Close



Results 1 to 11 of 11
  1. #1

    Default 1985 302 rebuild specifications?

    Good evening everyone,

    I am preparing to begin planning out a rebuild/reconditioning of my 85's well aged 302. While writing down my thoughts it had occurred to me that I do not posses any of the many needed measurements and specifications. I am sure I could go to a parts store and get the Chiltons or haynes manual and get what is needed for a stock rebuild. I however want to do a performance build. and with that being the case I want to read/learn when and where to go beyond factory service manuals in order to build a long living daily driver/street performer..

    The general idea for the build is:
    Daily driver City and highway
    currently 3.08 rear, upgrade to 3.55 in future
    Operating RPM range -1500-6500
    Starting with GT40P heads (Already have them), Future upgrade to ALums
    Dual pattern Camshaft around .550 lift, need to research to figure out desired duration and LSA
    Shorty Headers 1 5/8" Primary 2.5" collector. (Already have them)
    2.5" Off-Road H-Pipe and exhaust out the back
    Edelbrock Performer RPM 289 intake manifold (Basically got it for Free)

    I plan to do most of the work myself. I will farm out anything I can't do or can't (afford to)buy the tool for.

    I am willing to buy books. I am willing to read them and learn. Which ones would you guys recommend?

    Thank you in advance.

    I don't post much but, I have learned a lot from reading these forums and Ya''ll have already helped me figure out few head-scratchers' already. So thanks for that also.

    Have a great evening everyone.

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

    Default

    Are you assembling the bottom end or having it done?

  3. #3

    Default

    Short answer: yes, I'm going to assemble the whole thing if I can.


    Long answer below:




    I'm planning on assembling as much as I can. I have almost all the tools needed for a complete DIY except I am unable to reface valves, cant deck square the block or line bore, or bore cylinders or fly-cut pistons.

    I'm willing to buy spring pressure tools, vale height micrometers etc.

    This will not the the last rebuild I do. I'm planning on doing a "continuing education" approach with this. I intend on buying more tools and equipment as I go.

    Thanks again

  4. #4
    FEP Power Member
    Join Date
    Nov 2007
    Location
    San Mateo, CA
    Posts
    2,271

    Default

    Your machine shop can answer many of your questions. You will need them to machine the block, crank, prep the rods and pistons.
    Fox Body/3rd Gen MCA Gold Card Judge
    84 SVO 24K miles, 85 Mclaren Capri Vert. 84 GT Turbo Vert.
    88 Mclaren Mustang Vert 20K miles, 89 Mustang LX Sport Vert,
    03 Mach 1 7900 miles, 74 Mustang II, 69 Mustang, 67 Mustang, 07 GT500,
    14 Mustang CS/GT, 15 F150 FTX Tuscany, 16 F250 Crewcab, 67 Tbird 47K miles

  5. #5

    Default

    I found that it's also good to take an engine machine shop class at a local community college. It's not too pricey and you can get some very good knowledge/tips. And, most of the time the teacher will let you bring in your projects and do your own machining, no extra charge.

  6. #6

    Default

    Good evening all. I was driving around a couple weeks ago and noticed a bit of smoke coming from the tail pipe. At first I thought is was steam since it was still pretty cold in the mornings. then a few days later I look back into the rear view mirror and I see I GIGANTIC cloud of blue smoke as I am hitting the accelerator on the on-ramp to the highway. A couple more days go by and now I'm trying to be as gentle on the accelerator as possible. But no matter what I do or how I drive, I am now fogging the entire city for moskeeters, vultures and most species of wild animals. At this point the only good thing is there is no one tailgating me on the highway any more.

    I have pulled the engine and have disassembled it this past week. I have found almost every specification and measurement I need except for the Stock specs for piston to cylinder wall.

    Anyone happen to have that lying around? I have found alot of info on various aftermarket pistons, but not the stockers.

    Right now my feeler gauge says .002 clearance with about another 1 to 1.5 thou to go before the scar is gone. Even with the coarse stones it is a long and tedious process. I don;t want to Hone all of em just to find out i'm out of specs when I'm done.

    Thanks ALL!

  7. #7
    FEP Super Member bwguardian's Avatar
    Join Date
    Jul 2010
    Location
    Houston (Clear Lake), Texas
    Posts
    4,668

    Default

    How many miles on the clock? Can you post a picture of the cylinder walls? That 1985 motor was the first year for forged slugs and they had low friction rings...
    HAD
    '82 GT monochromatic (red)...black cloth

    HAVE
    '85 GT vert two tone (white on charcoal)...white leather
    '00 F350 two tone (white on silver)...gray cloth
    '00 Excursion Limited two tone (white on tan)...tan leather...wifes ride
    '08 Taurus Limited ice blue...tan leather...daughter ride
    '08 Edge Limited white sand tri-coat metallic...tan leather...other daughters ride

  8. #8

    Default

    I think there are about 200K on it. I'm not sure since I don't know how many times the odometer has rolled over. I have a pic of the cylinder I just finished honing out:

    Name:  20180417_212942.jpg
Views: 124
Size:  72.8 KBName:  20180417_212942.jpg
Views: 124
Size:  72.8 KB

  9. #9
    FEP Senior Member 854vragtop's Avatar
    Join Date
    Dec 2006
    Location
    Greensboro, NC
    Posts
    556

    Default

    What's the gap between the ends of the rings when you install one at various positions in the cylinder? As I remember the stock gap between the ends of the ring is about .019" when installed in the cylinder. I rebuilt my stock '85 with 192K miles on it and you could still see the factory honing marks when I pulled it apart. I ended up rebuilding it with stock rings and bearings and a hone job. Went back in with the original pistons too. Everything measured within specs. I bought the car with 40K miles on it in 1990 and have used Mobil 1 ever since we've owned it. See my sig for the stuff I added during the rebuild. Runs way stronger than it ever did. No smoke. Never has.
    Last edited by 854vragtop; 04-18-2018 at 07:45 PM.
    '85 Mustang convertible GT, 5 speed, 4V
    Stock bottom end, Comp Cams XE264HR-14, GT-40P heads w/ Alex's springs, Weiand 8124 Street Warrior,
    Summit Racing 600CFM carb, 8.8 Turbo Coupe rear end w/ 3.55 gears, '94/'95 Cobra brakes, '85 Town Car M/C, '93 Cobra booster, MM Panhard Bar, MM Strut Tower Brace, MM 4 point K-member Brace

    '68 Mercury Cougar, w/ '88 5.0L, 4V
    My photo website:
    http://www.twilightphoto.com/

  10. #10
    FEP Super Member erratic50's Avatar
    Join Date
    Dec 2016
    Location
    Nebraska
    Posts
    4,575

    Default

    Ring groove at the top of the bore is the tell on miles for an old carb motor. Not uncommon for a ton of taper on the bores.

    EFI usually 95% eliminates ring groove. Taper is vastly reduced usually too. I’m shocked at how often people bore EFI motors because unless something happened that’s not just normal wear it takes insane miles to cause enough taper to call for boring.

    The tell on wear with EFI is usually the ring landings on the pistons and the rest is wearables like bearings.

    Ill be interested to see how my 86GT looks now because at over 200K miles it still didn’t have any ridge or other signs of wear visible on a bore scope. Still had the ol factory cross hashed gone marks. And that motor spent 2 full seasons bracket racing at the track followed by 140+K miles of abuse by a teenager who loved to street race and drive WAY too fast, etc but knew the importance of changing oil. (Me) it had to be boreaxed because overuse of slick50 unseated the rings but that was as effective as any overhaul on the compression test gauge.

    it’s pushibg 1/2 million miles now. Had some power loss that Seafoam in gas and oil brought back. The valve guides are trashed but it still more than gets it done when encouraged by the loud pedal. Now that I have headers and a Typhoon 6000+ RPM powershifts are the norm and it’s conservatively turning high 12’s on street tires and pump gas. I’ve pissed a few local GT500’s off with it. I blame the driver because I shouldn’t have won but I did it to the same guy twice for what it’s worth....

    Anyway — my point is don’t over repair a motor that doesn’t need it. Many of stock parts are better than you can buy without way overpaying so use them!

  11. #11

    Default

    Quote Originally Posted by 854vragtop View Post
    What's the gap between the ends of the rings when you install one at various positions in the cylinder? As I remember the stock gap between the ends of the ring is about .019" when installed in the cylinder. I rebuilt my stock '85 with 192K miles on it and you could still see the factory honing marks when I pulled it apart. I ended up rebuilding it with stock rings and bearings and a hone job. Went back in with the original pistons too. Everything measured within specs. I bought the car with 40K miles on it in 1990 and have used Mobil 1 ever since we've owned it. See my sig for the stuff I added during the rebuild. Runs way stronger than it ever did. No smoke. Never has.

    I tested a couple cylinders and with the old rings on

    #5 I'm getting .0042 gap at about 1" down and at 3/4 the way down the bore i'm getting .0035 gap. Forgot to check the piston to wall clearance last night.

    On #8 I have a gap of .0065 at the top and .0064 bottom with a piston to wall clearance of .0045

    i'm getting close to finishing up the honing of the cylinder walls and removing the crud from the pistons. I plan to run the medium and fine stones on the cylinder bores tonight and then measure all the clearances.

Posting Permissions

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