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    rebuild kits?

    I'm curious about rebuild kits to use in conjunction with some gofast parts when I eventually do something with my 302. Thought I would post it in here because it'll be the basis for a non-stock motor

    Do you folks usually buy rebuild kits from places like Summit? Or do you piece them together yourselves (either for cost effectiveness or part quality or something else?)


    The price tag on some of them on Summit is quite tempting when the time comes

    http://www.summitracing.com/parts/FEM-EMKP260A-000/

    Pistons Included Yes
    Piston Material Cast aluminum
    Piston Style Flat top, with no valve reliefs
    Piston Rings Included Yes
    Piston Ring Facing Material Cast iron
    Piston and Ring Oversize (in) Stock
    Rod Bearings Included Yes
    Rod Bearing Undersize (in) Stock
    Main Bearings Included Yes
    Main Bearing Undersize (in) Stock
    Cam Bearings Included Yes
    Gaskets Included Yes
    Oil Pump Included Yes
    Oil Pump Volume Standard-volume
    Oil Pump Pressure Standard-pressure
    Oil Pump Driveshaft Included No
    Freeze Plugs Included Yes
    Camshaft Included No
    Lifters Included No
    Timing Chain and Gears Included No
    Assembly Lubricant Included No
    Plastigage Included No
    Quantity Sold as a kit.


    The prices go up from there as the kits include more stuff.


    Would you buy a rebuild kit or just buy all of the parts yourself?
    sigpic


    - 1990 Ford LTD Crown Victoria P72 - the street boat - 5.0 liter EFI - Ported HO intake/TB, 90 TC shroud/overflow, Aero airbox/zip tube, Cobra camshaft, 19lb injectors, dual exhaust w/ Magnaflows, Cat/Smog & AC delete, 3G alternator, MOOG chassis parts & KYB cop shocks, 215/70r/15s on 95-97 Merc rims

    - 2007 Ford Escape XLT - soccer mom lifted station wagon - 3.0 Duratec, auto, rear converter delete w/ Magnaflow dual exhaust

    - 2008 Mercury Grand Marquis Ultimate Edition - Daily driver - 4.6 2 valve Mod motor, 4R75E, 2.73s. Bone stock

    #2
    additionally, I'm a bit lost when the topic of piston material is mentioned.
    sigpic


    - 1990 Ford LTD Crown Victoria P72 - the street boat - 5.0 liter EFI - Ported HO intake/TB, 90 TC shroud/overflow, Aero airbox/zip tube, Cobra camshaft, 19lb injectors, dual exhaust w/ Magnaflows, Cat/Smog & AC delete, 3G alternator, MOOG chassis parts & KYB cop shocks, 215/70r/15s on 95-97 Merc rims

    - 2007 Ford Escape XLT - soccer mom lifted station wagon - 3.0 Duratec, auto, rear converter delete w/ Magnaflow dual exhaust

    - 2008 Mercury Grand Marquis Ultimate Edition - Daily driver - 4.6 2 valve Mod motor, 4R75E, 2.73s. Bone stock

    Comment


      #3
      Most of the pistons in those kits are not up to snuff for a performance build.

      The manufacturing tolerances are typically not as good as even cheap performance alternatives. I've head of poor tolerance on the pin height, and the piston 'sitting' lower in the hole'.

      As far as pistons types...

      All of the pistons you find should/ will be some type of aluminum alloy. Most of the time pistons are characterized by their manufacturing process (how they're made), rather than material. There are varying grades of alloys, but that usually depends on the manufacturing method.

      There are 3 basic processes.

      Castings, which are cheap, and essentially made by pouring molten metal into a mold, and then finish machined. They are cheap, and are fine for a stock rebuild. But they are not performance pieces.

      Hypereutectic, which are also cast pistons. However, they are cast from a different alloy that is more homogeneous. There are a ton of metallurgical terms we could throw around here, but the bottom line is they are more durable, and will perform better. The name comes from the fact that the alloy is actually beyond the eutectic point (hyper for extreme/ beyond), and eutectic to designate the point the composoition is 'beyond.' These are fine for a naturally aspirated performance build. They are also less prone to thermal expansion, which means they won't piston slap like some forged pistons, and will hold tighter tolerances.

      Forged pistons are essentially made by sticking an alloy in a press/ die that forces the metal to deform to the shape of the die. They are strong, and are more ductile than their counterparts. Cheap forged pistons may slap a little until the engine warms up, but it isn't a problem with good pistons. They should be used for power adder builds, or high performance naturally aspirated builds.
      **2012 Ford Mustang Boss 302: 5.0/ 6 spd/ 3.73s, 20K Cruiser
      **2006 MGM,"Ultimate": 4.6/ 2.73/ Dark Tint, Magnaflows, 19s, 115K Daily Driver
      **2012 Harley Davidson Wide Glide (FXDWG):103/ Cobra Speedsters/ Cosmetics, 9K Poseur HD Rider
      **1976 Ford F-150 4WD: 360, 4 spd, 3.50s, factory A/C, 4" lift, Bilsteins, US Indy Mags, 35s Truck Duties

      Comment


        #4
        truth be known, you may be better off buying a remanufactured short or long block for a Mustang. That would get you an already assembled motor with the forged pistons and a warranty. By the time you buy the kit and have the machine work done, there isn't significant savings when you're talking a more or less stock bottom end.
        86 Lincoln Town Car (Galactica).
        5.0 HO, CompCams XE258,Scorpion 1.72 roller rockers, 3.55 K code rear, tow package, BHPerformance ported E7 heads, Tmoss Explorer intake, 65mm throttle body, Hedman 1 5/8" headers, 2.5" dual exhaust, ASP underdrive pulley

        91 Lincoln Mark VII LSC grandpa spec white and cranberry

        1984 Lincoln Continental TurboDiesel - rolls coal

        Originally posted by phayzer5
        I drive a Lincoln. I can't be bothered to shift like the peasants and rabble rousers

        Comment


          #5
          Unless you know someone in a machine shop and can do machine work like so.

          Comment


            #6
            Originally posted by gadget73 View Post
            truth be known, you may be better off buying a remanufactured short or long block for a Mustang. That would get you an already assembled motor with the forged pistons and a warranty. By the time you buy the kit and have the machine work done, there isn't significant savings when you're talking a more or less stock bottom end.
            Was speaking hypothetically, I don't intend to buy anything for a long while. Just trying to learn about the process.


            Does prettymuch every build require machine work?
            sigpic


            - 1990 Ford LTD Crown Victoria P72 - the street boat - 5.0 liter EFI - Ported HO intake/TB, 90 TC shroud/overflow, Aero airbox/zip tube, Cobra camshaft, 19lb injectors, dual exhaust w/ Magnaflows, Cat/Smog & AC delete, 3G alternator, MOOG chassis parts & KYB cop shocks, 215/70r/15s on 95-97 Merc rims

            - 2007 Ford Escape XLT - soccer mom lifted station wagon - 3.0 Duratec, auto, rear converter delete w/ Magnaflow dual exhaust

            - 2008 Mercury Grand Marquis Ultimate Edition - Daily driver - 4.6 2 valve Mod motor, 4R75E, 2.73s. Bone stock

            Comment


              #7
              Not necessarily. If the cylinders are within spec and the block doesn't require decking or line-boring or anything like that, there's the chance of getting away with just a hot-tank and a hone. Such was the situation when I rebuilt my '87 302; the machinist cleaned and checked the hard parts, resized the rod ends, polished all the journals, and honed the bores, and that was it. Since I wasn't going oversize, I didn't bother buying new pistons for that rebuild, so that engine still has the original cast dished pistons.

              For my '96 motor, I knew it was going to be bored, so I ordered the $250ish Summit Racing rebuild kit. That kit includes all the bearings, new SpeedPro hypereutectic pistons with coated skirts, and all new FelPro gaskets, and could as of '06 be ordered for any standard overbore AND any standard undersize on main and rod journals.

              For some people, of course - and this will depend on your needs - it'll be more economical to buy a supergreat-quality preassembled shortblock from someone like FordStrokers.com than to mess with machining an old block and assembling it yourself. I can't afford FordStrokers, but there may be others of reasonable quality that cost less. It also helped me that I had a machinist that had pretty good prices, and of course that I ended up not getting (and paying for) align-honing, torque-plate honing, and all that good stuff that really ought to be done to every engine anyone ever assembles (IMO).
              2012 Mazda5 Touring | Finally working on the LTD again!

              Comment


                #8
                I didn't even consider something like a preassembled shortblock. If I went that route I wouldn't bother with anything 302 based....a 427w would be fun :evil:
                sigpic


                - 1990 Ford LTD Crown Victoria P72 - the street boat - 5.0 liter EFI - Ported HO intake/TB, 90 TC shroud/overflow, Aero airbox/zip tube, Cobra camshaft, 19lb injectors, dual exhaust w/ Magnaflows, Cat/Smog & AC delete, 3G alternator, MOOG chassis parts & KYB cop shocks, 215/70r/15s on 95-97 Merc rims

                - 2007 Ford Escape XLT - soccer mom lifted station wagon - 3.0 Duratec, auto, rear converter delete w/ Magnaflow dual exhaust

                - 2008 Mercury Grand Marquis Ultimate Edition - Daily driver - 4.6 2 valve Mod motor, 4R75E, 2.73s. Bone stock

                Comment


                  #9
                  Hm................. http://www.fordstrokers.com/fordstro...hortblock.html

                  And yeah, that's what some folks were telling me, that a good preassembled stroker can be had cheap enough that supposedly a lot of people don't find stock displacement even worth bothering with.

                  How hard is it for you to get stuff to you from Chicago?




                  (BTW, I forgot to add "I'm told that ..." to the last bit of my previous post. Don't want to appear to be speaking from experience, or even from having assembled a particularly accurate estimate of what one approach would cost versus another one.)
                  Last edited by 1987cp; 02-13-2011, 12:34 AM.
                  2012 Mazda5 Touring | Finally working on the LTD again!

                  Comment


                    #10
                    It's a lot of money but to have a fully assembled 408w bottom end of that quality would be worth it I think. Putting together the right top end for it would be the hardest part
                    sigpic


                    - 1990 Ford LTD Crown Victoria P72 - the street boat - 5.0 liter EFI - Ported HO intake/TB, 90 TC shroud/overflow, Aero airbox/zip tube, Cobra camshaft, 19lb injectors, dual exhaust w/ Magnaflows, Cat/Smog & AC delete, 3G alternator, MOOG chassis parts & KYB cop shocks, 215/70r/15s on 95-97 Merc rims

                    - 2007 Ford Escape XLT - soccer mom lifted station wagon - 3.0 Duratec, auto, rear converter delete w/ Magnaflow dual exhaust

                    - 2008 Mercury Grand Marquis Ultimate Edition - Daily driver - 4.6 2 valve Mod motor, 4R75E, 2.73s. Bone stock

                    Comment


                      #11
                      From what I've read, those guys are willing to provide input on the entire build. You know sbftech.com has a FordStrokers subforum?
                      2012 Mazda5 Touring | Finally working on the LTD again!

                      Comment

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