Technical Slow Cranking 318 Poly

No disrespect to anyone,,,,but is anyone reading the original post ?
He said,,,,,the problem is it cranks very slowly and won’t fire .

Okay,,,,,now from the rest of the first post,,,,I am figuring he meant won’t start,,,,,not fire .
Because he has got it to “pop “ a few times and even backfire.
If it will pop and backfire,,,it is getting ignition,,,,,so that is probably not his major problem .

I am most concerned with the slow cranking speed !
Like someone stated before,,,it almost acts like it has tried to seize from sitting .

This engine should turn over easily with the plugs removed,,,,,I believe it would rotate by hand by turning the fan with the belts tight .
If not,,,,it should turn easily with a breaker bar on the balancer bolt,,,,for sure !

Remove the plugs and squirt some atf or Marvel or similar lube in the bores,,,,wait a few hours or a day,,,,,then try to spin it,,,,,
Because if it doesn’t rotate easily by hand,,,,,it’s not the starter cables,,,or the starter,,,or the distributor .
A process of elimination,,,,,go the simple route first ,,,then move on to bigger issues .

Tommy

 

What @TA DAD said, the 318 it’s almost impossible to remove the gear with the intake on. It can be done if your patient, I’m not. The intake comes off easy on these engine but then your into a set of gaskets .

ive never done it but you can try pickling the engine . Fill it right up all cylinders snd sump right full of your lube/ solution of choice snd let it fill up and saturate everything drain it snd see if that helps to free stuff up. Let it sit a few days / weeks before draining it!

good luck. Keep us posted .

Amd a engine with the spark plugs removed should spin over easily with a 1/2 inch ratchet on crank bolt , almost no effort.

 

To be brief I would check the following, only going on to the next problem when the last was fixed.
1) How hard is it to turn over with the plugs out? Check with a torque wrench on the crankshaft or by hand turning by the fan.
If it turns over fairly easily
2) Get it spinning on the starter
3) Be sure you are getting a good spark to all cylinders, in the right order, timed properly
4) See if it will fire with a little gas down the intake
5) Be sure the carburetor is working. Usually if you can get gas to the carb and it starts, the engine will smooth out as it warms up, after 10 minutes or so should settle down and idle like a good one.
In doing this work I would make the minimum changes, only changing something if testing proved it needed changing. You already tried throwing random parts at it and that didn't work, now how about diagnosing the problem or problems and fixing it right?

 

At some point you might want to take off the valve covers, check for sticking valves and oil the valve stems and rockers with an oil can. Sticky valves can account for low compression. So can ring wash down from excess gas, a squirt of oil down the plug hole will fix that.

 

First I would do what Vandenplas in post 33 about turning the engine over with a ratchet. Then do a voltage drop test as post 13 I like to find the problem not just throw parts at it. If the engine turns OK and you don't find a voltage drop It's time to think starter.

 

Agreed, the oil pump shaft is ok wherever. Determine where the rotor points at #1 TDC and wire cap accordingly. From what I observed it seems correct.

Better grounding and bypass the ballast resistor will be looked at.

Saw a video of a guy reviving a similar vintage poly. Crank speed sounded very close to what we had.

 

If you decide to remove the oil pump drive shaft you may be able to do so without any tear down. You'll just need a good pair of external snap ring pliers. I've done this on a 340 LA which I suspect is similar enough to your 318 poly.

https://www.jalopyjournal.com/forum/threads/hemi-disaster-school-me.1199991/#post-13675410

https://www.jalopyjournal.com/forum/threads/hemi-disaster-school-me.1199991/#post-13677512

To pre-oil the engine I recall that we used an old pump drive shaft with the gear teeth ground down far enough to not engage the teeth on the cam.

 

Update. Engine got another dose of Marvel. Sat for a few days then instead of dumping gas down the carb, used a shot of ether. It fired. Some more coaxing with a little gas and it came alive. Idles nice. Not sure why we couldn’t get it to start on earlier attempts. Best guess is that it got flooded. So success! Even with low compression. Those rings probably loosened up some after it started.

 

That is always a good feeling !

 

Marvel Mystery Oil strikes again! That stuff will work miracles in any stuck engine or part.