Used aluminum timing gear

[tubman]

Yesterday, I pulled the timing cover off of my '51 Merc to replace it with a nice shiny aluminum one. I see that I have the fiber cam gear, and while it overall looks pretty good, there are a couple of fibers sticking out on one tooth. Last night I was browsing the internet, and low and behold, what should appear but a used 8BA aluminum gear for less than $10. I looked it over pretty well (you know how they have the magnifying feature for pictures), and though kinda dirty, it looked good, so I bought it.

Are there any checks that can be made on these gears to see if they are too worn to use? I would think that since they are aluminum (harder that the fiber gears, but softer that the steel crank gear), the should last darn near forever. Anybody have any thoughts about this?

[19Fordy]

I'm no expert, but you might want to apply layout dye to the alum gear teeth and turn the engine over by hand to see how the teeth mesh.
Just an idea for piece of mind. Those in the know will tell you which way to go.

[flatheadmurre]

Put it in the engine and check the backlash.

[tubman]

Originally Posted by flatheadmurre

Put it in the engine and check the backlash.

Mauritz,

Do you know the specs or where they are available (looking for a shortcut here; it's easier than going through all my books).

Denny

[J Franklin]

Rule of thumb: Not too tight & not too sloppy!

[tubman]

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Originally Posted by J Franklin

Rule of thumb: Not too tight & not too sloppy!

Ah! I love the precision measurements required on these old Fords!

[J Franklin]

Some of the necessity of written specifications is so our wives can work on our cars after we croak.

[rotorwrench]

Timing gear backlash is .002" to .003" for the 8BA family.

[tubman]

Originally Posted by rotorwrench

Timing gear backlash is .002" to .003" for the 8BA family.

Thanks. How is that measured, with a skinny feeler gauge? I've never had the occasion to check this before.

[rotorwrench]

You can try and use a feeler gauge like the ones that taper down to a smaller radius but a wire gauge might be easier to use if you can source one.

[Charlie ny]

tubman,
To get accurate backlash measurements you must use a dial indicator.
When you get the gear count the teeth to be sure it is an 8ba.
Charlie ny

[Ol' Ron]

I've used them for years. If they look OK, why not?

[Tim Ayers]

Originally Posted by J Franklin

Rule of thumb: Not too tight & not too sloppy!

Love it! My father was a teenage mechanic working in a Sinclair Station in South River, NJ. He tells me stories of "rebuilding" flatheads in their sandpit.

You are right about the measurements. He was happy if there weren't any left over bits and pieces after the heads went on. Never had one come back so I guess those measurements were close enough for government work.

[Bored&Stroked]

This is the only type of timing gear that I use . . . have never had an issue. They did make some 'undersize' ones - for the situations where the block was align-bored and the crank-to-cam centerlines were closer together - but I've never actually had one in my hands.

[Ross F-1]

Originally Posted by Charlie ny

tubman,
To get accurate backlash measurements you must use a dial indicator.
When you get the gear count the teeth to be sure it is an 8ba.
Charlie ny

Aren't 59-series teeth cut the opposite angle?

[GOSFAST]

Originally Posted by Ross F-1

Aren't 59-series teeth cut the opposite angle?

Yes they are.

Thanks, Gary in N.Y.

P.S. Here's a couple shots of the 2 side-by-side.