View Full Version : Mallory Dual Point Question


chuckspeed
07-21-2007, 07:58 PM
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.

GMC BUBBA
07-21-2007, 09:09 PM
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.

dare-to-be-different
07-21-2007, 10:45 PM
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.

GassersGarage
07-21-2007, 10:52 PM
I've had several bad condensers from local auto parts stores. Now I either go to a GM dealer or use Accel.

dare-to-be-different
07-21-2007, 10:55 PM
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.

chuckspeed
07-22-2007, 08:26 AM
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.

Jim - I think I'll take ya up on that. Will look for your address and ship it out tomorrow.

chuckspeed
07-22-2007, 08:35 AM
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.

Big Pete
07-22-2007, 08:58 AM
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.

52HardTop
07-22-2007, 09:29 AM
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

Flat Ernie
07-22-2007, 09:38 AM
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...

chuckspeed
07-22-2007, 10:10 AM
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.

Flat Ernie
07-22-2007, 12:30 PM
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!

chuckspeed
07-22-2007, 12:36 PM
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.

nexxussian
07-22-2007, 12:47 PM
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.

Flat Ernie
07-22-2007, 02:00 PM
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...

chuckspeed
07-23-2007, 06:20 AM
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.

Bruce Lancaster
07-23-2007, 08:51 AM
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...

Fifty5C-Gas
07-23-2007, 09:00 AM
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.........

revkev6
07-23-2007, 09:03 AM
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)

chuckspeed
07-23-2007, 09:39 AM
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.

fenderless
07-23-2007, 02:37 PM
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

Bruce Lancaster
07-23-2007, 02:46 PM
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...

chuckspeed
07-23-2007, 03:44 PM
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.

Bruce Lancaster
07-23-2007, 03:48 PM
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.

panheadguy
07-23-2007, 05:06 PM
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

Flat Ernie
07-23-2007, 11:19 PM
I would have been better off with a rebuilt 2 bolt dizzy and a throwaway coil from Pops' parts bin.
Probably...:(

Fourdy
07-24-2007, 12:16 AM
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?

HEATHEN
07-24-2007, 08:24 AM
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.

Bruce Lancaster
07-24-2007, 08:52 AM
Old flattop Mallory's are golden...ones made in recent years appear to be nade of something else.

Flat Ernie
07-24-2007, 10:22 AM
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!

revkev6
07-24-2007, 10:25 AM
flat ernie, wouldn't that SBC mallory still have the wrong advance curve.....

might as well fix the new mallory so you don't have to do the machine work.....

Flat Ernie
07-24-2007, 10:48 AM
But the SBC has a tach drive.... :D

I don't think the curves are that far off & it's relatively straight-forward to modify anyway...

Bruce Lancaster
07-24-2007, 10:50 AM
Old Mallorys have a very simple bit of tin limiting the curve, easily replaced with another to limit curve. I think spring kits are still available, but oldies with the HP curve are usually pretty good as is. Recurving a classic high quality piece of speed equipment is a LOT more fun than debugging a brand-new Chinese made piece of crap, IMHO.

alchemy
07-24-2007, 10:59 AM
I recently had Jere Jobe reset the advance of a modified SBC-into-flatty distributor. I used an old two-piece cap Mallory with a tach drive. Dual points, big brass condensor, traditional looks.....what more could a guy ask for?

I had it cut down locally to fit an aluminum 8BA front cover. Jobe didn't say it was hard to reset at all.

HOTRODDICKIE
07-24-2007, 11:09 AM
Had the same problems 5 or 6 years ago.
What kills these cheap modern condensers is heat, the chineese laquer in the capacitor dries out, on a flattie they are especially vulnerable. Relocated my condenser to under the dash nice cool place,the longer lead makes little difference. In 4 years no blown condensers.
Check modern capacitors in any electronic equipment and they have a max temp rating of 85 degrees I suspect they use the same stuff in these condensers hence the mega short life, stick it away from the motor where it will only see 20 - 30 degrees and the life is many times higher.

The misfiring at higher revs I suspect is due to Mallory setting the advance at the factory to stock SBC spec. If you take all the innards out of the dissy there is an adjustable plate underneath, loosen the allen bolts and turn this the opposit way to how it is set almost to the stops, you may need to play around with this to suit your motor, but should allow it to rev up.
Rich

revkev6
07-24-2007, 11:12 AM
i'd still rather start with the right part I think. I've got an nos flat top mallory (yc 365hp) to go in the 283 in my 32. I kinda hate the idea of cutting up an old piece of speed equipment like that even if it's for the more common chevy. I have a feeling you'd look back and regret cutting it up.

Stovebolt 6
07-24-2007, 11:13 AM
Had a brand new Mallory Dualpoint on the 235 inline6 - pain in the a...
It eats condensors and even with a lot of tweaking on a dizzy machine we never got the curve right. :rolleyes:

I was thinking about Tom Langdons Mini-HEI, but I want to keep my 6 Volt.

So I went back to stock dizzy (uhmm..well of a inline 6 Corvette) and got a great curve, better mileage power and response with the vaccum can.

Next stunt is a modified choke cable and dizzy bracket to tweak the spark from the dashboard. :D

Frank

panheadguy
07-24-2007, 02:00 PM
I'm waitng to hear what GMC Bubba has to say about Chuckspeed's dist after it's been in the machine.
PanheadGuy

chuckspeed
07-24-2007, 04:30 PM
Well...I'll speak for him.

turns out the dizzy ran perfectly...

Backwards. The centrifugal advance weights were in backwards and the ignition was all over the place.

GMC BUBBA
07-24-2007, 08:41 PM
As Chuck stated the distributor ran perfect when ran backwards , after a complete teardown it appeared the weights them selfs were ok BUT the advance stops were way out there 30-36 degrees total and the springs were very loose with little or no actual control of the weights etc.

( with some intial advance this unit could have very well seen 40 plus degrees of advance and i feel thats way too much for a flathead etc ??)
Bruce you got some orginal litature regarding this spec, i do but was unable to find it this evening?

I tightened up the stops using the allen adjustments and cut the total down to 10 degrees distributor ( 20 degrees engine), then readjusted the springs to make a nice curve with all in at 3000 rpm.
This way if we add 10 degrees static at the balancer the total spark advance will be 30 degrees at 3000 rpm. If more is needed then you add static or take away if thats too much.
As tested the unit would actually advance approx 35 degrees or so and then retard 10-12 degrees.
Not good at any rate.
I did three units today and all of them were all over the place. Just looks like our quality control guys have been drinking again.:)

GMC BUBBA
07-24-2007, 08:46 PM
A couple pics , note the adjustment stops for the advance. Before and after the adjustments. Also the springs are very adjustable on these units.

Flat Ernie
07-25-2007, 05:03 AM
Flathead timing is about 24* total - all in by 2500 or so - at sea level. Knock of a degree of timing for every 2500' above sea level or so...

Still think you're going to be a bit too advanced with 30 total...but try it and see. Every engine is slightly different....

Danimal
07-25-2007, 05:29 AM
Maybe someone should send this link to the boys at Mallory. Kind of a shame that a good family name is going to the dogs because they are letting crap out of their factory.

It was good to read the whole post, looks like I can (and should!) learn a thing or two about this stuff!

GMC BUBBA
07-25-2007, 06:17 AM
Flathead timing is about 24* total - all in by 2500 or so - at sea level. Knock of a degree of timing for every 2500' above sea level or so...

Still think you're going to be a bit too advanced with 30 total...but try it and see. Every engine is slightly different....

I agree , the distributor is set at 20 degrees max and then he can start with 2-4 getting the 24 degrees.
I only used the intial of 10 as a example. Most factory flatheads only had 2-4 on the balancer.

nexxussian
07-25-2007, 06:42 AM
Next stunt is a modified choke cable and dizzy bracket to tweak the spark from the dashboard. :D
Frank

Wouldn't a Vernier throttle cable work better (more precise adjustment)? I actually had thought of that and that seemed the best to me. I however, have not tried it yet, as any project I wanted to do that with always went another direction (or I had to sell it) before I got that far. So I am asking, because I figure someone else has already tried it.

Bruce Lancaster
07-25-2007, 08:19 AM
I can post curve for 21A crab types, a good gneral curve from Ford...
Ol Ron (Holleran) has been flogging timing on the dyno lately. His generic recommendations are currently 4 initial, 16 centrifugal, fast curve finished before 2,000 as a starting point. Ford calls for curve to start moving IMMEDIATELY off idle. Ron likes 6 or 7 added by vac--on a flathead, this means use Chevy or MSD, I think, as older distribs lack modern vac system.
On Mallory's, most have basic limit set by a post in a slot, said slot partially blocked with a numbered plate to limit it. All you need is to add to this limiter plate and MEASURE result--Mallory makes a gauge, but it is apparently not accurate at all.
Remember you can pretty closely measure your mechanical advance right on distrib while working on it:

Make a protractor that fits in place where cap would sit. Hold distrib drive still, twist rotor/cam in direction of normal rotation. Resulting measured movement is your advance in DISTRIBUTOR degrees, multiply by TWO to get crankshaft degrees.

Bruce Lancaster
07-25-2007, 08:20 AM
Test RATE by measuring off 30 degrees in blocks of 5 or so on your pulley, run with timing light. You want to see advance as soon as engine speed starts to rise, reach number measured above by 1800-200 or so.

Stovebolt 6
07-25-2007, 11:52 AM
Wouldn't a Vernier throttle cable work better (more precise adjustment)?

You are right. Actualy I have a complete throttle asembly of a lawnmower that can be modified for that propose.

I got that idea (not the lawnmower thing) of an 50s J.C. Whitney Catalog where they sold such a gizmo from Almquist called Spark-O-Matic.

I probably make a little aluminum plate with a Spark-O-Matic Script an a nicer "ivory" knob for that.

Frank

Flat Ernie
07-25-2007, 12:02 PM
I got that idea (not the lawnmower thing) of an 50s J.C. Whitney Catalog where they sold such a gizmo from Almquist called Spark-O-Matic.


All flatheads used one - Harley Flatheads that is. The left grip twisted to advance or retard the timing using a cable that went directly to the distributor. The "automatic advance" distributor didn't come out until well into the Panhead era...

:D

I don't know what you would gain with a normal distributor by doing this. I could maybe see a setup like this if you were using a distributor that had a fixed advance for some reason...

chuckspeed
07-25-2007, 12:09 PM
Model A's have the same thing - right on the steering column.

the idea has merit if you were to eliminate the centrifugal advance - but that would be silly.

FWIW, I'm partial to a wee bit more initial advance with some subtracted out on the topside - with a slightly stiffer set of springs to flatten out the advance curve. this, of course, is on OHV motors - seems like a flattie would respond to a different curve.

I really need to find the factory literature; they 'claimed' factory calibration.

Bruce Lancaster
07-25-2007, 12:21 PM
Factory specs for '49-53 are useless...21A specs are in service bulletins at home, but a book here says 11 degrees in distributor starting at 600, finished at 1200...Ford specs are more detailed. Will lookup Ford specs.

Bruce Lancaster
07-25-2007, 12:28 PM
Hmmm...found one Ford screed on this, crab specs:
Starts 400 rpm, ends 3,000...seems way slow. Will see what bulletins say.
22 degrees (crank) in distrib, same as above...26 total with the 4 static. Canadian specs...I guess their advances move slower because all the molecules are frozen.

nexxussian
07-25-2007, 12:42 PM
I don't know what you would gain with a normal distributor by doing this.


Tuning as you drive for initial setup (and with no laptop, how about that:rolleyes: ), and the ability to yank out the extra lead if you get a bad load of fuel (cause the freeway off ramps almost never show up when you REALLY need them).

Stovebolt 6
07-25-2007, 01:22 PM
I don't know what you would gain with a normal distributor by doing this. I could maybe see a setup like this if you were using a distributor that had a fixed advance for some reason...

I´m experimenting a lot with vintage water injections and other gizmos that makes it usefull to tweak the spark while driving.

It is also a nice way to find out what your curve is all about at "real world" conditions. Going up a steep hill I learned that the engine can take more advance than the vaccum can thinks, before it starts pinging.

Have you ever seen a 3D Plot of a computerized ignition vs. a centrifugal/vacuum ? You will see that under differnt conditions the electronic curve is way more complex.

Not that I belive it would make THAT big difference, I just love to fiddle arround with this kind of stuff. :D

Frank

Bruce Lancaster
07-25-2007, 01:29 PM
This would be most useful on engines requiring lots of advance like Model A and B, and also engines with lots of sensitivity to octane and generally prone to spark knock...don't know where Chevy early sixes are on those scales.
Engines like Flathead and SBC with fast burning chambers need curves that are easy to get into a simple advance mech and aren'r usually very sensitive to minor changes in diet.
Interestingly, the first Mallorys made for Model A, in roughly 1929, had centrifugal advance and a hookup to the stock advance mechanism (the driver), possibly because total advance was hard to build into a centrifugal system. Ford coped with this (Model B) by using a startling amount of static advance...19 degrees crank!

chuckspeed
07-25-2007, 01:33 PM
Factory specs for '49-53 are useless...21A specs are in service bulletins at home, but a book here says 11 degrees in distributor starting at 600, finished at 1200...Ford specs are more detailed. Will lookup Ford specs.

dude - I'm talkin' about the Mallory spec sheet. I'm thinkin' about sending them an invoice for Bubba's time, along with a photocopy of the statement about the damned thing being factory calibrated.

If Jim hadn't checked the unit out - I doubt I'd been able to ID the issue on my own - although it prolly would have jumped out at me when I thew a timing lite on it.

C'mon guys...think about it...who'da thunk a brand-spanking new $300 dual-point dizzy would have a centrifugal advance so bunged up outta the box that the engine barely ran? Betcha a good portion of the overheating issue is tied to that, too.

Someone at Mallory's gettin' a letter...

nexxussian
07-25-2007, 02:15 PM
$300.00??!!!!!:eek: :eek: :eek: Gag, hack (think cat with hairball), puke, ralf, retch (etc.... chunder?). All that for a "factory calibrated" POS. Damn, it sure is a shame you can't seem to count on corporate anything these days. It's one of the reasons I like Edelbrock. At least the family still owns it. Of course having said that I expect to get flamed instantly about how they sold out to _______ group Last week that will now produce em in Uzbekistan because the Chinese charge too much.:rolleyes: I certainly hope not.

nexxussian
07-25-2007, 02:16 PM
Letter:confused: , how 'bout a boot in the ass?;)

Flat Ernie
07-25-2007, 02:49 PM
Im experimenting a lot with vintage water injections and other gizmos that makes it usefull to tweak the spark while driving.

It is also a nice way to find out what your curve is all about at "real world" conditions. Going up a steep hill I learned that the engine can take more advance than the vaccum can thinks, before it starts pinging.

Have you ever seen a 3D Plot of a computerized ignition vs. a centrifugal/vacuum ? You will see that under differnt conditions the electronic curve is way more complex.

Not that I belive it would make THAT big difference, I just love to fiddle arround with this kind of stuff. :D

Frank

Why not just go electronic (or change the guts to electronic) & program it yourself? Maybe monkeybiker will chime in with his home-made electronic ignition! Pretty neat & he can modify it with a laptop...

I'm all for tinkering...

tommy
07-25-2007, 02:49 PM
Im experimenting a lot with vintage water injections and other gizmos that makes it usefull to tweak the spark while driving.

It is also a nice way to find out what your curve is all about at "real world" conditions. Going up a steep hill I learned that the engine can take more advance than the vaccum can thinks, before it starts pinging.

Have you ever seen a 3D Plot of a computerized ignition vs. a centrifugal/vacuum ? You will see that under differnt conditions the electronic curve is way more complex.

Not that I belive it would make THAT big difference, I just love to fiddle arround with this kind of stuff. :D

Frank
http://fototime.com/%7BC2932BAA-F054-4356-8E1F-5FC9ACDD75BC%7D/picture.JPG

I've got one of these (no-functional) on my sport coupe. It requires replacing the hold down bolt with a stud and double nut so that the distributor can be rotated while not being loose. As shown it connects to the vacuum advance can to get enough leverage to move it. I think it's cool looking. I never bothered to hook it up. It's just for decoration.

Stovebolt 6
07-25-2007, 02:59 PM
Im not going electronic cause I like the charme of analog mechanical devices.

Cool gizmo Tomy, exactly the stuff I love.

Frank

HEATHEN
07-25-2007, 03:17 PM
dude - I'm talkin' about the Mallory spec sheet. I'm thinkin' about sending them an invoice for Bubba's time, along with a photocopy of the statement about the damned thing being factory calibrated.

If Jim hadn't checked the unit out - I doubt I'd been able to ID the issue on my own - although it prolly would have jumped out at me when I thew a timing lite on it.

C'mon guys...think about it...who'da thunk a brand-spanking new $300 dual-point dizzy would have a centrifugal advance so bunged up outta the box that the engine barely ran? Betcha a good portion of the overheating issue is tied to that, too.

Someone at Mallory's gettin' a letter...


I still occasionally pick up an old waterproof Mallory dual point for early Chevy sixes for <$75.....in fact, I just did recently. The one I stuck in my '53 years ago gave the 0-30 time a noticeable improvement, but it never pinged, so the advance curve must have been right on the money. Honestly, find an old Mallory and sell the new one for whatever you can get. You'll have proper performance as well as the correct look.

chuckspeed
07-26-2007, 07:42 AM
Well...

Dizzy showed up yesterday - I plopped it on and lit her off.

Motor sounded COMPLETELY different; I had attributed the choppiness of the idle to the cam - turns out a lot of it was due to the distributor. the engine ran much smoother at idle and off idle, spooled up under no load with minimal prob...but...

under load it still breaks up.

Goin' to Napa at lunch to buy another coil and a couple of condensors.

<sigh>

I'll lick this - eventually.

Petejoe
07-26-2007, 08:00 AM
Well...
Dizzy showed up yesterday - I plopped it on and lit her off.
Motor sounded COMPLETELY different; I had attributed the choppiness of the idle to the cam - turns out a lot of it was due to the distributor. the engine ran much smoother at idle and off idle, spooled up under no load with minimal prob...but...
under load it still breaks up.
Goin' to Napa at lunch to buy another coil and a couple of condensors.
I'll lick this - eventually.

I wonder if your getting good fuel pressure but the pump is not providing enough volume during high output. If your running an electric one with a regulator I would especially suspect this.
I could have sworn the cutout with my setup was totally attributed to an electrical issue and here to find out it was put to bed with increasing the jet size. I once suspected a fuel supply issue until I installed an in line fuel pressure gauge and found it to have plenty of fuel and volume. Missed the fact the fuel issue was within the carbs.

revkev6
07-26-2007, 08:15 AM
Well...
spooled up under no load with minimal prob...but...

under load it still breaks up.

Goin' to Napa at lunch to buy another coil and a couple of condensors.
<sigh>

this is EXACTLY what my flat motor was doing. this symptom ended up being the coil. later, I found the cheap as mallory condensor would cause the motor to break up after between 5-10 miles of driving. get the echlin parts, they seem to work good. I just got a condensor for a 60's small block chevy

</sigh>

chuckspeed
07-26-2007, 09:30 AM
I wonder if your getting good fuel pressure but the pump is not providing enough volume during high output. If your running an electric one with a regulator I would especially suspect this.
I could have sworn the cutout with my setup was totally attributed to an electrical issue and here to find out it was put to bed with increasing the jet size. I once suspected a fuel supply issue until I installed an in line fuel pressure gauge and found it to have plenty of fuel and volume. Missed the fact the fuel issue was within the carbs.

I'd buy that, except...

pulled the plugs and they were sooty again; the smell outta the pipes is unburnt fuel. I've got a clear red line to the carb and can see that I've got fuel to the carbs.

I'm also runnin' #54 jets - quite a bit bigger than yours.

Bruce Lancaster
07-26-2007, 09:45 AM
OK, found specs on crab advance curve, which is generally pretty functional. This is actually a Ford 11A advance unit, also adapting to the '37-41 types...


These are DISTRIBUTOR degrees and RPM's, so double them:

200RPM...0--1 degree
400RPM...6 1/2-8 degrees
600...10 1/2--12 degrees, which is to say all in at 22 degree spec.

Total Ford is 4 degrees initial plus 22 in curve, all in before 1500.
My Mallory collection is spotty...will see if I can find any early specs from them.

Bruce Lancaster
07-26-2007, 09:48 AM
Note that is the fastest Ford curve...the vac brake if turned in some (another Mallory patent part) slowed the curve as adjustment for bad gas.
For most modern purposes, start by turning out brake adjustment til it stops BY HAND (wrench will pop off the spring seat) , turn it back in maybe two turns. Some light tension is needed to stabilize the brake disc that adjusts advance.

Bruce Lancaster
07-26-2007, 09:50 AM
Design of this Mallory system, used on flttop Mallorys and '32-48 Fords, zero vac/full throttle lets brake apply, shortening curve for full throttle, high vac releases brake for extra advance at cruise...most use on modern gas can back this way off and use whole curve.

revkev6
07-26-2007, 10:03 AM
I've still got my money on poor spark. rev's decent with no load, and breaks up under load sounds like weak spart to me......

flatheads aren't really that sensitive to timing, if you get it even close it will run good. i've set mine within 15 degrees either way and the only thing that happened was if it was at almost 40 degrees of advance it was pinging just a WEEEEEE bit. lol


might want to mess around with internally ballasted coil

Bruce Lancaster
07-26-2007, 10:07 AM
Flatheads in my experience don't mind a bit of excess advance, but heat up rapidly when retarded much. Those 54 jets sound pretty rich to me.

revkev6
07-26-2007, 10:11 AM
ya know bruce, I missed that. I'm running 43's on mine and the plugs still come out a bit dark. were they 97's??

Bruce Lancaster
07-26-2007, 10:14 AM
they're 94's...stock usually 50-51.

RopeSeals???
07-26-2007, 10:34 AM
I just had a coil wire(non-metallic core) burn up internally about a 1/2" up from the distributor end, causing the symtoms you've described...

chuckspeed
07-26-2007, 11:04 AM
I had 51's in and they were coming out with white insulators, so I went up a couple of jet sizes. I can go back, but that's not what's causing breakup...I was able to run the car quite some time on 60's, too. Remember this thing's ported, an eighth over, and has a 400 jr cam...

Fourdy
07-26-2007, 04:41 PM
I called Mallory (Mr Gasket) and told them to check out this thread and maybe shed some light as to their side of the story. I was told they would do so.

Tech told me that the Mallory dual distributor is made in Carson City and that the condensers are Performance (something). No chinese parts. Will be interesting to see if they do come on in fact. Hope so.

Fourdy

tommy
07-26-2007, 05:59 PM
http://fototime.com/%7B792C02F3-176F-4ACE-802B-2EF66CEC3B48%7D/picture.JPG
http://fototime.com/%7BEA8ECFDB-F1C5-4355-A758-2646672792E5%7D/picture.JPG

The early style Mallory's for the 8BA can be easily and cheaply converted to Chrysler electronic ignition. You get the look and electronic ignition all in one package. The only thing I miss is the sound of the flatty starter motor growl. It starts instantaneously now. Ker-brooom and it's running!!! The mechanical advance was left as it was found. It ran so well I felt no need to check it.

Flat Ernie
07-26-2007, 07:02 PM
That's a clean install, Tommy.

chuckspeed
07-26-2007, 08:23 PM
I called 'em, too...after 20 minutes of hold music - I hung up.

Coil was funked up, too. Have a fresh coil and the car finally spools. will sort it out tomorrow.

Guys...the dizzy was essentially inoperable out of the box. A part whoich retails for nearly $420 but requires major rework is just sad. Even worse...it sez Made in USA.

Orig coil was USA made, too.

Bruce Lancaster
07-27-2007, 08:28 AM
I have had extensive contact with a friends SBC Mallory...actually, 4 of them to get his car through its first 4,000 miles...identiacl in most ways to '49 flathead model.
I dn't think we ever found anything wrong with the drive gear, but maybe we didn't look. Everything else was multiple layers of bad design, incorrect assembly, parts with incredibly short lives. I'm pretty sure mechanical advance is too slow and vac advance doesn't work, as well, but my friend refuses to let me touch that because there id so much fiddling necessary to run.
I have had a LOT of experience tuning both dual point and electronic distribs...I have NEVER had reliability problems from a distributor before, even old frapped out ones.
I don't know where these parts are made, but HOLY SHIT!!

Bruce Lancaster
07-27-2007, 08:36 AM
By the way, I love OLD Mallorys for 4-bangers and '49 flatheads, and collect Mallory literature...it pains me to see the garbage sold under an old genius inventor's name.

HEATHEN
07-27-2007, 09:22 AM
A good testemony to the quality of the original Mallory distributors is that, over the years, I've seen several '40s/'50s Buicks, Cadillacs, and Oldsmobiles that were completely stock under the hood with the exception of a Mallory ignition system. One of the local independent garages in the '50s and '60s was an authorized Mallory dealer.

lonewolf
11-24-2007, 06:54 PM
tommy .........can you tell me how you did the conversion that is too cool

21stud
11-24-2007, 11:06 PM
I recently had a similar issue with a bad Dist cap. It was a NOS cap. I think the hotter spark with the new dizzy broke down an already weak cap. I could see a carbon trace forming between cyl 4&8 but my timing marks were all off and all over the place. Turns out cly 1&2 were also shorting. This all took place during initial run up. Makes you second guess everything. Good luck.