flathead interupts under power

under full power, mainly noticeable in 3rd and 4th gear im getting very brief moments of interuption. i dont run a tach so im not sure of the exact rpm range but its certainly under the 5,000 mark. It will briefly skip until i power through it.heres the setup, a dual point malory ignition, and 2 rebuilt 97's. is this more likely to be an ignition/electrical problem, or fuel related. I ran the car about 2,000 miles last year with out changing anything. this jst started out of the blue, shortly after a refuel (water maybe?)

 

I just went through this for a Customer. Last summer he came in with the hickup, He had one set of Points burned pretty good. We changed the points against my recomendation of going to Pertronix at the time. He ran it 2800 miles since and came in with same problem two weeks ago. This time we put in the Petronix. Both times the problem dissapeared, this time it won't come back. So I would say at least take a good look at your points first and take it from there.
The Wizzard

 

ya i think it s ur points to or somthin in ur lines

 

On recent type Mallory, look at case adjacent to points and connector wires bur burn marks. I have seen them (New ones, factory installed points, low mileage!!) with evidence of shorting there but still running.
Better quality points for late Mallory are available from NAPA.

 

The last time my 8BA acted like that it had a set of burned points.

 

thanks guys, im gonna check it first thing in the morning. ill let you know what i find.

 

My father had a similar issue in his 1947 Ford. He originally thought it was the points, replaced points and still had the issue. Wound up being a bad ignition switch.

 

checked the points. they were not burnt. Made sure all my connections were secure also. im gonna check the gapping of them tomorrow. so no one thinks this might be fuel related im taking it?

 

With lack of Fuel you'd get a surge and letting up on throttle (less demand) would clear up the problem. If you'd make it a little clearer what you mean by "Interupts" it would help. I take it that it just totally looses power momenterrialy. Does it cough up through the Carb? How about backfire out the Exhaust?
The Wizzard

 

The dual point mallorys are hard on the currently manufactured condensers. The condenser goes bad, and then the points burn. Get the best quality condenser you can get and see if that straightens it up.

 

What they said, or same thing with a dud coil.

 

Yes the Condenser causes the points to burn and good condensers don't last long enough. You won't believe the difference all around once you put a Pertronix in it. No body will know if you don't tell.
The Wizzard

 

Points, condenser...I have worked with late Mallorys and talked with others who have; aside from the incompetent factory installation/shorted against case issue I mentioned, the points wear VERY rapidly both on rubbing block and actual contacts, and the condensers are CRAP with two entirely different failure paths happening simultaneously.
Even if yours is NEW, remove points and condenser and replace with NAPA Mallory parts or you'l never get 1,000 mile without work. Points and condenser ARE a reliable technology, good for many thousands of miles between flogs, if you have good ones. So far, I don't think NAPA has started selling crap ones, but Mallory, once the Rolls-Royce of ignitions, now is selling garbage. Rebuild it to right or toss it. Getting it right seems to be possible without too much messing.

 

Bruce; Do you happen to have the NAPA part numbers your referring to? Your right on with about 1K miles on replacement parts from Pep Boys and Schucks. The one thing I do like about points is even when they are having issues you can get home. Electronix on the other hand, when they are done your Dead.
The Wizzard

 

I'm searching...they've been posted online several places, and are under Mallory in the Echlin catalog. From memory, may be wrong, they seem to be the same as '57 Ford type points with only an adjuster notch differing...gotta research more.

 

This has turned into an ignition discussion...we should remember problem is still not diagnosed, and might not be ignition even with a Mallory.

Echlin points CS2301
Echlin condenser MA3
These are from a search...I have not checked them...Echlin has a pictorial catalog: Turn that to Mallory section, match the 2 or 3 Mallory listings to the points you have before ordering!

 

I have this same problem on a stock 8BA. Its only when I wind it out good. I shouldnt be hitting the old girl that hard but I figured it was springs in the dist or points. It runs fine otherwise.

 

On a stocker, it is quite likely that you are running badly retarded at full throttle. This is a problem area for the late stock distributor.

 

Im changing out the condenser now, will keep you posted as to the results.

thanks

 

It was the Condensor. Put a new one on, started right up, runs like it did when ifirst built it. thanks for the help guys