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Tappet adjustment
Posted: Sat Aug 12, 2023 8:41 am
by Dfisher32
I read in Chrysler's service manual to do a tappet adjustment when the engine is warm. Why? I've always made these adjustments on other engines when they are cold. I'm currently struggling to get one of my 318s to run, and it sounds like the valves could be out of adjustment, so I'd have to check clearances while the engine is cold. The first issue I had was no spark, which was mainly a grounding issue--replaced all ground straps. I also installed a hard start relay. I have replaced the battery with a 4D size battery--plenty of cranking amperage. I've also replaced the starter solenoid, ignition coil, distributor cap, and electronic replacement for points. When the engine turns over now it is slow and uneven, as if it is under a load. I'm thinking I should pull the plugs out next and turn the engine over to see if the valve adjustment has anything to do with this. Does this make any sense?
Re: Tappet adjustment
Posted: Fri Aug 18, 2023 12:49 pm
by BlueSkye
What kind of engine do you have? There is no valve adjustment on the 318. It's unclear if this engine is new to you.
Another grounding vulnerability is the connection of the starter to the block. I have had trouble once with the red wire connections being dirty.
Re: Tappet adjustment
Posted: Fri Aug 18, 2023 7:21 pm
by tundrarules
Did you check your cylinder pressures? Pressure gauge can tell you lots of info.
Re: Tappet adjustment
Posted: Sat Aug 19, 2023 5:51 am
by Dfisher32
I’m not new to this engine, but it has been several years since I’ve fooled with one. I have considered doing a compression test. I think I’m going to check distributor adjustment next.
Re: Tappet adjustment
Posted: Sat Aug 19, 2023 7:41 am
by Fastjeff
Check the advancement set up in the distributor. They are notorious for sticking and messing up the timing of the engine.
No valve adjustment on 318s and 360s.
Jeff
Re: Tappet adjustment
Posted: Sun Aug 20, 2023 9:52 am
by Dfisher32
Fastjeff—when you say “sticking” what usually causes that—age, lack of lubrication?
Re: Tappet adjustment
Posted: Mon Aug 21, 2023 6:47 am
by Fastjeff
The advance mechanism under the plate (where the hall effect sensor is attached) tends to hang up and not return all the way at idle speeds. When that happens, and you time the motor, it ends up a bit retarded.
To avoid that, I "exercise" the mechanism by flipping it to full advance, then letting it snap back, several dozen times. That cures it for a while.
Jeff