Photographic reminder to replace your timing set

[66Lincoupe]

What year did they start the nylon gears in the 430? Or did they ALL have them?

All of them.

[TonyC]

Starting with the 1961 models, all 430s had nylon teeth on the cam gear. They did that to make the engine quieter. At the time, nylon was still a new application to everything, and they figured it was an ultimate material--strong and lightweight. They had no idea back then that nylon has a limited life span. That was why Lincoln's use transferred to the rest of the industry; most engines that came after the 430 utilized nylon timing gears.

Now we know better, of course.

---Tony

[thegermanfan]

missing teeth camshaft gear result in excessive slack in the timing chain. This usually deteriorates the idle quality - especially with the engine up to operating temperature. Strangely enough the idle might be OK with the engine cold and then worsen as the temperature rises.

I can recommend the following method to check for excessive timing chain stretch (which is in effect the same as missing teeth on the cam gear):

• Bring engine up to normal operating temperature.
• Remove vacuum hose from the distributor and plug the hose.
• Attach timing light and check timing at idle speed.
• Rev Engine to approx. 1500rpm while still shining the timing light on the damper.
• Release throttle suddenly and note whether timing changes momentarily. If in doubt: repeat!
• If the timing mark does move when you release throttle - you need a new chain and gear set.

[jetmech5]

So is it ALL of them...or did they start in 61'? I have a 60 and don't want to tear into it if i really don't need to.

[Dan Szwarc]

At the time, nylon was still a new application to everything, and they figured it was an ultimate material--strong and lightweight. They had no idea back then that nylon has a limited life span.
---Tony

This is not true. They knew. They already knew that metal timing chains can stretch. The simply didn't care that after 30 years, the nylon would degrade due to age and heat. It met the operational requirements of the vehicle in a normal lifespan.

No automaker designs beyond 15 years and 200,000 miles. If a product goes beyond, it doesn't matter because it is out of warranty. Heck, the warranties don't go past 10 years and are typically 5 years or less.

Designing quality products does not clash with the concept of designing products that last. They depend on owners buying new vehicles regardless of how long the other ones last. However, they amount of breakdowns that occur in the early and medium lifespan are critical to making another sale.

I'm not sure if any engine today uses nylon anymore. The designs may not be appropriate for nylon anymore.

[66Lincoupe]

I'm not sure if any engine today uses nylon anymore. The designs may not be appropriate for nylon anymore.

As far as timing applications all we use "nylon" for is the tensioners, Can't comment for brand X's though.

[7579lincoln]

Just a question for all of you who know 460 engines. About 2 years ago I replaced the timing gears, chain, oil pump, main bearings, rod bearings, water pump, starter and alternator on my 75 Towncar with a 460. I did not replace the oil pump drive shaft as it looked brand new even though it is the original. Is there any reason to replace the oil pump drive shaft, and if so why as everything else related to it was replaced?

Harv

[66Lincoupe]

What year did they start the nylon gears in the 430? Or did they ALL have them?

All of them.

Starting with the 1961 models, all 430s had nylon teeth on the cam gear. ---Tony

Sorry - I guess it's '61 and newer... I keep forgetting the 58-60 was the 430 as well.

[jetmech5]

That's OK everyone forgets about the 58-60 Lincolns. We are the red-headed step children of the Lincoln family

[Barry Wolk]

Yes, yes you are.

Did the '68 460 have a nylon gear? Have all the teeth fallen off of mine, causing a loose timing belt or is my belt just stretched? How much slack should there be?

[MarkIII]

Did the '68 460 have a nylon gear?

It had the nylon-overmolded die-cast zinc alloy cam sprocket.

Have all the teeth fallen off of mine,

Don't think so. That pic looks to me like an after-market sprocket. The original early 460 cam sprockets that I have seen have the part number C8VE-6256-A and a small FoMoCo logo molded into them. They also have eight through-holes about 3/4" diameter molded into them spaced around between the center and the outer edge. And another through-hole, a 1/4" one, as an accent to the small triangular timing indicator mark on the periphery.
So they look a lot different than the picture you show.

[66Lincoupe]

Barry, I think you're okay as far as slack. I put a new silent chain on my 462. I only ran it a few hours and it had about 3/8" -7/16" of slack similar to what you've got - My parts all still look like new and there are very minimal shiny spots where the chain rides on the sprocket. Everything was well-oiled (Oiling is what I've been working on with my engine.)

My grandpa and my auto shop teacher in high-school told me the best way to check the chain without pulling everything apart is to spin the crank in one direction until the timing marks line up with the pointer halfway through the scale and make a note of where you stopped. Remove the distributor cap and watch the rotor as you turn the crank in the opposite direction. Stop when the rotor begins to move again and note the scale. I was told more than 3-4 degrees is worn.

I think I also read this on this forum too somewhere...

[Dan Szwarc]

I say if you're in there already, why not just replace it with a double-roller and be done with it?

[66Lincoupe]

I say if you're in there already, why not just replace it with a double-roller and be done with it?

Cheap insurance. Good advice.

[Barry Wolk]

By double roller, do you mean two chains or two that are linked together? It that the gear I've seen with two sets of teeth?