greased.

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    Are springs on the ford heads the same diameter/height?

    The springs in question have like 1K miles through them and they are 120 pounders.

    I'm pretty sure they are low risk. I'd be willing to be they are much better than the stock 40-p springs.
    #37
  18. youngone

    youngone New Member

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    Springs are very important, as I found out. Broke a spring and bent a valve. I'm not happy.



    Will BBk long tubes work with P heads? Please say yes.
    #38
  19. tmoss

    tmoss Gettin Wired Founding Member

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    I think all the reports I've seen say long tubes (BBK included) work with P heads.
    #39
  20. Zero Signal

    Zero Signal Active Member

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    Seriously, it would be worth your while to give them to a shop.

    I picked up some standard GT40's for dirt cheap. I took them apart and ported/polished them myself with advise from a local engine builder. He magnafluxed and baked them for me before I started porting. Then I handed them over to him for the mill, valve guides, 3 angle valve job, flow test and cam design. All of his work will run about $300. I'm having him assemble them so he can shim the springs as required. I'm not getting new springs since I'm designing the setup for a hp peak of around 4800 rpm. I'd challenge anyone who days it's not worth it, especially when you are going to spend the money on gaskets and all that time doing the swap. So for these heads, I'm looking at

    Heads: $200
    Head work, cam design: $300
    Porting kit: $35, and about 15 hours of work.

    For a total of around $550 for the heads + work.

    Some things you just don't want to skimp on.
    #40

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