I was doing some thinking a on this and was wondering why I cant seem to get this engine to run smoother.


This is besides my '63 the only vehicle I have that uses breaker points.


When I tested mine after I set the point gap to specs I noticed the dwell was not with in specs.


I know in theory the lobes on the distributor as they wear down will change the dwell.


My question is if the dwell is out of specifications will it cause a rough idle but seem to have the power it should have?


I am just thinking on this as I will be using the vehicle as is till I pull the body off for restoration at which point I was going to pull the dist and install a new one.

 

There are several things that can cause an engine to idle rough, miss gapped points and plugs, bad wires, carb and timing not adjusted right, leaky valves, or vacuum leaks.

 

A worn distributor will definitely contribute to rough running and erratic idle. They wear out quicker than you might think, not just lobes but end run out, wobble, etc. rust, slots worn, gummed up. Makes setting points near impossible, and that's probably the real reason hardly anyone runs points anymore.

 

Setting the points with a feeler gauge only gets you in the ball park to get the engine fired up. Sometimes the dwell comes out correctly if you are lucky. The dwell is what is important even on a worn dizzy. Why not set the dwell to spec and see how it runs? If it won't hold a steady dwell it's probably the bushing letting the shaft wobble.

 

exactly.......typically a cheap & easy fix!

 

And how would you set the dwell since you cant run the engine with the distributor cap off?


I know its not vacuum leaks I know its not carb, I know its not ignition related because the carb I rebuilt, there are no vacuum lines on this engine other than for the vacuum wiper motor and the vacuum heater switch which I need to check as I have no vacuum at the hot water valve on the manifold. The points, condenser, cap, rotor, plugs, plug wires were all replaced and set to specifications. Only thing I have yet to do is actually check timing but the engine starts up way too good and way too fast to be a timing issue. I do know that the dwell was 1* more than what specifications said it should be. That's why I was wondering on this because if that is the likely cause I am thinking of simply replacing the dist.


Now I did set my points in the middle I think it sai 0.014 to 0.016 and I set mine at 0.015. Maybe I could try resetting it to the higher end of the spec to try and drop the dwell down some. I just remembered that the spec listed has three different settings and I just went with the middle as it was a good place in the middle of specs.


I am also thinking right now if I should just not say screw it and go ahead and invest in the Petronix kit and just get away from points and see if that helps but the points are actually not hard to set on this as it is on my '63. I don't think I will mess with it just yet as I am not driving the car yet and it has good power when moving up and down the driveway. I just am not a fan of a roughness at idle where the steering wheel vibrates slightly and your hand shakes on the wheel.

 

You can crank the engine over with the distributor cap off to observe the dwell. Check again with the engine running to verify.

I wouldn't spend money on anything until the problem is discovered and fixed. Pertronix does not fix a worn out distributor, if that is the cause.

 

Well Petronix would fit the problem if the lobes on the dist is worn resulting in the point not opening and closing at the rate they should. But now if there is slack in the dist it wouldn't make a difference.


I honestly don't think that is the case as the lobes you can clearly see are very rounded and blunt unless that is how they are supposed to be but that's not how the lobes on my other dual points dist look like. They have more of a point to the lobe.


In any case I am not messing with it as the car runs just fine, I don't think I will be putting it on the road anytime soon as I was told to wait and do it after I move out of the city as it would be easier than trying to get it registered in the city. I just know if this is the cause of the roughness of the idle but will have a smooth idle when at a fast idle or you hold the RPM up then I would have to look at fixing it as I cant stand a vibration at idle felt in the car and through the steering wheel.

 

Just tell folks that it has a Hot Cam in it.
That's how they idle. Right? And maybe
even convince your own self of this and
be able then to sleep at night's.

It is a stock cam, right?

 

Everything is stock on this car, OEM Ford 60 years old 155,000 original miles never been rebuilt.


I honestly don't know maybe these cars have this slight roughness at idle in gear. I honestly haven't had a vehicle this old let alone one with a solid lifter cam that's not been rebuilt before so I don't know if this is how they all idled from the factory or not when new. I do know my dwell is 1 point off I could play with my point gap since I am set in the middle of the specs I could go to the wider gap spec and see if that moves it into spec on the dwell or further away from spec.


I also uploaded finally the latest video I took of the engine running on Youtube and embedded it on here in my Y-block revival thread but now it says when I go to page 9 the page cant be found. Hope the embed didn't screw it up.

 

1 or 2 degrees of dwell will not make a noticeable difference in the engine idle. If the distributor is not too worn then I would expect 1 or 2 cylinders to be low on compression.

 

I could do a compression test but the thing is though I don't believe that I have one or two cylinders with enough of a difference to cause this. I rotated the engine over by hand with the plugs in when I was setting the valves and after wards I did four complete revolutions and I did not feel any change in the engine when rotating it through its four strokes.


I could hook up a gauge and test it, I could also check the timing on it but I don't believe its timing as the engine starts up way too fast, I also don't believe it could be the engine is worn resulting in low compression as switching the key off the engine stops fast like the motor is still nice and tight. Ive seen worn engines you turn the key off they spin back wards a little or they spin forward a little bit then stop, this engine actually stops fairly quickly.


I also believe I did a load test on this holding the brake and stepping down on the throttle with it in gear and felt no misfire typically and this is from personal experience on testing for misfires at work, if a cylinder is down on compression enough to cause a roughness at idle it also results in a misfire under load.


Maybe it is nothing, maybe its just one of those things I need to just run the engine and drive it an it will clear out on its own. I coudnt say I know my Mercury has been sitting a lot lately since I been driving my truck and I noticed that 351W in her now has a slight roughness in the engine at idle in gear. I guess its one of those things I will just wait and see on.

 

It is true, if the lobes are worn, Pertronix would fix that aspect. However, if the distributor is to the point that the lobes are worn, the whole distributor is probably worn and needs to be rebuilt, even if you plan to use Pertronix. With 155000 original miles and never rebuilt, your distributor is worn out and needs to be rebuilt or replaced for the best results.

More concisely, the point I wanted to get across is find out why something is happening before throwing parts at it.

You're not going to solve problems based on belief. Perform a compression test and get actual numbers for each cylinder. You may not feel a difference but it can still be there.

There should not be any roughness so something is off. The carburetor, distributor / ignition and compression are all suspects.

I see the video in the revival thread. That is not how it should idle.

Do a compression test, check timing, get real data and see where that leads you. That's the only way you find the cause.

 

What is wrong with the idle, I personally don't see anything wrong with how it idles but I would like more information on what is wrong as that is very vague saying that's not how it should idle. too fast, too rough, too slow, please elaborate.

 

It sounds like the idle speed is wandering and is not stable.