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Subject: The mighty 318

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Island Mike    Posted 01-14-2023 at 20:51:11 [URL] [DELETE]        [Reply] [Email]  
  • The mighty 318
  • Did a bit more checking on the 77 Dodge 318 in my camper van. Compression is 135 to 150 over the range of 8 cylinders. Squirting oil in one of the 135 holes, pumps it up to 160. This van had been sitting for about ten years, and has around 55000 miles.
    Vacuum is 18, pounds I assume, with a very minor flutter. Not even one quarter of a pound flutter, but the needle is not rock steady. Watching stuff on you tube, shows flutter at 2 or three, or more pounds of flutter. So I assume this is not bad. But I can hear a flutter when I rev the motor. Next on the list is to check the valves for opening and closing, and checking all the rubber lines/hoses for possible vacuum leaks.
    I will be removing the radiator, alternator and power steering pump. That will give me access to the font of the engine, so I can turn the crank.
    The engine pros are welcome for their input.
    Herb 9N has about 112 pounds of pressure. Island Mike

    Bruce(OR)    Posted 01-14-2023 at 23:13:20 [URL] [DELETE]        [Reply] [No Email]  
  • Re: The mighty 318
  • If you did the oil addition on a warm engine, That is to say run more than 20 minutes to achieve normal operational temp, Then gaining 25PSI on a cylinder with a wet test is a fair indication a ring job is not too far away.
    Dry comp check of 135 to 150 is within an acceptable number, generally no more than a 20 PSI difference.
    18 inches of vacuum is a good number and the minor fluctuation should not be an issue.
    Since you like playing, grab a tachometer and a pair of nylon pliers used for pulling fuses out of a household fuse box. Nicely insulated to work with.
    With the engine running, pull one wire at a time with the pliers.
    Note the cylinder that has the lowest RPM drop when pulling the wire.
    Two cylinders drop? Firing order is what? Crossed a wire or two?
    Maybe?
    Now if you have a fair comp gauge set, you can pull the shraeder valve out of the hose, spin that cylinder to TDC compression, and do a leak down check with compressed air. Hissing noise in the oil fill is bad rings, from the carb is a bad intake valve and exhaust noise is a bad exhaust valve.
    My money is noise from the exhaust valve but with that 135/160 increase, that cylinder might should be making noise out the carb throat.
    Engine pro? No. Just a lucky guesser.

    Bruce(OR)    Posted 01-19-2023 at 00:06:59 [URL] [DELETE]        [Reply] [No Email]  
  • Re: The mighty 318
  • 318. I believe the nickel finally dropped. Firing order of 1-8-4-3-6-5-7-2, same as the small block Chevy from about 1955 to 1985 or so. Distributor rotation direction has faded from memory. Hope you got it figured out by now. However, I believe it spins counter clockwise.

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