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289 cam gear alignment

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  • #16
    If the crank gear and cam gear line up then the cam is installed "straight up". And is Not 180 out of phase. So that part is correct. You now must adjust each intake and exhaust lash on each cylinder WHEN the cylinder piston is at TDC "ready to fire" or Power stroke phase for the cylinder. Start with # 1, then 8, 4,3 etc.

    Firing order is cast on the intake manifold. Your reference for this is the timing mark on the crank damper (for # 1 piston) Just remember that # 1 comes to TDC twice in 720 degrees of rotation and you want the power stroke phase not the induction or overlap phase. You must be at the power stroke phase for each cylinder for the lashing of that cylinder.

    Again. if the cam and crank mark line up the cam is installed correct. But do not use them for lash adjustment.
    Start and Stage Your Studebakers

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    • #17
      When the cam and crank gears are lined up as you said they are, the no. 6 cylinder is at top dead center on the combustion/firing stroke and no. 1 cylinder is at top dead center on the exhaust stroke.
      When both marks are at 12:00 no. 1 cylinder is at top dead center on the compression/firing stroke and no.6 cylinder is at top dead center on the exhaust stroke.
      The engine WILL run with both marks at 12:00 but the plug wires on the distributor will have to be routed incorrectly to match the timing gear marks.
      The engine will NOT run when the wires on the distributor are installed the way the shop manual says and both the timing marks are at 12:00.
      Jerry Forrester
      Forrester's Chrome
      Douglasville, Georgia

      See all of Buttercup's pictures at https://imgur.com/a/tBjGzTk

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      • #18
        I think "straight up" in hot rod circles often means the cam has been "degreed" and the valve opening and closing events have been found to be just as the cam card describes. Some go to heroic measures to change the cam timing a few (crank) degrees hoping to modify the powerband a little. Installing any cam 4 degrees advanced is touted by some as "better" in nearly all cases. Popular engines often have aftermarket timing sets with features that allow adjusting cam timing a few degrees in each direction for "blueprinting" or fine adjustment.

        My boss was fond of proudly announcing he had installed a cam straight up because the factory marks were used, without ever confirming the event timing in the engine.
        He may have been overlooking something quite important in my opinion. I'm not all that comfortable assuming cam timing marks are correct. There is a manufacturing tolerance on the location of the keyway locations on all the crank, cam, and timing components. When manufacturing tolerances all add up the "wrong" way the result can be significant.
        And manufacturing mistakes happen. A friend has developed a good reputation building engines for race cars and specialty cars. A desperate owner brought him a land rover with inline engine was running weakly after an expensive rebuild with lots of new factory parts. The degree wheel quickly revealed the crank sprocket had the key generated in the wrong location by 16 or more degrees if I recall correctly. Re-timing it 6 times to the factor marks would not have fixed that.

        Assembly mistakes happen too. Some engines make it difficult to keep the cam(s) and crank in position while installing gears, sprockets, chains, or belts.
        A mechanic of a friend of my daughter was recommended because "he works on Corvettes, and has a race bike." He changed the timing belt, and got the exhaust cam timing wrong by a tooth on her INTEGRA 3 times (and left the crank bolt just snug the last, and I do mean LAST time. The key and keyways were lightly battered after just a week or 2 in gentle service) . They had my daughter in tears because they insisted her Integra was running fine, and what she perceived as reduced power was really because she had been driving Pete's GrandPrix while her car was being repaired. Well, running with one cam and the cam mounted distributor retarded almost 20 degrees tends to do that. If Mr Racer had not been stubbornly fixated on a few marks, and dug out his degree wheel or even just his timing light he would have seen he had messed up, and how.

        Often a decently useful valve timing check can be made with the engine assembled.
        Last edited by Dan Timberlake; 03-20-2015, 09:05 AM.

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        • #19
          Stude factory cam have a 4 degree retard in the profile specs. Most people are not aware of this and can add to the confusion. In a perfect world "straight up" means the ICL and the ECL are the same degrees. So to be perfect the standard keyway would have to be changed and advanced 2 degrees to be perfectly straight up.

          Since he may have a hotter cam and doesn't know the grind then it may be best to degree wheel the cam to see the running spec.
          Start and Stage Your Studebakers

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          • #20
            I agree with Dan's #18 post. A number of years ago I installed a Cloyes True Roller set in a 455 W30 Olds. I did degree it and found the marks were out profoundly(I don't recall the exact amount). You simply can't assume that any manufactured parts are exactly as they should be.
            Bill

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            • #21
              R1/R2
              Camshaft Specifications
              (Part # 1557663)
              Copies of the camshaft drawing (1557663) and the lobe profile drawing (1557662) are available for purchase from the Studebaker National Museum. Contact Andy Beckman if you are interested. Here are some particulars of the R1/2 cam;

              • .4295 gross valve lift minus the running clearance = .406 valve lift.
              • ICA


              Other pertinent dimensions;
              • 1.5 to 1 rocker arm ratio
              • 1.34887 base circle to lobe tip


              These specifications can also be used to degree a cam during engine assembly.

              The industry standard today is to measure cams at .050" lifter rise. Using these criteria, the R1/R2 cam specs out as follows:



              Stock 259/289
              Camshaft Specifications
              ( Part # 534131)


              • ..359 gross valve lift minus the running clearance = .336 valve lift.






              Camshaft drawing bearing journal size is front to back;
              #1 1.8685/1.8690
              #2 1.8520/1.8527
              #3 1.8370/1.8377
              #4 1.8210/1.8217
              #5 1.2430/1.2437

              Genrally speaking advancing a cam aids power on the low end while sacraficing top end power. Retarding a cam does the opposite. Most performance cams are ground with some advance in them. Crane and Isky would stamp a grind number on the end of their Studebaker (and other) camshafts for identification. If this cam is a regrind, it probably will not be marked. Degree it and see what it measures out to.

              Jim
              james r pepper

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