Technical Re-phasing a Mallory YL series distributor?

Hey all, new guy here but not to the combustion engine, I've worked on everything from lawnmowers to the 3516 Caterpillar marine power plant (Bering Sea crab boats) and finished my career as a disabled civilian heavy equipment mechanic for the US Army.

I have a head scratcher, my 1928 model "AA" four bangers distributor has waay too much movement by the point plate in its groove in the distributor body, as such it won't keep a correct point gap, it's junk.

My Father had a Mallory Dual Point "YL" series distributor in the box and I do remember seeing it on the engine years ago, it's part #2501105.

I pull the old dist and drop the Mallory in but one problem, it's not phased correctly, in fact the rotor is nowhere near were it should be.

I know you can make a dist work even 180 degrees out if you swap the plug wires in the cap, (but why?)

The rotor isn't 180 out though, it's about 145-150 out, a real head scratcher.

My question is: can the four lobe point block be re-phased to the correct position?, I pulled the point plate out but have not tore it down any farther than that due to I don't want to get into the centrifugal advance gear with out a little investigation beforehand, I found a few exploded diagrams of the Distributor so I can reference those.

Any body have any experience with the "YL" series distributor along these lines?.

Any help would be appreciated.

Thanks, Uncle Mark

 

I don't remember what the Model A drive shaft that turns the distributor looks like...

Is it like a slot with a tang on the bottom of the A dist? Then if so, the drive shaft in the block should be a gear on the lower end or not? If it was a gear, then reclock the drive shaft?

 

No gear, just an offset slotted shaft, only goes in one way.

That's the weirdness, it's a Mallory model A distributor, as such it also has a set screw to keep the distributor from rotating in the block with a corresponding indent in both old and new distributors.

Otherwise I could just turn the distributor body anywhere I want and run it.

I just can't figure why Mallory is off like that, my Father passed away 5 years ago so no answers.

But I know I saw the Mallory on the motor I think in the late eighties early ninety's, it even has wires with the blade ends for the type 16-C spark plugs.

A mystery.

Thanks

 

I believe "Moriarity" is right on. I remember seeing this exact procedure in a set of original Mallory instructions I got when I purchased a NOS Mallory "Y" series distributor. I don't think you'll need it, but I could dig that old instruction sheet out and repost it.

 

Moriarity has it correct. To add : Place engine on tdc #1 cylinder using cover pin on engine, Install distributor in engine using the detent hole. Loosen rotor like above and turn rotor until its pointing at number one with both sets of contacts open.
(by the way rotor to cap index or rotor phase is not effected by turning housing )

 

Outstanding!, I saw the clamp on the block after I pulled the point plate out, I knew it wasn't solid to the drive shaft as it turns on it due to the centrifugal advance system.

I just didn't want to dig in there any farther without a little more info, thank you all so much for your reply's and guidance.

I'll drive it today for the first time in 10-11 years, it's a 1928 model "AR" one ton flatbed that's had a body off frame ground up restoration by my Father and I starting in 1974.

My Grandfather borrowed it to move to a new house in 1932 and my Dad rode in it as a one year old child, four generations of my family have driven it

Btw, I have a Sun CC-10 coil/ condenser tester that still works, man I wish I had the distributor machine also.

Thanks again and enjoy the Fourth of July.

 

If you could I'd really appreciate it, all I have is the directions for setting the advance with the red key, luckily the distributor is essentially brand new, it looks like it had been mounted of course but zero oils or gunk anywhere, I mean it looks a week old.

I put new points set at .20 and a new condenser in it yesterday, now if I could only know how to adjust the dwell, I have an old cal-custom chrome dwell meter that works, I can't seem to find any literature on the net for this distributor yet, there's not even one blurb about its part number out there.

 

Well the rotor can't be re-phased it seems, it has a clamp but the clamp has a flat portion and a corresponding land on the base of the rotor.

Only on one side, there is a screw hole 180 from the land but I can't get the rotor to turn in the top plate for the centrifugal advance mechanism.

I can turn it 180 and Daren it down but the rotor is still 140-150 degrees instead of 180, as such I just swapped the leads 180 and put it in but it won't run, close but no cigar.

So the drive shaft is fixed, the dist body is fixed and so is the rotor, what gets me is that it's a model A distributor but will not work in a model A.

All I can think of is maybe the driveshaft can be moved to line up the rotor correctly but that's for another day.

I bought a "Nu-Rex" point plate and it will be here in a few days, it'll run just fine after that's in and I'll save the Mallory for another day.

Thanks for all your help and replies, I'll see if I can upload a pic or two of the truck.

 

This one is next, I'm swapping it over to twelve volt, it'll be on the road by September

 

I have a similar problem on my mallory 27 series i had to remove the points cam from the shaft ( its just a press on interference fit with no definite location) to fit an e-spark electronic ignition module that has the trigger wheel fitted to the rotor arm.
The e-spark module has failed and i need to refit the points cam to run on points while i sort out a replacement module.
My problem is how to set the position of the cam relative to the rotor arm so that when the point open the rotor is pointing at a plug lead post in the cap and not between posts.
Do you think your points cam could have been removed from the shaft at some time and not pressed back on in the correct location.
If you decide to reposition it then look on the net for e spark instructions the kit came with a bobbin that sits on the top of the shaft for a puller centre screw to sit on. Hope this all makes sence and helps, George.
P.S. anyone know what the relevance of the black dot on the points cam is