I have a rather odd scenario that I can't quite figure out. Working on a 66 valiant 225. The guy had taken it to a shop that had a bunch of kids working for him that didn't have a clue what they were doing and now the car was running like crap. I pulled the distributor out and changed the points and replaced the vacuum canister, as it was dead. When I stabbed the distributor back in, I get the timing either too far advanced or too retarded, but staying within the allowable range of the distributor rotation, I cannot pull it in to the proper timing. Also, the mechanical advance seems to start coming in right away. There is no baseline, so to speak, with the engine idling because the mechanical advance has already kicked in.

1. The way I checked the timing was by manually rotating the engine until I got a spark. I couldn't tell you where that timing would have ended up being, as every time it was outside the bounds of the timing indicator on the block.

2. Each time, I would lift the distributor just enough to free up the shaft and spin it ever so slightly, just enough to come off of the tooth it was on, then re-stab it.

3. I've had balancers slip around in the past, but this one doesn't look like it could slip off of top dead center. It's rather difficult to get anything in there to determine if it truly is at top dead center.

4. I would expect that from one tooth to the next, there wouldn't be that great of a distance between where the timing kicked in, but with it fully advanced on one tooth, it was just outside of the range of the scale on the AFTER side. Then, backing it off a tooth and setting the distributor to fully retarded, it was almost 1/8 of a rotation away from the scale on the BEFORE side.

I must have stabbed that distributor 20 or 30 times, and every time it came out pretty much like that. If anyone can offer any insight here or send me off in a direction, I would appreciate it.

Read this. Also, take note: there is a second bolt. The one you already know about holds the distributor hold-down plate to the block. The other, second one holds the plate to the underside of the distributor, and it has a longer adjustment slot than the one you know about. If you cannot get the adjustment range you need, you loosen that second bolt and rotate the distributor relative to the plate, setting it so that your desired timing setting is somewhere other than either extreme end of the plate-to-engine-block bolt slot. There used to be a special wrench that allowed you to reach that plate-to-distributor bolt with the distributor installed, but it has been discontinued for quite awhile now, so unless you bend up your own, you will have to pull the distributor to reach that second bolt.

Don't forget about the two O-rings that belong on the distributor; see here. And find tune-up parts and technique suggestions in this post.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Damn, I never even suspected there would be a second bolt to adjust the distributor angle. Kind of makes sense given the limited space for rotation in that area, but it seems a little odd.

Thank you very much, I'm sure this will solve my problem.

By the way, I haven't read the posts you linked to, yet, but will do that shortly. I've been finding a lot of contradicting information about what the timing should actually be for this particular year. I ran across something that said it was five ATC and things that said five btc, two and a half BTC, 12 BTC, etc. I'm hoping those posts clear this up

'66 Valiant with a 225: set it to about 5° BTDC with the engine idling at about 600 rpm and the vacuum hose disconnected from the distributor and plugged.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Ha! That last post is actually the post that I used as my baseline while going through all this.

Thanks. When should it be all in, and what is all in? Also, how much should the vacuum advance add at idle?

The vacuum advance should not be receiving enough vacuum at idle to move the timing much at all; disconnecting it before setting the base timing is just to make sure.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

It's definitely receiving vacuum at idle, the RPM jumps significantly when vacuum advance is plugged in. I didn't really measure the result or pay much attention to it, as plugging it in was the last thing I did before I closed the hood for the day. The canister that I put on it begins to apply advance at 10" of vacuum, and a good engine should definitely have more than 10" at idle.

I did notice that the air mixture screw was four or five turns out and so little as a half a turn in caused the engine to react poorly. Again, though, that was something done quickly in passing as I was wrapping up for the day and I didn't spend much time thinking about it.

I will be getting back to it here in a couple of days to change the timing chain, as I noticed a significant amount of delay in the distributor when moving the crankshaft back and forth

Make sure the vacuum line is running to a ported vacuum source, not manifold vacuum. The ported vacuum is a port on the carb intended specifically for vacuum advance, and it doesn't apply very much vacuum with the throttle closed.

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Matt Cramer
1966 Dodge Dart turbo / EFI project

Mixture screw 4-5 turns out? I've never had to run one that far out on any engine from a single cylinder Kohler on a garden tractor to a slant 6 or a small block, big block, stock, wild or anything else in between. Usually when I find something wanting more than half of that there's a problem either with a vacuum leak or dirt somewhere in the carburetor.
Most engines I have worked on wind up with mixture screw(s) at least than 2 turns from seated when all is well

Carburetor operation and repair manuals and links to training movies and carb repair/modification threads are posted here for free download.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.