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  • Milling Engine Blocks On Home Mill

    Anyone do 8 cyl block machining (decking) on there Mills?? I have a old B-Port but need something a little bit longer table wise. Was looking for a Mill that could do it all. Hate to trade the Old Mill or sell it (mint shape ) but,,,I just would like to do all my own work ,have had horrible luck (actually no luck at all!!) with outside engine machine shops and Garages in General, Just curious if anyone does there blocks and what Mill they are using ,I will be doing big block 460 s ,Thanx Mike

  • #2
    Still a Ford guy hey Mike!!!
    Lol...me too now....been driving a 1995 Ford F350 4x Crewcab for 4 yrs now.
    7.3 Turbo...by FAR the best vehicle Ive ever owned.
    Russ
    I have tools I don't even know I own...

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    • #3
      Will the block fit under the head and cutter with enough clearance ?

      If the table length is your only drawback then dial things in and machine one end and move the block over - dial in again and match it up and repeat to proper depth,
      then repeat the whole process on the other bank,,,

      Yes a pain in the butt but you can achieve accurate results and if this is just a one time deal then no need to get a bigger mill as that's a huge PITA and immense expense,

      The things iv seen on those types of "dinosaurs" that use the big old fluffy style headgaskets is unreal, seems like half the shops out there think the way to remove an old headgasket is to take an abrasive circular disk to it and erode lots of the blocks material in the process, to lazy to scrape I guess - what's crazy is even with some MAJOR deviation they seem to hold back the gasses just fine... (most of the time)

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      • #4
        Shifting the block will only work if the machine is not worn and really tight. Otherwise, when the weight is shifted and overhung it will lift the table by any wear or slack amount so you essentially wind up with two surfaces at a slight angle to each other, high in the middle and low at each end.

        I've watched this work. I have an old horizontal mill with a Bridgeport head. The friend I got it from said, "That's a great machine because horizontals didn't get much use so it's unworn." Bullfeathers. I machined a straightedge casting that used all the X travel there was. A flycutter would just reach end to end without shifting anything. So I've got one smooth surface from one end to the other, but checking with my good straightedge I could get a .007 feeler gauge under EACH end. That's after tightening the gib so much I could barely move the table at each end.
        .
        "People will occasionally stumble over the truth, but most of the time they will pick themselves up and carry on" : Winston Churchill

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        • #5
          Your right if the machine is pretty clapped out and such - But - that's going to show when re-indicating and running the length of the old blocks surface,,, and to some degree you can make the needed adjustments for that --- .007" is way out of wack - even for the entire length of the block and a big old fluffy gasket...

          My mills table is only 30" long and I do have to improvise on occasion,,, Iv had great results doing so but my Mill is like New also and has an excellent table,

          It's a great compromise for me as I do not want some oversized machine that I rarely ever use the "oversize" part for - I simply don't have the room in the basement and I don't want to put extra monies into something I don't need...

          If his mills fairly tight and doesn't "shift" while cutting and he's careful and pays attention there is really no way he can get .007" out of wack without knowing it on the first little skim cut...



          and by all means he needs to check the accuracy of the existing surface before anything...
          Last edited by A.K. Boomer; 10-23-2013, 12:25 PM.

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          • #6



            This is a Chevy 250 inline done on an import 8x36 (looks like a 7/8 scale BP) with a J head on it. Tram was spot-on, table is true. Table travel only block length minus cutter swing diameter to minimize weight hanging off to the side. I wasn't in a hurry.... Final result was flat within .002 or less as best I could tell with my straight edge. Plenty close enough. a larger machine would certainly be easier and faster. I only shared this to point out that it can be done with smaller equipment if you are careful and not in a hurry.
            Last edited by strokersix; 10-22-2013, 12:34 PM.

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            • #7
              I used to do a lot of "decking" and resurfacing in an automotive machine shop. Not a lot of blocks need to be decked. Of course, a lot of people are doing it wrong, too. A block needs to be referenced to the main bearing journals for all machining operations. We used to have an assortment of centerless ground shafting that was supported over the table of a block milling machine. all of the surfaces were cut true & square from the crankshaft centerline. The shafting supported the block through all of the main bearing bores. Usually, as an added assurance of squareness and straightness the block was align bored through all of the main bearings and caps of the block before it was put on the mill, for decking, or boring.
              It requires a large, and quite heavy machine to keep things square while the block is machined. Yes, one can perform this nature of work on a smaller machine, but the cuts will have to be light to prevent deflection. By the way, the bottom of the block isn't necessarily always square with the crankshaft bores or the block deck. That's why you reference from the main bearing bores.

              If you want, Madman. I know where there's a perfectly serviceable 460 Ford engine that needs bearings (in my nephew's boat) I'm pretty sure he would like to make you a deal on it.
              Send me a PM and I'll get his e-mail address for you. The hour meter says it's got 535 hours on it.
              No good deed goes unpunished.

              Comment


              • #8
                If you fill up the X, Y, and Z working space of almost any mill with a cast iron block you will almost certainly have exceeded or at least strained it's weight handling capability. When the table is moved from one side to the opposite side that weight WILL cause it to drop on each end of travel and a 0.007" tilt is not out of the realm of the possible. The 6 to 10 inches of dovetail in the middle just can not hold that outboard weight up. The table and the work being machined WILL TILT. Just because you CAN fill up the work envelope does not mean that you will not have problems. And when you have to shift it side to side to machine both ends, .....

                On the other side, the cutting action should always be taking place directly above that dovetail area and if the mill is properly designed, constructed, and operated; the 0.007" discrepancy mentioned above is almost beyond the realm of what is possible from tilting. The tilting will occur, but the cutting action is at or near the center point of that tilting action and it will move by only a very small amount. If you get a 0.007" bow in the machined surface, then something else is wrong with the mill. The most likely cause is wear in the center of the ways where most of the previous work has taken place on that machine.

                Gentlemen, know your machines.


                Originally posted by A.K. Boomer View Post
                Your right if the machine is pretty clapped out and such - But - that's going to show when re-indicating and running the length of the old blocks surface,,, and to some degree you can make the needed adjustments for that --- .007" is way out of wack - even for the entire length of the block and a big old fluffy gasket...

                My mills table is only 30" long and I do have to improvise on occasion,,, Iv had great results doing so but my Mill is like New also and has an excellent table,

                It's a great compromise for me as I do not want some oversized machine that I rarely ever use the "oversize" part for - I simply don't have the room in the basement and I don't want to put extra monies into something I don't need...

                If his mills fairly tight and doesn't "shift" while cutting and he's careful and pays attention there is really no way he can get .007" out of wack without knowing it on the first little skim cut...

                and by all means he needs to check the accuracy of the existing surface before anything...
                Paul A.
                SE Texas

                And if you look REAL close at an analog signal,
                You will find that it has discrete steps.

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                • #9
                  Ive flycut a 4 cylynder block, it was nerve wracking, and that was on a 50 inch table of a cincinatti, dont think i would bother again!
                  Mark

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                  • #10
                    Well you did say you wanted it done right and of course machining an engine block is not a job where you can take shortcuts and expect consistently good results.
                    Like Saltmine said quality engine block machining is referenced from the crankshaft centerline, without an accurate reference it's very hard to get quality repeatable results.

                    Not sure exactly how deep you intend to get into it, but the equipment to do this has to be used a lot in order to make it pay. Either that or one should at least have deep pockets.
                    Milling a set of heads is one thing, decking a block, and plateau honing a set of cylinders straight is an entirely different game. If you are only doing a few and aren't interested into getting into the bizz then it would pay to take a drive out of town in order to find a machine shop that specializes in this type of work and has a good reputation for putting out a consistent quality product. They are out there and usually busy, but well worth the the time it takes to find them.
                    Home, down in the valley behind the Red Angus
                    Bad Decisions Make Good Stories​

                    Location: British Columbia

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                    • #11
                      There are a few videos on you tube, Kenny g of this parish uses a bridgeport, for this sort of thing, showing how to mount the block

                      http://m.youtube.com/watch?v=8H5-HPq...%3D8H5-HPq05F0

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                      • #12
                        That's one problem Willy didn't elaborate on....skilled help. With all of the experienced tradesmen retiring, becoming unable to perform the work or just dying off, there doesn't seem to be anybody out there to fill in the gap. And I don't mean some zit-faced kid, who has resurfaced a couple of cylinder heads and has the balls to call himself a machinist. Most of today's kids aren't interested in things that don't have an iPad app. I'm afraid it's going to get worse as the pool of experienced guys slowly dries up.
                        No good deed goes unpunished.

                        Comment


                        • #13
                          Thanx for the Opinions guys. Yeah I didnt think about the table shifting under the weight, After my crap dealings with car quest and also meineke in the past , i was so sick of paying money for complete morons to screw up my stuff figured Id screw it up myself Thanx all

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                          • #14
                            Originally posted by A.K. Boomer View Post
                            and by all means he needs to check the accuracy of the existing surface before anything...

                            This pretty much covers all the over concern about alignment issues and such, by all means use common sense - and you don't need to get all carried away with worrying about main alignment and such, if it's a factory engine and it's its first time down then someone else has already done that for you,,,
                            cast iron is not called "the dead metal" for nothing - it simply does not change much - it's not like aluminum, unless the engine was severely overheated then believe me everything remained the same,

                            If you don't have a history yet you know the engine has logged a quarter million miles before tear down and you look at all the rod bearings and they are wearing dead nuts center then run that pig,
                            again - use common sense and also recognize the fact that no matter what you do this thing is a crude dinosaur,
                            Take care of the basics and don't get too carried away...

                            remember - were not blasting off into space here, where just basically using an over displacement tractor type engine to get our phat little asses down the road @ the expense of $3.50 + a gallon for every 8 miles traveled.
                            unfortunately --- You would have to screw up pretty bad to stop the pig from running...

                            but again, use common sense and don't take anything for granted as there may have been some hack who got his hands on it before and took 1/64th" off one end of the engine block while leaving the other side un-touched...

                            Comment


                            • #15
                              Originally posted by A.K. Boomer View Post
                              The things iv seen on those types of "dinosaurs" that use the big old fluffy style headgaskets is unreal, seems like half the shops out there think the way to remove an old headgasket is to take an abrasive circular disk to it and erode lots of the blocks material in the process, to lazy to scrape I guess - what's crazy is even with some MAJOR deviation they seem to hold back the gasses just fine... (most of the time)
                              If you mean 3M Rolocs, they're perfectly fine for cleaning up old head gasket material on older* iron blocks, aluminum blocks, manifolds, water pump housings, ect. provided you use the correct pad for the job. I've replaced dozens of head gaskets (a lot of first generation Ford Escort 1.6 liter) with no leakage issues. Scraping gaskets on aluminum castings can damage them. Also, professional technicians get paid by the job, so painstakingly scraping gaskets by hand is not in the program.
                              In ten years of heavy engine repair, I never saw a mating surface damaged by a Roloc pad. One customer did use a belt sander with 80 grit on an inline four block- what a mess!

                              *Some newer engines (Ford) require very specialized head gasket material clean up tools and procedures. The head gaskets (and internal engine parts) are available only to Ford certified dealer shops and technicians. Probably the wave of the future

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