139 0306 Claim Lead Z
How important is detailed machining in building a competitive engine? The folks at Federal-Mogul decided to find out.
How important is detailed machining in building a competitive engine? The folks at Federal

When it comes to racing engines, the performance potential begins well before the first green flag. The time spent in preparation can result in time spent in Victory Lane.

The Federal-Mogul Technical Education Center wanted to see how effective it would be to put the emphasis on preparation. Richard Kearns, the system curriculum training manager, headed the project. No exotic parts were used. A major difference for this engine is the extensive and immaculate preparation. To help accomplish the meticulous work, a wide range of high-quality Sunnen machines in the tech center were put to work. The work was done by students at the center. Remember, you will need to consider outsourcing costs for work you are unable to do within your own shop when considering a build-up like this.

It's understood racers will look for any advantages they can find. If racers can find a horsepower advantage through a little extra prep work, most are more than willing to invest the time and effort. We followed the build-up of this claimer engine, which will be presented in two parts. The first part will be short-block machining and preparation. Next time, we'll look at valvetrain preparation and engine assembly. You'll be able to make your determination on the project's overall success when we show you the dyno numbers.

  • 139 0306 Claim 3 Z
    A ton of time was spent just on block preparation. Many builders either paint the lifter valley or ignore it. This one is polished to eliminate any possibility of paint peeling off and gumming up the works in the valvetrain. This may be overkill and doesn't add horsepower, but it just might eliminate a potential failure.
    A ton of time was spent just on block preparation. Many builders either paint the lifter v
  • 139 0306 Claim 4 Z
    All the oil galleries in the block are drilled out to 1/2-inch to increase flow and eliminate blockages from overcast. To get in at the filter mount, the block has to be notched for clearance (bottom).
    All the oil galleries in the block are drilled out to 1/2-inch to increase flow and elimin
  • The oil passages between the cam journals and the crank mains are opened up to 5/16-inch.
  • 139 0306 Claim 6 Z
    The oil pan rails are machined minimally (0.003- to 0.005-inch) to provide a good baseline for every other measurement on the block. This process, of course, also ensures that the oil pan and gasket will have a clean surface to seal against.
    The oil pan rails are machined minimally (0.003- to 0.005-inch) to provide a good baseline
  • 139 0306 Claim 7 Z
    The main registers are measured to make sure the main caps fit properly. The register should measure 0.002-0.004 less than the width of the main cap to provide the proper interference fit.
    The main registers are measured to make sure the main caps fit properly. The register shou
  • 139 0306 Claim 8 Z
    Once the registers are measured, the caps can be milled to the perfect size. Remember to take the same amount off each side of the main cap. This procedure is only for four-bolt mains; the procedure for flanged four-bolt mains is different.
    Once the registers are measured, the caps can be milled to the perfect size. Remember to t
  • 139 0306 Claim 9 Z
    After the main caps are cut to fit the register, they are torqued into place to be line bored. Make sure to leave 0.003-0.005 inch for the final honing. Also, be aware that the boring bar will leave a slight ridge of material that must be removed by machining a slight chamfer into the caps.
    After the main caps are cut to fit the register, they are torqued into place to be line bo
  • 139 0306 Claim 10 Z
    The cam journals are also align bored and then honed so the final size is 2.030 inch. Federal-Mogul makes a special oversize bearing to fit the bores after this procedure has been completed.
    The cam journals are also align bored and then honed so the final size is 2.030 inch. Fede
  • 139 0306 Claim 11 Z
    The cam bore oiling groove has to be cut back in after enlarging the bores. This is done by hand on the boring mandrel.
    The cam bore oiling groove has to be cut back in after enlarging the bores. This is done b