Bronze drive gear

[crenbbf]

Morning All

I am bit confused about the shaft diameter of my dizzy.

Most gears seem to be quoted at 0.5" and 0.467" but how can both sizes be compatible with the block?

When I measure my dizzy shaft I get 0.46" (standard autolite) so possibly slight wear?

Any recomendations as to which gear to go for?

cheers Kiel

[Gaz64]

The sizes are related to distributor shaft size.

Go for the 0.467.

[RICK LAKE]

crenbbf Cren Stay away from bronze. This is for billet camshafts and racing. They have a short life in a motor. Without and info on the camshaft, iron gear or ploymer gear would be the choice. I don't know if you have any oil modification to the block. Also what setup to hold the camshaft in place? Torrington bearing or steel plate. What is the end play of the camshaft? I run .003" to .005". This is race spec. Max is maybe .010" play. The movement on the camshaft sliding in the bore also put a heavy load on the distributor gear. Oil pump is being turned by bottom of distributor also. Made sure you have a ARP or harden shaft for the oil pump. There is an oil galley behind most distributor opening, some guys drill a .015" hole to help oil this location of the 2 gears. Other wise the gears depend on splash or drain from the rest of the motor. It's not manditory but doesn't hurt either.
If you can find out what the maker of the camshaft is, they have the correct gear for that camshaft to pervent wear out. The only plus I can say about running a bronze gear is I have seen no major damage to a motor where the gear was shaved. Most partials went into the oil filter and the small amount that got pass it where bonded into the rod bearings. These gears will last about 5-7 K miles. Some alot less. Good luck Rick

[Jamo]

Let me say this about that...yup, what Rick said.

[blykins]

It hasn't worn, that's just the size of that particular shaft. The part of the shaft that interfaces with the block (goes down into the hole to contact the pump shaft) is always going to be the same diameter, no matter what. However, there is a difference in the diameter of the shaft based on whether or not it's a factory or aftermarket distributor. That difference will be up much higher, where the gear rides.

I'd stay away from both bronze and polymer gears.

It's pretty clear cut: if you have a flat tappet camshaft, you'll want to use a cast iron gear. If you have a billet core roller cam, use a steel gear.

If you're unsure about which inside diameter to get, you can measure the diameter of the shaft and get an approximate diameter, but the only perfect way is to press the gear off and measure the shaft where the gear rides.

I get to do this task very frequently and it's a pain in the hindend, but if you do change gears, here are a couple of pointers:

1. Do not assume that you can press the new gear on, line the holes up, and everything will be fine. There is a dimension on how far the gear needs to be pushed onto the shaft and you will have issues if it's not in spec. If I remember correctly, that spec is 3.045-3.050" (on an FE) from the bottom face of the gear up to the distributor housing flange.

2. I use Mallory or Crane gears. Mallorys will come with 3/16" roll pins and the hole is probably 1/8" on the shaft. You will need to get the gear pressed onto the shaft on the correct dimension, then drill through it all with a 3/16" drill and knock the pin in.

[crenbbf]

Thanks Guys

Blimey nothing is straight forward with an FE

The cam is a lunati Voodoo roller (so steel billet)and acording to Lunati it doesn't have the iron gear fitted.

so steel gear it is then yes?

Only oil mods are as per Barry's book so no drilling of the plug behind the dizzy.

cheers

[blykins]

The distributor gear fiasco is pretty common with all Fords. I can get billet steel cams from Comp with provisions for an iron distributor gear, but they are not available for the FE yet.

Yes, steel gear. No oil mods needed.

[crenbbf]

Originally Posted by blykins

The distributor gear fiasco is pretty common with all Fords. I can get billet steel cams from Comp with provisions for an iron distributor gear, but they are not available for the FE yet.

Yes, steel gear. No oil mods needed.

thanks again Brent

[Barry_R]

Yep...

Steel gears from Crane here.
.467 shaft for OEM distributors
.500 shaft for Accel, Mallory & some others
.531 shaft for MSD

They are generally marked as "460 and 351C" parts. They fit fine. BUt as Lykins mentioned, there is a specific height that you need to press to. Rotate the shaft 90 degrees from the original location and drill a new hole - the original will never line up correctly.

[crenbbf]

Originally Posted by Barry_R

Yep...

Steel gears from Crane here.
.467 shaft for OEM distributors
.500 shaft for Accel, Mallory & some others
.531 shaft for MSD

They are generally marked as "460 and 351C" parts. They fit fine. BUt as Lykins mentioned, there is a specific height that you need to press to. Rotate the shaft 90 degrees from the original location and drill a new hole - the original will never line up correctly.

Thanks Barry

And thanks to everyone that replied as well to another of my daft questions.....









.......don't worry there's plenty more where they came from

cheers Kiel

[tcabece427]

I was confused about this too. The Ford distributors like the duraspark II are .467 as is the small hole in the block where the oil pump shaft engages the distributor. The different sizes for the distributor gear is up higher on the shaft. for after market like MSD and Pertronic's the shaft "steps" up to .500.

As for the distributor gear material for the billet steel cams, I am running a COMP cams retro roller rocker cam. I used the Crane distributor gear 52970-1 from Summit Racing on my Pertronix PNX-D7133700 also from Summit.

The Pertronix III uses the black distributor cap like on the period correct Chevrolets. It looks almost identical to the Ford distributor caps except it has (in my opinion) the better mounting screws instead of those clips.

[crenbbf]

Hi '427

We too are going to use a Pertronix III unit but hidden in the standard dizzy.

As a matter of fact the III is hard to come by over here but I like the rev limiter feature they have.

Totally agree about the cap fitting so will decide before we change the dizzy gear whether or not to change to the full system

cheers

[tcabece427]

If you do go with the Pertronix distributor with the Chevrolet cap. Beware of clearance issues between the burp tank and the screw "ears" on the cap. I am using a Kirkham burp tank and it mount flush with the intake. The Ford "tin" burp tanks have like a 1/4 - 3/8 spacer.

My Pertronix cap does hit the Kirkham burp tank so I have to be careful setting up the timing. It limits how far I can twist the distributor back and forth. Right now I have it setup so it is timed correctly without the distributor cap contacting the burp tank.

[crenbbf]

Thanks

All good info, we are sticking as much as possible to the original (SC) look

Our kit (Crendon) requires a spacer to tip the tank forward slightly so might do the trick for the dizzy as well.

cheers