Mileage: 4 rph [rotors per hour]...What Gives??

[Guest]

I made it across town with my car (first time out since rehab) and she started sputtering like crazy. Checked ALL settings, everything good. Changed ALL ignition component expendables and still no go. Put a 2nd new rotor in and ~BINGO~ she cranked right up. Drove an hour hard, sputter, pop, slipped on a new rotor, off she goes. Two hours later, same scenario. This is getting old quick. I am using a Lucas Sport Coil and have the points opened a bit over stock. Am I cracking these things or are they just that poor? (I use the work crack, only because I don't see any visible failings.)

 

[rotoflex]

Re: Mileage: 4 rph [rotors per hour]...What Gives

There are some REALLY bad rotors out there. The bad ones I got were in an Intermotor box, but the new ones in a "new" Lucas box. From what I understand, both are mfd. by Intermotor now, & some are just sold to Lucas. Go figure.

The bad ones I received had the brass arm loose on the bakelite body, & woggling back & forth.

I would also check to see if the shaft of the distributor is running true.

What did the pathology lab say when you sent them the dead rotors? Did they crack on the bakelite body, did the brass part deteriorate, or whut?

What does the inside of the cap look like now?

Have you somehow gotten the wrong cap (like a flat Delco on a Lucas distributor)?

 

[Guest]

Re: Mileage: 4 rph [rotors per hour]...What Gives

The distributor is a resent rebuild by Mark at British Auto. Works well. The caps are all Lucas from TRF. The caps don't seem to be a problem, even wear on all contacts. The rotors are also "Lucas" from TRF.


On another note, when I re-ran my 5/16" steel fuel line down the tunnel in the center of the car, this thing seems awfully close to the exhaust pipe. Maybe 3/4" away in some spots. Could I be overheating my fuel line? Never seemed a problem before now.

I had the popping problem before and managed to get it to work itself out. Now it's back and I am befuddled.

On a third note, that aluminum flywheel sure turns up fast! Kind cool.

 

[Brosky]

Re: Mileage: 4 rph [rotors per hour]...What Gives

Do these rotors have the rivet in the center? Did it come loose?

The fuel line seems a little close to the exhaust to me.

 

[TR6oldtimer]

Re: Mileage: 4 rph [rotors per hour]...What Gives

<div class="ubbcode-block"><div class="ubbcode-header">Quote:] On another note, when I re-ran my 5/16" steel fuel line down the tunnel in the center of the car....[/QUOTE]

Bill, one of the things I learned in a past life as a programmer, was when something 'broke' I asked myself "Self, what was it that you changed last?" In this case did you mean re-ran or relocated the gas line? If the later, then perhaps that is your problem.

The rotors my only be coincidental in that the gas had a chance to cool down while you worked under the hood. A quick check to rule out the rotors would be to re-install the 'defective' rotor and see what happens.

 

[Guest]

Re: Mileage: 4 rph [rotors per hour]...What Gives

Rivet off-center, half way to end of arm. The Bakelite cracked from the inner contact out up to the brass arm.

That is the way the gas line has been, maybe I can torque it out a bit to hug the wall a bit more. The riveted latch is there, but broken. The line stands out from the wall about 1/4".

 

[Brosky]

Re: Mileage: 4 rph [rotors per hour]...What Gives

All of the problems with the rotors that I've heard of recently involves the darned rivet coming loose.

Cracking is a new issue. The big question is why would the Bakelite do that on several unless the molding on all was porous or had air pockets?

 

[rotoflex]

Re: Mileage: 4 rph [rotors per hour]...What Gives

I've cracked one of the modern replacements.

I distinctly remember not having it exactly over the key when starting down, & sort of mashing & turning as I pushed it on to find & get it on the key. That has actually long been my customary rotor install procedure.

About 1 day later - broken bakelite.
Might not be cause & effect, but since then I line that sucker up dead on 1st before pushing it down.

Other rotor issues related to the brass arm woggling on the rivet like a clock hand.

 

[Don Elliott]

Re: Mileage: 4 rph [rotors per hour]...What Gives

There's a specialist in England who calls himself the Distributor Doctor who wrote all about bad rotors. He even showed a photo. https://www.distributordoctor.com

 

[Brosky]

Re: Mileage: 4 rph [rotors per hour]...What Gives

<div class="ubbcode-block"><div class="ubbcode-header">Quote:] I've cracked one of the modern replacements.[/QUOTE]

Roto, I've done that plenty of times over the years, but I would never expect that of Bill. When you can drill and fill teeth successfully, you generally don't have the "500 lb. Gorilla" touch.

 

[Guest]

Re: Mileage: 4 rph [rotors per hour]...What Gives

Bill, you can get heat shield for the fuel line.
It's not that expensive, but I'm in no condition right now to go on google and find it - one too many margueritas...
Do a search and you should see the stuff I mean. If not I'll look tomorrow.

Oh and I had a new trf intermotor rotor crack just like yours after I replaced it. Had to duct tape it to get home. Ended up putting the old one back on to get it to run...

Pretty sad imo.

 

[Andrew Mace]

Re: Mileage: 4 rph [rotors per hour]...What Gives

I'm ever so grateful that I've been a packrat all these years and kept all my old rotors in the rare cases that I ever actually replaced one. Had a buddy with an MGA that I helped "rescue" a couple years ago...by borrowing the (none too current but perfectly serviceable) rotor out of my Herald. Of course, I then needed to put something in the Herald, so I borrowed an ancient rotor out of a long-dormant Standard Pennant I have, cleaned it up a wee bit, and the Herald has run ever since.

I saw the same information Don did (presumably in the TR Register UK "TR Action" magazine). Sounds like there might be a solution, with this "distributor doctor" sourcing or manufacturing some much better rotors. But I suppose it will be some time (and MUCH AGGREVATION) before all the bad ones are taken out of circulation. /bcforum/images/%%GRAEMLIN_URL%%/frown.gif

 

[rotoflex]

Re: Mileage: 4 rph [rotors per hour]...What Gives

<div class="ubbcode-block"><div class="ubbcode-header">Quote:] I've cracked one of the modern replacements.

Roto, I've done that plenty of times over the years, but I would never expect that of Bill. When you can drill and fill teeth successfully, you generally don't have the "500 lb. Gorilla" touch. [/QUOTE]

I've seen how much gorilla it takes to divorce a molar from a mandible. I'll bet he knows how to operate the BFH when it's time to use it.

Haven't you ever noticed that dentists have forearms like Popeye?

 

[Dave Russell]

Re: Mileage: 4 rph [rotors per hour]...What Gives

The distributor is a recent rebuild by Mark at British Auto. Works well. The caps are all Lucas from TRF. The caps don't seem to be a problem, even wear on all contacts. The rotors are also "Lucas" from TRF.

I'm not sure what you mean by "even wear on all contacts." There should be absolutely no contact between the rotor & the cap terminals except for the center carbon brush. The terminals should have a noticeable & uniform air gap to the rotor arm.

It's not uncommon for particular rotor & cap combinations to have dimensions that result in contact which results in cracked rotors. It's just that some caps have a slightly smaller terminal/contact radius, some rotors are slightly longer. The most common problem is a rotor that sits too high & scrapes the under side of the cap terminals. The bottom seating surface of the rotor can be relieved slightly to lower it a bit. This is especially necessary if you hapen to have a Pertronix magnet sleeve installed over the distributor cam.

Not getting the cap firmly seated, concentric, & square to the distributor body is another cause of rotor to cap contact.

I think a lot of rotors get a bad rap when it is really this cap to rotor contact problem.
D

 

[rotoflex]

Re: Mileage: 4 rph [rotors per hour]...What Gives

<div class="ubbcode-block"><div class="ubbcode-header">Quote:]I'm not sure what you mean by "even wear on all contacts." There should be absolutely no contact between the rotor & the cap terminals except for the center carbon brush.[/QUOTE]

I imagine it could be the case with these replacement rotors with the wobbly brass arm could pivot out & abrade the contacts in the cap.

It might not take much of that to break the bakelite.

 

[Dave Russell]

Re: Mileage: 4 rph [rotors per hour]...What Gives

The brass arm is not wobbly until after it contacts the inside of the cap. If it were loose in the beginning, no one would install it - I hope.
D

 

[Bugeye58]

Re: Mileage: 4 rph [rotors per hour]...What Gives

I have never installed a rotor with a "wobbly" brass arm, and I have never had a rotor failure, either.
I do all my distributor work on the bench, and verify the clearances by turning everything by hand before installation.
Anal perhaps, but I think the results speak for themselves.
Jeff

 

[Tinster]

Re: Mileage: 4 rph [rotors per hour]...What Gives

Bill, remember back in October when Crypty "almost"
functioned but the dizzy failed? And they Crypty's
dizzy was rebuilt by Jeff, cranked right up but
quickly died the same day? Two new aftermarket rotors
in one day cracked and shattered the bakelite.

Jeff kndly send me a replacement and there has been
no problem since .

d

 

[tomshobby]

Re: Mileage: 4 rph [rotors per hour]...What Gives

I had a problem with two rotors not fitting far enough onto the shaft with the Pertronix rotor under them. They were high enough that they pushed the top spring-loaded contact up and rubbed on the cap Bakelite when they turned. They also pushed the cap off the base so that it could "wobble" and the rotor could hit the plug posts (sure that is not the tech term).

For a temp fix I used my grinder to take a small amount off the rotor base. They then installed far enough that there was no problem.

I noticed that the setup from Jeff does not have this problem. But then, not all rotors seemed to either.

 

[bobh]

Re: Mileage: 4 rph [rotors per hour]...What Gives

The only problem we encountered on the drive from Seattle was the new rotor cracked after less than 200 miles. Replaced it with the 30 year old original and it's been running ever since.