It has always (by always I mean over 40 years) been very finicky. When it was new and gas had octane it ran pretty good, but it seemed like we were always adjusting the points and fighting hard acceleration pinging. As the thing got older and gas quality dipped, it got much worse. It spent some years at high elevation in Colorado and was leaned out and recurved and it was ok. Back here at 150 ft instead of 10,000 we put the original jetting back in and it just never wanted to run the same any two times. Adding the PerTronix made it start easier and lessened the pinging, but it still wasn't right. I'm pretty sure the springs are shot and the advance is sticky and I can fix it, but knowing what I didn't know at 17 means I am really happy to have vac advance now and have eliminated the pinging by careful tuning. Sent from my XT1650 using The H.A.M.B. mobile app
Big block Mopars have 2 different length shafts... Low deck (B) and tall deck (RB). Sent from my Moto G Play using The H.A.M.B. mobile app
I am a more seasoned car fancier than many of you, had a Speed Shop in the 60's, first trip to Bonneville was 1960, have been taking my daughter along for years, who crews with us. We are have been running a Banger, my wife thought I should give up the RED Dragster stuff and play with Model A's. Which brings me to my experience with Mallory's. Had an old cast body with the two piece cap, but it needed a shaft, they told me to send it in and they would rebuild it, but then they said they couldn't. No shafts available, but for x dollars they would send me a rebuilt later model. It has sat on the shelf for a few years until last year when I put a inserted slightly modified "A" block engine in one of our touring cars. So I slipped in the Mallory (single point) off the shelf, it looked like it was brand new, no evidence of ever being installed, no scratches, it sucked. I pulled it and tore it apart, the upper bushing and shaft were excessively worn, noted .020 slop. My fault, should have taken it apart when I got it back several years ago, but I trusted them. Don't have to worry any more as they are gone with the buy out by MSD. But I noticed way the dumb thing did wear out, they is no provision for lubrication for the upper bushing. Have two of these, neither has a oiling feature. I have modified them with a zerk with provisions for the surplus grease to exit just ahead of the lower bushing. I am still going to use them, along with the FS and Model "B" stock dist. that I have converted to electronic. I am sure that those of you that are using points and condensers are experiencing excellent results, but I have always looked for something that might be better. However those of you that have the later model Mallory's you might want to see if the upper bushing can get lubrication.
Guys, Mallory has a great early history http://www.dragzine.com/news/video-a-brief-look-into-the-history-of-mallory-ignition/ However, it was not the same by the 60s and especially later. The OP got a "HP" part for a 1969 Mopar 318 in his '37 truck. I am guessing here, but I doubt this is a race vehicle. Apples to Oranges. If this was a '48 flatty, I'd agree. Get an old aftermarket part for the engine. HAMB friendly! Since it's a late model Mopar, my opinion is that it's like putting a slingshot carb adapter on a 305 TBI intake 'cause it has history. https://en.wikipedia.org/wiki/Chrysler_LA_engine It's like running a solid flat tappet cam in a modern engine for street use, IF the distributor is good. It will not improve performance under the street operating conditions and require additional effort to start along with regular maintenance EVEN though it's traditional and a HP part. HAMB is also about matching eras (no wire wheels on a late 50s custom build) and components (no Moroso valve covers).
I had a warranty pull out '52 Chrysler engine around here for some years. I also had a couple of 392s. one with the early two piece Mallory cap and one with the later cap. The stock Chrysler was a dual point distributor from new. The insides looked very much like the Mallory part. I got the idea that Mallory was repackaging stock MoPar parts in their own housings and selling them. I also worked on a 455 Pontiac that had an Acell rack dual point. It had a cracked cap. I took the cap of of a '56 Dodge 325 that was here and it was the same thing. Put it on the 455 and ran 208 mph. Still on the motor 20 years later.Owner has not run the car in a long time.
Guys I want to apologize if this is considered bad thread etiquette (hijacking thread) but needed to ask you guys about a distributor I have and many of you seem to know Chrysler products pretty well. It is a dual point distributor in nice shape but not sure what it fits. If anyone has any info about it I would appreciate knowing it. I am not doing anything with it and wanted to sell it but need to know what it fits. Again, sorry for the hijack.
Can anyone tell me how to change the rotor Direction on a dual point Mallory the one on the right is stock and the rotor is in line with the shaft the one on the left is a dual-point and it's like one cylinder off if I put it in will it change because it's a dual point. Mallory part number is2557901. Tony Sent from my SM-G930V using The H.A.M.B. mobile app
Here is the pic. This is going in a 1970 318, that is in my 1937 truck. I plan on racing it at Rockfalls on Sept. 8th against my youngest daughter's mustang, should be fun. I ordered my Radir pie crust slicks on Monday. I gotta do anything I can to beat her. Sent from my SM-G930V using The H.A.M.B. mobile app
I might be missing something here but if you put the "left" dissy in then all you need to do is rearrange the plug leads on the cap to line up with where # 1 is now..........at least thats what it seems to me........I think...........lol..........andyd
It seemed like that to me at first too. Mallory listed separate part numbers for advance plates and cams for right and left had rotation distributors, so there must have been a difference. I never had an occasion to get further into it than that.
Andydodge I just put the distributor in move the plug wires over one and it fired right up now all I have to do is set the dwell and everything else I was just looking at it too hard. Thanks Sent from my SM-G930V using The H.A.M.B. mobile app
Check tour harmonic balancer for advance (OR 'RETARD!') when running engine up, say 3500 RPM. I've done lots of 'Mallory Mix', there are clockwise and counter-clockwise. Best not to mix these two fellas up. You could be 'spinning backwards'!
Just cant imagine why in the hell a hot rodder like you would ever run a Pertronixs anything????? rbg To the orginal OP , clean off the points , set both at .018 and run it , it will be fine................Vac advance isnt needed.
I got it running pretty good, but has a small backfire through the carb when I step on it from idle. I did check the point gap and they were .011", so I need to increase them. I have had this thing for a while and was going to put it in one other time, but didn't because I couldn't figure out the offset, so simple now that I know. Last year at the HAMB drags my truck ran a 15.3 If I remember right. Since then I have changed a few things and cant wait to see what it is going to run. Tony
MC..........lol.......no worries.........sometimes we overthink things, believe me, I've certainly done that.......I've had a Mallory YL dissy in my 318 Poly for the past 40yrs..........have considered running an electronic dissy but as the Mallorys running fine still I talk myself out of this idea soon after I talk myself into it..........lol..........oops.........think I'm gunna start talking to myself again.........lol..........regards from Oz........andyd
So, have you checked the timing with a light? Is the timing advancing when the motor rpms are brought up? If you had to change the rotor direction, the advance weights should retard the timing as the rpms rise, unless you changed them as well. Or, did I miss the advance weight change? Gene
gene, I didn't change the weights, and the timing is advancing with rpm's. I am running it at 22 degrees, and have to fine tune it, now that it is running. Thanks for the input, and any other ideas to help my 275 hp truck, beat my daughters 500 hp ot car. Is there a different coil besides the stock one I should be looking at?
Ran the truck at Rockfalls, ended up setting the timing at about 30 degrees, and it was happy. My best time was 14.63, that was a good improvement. Next it gets a new motor.
Bringing up a old thread. I raced at Rockfalls last night and turned in my best time, 13.47 @ 99.91 mph. I put in a new set of dual points for a high rpm and it worked. I believe there is a 12 in there. My question is on how I set them up, I did it the way I have always done it .017 gap gave me about a 32 degree dwell, with 17 pounds of vacuum. While I was reading more I found a couple of spots that said to set the initial set first then the second set to get the proper dwell. Not sure how to do this and is it the proper way. Here is one of the sites, did I misread this? https://mgaguru.com/mgtech/ignition/ig200.htm Tony
I just put a new set of points in the flattop in my '51 Merc so I am familiar with this technique. The bottom line for me was that I set both sets of points to .018 and checked the dwell and it was 33 degrees. I didn't even bother checking the individual points, as I knew I had set them both as close to .018 as humanly possible. The points in the Mallory I have are extremely difficult to adjust, as they lack the screwdriver slots in the points and breaker plate.; you have to pry against the rotor to go one way and the distributor body to go the other, so it's a real pain. Since both the dwell and the points were at Mallory specifications, I figured anything I did further would probably be counterproductive. Mallory specs say 35 degrees total with 21 degrees for each individual set. I may be at 20 and 22 degrees rather than 21/21, but I don't think that will make the least bit of difference. The car runs great, by the way.
You can take the box flap and tuck it into each set of points (one at a time) and check dwell for each set of points while running. I know some Ford distributors tend to change dwell as the advance moves, so I'd also check total dwell at various RPMs and with vacuum applied and removed, to make sure of what is happening under different conditions. It's amazing how that high RPM miss can sometimes be traced to dwell dropping... BTW, it's inches of vacuum. https://www.dekkervacuum.com/resource-library/knowledge-database/technical-data/what-is-vacuum/
The Mallory YL series dual point in my OT Mopar has been working just fine for 37 years. The advance curve is easy to dial in, tune up parts are readily available and the timing is rock steady. I prefer it over the off-shore "performance" distributors being marketed today.
My next question is how do you check one at a time. Do you disconnect one and roll the engine with cap off? I know my meter don't have a way to separate them. Truck is running great, just want to learn more. Tony
If you tuck something non-conductive between the contacts in one point set, it electrically disconnects that point set (always 'open'). This causes the other set of points to 'make' and 'break' the electrical circuit. You can then use a dwell meter to measure the dwell on the set of points that are working. Swap the blocking material, and the other set of points is doing all the work and can be measured. As I mentioned in passing, the box the points come in is made of cardboard and using the flap will work. Read the third post here... https://www.jalopyjournal.com/forum...o-set-gap-on-a-dual-point-distributor.459917/
Recently decided to give the 'ol brown turd a tune up, plugs, leads, cap, rotor, coil, condensor and points.........all went well until the points installation..........I had the dissy out and after removing the old points installed the new sets and found that I could not get the 2nd set to adjust, no way to get enough adjustment..........we, a mate & I compared the new and old points sets and found them to be identical except that one of the new sets rubbing strip was about 1/16th longer which was pushing the points open wider than I could adjust closed...........got a very fine file and gently filed the rubbing strip down to the same length as the other set of new points and the old set.........then set the correct points gap and all was good............the points were in a genuine Mallory, made in the USA box( well at least maybe the box was, "made in the USA") as was all the other bits but just thought I'd mention this problem with the points rubbing strip..........once we looked it was quite easily noticed and repaired......tho' you'd think that this would have been discovered in manufacturing............or maybe not...............andyd
RodStRace, sometimes the answer is so simple that I don't even think about it. The only problem with using the box that the points came in is that it was a plastic box. I got them set now, but might as well check them, just for fun. Tony
Well, That's a new one! As mentioned in the post I referenced, a matchbook works too, but those are even more rare today! Any clean, dry non-conductive material about .020" thick or thicker (so it doesn't fall out) will work. Another old time method is to use a cigarette paper to set timing. Often used on motorcycles where the ignition is behind a side cover. 1. Rotate the engine to before TDC #1 at the spec you want (example - 10 BTDC) 2. Place a cigarette paper between the points so it's held in place. 3. Rotate the point plate or distributor back and forth until it's just at the spot where the points open enough to release the paper. 4. Tighten the plate or dist. Install any other parts and start engine. Check timing. BTW, I hope you lubed the rubbing block! https://www.jalopyjournal.com/forum/threads/distributor-point-lubrication.261131/ The way I was taught was apply to the leading edge of the rubbing block (towards the pivot, opposite the point contacts) the full width (up and down) a bead about the thickness of a pencil lead. It should ride against the point cam and point rubbing block as the shaft spins. and a thin film on the shaft after wiping clean and before point installation. Also, if it has mechanical advance (the rotor is spring loaded when you twist it), a couple drops of oil down the center of the shaft under the rotor will keep things happy. There is normally a felt/fiber disc in there, but these get lost over the years. This has a bunch of Mallory info that might help
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