Poly 318 timing gear NYLON?

Engine, Transmission & Driveline

  1. Rusty Muffler

    Rusty Muffler Member

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    Can someone tell me if my 66 Fury III with poly 318 and 120k miles has a nylon (plastic) timing gear?

    My Fury suddenly started running badly at cruise and was wondering if the chain could have anything to do with it.

    Rebuilt 2 barrel Stromberg carb, pointless ignition, valves recently adjusted, stock engine.

    Thx!:icon_rolleyes:
     
  2. CBODY67

    CBODY67 Senior Member

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    The factory equippment camshaft sprocket would be nylon teeth on a cast iron base "gear". At 120K miles, I suspect it could well have already been changed to a "normal replacement" cast iron sprocket/chain set.

    If the chain "jumps", it'll cause much more than just lower power at cruise. Starting will probably include much cranking and many backfires. One trick I remember seeing the local Chrysler dealer's service manager do on a TX DPS car (in the early 1970s), which started having performance issues, was to advance the distributor "one plug wire's space on the cap". The engine smoothed out and sounded more normal, but got flaky when returned to the factory setting. That was their way of checking for a "jumped one tooth" timing chain.

    If changing the timing gear/chain set, one very popular choice would be from Mopar Perf for their roller chain set. Otherwise, the Cloyes Plus Roller chain is a good one too (I put over 450K on one of those in a non-Chrysler engine).

    Have you checked for a possible muffler internal restriction (loose baffle?) issue? Or an exhaust pipe that's collapsed internally?

    Just some thoughts,
    CBODY67
     
  3. Rusty Muffler

    Rusty Muffler Member

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    Thx CBODY67,

    Are you insinuating my muffler is rusty???(lol). Thinking it was a fuel problem, I took the top off the carb to search for dirt and float level and such. I didn't find anything but did notice the fuel filter was almost empty of fuel.
    I checked it with a fuel pressure gauge (one for more modern engines with injection so it wasn't as sensitive to lower readings) and it showed about 2 pounds pressure. I then went to a vacuum/fuel pressure gauge and as I cranked it the fuel filter suddenly started filling and the reading was 5 pounds (normal)

    Anyone heard of a intermittent mechanical pump? I haven't unless something was blocking the pickup in the tank. Anyway its running fine now so go figure.