Distributor drive gear

[pistonbroke]

Just another EAC assembly question. The distributor drive gear on the front of the camshaft was left exposed for to long and had rust pits. I have purchased a new one and want to press it on the cam. I don't see any index marks on the gear or the camshaft . What's the deal? Thanks, Tim

[19Fordy]

Scroll down to Post #5 here that shows alignment marks on small cam gear.
https://www.fordbarn.com/forum/showt...1832&showall=1

I can't think of the correct name for it but you might want to consider installing a small set screw at the edge of the circumference of the small cam gear and the cam so as to prevent the cam gear from coming loose and rotating. The set screw also prevents the gear from walking forward or backward. It's like a round keyway with threads.

[flatjack9]

Really makes no difference. I have a lot of cams with no marks. The timing is set by how you install the distributor.

[V8COOPMAN]

Originally Posted by flatjack9

Really makes no difference. I have a lot of cams with no marks. The timing is set by how you install the distributor.

The cam-timing must be set to coincide with where the pistons are in their up/down cycle, probably most accurately by referencing TDC on #1 piston. IGNITION timing is normally set with distributor. I KNOW that YOU understand this Jack, but just clarifying for SOME! Coop

.

[deuce_roadster]

Good clarification to make Dick, I was wondering if Flatjack9's post would confuse some with less experience. There is quite a range (which is good) on here and a good place for novices to learn.

[Flathead Fever]

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I'm sure ford had some kind of alignment jig so the distributors would all end up rotated with the vacuum advance in the same spot when the timing was set. But it really doesn't matter because there should be enough adjustment to set the timing no matter where the gear is put on.

Most distributors I have worked on have a roll pin holding the gear on. I had one shear a roll pin. I could easily turn the distributor by the rotor. That was the clue to where the "no start" problem was. I've had a couple strip all the teeth off of the gear too on the phone company trucks. I should have some 8BA distributers out in the garage. I'll take a look and maybe I can line up the points with number one and we can find a reference point to see where the gear teeth are at. If I have more than one, it will be interesting to see if they are the same. Kind of a fun little project. I'm with you, anywhere will work but there probably was a gear tooth alignment spot. Why not make it right if you can? If they used a metal vacuum line the factory assembly line would have needed the vacuum advances in the same spot on each engine so the metal line would not require bending.

[flatjack9]

Originally Posted by V8COOPMAN

The cam-timing must be set to coincide with where the pistons are in their up/down cycle, probably most accurately by referencing TDC on #1 piston. IGNITION timing is normally set with distributor. I KNOW that YOU understand this Jack, but just clarifying for SOME! Coop

.

Right, we are talking about the distributor gear and not the cam gear. Read the OP's post.

[flatjack9]

I have many cams and a few have marks on the cam and the gear. Some that have the marks are misaligned. The cams do have a mark on them, but a lot of gears don't.

[Don]

What about the early engines,where the dist is timed on a machine,if cam gear was off a little ,how do you check this,,??

[flatjack9]

Again, this is about the distributor drive gear. Has nothing to do with the cam timing.

[Flathead Fever]

I went out to the garage and found two late model flathead distributors for our gear placement experiment. I also found three Mallory dual points and a few Lincoln V12s too, even one converted one that I had forgotten about. I have a Sun ignition scope and a distributor machine crammed full of distributors, mostly flathead stuff

The gear driven distributor was a new adventure for Ford in 1949 compared to the slot driven front mount distributor from ’32-’48. Even the Ford 8N tractors switched in ’49 to a gear driven distributor Being that the gear drive was new there were probably some issues early on. Both of my distributors have riveted on gears and your does not. Maybe this means these are later versions and the earlier ones might have had a gear slipping issue. Notice these two distributors do not have a shaft extending below the gear. The extended shaft was another late 8BA modification they made. Most likely without the shaft supported on the end the distributor bushings would have a side load on them and when the bushing wear got to the point the shaft had play the points could not hold an accurate gap.

I included a picture of early cast iron cover on an engine without the extended shaft support and a NOS aluminum cover with the support. I removed the cover so you can see how the shaft is supported. This is a lot nicer setup. That cover has been on that KRW engine stand for 25 years. Someday, the engine is going in a 4” chopped ’32 3-window. The Mallory dual point distributor was so dusty I didn’t realize it was NOS until I saw it from the backside of the cover.

That is a standard bore ’51 Merc block that was acid dipped 25 years ago or more. The Merc crank was turned 10/10 and polished. It has new truck pumps with the mounting pads cutoff because I’m using the stock ‘32 motor mounts which you can see bolted on there. The pulley is a ’49 Ford, the ’49 pulley has the wide belt that matches the truck pumps. The heads are kind of rare. The late model block -lettered heads were only made for about month when the ’49 engines came out. Edelbrock called them the “new-forty-niners” I think that was in the December ’48 issue of hot rod magazine. After the first month Edelbrock switched to the modern script heads. I don’t think they sold very many of them. Not too many people would have been tearing the heads off their new ’49 Fords. I’ve only ever seen two other sets of those late block lettered Edelbrocks. The intake is an original Eddie Meyer 8BA The air cleaner was something I saw on a ’36 Ford years ago, and I asked the guy where he got it? And then I ordered one. I don’t think advertised. It wasn’t cheap, but it was just too cool. The guy that made them said the very first ones had small louvers but then a customer called and told him the small louvers were choking off the air to his flathead, so he made the louvers larger. It has been so long, but I think it has a F-100 filter element inside. I have a new Melling pump, new timing gear, Clevite cam bearings, Felpro gasket set and Isky springs. I have reground adjustable lifters and I had a Potvin Super 3/8 cam ground before Bill Jenks at Moon eyes passed away. He was the only cam grinder Potvin ever had. Basically, it just needs pistons, crank and rod bearings, a new clutch and the machine work done, and I could be cruising in a chopped ’32 3-window. I have twenty vehicles and a retirement budget to maybe work on one or two. My vanishing IRA is not helping things.

Here is what I came up with, a square laid across the top of the housing and down the side of the hold-down (I could have used a couple more hands to hold the pieces and take photos). I lined up the rotor, so it points straight up at the 2" mark. Then I took a pair of dividers and measured from the square over to the center, top, of that tooth, and I came up with exactly 1" on both distributors, which they should, with a rivet hole to align the gears. I’d like to check one without the rivet. I might have one like that in a core engine. The idea of a set screw is probably a good one.

[pistonbroke]

OK guys, Let me rephrase my post. I'm talking about the pressed gear on the camshaft that drives the distributor. Not the gear on the distributor and not the camshaft timing gear set. Thanks ,Tim

[rotorwrench]

Flatjack9 has a point that the degrees of spacing between the teeth on the gear isn't very much. No timing marks are needed there. It won't adversely affect distributor position much at all. The vacuum advance tube will still fit after the distributor is timed to align the crankshaft timing mark on #1 cylinder.

If any given tooth aligns with some reference mark on the cam then just align any tooth with that reference mark when installing the replacement gear. Make your own mark before removal of the old gear.

[flatjack9]

Originally Posted by pistonbroke

OK guys, Let me rephrase my post. I'm talking about the pressed gear on the camshaft that drives the distributor. Not the gear on the distributor and not the camshaft timing gear set. Thanks ,Tim

I think you were quite clear on your original post. Things seed to always drift off topic.

[Flathead Fever]

I screwed up and wasn't paying attention. I do this kind of crap all day long and its begining to really bother me that I might be losing it. I lost an ink in and looked for it for 20-minutes before I found it between my teeth, true story and I'm only 60??? I have a bunch of late model cams. Maybe if we point the front lobe straight up you can see where the teeth are at, we can get an idea At least you got to see a bunch of flathead pictures so it wasn't a total loss. I will try to redeem myself and go out there and get a camshaft.

[flatjack9]

Originally Posted by Flathead Fever

I screwed up and wasn't paying attention. I do this kind of crap all day long and its begining to really bother me that I might be losing it. I lost an ink in and looked for it for 20-minutes before I found it between my teeth, true story and I'm only 60??? I have a bunch of late model cams. Maybe if we point the front lobe straight up you can see where the teeth are at, we can get an idea At least you got to see a bunch of flathead pictures so it wasn't a total loss. I will try to redeem myself and go out there and get a camshaft.

Hey man, we all do it.

[69a]

The distributor drive gear can go on anywhere. The discrepancy is taken care of when you fit the distributor body with the vacuum can in the right place and the rotor pointing to #1 (TDC on compression stroke, obviously)

[Flathead Fever]

They have me hopped on opioids and nerve meds and they kind of screw me up. I'm little out of it half of the time half of the time. Sometimes I think I see what I expect to see.

This is the original Merc cam that came out of that engine on the stand in the photos above It was reground into Potvin Super 3/8. With the first lobe pointing up I stuck a bolt in the closest cam gear bolt hole. I rolled it over and you can see that the bolt falls between two teeth. But then I noticed the alignment marks on the gear and cam are slightly off. Are they Ford marks or the cam grinders marks? Because I got to thinking maybe that gear needs to be removed to chuck the cam up in the cam grinder. Since they are off a little that means the bolt centered between the teeth would be off a little too. If they are the cam grinders marks that means he thought the gear needed to be put back in the original spot as your thinking. So, I went back out to the flathead junkyard to find an unmolested cam. It would be nice to have one the gear has never been off of. I found six early cams but no late model one's with gears. It would be nice to check a couple originals to see if the bolt lines up in the same spot, but this is the best I can do.

[69a]

Perhaps they were assembled with a jig at the factory, both the drive gear and the distributor. So that the timing was within a degree or two. I can't imagine one man dedicated to installing and timing an engine at the factory. But for the OP it makes absolutely no difference where the drive gear goes. I have never aligned the drive gear when I have fitted them.

[rotorwrench]

A lot of the ones I've seen that have marks look like that potvin cam where the marks are a little off. With 11 teeth that would only be 32.7 degrees of separation. That close to the center of the cam isn't a lot of distance between centers.

I don't think the distributor will care if it's rotated one way other the other a little bit. A person's going to have to time the engine anyway so it's not going to make much difference if the distributor is off a few degrees from where it was before the gear was replaced. The vacuum advance can may be off 16 degrees one way or the other and the vacuum tube will still screw on there.