Camshaft sprocket spacing

  • I am replacing my timing chain, cam, and cam shaft sprocket on my 64 engine, built Nov 1964. The cam sprocket is currently a S-406T. The engine has the 0.250" thick cam thrust plate with the hex bolts. I've seen the warning sheet like the one I've attached here that indicate than an extra spacer might be needed - how do I know whether I need that? The engine, as assembled, did not have another spacer. Neither the old cam sprocket of the replacement sprocket I bought has an extra step on the rear boss like shown in the aarning sheet. The crank is the original Hi-Po with the pinned hatchet balancer. The crank sprocket has no markings that I can see. Do I need to worry about a spacer?

    Cloyes S-406T sprocket info.jpg
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    I am replacing my timing chain, cam, and cam shaft sprocket on my 64 engine, built Nov 1964. The cam sprocket is currently a S-406T. The engine has the 0.250" thick cam thrust plate with the hex bolts. I've seen the warning sheet like the one I've attached here that indicate than an extra spacer might be needed - how do I know whether I need that? The engine, as assembled, did not have another spacer. Neither the old cam sprocket of the replacement sprocket I bought has an extra step on the rear boss like shown in the aarning sheet. The crank is the original Hi-Po with the pinned hatchet balancer. The crank sprocket has no markings that I can see. Do I need to worry about a spacer?

    Cloyes S-406T sprocket info.jpg

    Cloyes S-406T sprocket info.jpg

    That paper that was included with your sprocket is very confusing as it apperas to not be to scale and should not be relied upon for accurate information. Your actual original sprocket would have had a retainer plate held in place with clutch head screws. The original style sprocket would have been more or less flat on both sides where it mounts to the camshaft. There would have been a spacer between the camshaft and the sprocket as a separate piece. Based on your description of a .250" retainer plate, you have the later design retainer plate which is retained with thin headed hex bolts. That retainer plate uses a sprocket with a built in spacer which will appear obviously different from the front and back sides. This design was used at a change level later than your date code.

    -Fred-

    65 Koupe early San Jose Phoenician Yellow 4 speed
    66 GT Koupe Dearborn Blue 4 speed
    66 KGT San Jose fastback pony interior Silver Frost 4 speed
    64 Falcon sedan delivery 289 4 speed
    65 Ranchero 289 4 speed
    66 Corvette roadster 427/425 4 speed

  • Thanks Fred. I agree that the C-spacer and thicker thrust plate, with the clutch-headed screws are missing and I have something like the later (after L7) pieces in its place. How critical is the cam sprocket line up with the crank sprocket? Seems like spacing stack up may not align perfectly.

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    Thanks Fred. I agree that the C-spacer and thicker thrust plate, with the clutch-headed screws are missing and I have something like the later (after L7) pieces in its place. How critical is the cam sprocket line up with the crank sprocket? Seems like spacing stack up may not align perfectly.

    Everything lines up perfectly with the later setup as it should because that was designed that way by Ford.. The later setup is my preference for all of the Hipo engines that I build. Even though I have the earlier setup in stock, if I wanted to use it, the later setup is less expensive and currently readily available. The earlier setup has become very tough to locate and the price, of course, reflects that.

    -Fred-

    65 Koupe early San Jose Phoenician Yellow 4 speed
    66 GT Koupe Dearborn Blue 4 speed
    66 KGT San Jose fastback pony interior Silver Frost 4 speed
    64 Falcon sedan delivery 289 4 speed
    65 Ranchero 289 4 speed
    66 Corvette roadster 427/425 4 speed

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