Can't get dwell high enough...

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TylerW

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Hello again:

I am dealing with an unusual issue on a common '67 single-point distributor. I cannot get the distributor to come into spec regard dwell and point gap. Point gap spec out of the FSM is .014-.019 and dwell angle is supposed to be 28-32 degrees. Both of these are very common specs.

At .017 point gap I have about 11 degrees of dwell. I closed the point gap up to .014 and that increased the dwell to 15 degrees. At this rate the point will nearly be closed up before I can get the dwell where the book specs it and that's nowhere near normal. That's asking for a set of burned points IMHO.

This is annoying, because I went to much effort to set up the points with the distributor out on the bench. The distributor shaft is nice and tight with thrust within spec. it has not been rebuilt. The points are new old replacement stock Mopar points(in the old green box), the rotor is NORS Mopar and the cap is NORS Standard...for what it's worth.

How does it run? Well it runs good most of the time. The only time it doesn't run good is when I lean on the secondaries hard for a while, then it starts to miss. It also breaks up when you have it in neutral and hold the engine at about 3K....so, something's not right.

So...what is the general consensus when the specs won't jibe? Wear somewhere in the distributor? I did double-check my readings with two different "period-correct" dwell meters I have and they both agreed. Thanks for any advice.
 
I bet your distributor cam is worn. The rubbing blocks do need a little grease.
 
What are we workin on here, a briggs and stratton?
 
I bet your distributor cam is worn. The rubbing blocks do need a little grease.

And or the shaft bushing is slap wore out! Or your dwell meter is just flat out lying to you!
 
You guys hit it one of three things the cam plate is worn and smaller than it should be, ditrib bushings can be worn and also the top of the distrib shaft can also be bent, You will see that cranking the engine it will wobble.
 
Ok, define slap. I just need to know what scale slap correlates too.

Thanks In Advance.

YR

"Slap" means moreso than normal. Like Brenda has some good stuff, but Trixie can slap suck a golf ball through a garden hose. See how that works?
 
It's an adverb, since in this example, it's describing the verb "worn" as in worn out.
You're probably correct I just got my first cup of coffee yet still 5 in the morning..
at any rate this is exactly why I have all my customers just put in electrical module in there. It's almost 2020, at this day and age filing points and reading dwel meters is ridiculous... Not one of my customers likes paying for the electronic conversion but all of them loved the idea of one less thing to worry about more..
Edit; the last one was a 65 Ford Mustang and it fired right up and he loved it...
 
Points distributor, maintenance. Electronic, no maintenance set it & forget it.
 
Points distributor, maintenance. Electronic, no maintenance set it & forget it.

I don't disagree at all, but it's what he has now. It's almost always cheaper and easier to fix what you already have than to convert to something else.
 
This is annoying, because I went to much effort to set up the points with the distributor out on the bench. The distributor shaft is nice and tight with thrust within spec. it has not been rebuilt. The points are new old replacement stock Mopar points(in the old green box), the rotor is NORS Mopar and the cap is NORS Standard...for what it's worth.

I'm gonna guess the Dwell meter is on wrong scale, or the rubbing block is too short, or the corners of the breaker cam are really really worn off, or your feeler gauge is in metric,lol. Of these, the meter is the most likely.
Here's how you prove the D is ok ;
Firstly vertical thrust on Mopar Ds pretty much doesn't matter. But side play, as mentioned, sure does.
So just set the points to whatever, just get a number. Then check the pointgap on every lobe; it should be the same. Then pick a lobe any lobe, and measure the gap with the lobe pushed as far away from the rubbing block as it will go, and then pull the lobe as close to the rubbing block as possible and remeasure the gap. As you have discovered, there is a direct correlation between the pointgap and the dwell, with the variation being something like 1* per thou change in gap. So that's why .003 side play takes you from one side of the spec to the other. But worse is that this varying pointgap plays havoc on cylinder to cylinder timing.
I'm gonna guess that your D will be close enough to run, cuz I still think it's your meter.(or feeler gauge lol)
So reset the gap to the wideside of the spec and call it done. Then go borrow a second dwell meter and recheck the dwell, with it set to the proper number of cylinders. If it still acts gooffy, I would check the alternator output looking for an A/C component and fix that; it ain't supposed to be there; one or more of the diodes is leaking.If it still acts goofie,I would suggest to replace the condenser. If it still acts gooffy IDK.

If this is a slanty; I feel your frustration.
If a slanty in an old combine, with the D on the backside. I think I'd rather go dig a latrine
 
Thanks for the help so far. I'll try to address the questions for clarification:

1. It's not a Briggs. It's a 383. I purposely keep some details out of the question so that the replies are not unduly influenced.

2. The dwell meter is on the right scale. Both of them. That's too easy of an answer.

3. Living in the south, I understand "slap", along with pretty near, about liked to and won't stay cranked...lol.

4. I had 4 different distributors to choose from. Two were original un-rebuilt units and two were remans, which I don't ever use. All of the distributors, with the exception of one original unit, had negligible side to side shaft movement. I selected what I thought was the best unit to clean and use. I suspect that the worn cam lobe is a possibility. I'll look at it again.

5. I agree that points "can" work as well as electronic. My slant runs just fine with points. However, you constantly have wear going on with points which leads to something like what I am going through.

Thanks again.
 
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