Guys - Got a nose mount Mallory dual point on the Track Roadster; after much carb T-shooting, I'm convinced there's a prob up there. dizzy is brand-new - as is the internally ballasted 6V coil. Here's the deal - motor runs okay from idle to *about* 2500 RPM, then the ignition starts to break up - like spark blowout. I've run a hand tach on the belt...she's idling at 600 RPM now (turned the idle down) and the plugs are fresh. I tried to wind it up past 2500...it's done (as in won't wind any further) at 3500. Have tried several timing settings all the way back to TDC - same result. Looked for my Mallory paperwork, and can't find it. What gap are the points supposed to be set at - and how do you limit the total advance? Unit is a full centrifugal (mechanical) advance dizzy. As always, advice is appreciated. I'm stuck waiting for the driveline bearings, so I might as well resolve this issue in the meantime... Thanks! Chuck.
Chuck, I have the specs at the shop and will look tomorrow. But if ya want UPS ,the evil distributor to me and i will check it and adjust on a distributor machine and ship it right back to ya. Cant even begin to tell ya how screwed up some of these ( nameless-starts with a M) distributors have been over the last few years.
I would take apart that Mallory and check everything for wear or looseness anywhere. Several years ago we had a dual point Mallory on an engine we were dyno'ing for Bonneville. On the strobe light, the timing marks were wandering all over the place. When we stuck in an ordinary well used GM Delco distributor, the ignition marks were dead-on. That Mallory could be simply worn and loose inside. Long ago I had an early Hemi with a bad distributor that wouldn't run right when the points were set by the gap in the shop manual, but would run much better when I set them by dwell and ignored the fact that the points were left with a very small gap. I believe the shaft was worn sloppy where it passed through the distributor cam on the 30,000 mile engine and let the cam move around. It wouldn't rev very well at all until I got another distributor for it. Weak springs on the points? Old wires with questionable connections? I believe it is rare that a condensor would act up, but it might be worth changing a very old one just for the sake of eliminating one question mark. If you really like the looks of that kind of distributor I would look into the possibility of putting modern electronic distributor parts inside of it if that can include a fresh advance mechanism and all.
I've had several bad condensers from local auto parts stores. Now I either go to a GM dealer or use Accel.
I reread the post and saw that it was a new distributor. That will change a few things, but I would still look for looseness of internal parts or weak springs or a wire routed where it may rub something it shouldn't.
I ran the new Mallory with dual points on account of I wanted to avoid probs outta the box...also, this is a 6V system which precludes using an electronic point set. the car has very few new parts hung on it - this is one of them, and it seems ironic that it may be the source of issues.
If it's a mechanical advance only you're either sitting at full advance at idle springs too weak, or never advancing wrong weights/springs. Maybe it's made for reverse rotation and sitting at stops all the time.
I used a Mallory dual point on my 235 six. Nothing but trouble. A big mistake and a bigger waste of money. It ate condensers. Wish I could send it back to where I got it. I swapped to an HEI and couldn't be happier. Don't they make a Pertonics for the 6volt dizzy? Dom
As mentioned in your other post, I would replace the condensor with NAPA Echlin brand - made in USA. Mallory condensors are known bad from get-go & Mallory doesn't seem to care. Echlin FA54 or FA66 seem to work well for most folks. Otherwise, your symptoms are also the same as a coil that is breaking down - perhaps your earlier overheating issue damaged the coil or it was bad out of the box... Finally, verify the advance on the Mallory - take GMC Bubba up on his offer to put it on the machine. Normally not a problem on the front-mount distributors, more on the 8BA style, but worth checking...
Thanks, Flat! The coil is a new Standard Auto domestic built coil - I went with the best one they had as opposed to the cheapo foreign coil. Even when the motor was a few minutes old, she'd miss on the way up. When it had about an hour of runtime on it, I took the frame and motor around the block; one tip in and the ignition broke up. Based on the repeatability of the breakup point (2500 RPM independent of initial advance) I'm inclined to agree with your diagnosis. I'd worked diligently to eliminate any other issues, as I'd hoped a brand-effin' new dizzy would be reliable - eliminating a variable. Now it appears that's not the case.
The Mallory name ain't what it used to be...but they're decent distributors once you get the good points & condensors on 'em!
Well... I found a condensor of indeterminate flathead origin laying about the garage - decided to toss it in and see what happens. inspired, I redid the wiring between the coil and the dizzy (both hi and low voltage) and relocated the coil. points are at 0.017" both sides. Fired it up...same result. retarded the snot out of it - same result. The centrufugal advance seems to be both light (minimal resistance) and opens a long way B4 hitting the stops. If I had to guess - that's where the prob is. She'll backfire if I hot it WOT; only way I can get much past 3500 RPM is to really hit it and it feels like I'm out-running the advance. When it catches up - she'll backfire. I have enough gas to the carb, FWIW.
When I was racin' water cooled VW's I had a distributor do that to me. It turned out to be the distributor shaft bearings (bronze busings for that one actually). I was able to replace them, problem solved. Hope that helps.
I guess send it to GMC Bubba for a proper advance curve on his distributor machine... EDIT: As I think about it, I had a similar problem with my Ford dizzy (Mallory design) for a while after I converted to crab-style on my '40. I swapped two known-good condensor in during the trouble shooting epic with no avail. On a whim after changing something else, I added a SECOND condensor up at the coil (in addition to the one down on the distributor) & it cured my sputtering problem. To this day, it's still there. Something to consider anyway...
It's funny you mention that; was shown a pic of a H&C dizzy which ran two condensors. Guess I'll beome a parts swapper and buy some more stuff.
New Mallory problems (not applicable to old flattops...)...toss condenser at once--defective inside, painted on outside to prevent ground!! Replace point with NAPA USA made--rubbing blocks of M ones are only good for about 1,000 miles! Look over the internal wires/straps connecting points sets...they are sometimes shipped with those grounding against case! I've seen them on running cars nearly enough to grounded to leave burn marks on case...
This is unbeleivable, I just put in a brand new Mallory Unilite, and im having the same problems, at aaround 3,000 rpm, the motor starts to break up...WHAT THE FUCK.........
have you replaced the coil yet?? there's been alot of bad coils around lately as well. the local flathead rebuilder got a big lot of DOA coils in. all made in america good quality coils. JUNK. replace with a known good coil. that sounds EXACTLY like what my flatty was doing with a bad coil. (mine got burnt out when the ignition key was left on)
I've not replaced the coil - yet. You're right - the motor is operating like it's got a bad coil. Frankly, I'm completely irritated at this point; spent an hour on the phone last nite ranting to Pop about it. I spent several hundred dollars on the BEST new electrical components available - and as it turns out, these parts appear to be SIAB (shit in a box). I would have been better off with a rebuilt 2 bolt dizzy and a throwaway coil from Pops' parts bin.
Very interesting thread. Have had similar problems with the Mallory 8BA style distributor Does anybody have a parts source for good condensers and points for these? Br Kjell
Your original crab is a far better distributor than a new Mallory. By the way, it is a Mallory design, built under Mallory patents and sometimes by Mallory before Mallory became SIAB. You'll still have a Mallory distributor, the only difference is that it will work. Unless you buy restoration place points instead of real car parts...
Umm...since my engine was an 8BA, it didn't come with a crab, it came with one of them crappy ford bevel drive units. After studying the bevel drive and its alternates, I figured out I'd have to convert to a nose-mount dizzy to get a functional unit to fit within the constraints of the Roadsters hood and sides. Since I didn't have a two bolt crab dizzy to start with - I had to buy one outright. I'd place orders with two separate rebuild houses - only to discover they were only more than happy to take my money, THEN advise me after the fact they were outta cores with no hard date as to when they could ship out a rebuilt unit. the other alt was to take a chance by buying a couple of two bolt dizzys on ebay in the chance that one was rebuildable. By the time I'd tallied of the cost and time, the new dual point looked good...After all, it's a Mallory, right? Wrong. some rat bastard is living off the name made by some good ol' fashioned hard working Detroiters. I'm soo irritated right now - not by the fact my car don't run right - but that I'd bought premium parts so as to avoid the current set of problems. Jim Linder (GMC Bubba) will have the dizzy this time tomorrow and hopefully will advise what the hell state it's in. It's got about 3 hrs of run time on it...will be interesting to document what he has to do to it to make it functional.
I did some measurements on early style engine front ends, posted on here under "flathead dimensions"...the shortest arrangement using early pumps and crab saves you several inches in engine length over the 8BA setup.
Look for problems in the Mallory distributor. I put one in my 8BA. First I found the leads to the points were grounding against the dist housing. In the process of fixing that I found the female spades were loose as a goose and found myself crimping the connector to get a good connection. To fix the grounding issue; I put some shrink tube over the connectors. Hmmmm. Wonder if the problems I blame on the PV might be inconsistant distributor problems? PanheadGuy
Hmm, I just put a dual point mallory on the 8ba flatty motor I am building and found that the wires in fact were touching the case also. If I need to replace the points, what is a good set? My condenser is a nice gold color, after I buffed it up. lol Guess I need to get a new one of those also huh?
Anyone with a late flathead or 216/235/261 that wants to run a Mallory should pick up a 40-50 year old unit from swap meets or Ebay. I ran a vintage Mallory in my first '53 Chevy for years with zero problems.
I've got an old flat-top Mallory that will likely go in the next build. Also have a flat-top with Unilite conversion for a SBC that might be in the cards too - it has a tach drive - so might convert it for flatty use!
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