@@Silver_othe originals broke all the time too. The hundred year examples are on cars that do 20 miles a year and get serviced every other weekend. It’s survivorship bias.
Lol when the timing chain stretches u just gotta kill the engine without it idling so the cam can't catch slack the pistons slow it back down so it can't jump
These were put in cars all the way up to the early 90s.. obviously not all cars and trucks but the 91 f-150 with six cyl had the “plastic” gear as we called it
1978 318s are fiber gears too rebuilt mine a year ago was shocked to find it an tbf the chain itself have up long B4 the gear I didn't even have to remove the gears to change the chain I just slipped it off😂😂😂 an yes it would run just fine it sounded like the engine had a lifter rattle turns out it was the chain an inch to long after 50 years 😂😂
Had a '76 Mustang II with the 171 CID V-6 "Cologne" 4 speed. Absolutely loved that pos did a stupid and over reved it at -33F in EGF Mn and found another way home. Bought the part at Ford on Monday and pulled the mustang all the way home (35 or so miles). Put in the new one in less than 2 1/2 hours. Thanks Dennis for letting me use your heated shop, tools, and brain. 103 HP 140 FT-LBS. Tender Blue. Many, many, memories.
Well made fibre gears have a very long life. The strength is in the pressed canvas, not the resin. They do have the benefit of tolerating a little crankshaft bearing wear for quite a long time. The problem with cam gears is that a 2:1 ratio causes wear patterns; the expensive answer is to use an intermediate idler gear with an odd number of teeth so that the wear spreads out over the whole idler rather than bunching at the points where the cams are most loaded. The cheap answer is to use a fibre gear whose slight eleasticity prevents the bunching effect. Aluminium on steel if correctly designed is fine; take a look at modern camshaft bearings where the shaft runs directly in the head metal. But running a new aluminium gear on a worn steel one might not be a good idea.
I mean technically a cam on an aluminum head is a polished cam journal riding on a thousandth or so layer of oil, not directly contacting the surface. Think about how quickly a gear on a distributor will destroy itself if you use the wrong gear on the wrong cam. I think instead of pieces of soft gear material floating around, he is going to have aluminum chunks through everything.
@@ryurc3033 You certainly aren't wrong. All successful bearings and gear surfaces have some tribology involved. Fibre gears were designed to absorb a small amount of oil which lubricated the contact point. Thinking more deeply about this case, there won't be an oil feed into the contact point of the helical gears and yes, that's likely to cause rapid wear. The Nissan Leaf has a version of this problem; the helical reduction gear isn't pump lubricated, at least in the earlier ones, and this can cause quite severe tooth wear. Yet the need for pumped oil was identified over a century ago, on turbine ships.
Small block Chevy had those with a single row chain. Would last 100-150 thousand miles then leave you stranded. I could never hear the difference between the plastic chain sprocket and the metal ones. Of course with a straight pipe or even a glass pack you couldn't hear much of anything else.
👍 So, what he's saying is,,,😏 Add some glass packs or straight pipe that beautiful old ride, 😎 and you'll never worry about that little engine noise again🤣🤣
It's always very interesting to hear about the materials used in older vehicles when engine power was much much lower, another one I've heard is using leather for rod and crank bearing material
phonolic resin is actually still utilized in a lot of gearsets since its quiet, cheap, and fairly durable (lasts about 100k before failure), GM/Ford utilized it into the 80's in a few timing gear designs for light duty. (think i saw it in a late 60's ford galaxy once) Very neat advertised as a "silent gear"
Leather for rod bearings was an emergency thing and was only really used on steam engines, though I did hear people doing it with 1940s cars in emergencies.
A low rev engine works fine for leather. My grandfather told me a story of him blowing a rod on the way back from the East Coast towards Ohio. He pulled the rod out and replaced it with an oil can that fit perfectly in place. And drove the car home. He later on repaired it with some leather bearings. He said the bearings were soaked in an oil solution that they use during WWII. He said the solution help too, always lubricate the leather, but it actually helped to toughen it up. He said getting the leather to the right thickness was the real trick, but he drove on that car for almost 3 years before he had enough extra cash to change it out with some proper ones. Phenolic resin really wild stuff. I have used it in the past for making cooling blocks for a bandsaw that runs on two tires. Not kidding I can show you pictures. Backing board for high amp high voltage circuitry. And about three mills thick for making boomerangs. And yes, they do come back. Do you have to use the canvas style. Not the compressed paper. It won’t hold up.
Cotton rather than asbestos, surely? Asbestos is abrasive. Aramid fibres are terrible for machining (guess how I know?) and PTFE is not nearly strong enough for a gear substrate. There are laminates containing small particles of dispersed PTFE, but the base material is still cotton phenolic or epoxy and the PTFE is there as a dry lubricant used in slow moving bearings.
Just slap on a steel gear and never worry about it again. The noise mostly comes from the tooth pattern rather than the material alone,. Of course denser material will make a little bit of noise, but angled teeth like the gears found in a manual gearbox are much quieter than straight cut teeth like the ones found in racing gearboxes or in the reverse gear.
There's an inherent resonance in this engine that makes this gear aggressively wear its mate if it's made of a properly hard material. The old composite was elastic enough to simply accept the vibrations. The Aluminum one here also looks designed to flex, and is sufficiently soft as to not significantly damage its mate either.
2 дні тому
@@squidlybytes You're all don't want aluminium to e flexing as it won't be doing it for long.
Alll modern cars/trucks should come with helical cut gears in place of timing belts/chain just like most diesel engines. I think 99% of people would rather a engine that's a tiny bit louder compared to a quieter engine that could self detonate at any moment..
Totally what I was thinking when paying $5000 for having the timing chain and phasers changed in my Ford... gears would have lasted much longer than that 60000 km stretched out timing chain.
"Micarta" is a brand name for a vast range of laminates but yes they do make a phenolic cotton material used for gears. The UK equivalent is "Tufnol" which also covers a lot of different materials.
GM did this with the Iron Duke too; 300,000 miles on mine and it runs like a champ, but even with that timing gear it’s noisy as a bag full of hammers.
Ah, the good, ol' Iron Duke. It's about as exciting as reading the White Pages for fun, but these engines do seem to run forever. 300,000 is an impressive number to be sure! On my flathead V8, the aluminum timing gear isn't *too* loud, but it makes a light clacking sound that really annoys me for some reason. There was a gentleman in the Early Ford V8 Club that had a 1953 Mercury. He said the car had about 77,000 original miles on it and the engine had never been opened up. Well, that damn car was probably the quietest I've ever heard (or rather, not heard). You literally could not tell it was idling -- there was no ticking, no vibration, no rumbling, nothing. The only way you could see that the engine was on was a little water vapor coming out of the exhaust pipe. - Craig
GM used fiber cam gears on the "iron duke" 4 cylenders all the way until 1987. At roughly 60k miles they would develop an odd knock due to gear wear. Finally fixed it for the last year of production, required redesigning the camshaft to do it. Ford also used plastic gear teeth on early windsor engines in th mid-60s. Those teeth would break off, jam the oil pump & destroy the bearings. Don't think any of those were pressed on, always bolted to the cam.
If you listen while rotating before assembly, you can pinpoint the noise causing teeth. Knock off imperfections with a jewelers file and check again. Make sure it's well oiled for this. You can even use lapping compound. Works.
Teeth usually get stripped in a backfire situation. Many v8 engines ran those “nylon” gears as we’d call them. Many GM products for sure, Chevy, Pontiac Buick Oldsmobile v8s all used them but with a chain rather than in mesh. To keep the noise down. You used to be able to buy gear driven assemblies to replace the chain and gears but those were crazy noisy!
The chairman of Rolls-Royce once said he had difficulty in getting the financiers to understand that if RR never sold anything, starting tomorrow, they would still have a viable business keeping their products running 70 years later. RR and Westinghouse make stuff to last decades. Just not in the car industry.
I had a fiber gear on a 1963 Nova inline six. It cratered and left me stranded on the interstate just outside of my town. They were readily available at the parts store, and I walked into town and got one and, went out on the interstate and fixed it.
In the 87 Olds 88, 3.8 L V6. The timing gear was coated with Teflon. When Teflon wore off the teeth of the time gear, then the timing gear started to wobble. This cause the timing to be off. When the timing was off, the valves hit the pistons. This caused the valves to smash into the pistons, turning the engine into scrap. This generally happened around 80,000 miles. I bought a '87 Olds 88 with 50, 000 miles, a change the timing gear. The engine lasted 260,000 miles.
Holden 6 cylinder engines used these right from 1948 to 1986, and yeah, they had a habit of stripping the teeth, and yeah the fix was an alloy gear. The distributor drive was also fibre and it was common for that to break as well.
My main concern is that steel gear is going to eat away that aluminum gear like butter and if that aluminum making its way into the oiling system would be a catastrophe.
@@sixtakefives5325I promise those old fiber gears are almost like steel after being heat treated for several decades been there honestly if they would make just a new chain to fit the old gears i would have kept it even being fiber its still gotta be better than new crap
@@sixtakefives5325it does eat it over time. Just like any engine that runs long enough eats some of its own metal. A Suzuki engine with 250,000 miles on one timing chain has sharpened teeth like a worn dirt bike sprocket,
Years ago I had a 69 Mach 1 that I got cheap because the timing gear stripped. Got a new one and it was steel. Told the guy at the counter it was the wrong one but he said no, the manufacturers want them to be quiet, not last. That was for a chain and he was right.
Ive got a vintage Hamilton Beach stand mixer with similar fiber gears in it. One of them has been stripped for so long that the beaters are worn about half way through from pushing eachother all these years.
GM's 2.5L Iron Duke 4 cyl has one of these fiber gears. They typically last 250-300k miles. When they strip, you just put another one on, and go. Ford's 4.9L inline 6 had one, too.
I love the noises of a great running engine. They all make some kind of noise specific to the engine!? But that makes that engine special in its own way? From solid lifter noise to cam gears, turbos and super chargers they all have their awesome normal noises.
Those gears are touch and go...Sometimes they will last forever, sometimes they'll only last a short period. I still use them on really old machine shop equipment.
Ford had Teflon coated timing gears in the 80’s, they would get brittle and come apart around 80 or 100 thousand miles, my best friend’s dad was the manager of York refrigeration rebuild division in Houston and he and I would rebuild all the engines that jumped timing because of this problem, and they all had this problem amongst other issues, the pieces of Teflon would clog up the oil pump intake and then trash the bearings and cylinder rings, and they all did it between 70 and 120 thousand miles, we made a lot of money rebuilding all those Ford small blocks and replacing the Teflon gears with steel double roller cam sets in those company trucks, vans and cars!!! 🤑🤑🤑
On my 1986 Chevy V8, it had an aluminum timing gear with injection molded nylon on top. After around 25 years the nylon said "I'm done!" And bring away from the cam gear. The debris left behind broke teeth off the crank gear. All of the debris went into the oil pan. Replaced with all steel, but such an obnoxious repair.
Ford was using plastic timing gears on the 300 six cylinder engine all through the 1980’s. The aftermarket has offered steel replacements. If an engine has to have a weak point, I’m okay with it being something like this.
This might sound stupid but it's it a wet or dry gear? Because if it's dry as in no oil getting squirted on it, then that aluminum will get eaten up pretty quick as well
Not a dumb question at all! The timing gear and the crankshaft gear that drives it are wet, mounted under a cover at the front of the engine. Both gears are splash lubricated by all the oil whipping around inside the engine. - Craig
I've seen gears like that in very old laiths and mills. It's there for the case that someone shifts gears while it's still moving, and the soft fibre gears have a bit more chance to line up correctly. And if not they will strip and save the driveshafts, the motor and the made to fit soft brass bearings also reduces vibrations through the rest of the drivetrain, making the other metal gears last a little longer
My father once owned a 1939 Lincoln V-12 (yes 12) Zephyr and had such a pressed on timing gear. During an incident attempting to pass a truck, the gear slipped and the car was towed to a Lincoln dealer in Romulus, Michigan, where the mechanics went nuts trying to determine the problem. 2 full days later , another owner of one suggested they check the timing gear and after repositioning it correctly, match drilled an 1/8” diameter hole through the gear and crankshaft, placing a steel pin through it all. Problem solved
There is a modern inline 6 which has pretty much the same problem. I know people who have bought a van or truck with that engine and immediately changed the cheap gear for a metal gear and have gotten well over half a million miles on the engine.
The whole point of the timing gears being made of that material, was so that the timing gear broke before anything else in the engine, because a gear behind a timing cover is a lot easier to change then rebuilding your engine.
So I worked with 35 mm projectors. And we had gears like that and the purpose was not to be silent but to be destructible so if the projector bound up the rest of the projector would be saved buy that gear being shredded.
That's fascinating. The gears are like a mechanical fuse -- the weak link designed to fail in order to protect other, more expensive components. - Craig
A vehicle you obviously cherish can make a little noise it's just you and a select few that would even know the difference the majority of us would be telling you how cool your car is
Australian engines made by GM used fibre cam drive gears, failure occurs after 50,000 miles. Had one fail when quite some distance from home. Easy enough to change, but takes a few hours.
If they are noisy they probably aren’t meshing correctly. More than one tooth is engaged at any given time with a helical gear thereby reducing the sound of the loaded tooth letting go.
Only 80 years... If you want silence, and longevity, use an massively expensive material like VESPEL. Sure, the gear will cost $1000+ to make (just the blank) but it will be quiet and durable.
Great idea! Care to donate a chunk of Vespel to the cause? 🤣 Kidding aside, I'll stick with the aluminum gear and live with the small amount of noise it makes. Thanks for the comment. - Craig
Someone should make the gear and teeth a little smaller then mold a denim resin, phenolic, delrin, etc over the gear to get it up to its required size. You’ll have most of the core strength and the softness on the exterior for NVH. Theoretically
A good idea, but I wonder if they don't do this because there's a risk of the material coating the underlying gear flaking off/spalling. That could make a huge mess inside the engine. - Craig
seems like a smarty pants could have come up with a good modern replacement for so you get the best of both worlds with all the materials we have around today, but I'd rather know the noise is because its going to last forever
To eliminate the noise associated with metal gears, an anti-backlash design could be used. Essentially, it has a second gear with one tooth less in a sandwich. Commonly found in mechanical diesel injection pump gears, where backlash would interfere with injection timing. Too costly for mass production vehicles in non critical areas.
But I don’t understand if you want it to be strong make it out of steal, and if you want it strong and silent why not just coat the steal in a rubber type coating? Just my thoughts on it
Yeah he won't be doing that because of the horror stories of modern aftermarket ones being cheap crap that the teeth sheer off of after a couple hundred miles, leaving you stranded. That's why. But if you know where he can buy a many decades-old still in new condition gear that's the same quality and durability as the original that's lasted 80 years I'm sure he'd like to know where to buy them.
The fiber timing gears in GM engines is a pain. I have personally had two that slipped timing and it was those stupid fiberglass timing gears. Note the replacement gears were steel. The fiber timing gears in the 68 and 69 Oldsmobile 98s were failing around 65,000 miles.
phenolic ... pronounced fen ol ick .. is a compound containing a benzene ring with hydroxyl group added to one of the ring's carbon atoms. Phenolic plastics are actually laminates of other materials glued together using a phenolic resin.
If only there was an aluminum timing gear with a surface coating of phenolic resin so you have a composite gear that gives you the best of both worlds. Especially if it could be recoated when the surface wears.
80 years sounds like a perfectly acceptable life span for an engine part to me.
Only that they don't make new original ones anymore by that time.
@@Silver_othe originals broke all the time too. The hundred year examples are on cars that do 20 miles a year and get serviced every other weekend.
It’s survivorship bias.
Yea don't really understand this vid 80 yrs is plenty nothing u should be pre replacing, its one of those things u don't need to know until it happens
Yea i have body parts that probably wont last that long
I was going to say the same thing
80 years is better than 70-80,000 miles like most cars!😂
Good ole Survivorship Bias
Also modern cars hit 200,000 to 300,000 with ease. You could never do that with Model Fords without multiple rebuilds.
Lol when the timing chain stretches u just gotta kill the engine without it idling so the cam can't catch slack the pistons slow it back down so it can't jump
80 years the car will out live me. I think that’s where they get the old saying they don’t make them like they used to.
Exactly my point
Is he mispeaking?
These were put in cars all the way up to the early 90s.. obviously not all cars and trucks but the 91 f-150 with six cyl had the “plastic” gear as we called it
The 300 actually ran the plastic gears until '97, the industrial versions actually had cast iron gears
I have a 91 f150 with the 300 inline 6.
Modern plastic is completely different material than that gear
1978 318s are fiber gears too rebuilt mine a year ago was shocked to find it an tbf the chain itself have up long B4 the gear I didn't even have to remove the gears to change the chain I just slipped it off😂😂😂 an yes it would run just fine it sounded like the engine had a lifter rattle turns out it was the chain an inch to long after 50 years 😂😂
Volvo b18 and b20 had em
Had a '76 Mustang II with the 171 CID V-6 "Cologne" 4 speed. Absolutely loved that pos did a stupid and over reved it at -33F in EGF Mn and found another way home. Bought the part at Ford on Monday and pulled the mustang all the way home (35 or so miles). Put in the new one in less than 2 1/2 hours. Thanks Dennis for letting me use your heated shop, tools, and brain. 103 HP 140 FT-LBS. Tender Blue. Many, many, memories.
Well made fibre gears have a very long life. The strength is in the pressed canvas, not the resin. They do have the benefit of tolerating a little crankshaft bearing wear for quite a long time. The problem with cam gears is that a 2:1 ratio causes wear patterns; the expensive answer is to use an intermediate idler gear with an odd number of teeth so that the wear spreads out over the whole idler rather than bunching at the points where the cams are most loaded. The cheap answer is to use a fibre gear whose slight eleasticity prevents the bunching effect.
Aluminium on steel if correctly designed is fine; take a look at modern camshaft bearings where the shaft runs directly in the head metal. But running a new aluminium gear on a worn steel one might not be a good idea.
I mean technically a cam on an aluminum head is a polished cam journal riding on a thousandth or so layer of oil, not directly contacting the surface.
Think about how quickly a gear on a distributor will destroy itself if you use the wrong gear on the wrong cam.
I think instead of pieces of soft gear material floating around, he is going to have aluminum chunks through everything.
@@ryurc3033 You certainly aren't wrong. All successful bearings and gear surfaces have some tribology involved. Fibre gears were designed to absorb a small amount of oil which lubricated the contact point.
Thinking more deeply about this case, there won't be an oil feed into the contact point of the helical gears and yes, that's likely to cause rapid wear.
The Nissan Leaf has a version of this problem; the helical reduction gear isn't pump lubricated, at least in the earlier ones, and this can cause quite severe tooth wear. Yet the need for pumped oil was identified over a century ago, on turbine ships.
built a 350 into a 383 put timing gears on it the no belt kind car still running strong after 30+ years and still has that turbo wine
Small block Chevy had those with a single row chain. Would last 100-150 thousand miles then leave you stranded. I could never hear the difference between the plastic chain sprocket and the metal ones. Of course with a straight pipe or even a glass pack you couldn't hear much of anything else.
👍 So, what he's saying is,,,😏
Add some glass packs or straight pipe that beautiful old ride, 😎 and you'll never worry about that little engine noise again🤣🤣
It's always very interesting to hear about the materials used in older vehicles when engine power was much much lower, another one I've heard is using leather for rod and crank bearing material
phonolic resin is actually still utilized in a lot of gearsets since its quiet, cheap, and fairly durable (lasts about 100k before failure), GM/Ford utilized it into the 80's in a few timing gear designs for light duty. (think i saw it in a late 60's ford galaxy once) Very neat advertised as a "silent gear"
Leather for rod bearings was an emergency thing and was only really used on steam engines, though I did hear people doing it with 1940s cars in emergencies.
A low rev engine works fine for leather. My grandfather told me a story of him blowing a rod on the way back from the East Coast towards Ohio. He pulled the rod out and replaced it with an oil can that fit perfectly in place. And drove the car home. He later on repaired it with some leather bearings. He said the bearings were soaked in an oil solution that they use during WWII. He said the solution help too, always lubricate the leather, but it actually helped to toughen it up. He said getting the leather to the right thickness was the real trick, but he drove on that car for almost 3 years before he had enough extra cash to change it out with some proper ones. Phenolic resin really wild stuff. I have used it in the past for making cooling blocks for a bandsaw that runs on two tires. Not kidding I can show you pictures. Backing board for high amp high voltage circuitry. And about three mills thick for making boomerangs. And yes, they do come back. Do you have to use the canvas style. Not the compressed paper. It won’t hold up.
The original ones were made of asbestos and phenolic resins. The new ones are made of Kevlar/aromid fibers and PTFE.
Cotton rather than asbestos, surely? Asbestos is abrasive. Aramid fibres are terrible for machining (guess how I know?) and PTFE is not nearly strong enough for a gear substrate.
There are laminates containing small particles of dispersed PTFE, but the base material is still cotton phenolic or epoxy and the PTFE is there as a dry lubricant used in slow moving bearings.
Just slap on a steel gear and never worry about it again. The noise mostly comes from the tooth pattern rather than the material alone,. Of course denser material will make a little bit of noise, but angled teeth like the gears found in a manual gearbox are much quieter than straight cut teeth like the ones found in racing gearboxes or in the reverse gear.
Thank you.
Better yet: Titanium alloy
There's an inherent resonance in this engine that makes this gear aggressively wear its mate if it's made of a properly hard material. The old composite was elastic enough to simply accept the vibrations. The Aluminum one here also looks designed to flex, and is sufficiently soft as to not significantly damage its mate either.
@@squidlybytes
You're all don't want aluminium to e flexing as it won't be doing it for long.
Alll modern cars/trucks should come with helical cut gears in place of timing belts/chain just like most diesel engines. I think 99% of people would rather a engine that's a tiny bit louder compared to a quieter engine that could self detonate at any moment..
Totally what I was thinking when paying $5000 for having the timing chain and phasers changed in my Ford... gears would have lasted much longer than that 60000 km stretched out timing chain.
@@willmcgo8288only 60k on a timing chain? Not a belt? That’s completely unacceptable on ford’s part.
The GM 'Iron Duke 2.5' inline 4 used 'micarta' which is a phenolic linen material
"Micarta" is a brand name for a vast range of laminates but yes they do make a phenolic cotton material used for gears. The UK equivalent is "Tufnol" which also covers a lot of different materials.
yeap.
And is still noisy at idle
GM did this with the Iron Duke too; 300,000 miles on mine and it runs like a champ, but even with that timing gear it’s noisy as a bag full of hammers.
Ah, the good, ol' Iron Duke. It's about as exciting as reading the White Pages for fun, but these engines do seem to run forever. 300,000 is an impressive number to be sure!
On my flathead V8, the aluminum timing gear isn't *too* loud, but it makes a light clacking sound that really annoys me for some reason. There was a gentleman in the Early Ford V8 Club that had a 1953 Mercury. He said the car had about 77,000 original miles on it and the engine had never been opened up. Well, that damn car was probably the quietest I've ever heard (or rather, not heard). You literally could not tell it was idling -- there was no ticking, no vibration, no rumbling, nothing. The only way you could see that the engine was on was a little water vapor coming out of the exhaust pipe.
- Craig
Yeah, my daddy's truck had one Nylon on Aluminum, He put in a Dual Roller Timing Chain & Gearset
A1 ...........Pop knows the truth !
GM used fiber cam gears on the "iron duke" 4 cylenders all the way until 1987. At roughly 60k miles they would develop an odd knock due to gear wear. Finally fixed it for the last year of production, required redesigning the camshaft to do it. Ford also used plastic gear teeth on early windsor engines in th mid-60s. Those teeth would break off, jam the oil pump & destroy the bearings. Don't think any of those were pressed on, always bolted to the cam.
I thought the Iron Duke only got a timing chain and sprockets in 1991-1992. 1987 was the last year with no balance shafts.
@gregorymalchuk272 we are talking 30+ years ago but I do remember working on new Oldsmobiles at the dealer & changing alpt of those gears.
If you listen while rotating before assembly, you can pinpoint the noise causing teeth. Knock off imperfections with a jewelers file and check again. Make sure it's well oiled for this. You can even use lapping compound. Works.
Teeth usually get stripped in a backfire situation. Many v8 engines ran those “nylon” gears as we’d call them. Many GM products for sure, Chevy, Pontiac Buick Oldsmobile v8s all used them but with a chain rather than in mesh. To keep the noise down. You used to be able to buy gear driven assemblies to replace the chain and gears but those were crazy noisy!
A part lasting 'only' 80 years is completely unheard of nowadays
except these fiber gears don't last 80 years
The chairman of Rolls-Royce once said he had difficulty in getting the financiers to understand that if RR never sold anything, starting tomorrow, they would still have a viable business keeping their products running 70 years later.
RR and Westinghouse make stuff to last decades. Just not in the car industry.
I had a fiber gear on a 1963 Nova inline six. It cratered and left me stranded on the interstate just outside of my town. They were readily available at the parts store, and I walked into town and got one and, went out on the interstate and fixed it.
In the 87 Olds 88, 3.8 L V6. The timing gear was coated with Teflon. When Teflon wore off the teeth of the time gear, then the timing gear started to wobble.
This cause the timing to be off. When the timing was off, the valves hit the pistons.
This caused the valves to smash into the pistons, turning the engine into scrap.
This generally happened around 80,000 miles. I bought a '87 Olds 88 with 50, 000 miles, a change the timing gear. The engine lasted 260,000 miles.
Holden 6 cylinder engines used these right from 1948 to 1986, and yeah, they had a habit of stripping the teeth, and yeah the fix was an alloy gear. The distributor drive was also fibre and it was common for that to break as well.
They made the distributor drive out of this composite material, too? That sounds like a terrible idea.
- Craig
Dissy gear was nylon and they never fail. Steel ones have ben known to though. Which in turn makes the gears on the cam fail.
My main concern is that steel gear is going to eat away that aluminum gear like butter and if that aluminum making its way into the oiling system would be a catastrophe.
Why wouldn’t it eat away the fiber gear as well then?
@@sixtakefives5325I promise those old fiber gears are almost like steel after being heat treated for several decades been there honestly if they would make just a new chain to fit the old gears i would have kept it even being fiber its still gotta be better than new crap
@@sixtakefives5325 Actually, grit gets embedded in the polymer gearing enabling the plasti-gear to eat the iron gears.
@@sixtakefives5325it does eat it over time. Just like any engine that runs long enough eats some of its own metal. A Suzuki engine with 250,000 miles on one timing chain has sharpened teeth like a worn dirt bike sprocket,
Years ago I had a 69 Mach 1 that I got cheap because the timing gear stripped. Got a new one and it was steel. Told the guy at the counter it was the wrong one but he said no, the manufacturers want them to be quiet, not last. That was for a chain and he was right.
Yep, had to dig that shredded fiber out of the oil pump pickups a few times!
Ive got a vintage Hamilton Beach stand mixer with similar fiber gears in it. One of them has been stripped for so long that the beaters are worn about half way through from pushing eachother all these years.
Just being able to still fix it is amazing
GM's 2.5L Iron Duke 4 cyl has one of these fiber gears. They typically last 250-300k miles. When they strip, you just put another one on, and go. Ford's 4.9L inline 6 had one, too.
My '77 Oldsmobile 98 had a vinyl gear around a steel hub for a timing gear on it's 350
Modern timing gears use a split and spring loaded gear so it will prevent noise, made of steel
I love the noises of a great running engine. They all make some kind of noise specific to the engine!? But that makes that engine special in its own way? From solid lifter noise to cam gears, turbos and super chargers they all have their awesome normal noises.
Those gears are touch and go...Sometimes they will last forever, sometimes they'll only last a short period. I still use them on really old machine shop equipment.
What about delrin? It's almost as tough as aluminum and self lubricating.
Same as the fuser driver gear for the HPLJ-4.
Repair part is brass geared.
Ford had Teflon coated timing gears in the 80’s, they would get brittle and come apart around 80 or 100 thousand miles, my best friend’s dad was the manager of York refrigeration rebuild division in Houston and he and I would rebuild all the engines that jumped timing because of this problem, and they all had this problem amongst other issues, the pieces of Teflon would clog up the oil pump intake and then trash the bearings and cylinder rings, and they all did it between 70 and 120 thousand miles, we made a lot of money rebuilding all those Ford small blocks and replacing the Teflon gears with steel double roller cam sets in those company trucks, vans and cars!!! 🤑🤑🤑
On my 1986 Chevy V8, it had an aluminum timing gear with injection molded nylon on top. After around 25 years the nylon said "I'm done!" And bring away from the cam gear. The debris left behind broke teeth off the crank gear. All of the debris went into the oil pan. Replaced with all steel, but such an obnoxious repair.
Ford was using plastic timing gears on the 300 six cylinder engine all through the 1980’s. The aftermarket has offered steel replacements. If an engine has to have a weak point, I’m okay with it being something like this.
Properly designed and machined steel gears make almost no noise.
This might sound stupid but it's it a wet or dry gear? Because if it's dry as in no oil getting squirted on it, then that aluminum will get eaten up pretty quick as well
Not a dumb question at all! The timing gear and the crankshaft gear that drives it are wet, mounted under a cover at the front of the engine. Both gears are splash lubricated by all the oil whipping around inside the engine.
- Craig
@AutoEsoterica ok then aluminum is definitely fine then. Sucks you can't get any quality repo parts, have to manufacturer your own
I've seen gears like that in very old laiths and mills. It's there for the case that someone shifts gears while it's still moving, and the soft fibre gears have a bit more chance to line up correctly. And if not they will strip and save the driveshafts, the motor and the made to fit soft brass bearings
also reduces vibrations through the rest of the drivetrain, making the other metal gears last a little longer
"Hey guys this is austin"
You could also just always carry a spare if the noise is a big deal. That way you reduce the chances of getting stranded. How much are they anyway?
My father once owned a 1939 Lincoln V-12 (yes 12) Zephyr and had such a pressed on timing gear. During an incident attempting to pass a truck, the gear slipped and the car was towed to a Lincoln dealer in Romulus, Michigan, where the mechanics went nuts trying to determine the problem. 2 full days later , another owner of one suggested they check the timing gear and after repositioning it correctly, match drilled an 1/8” diameter hole through the gear and crankshaft, placing a steel pin through it all. Problem solved
Could you not incorporate a hard rubber/poly cush drive ? Or even a damper? Nice video, all the best !
Beautiful car bro
Place a work at use to make them. Can't rememeber exactly for whay motor but omce and awhile I'll find a couple laying around
The L134 in my CJ2 uses a fiber timing gear. No timing gear noise at all.
I think early volvo B18/B20 OHV engines used these aswell
Which were actually Ford V4 engines iirc...
@mikehunt8968 youre mixing them up with SAABs... B18/B20 is a volvo designed engine, its an inline 4
Are the phenelic timing gears the reason why all those flatheads were almost silent and smooth?
There is a modern inline 6 which has pretty much the same problem. I know people who have bought a van or truck with that engine and immediately changed the cheap gear for a metal gear and have gotten well over half a million miles on the engine.
The whole point of the timing gears being made of that material, was so that the timing gear broke before anything else in the engine, because a gear behind a timing cover is a lot easier to change then rebuilding your engine.
So I worked with 35 mm projectors. And we had gears like that and the purpose was not to be silent but to be destructible so if the projector bound up the rest of the projector would be saved buy that gear being shredded.
That's fascinating. The gears are like a mechanical fuse -- the weak link designed to fail in order to protect other, more expensive components.
- Craig
A vehicle you obviously cherish can make a little noise it's just you and a select few that would even know the difference the majority of us would be telling you how cool your car is
Is that material bakelite? Aka phenol formaldehyde. It's still made today and marked as >PF
Australian engines made by GM used fibre cam drive gears, failure occurs after 50,000 miles. Had one fail when quite some distance from home. Easy enough to change, but takes a few hours.
I'd rather deal with the noise. Well not deal with I love the sound of timing gears.
What lifespan and durability testing have you done?
When I was young we had old R4 soviet GAZ69 engine with them and they were separating always from inner part
If the original was fiber, can a replacement be 3D printed? How strong does it need to be?
I have a 1968 Chevrolet C10 truck I use absolutely steel timing gears in them.
ohhh, pressed on would be a problem 😅 but what if it they're made out of pressed ceramic? like modern break pads. I'm genuinely curious 🤔
Holden Red 6 motors had the plastic gear. I dropped back a gear to pass a 4x4 and cough fart, black smoke. Stuck on the side of the road for 6 hours.
Those fiber gears also absorb oil and keeps the wear down on both gears.
Can you make it sound like Pete Jackson gears?
so put a metal backup gear in behind the phenolic that doesn't touch until there is a problem, but it keeps in in gear.
Put a straight cut gear in and embrace the noise :)
Some 80s GM V6s had those.
Surely the materials in 3D printing would work and be quieter
So you’re saying they don’t make em like they used 2
"After 80 years, the teeth will break off" - yup, sounds about right.
Can’t you fill the gaps in the rim with sound dampening Mats?
If they are noisy they probably aren’t meshing correctly. More than one tooth is engaged at any given time with a helical gear thereby reducing the sound of the loaded tooth letting go.
1970S Chevy 250 I6 had fiber gears. replaced them with steel
Only 80 years... If you want silence, and longevity, use an massively expensive material like VESPEL. Sure, the gear will cost $1000+ to make (just the blank) but it will be quiet and durable.
Great idea! Care to donate a chunk of Vespel to the cause? 🤣 Kidding aside, I'll stick with the aluminum gear and live with the small amount of noise it makes. Thanks for the comment.
- Craig
I had a 66 mustang with the 289 and the cam gear was nylon. The chain stripped the teeth off and left stranded on the freeway
Ya had one in a 87 bronco fail. It took out the head a few pistons
Someone should make the gear and teeth a little smaller then mold a denim resin, phenolic, delrin, etc over the gear to get it up to its required size. You’ll have most of the core strength and the softness on the exterior for NVH. Theoretically
A good idea, but I wonder if they don't do this because there's a risk of the material coating the underlying gear flaking off/spalling. That could make a huge mess inside the engine.
- Craig
seems like a smarty pants could have come up with a good modern replacement for so you get the best of both worlds with all the materials we have around today, but I'd rather know the noise is because its going to last forever
Ford made a 1.5L V4 engine that had fibre timing gears. And some other variations too.
Yes the wierdest combination but it fucking worked.
So is that what the original had? Or was it metal?
Kinda weird people care about the sound. The first 300 straight six had timing gears. I never heard noise from that engine
The factor I work in has used the same fiber gears for about 50 years. I don't even understand how they still work
To eliminate the noise associated with metal gears, an anti-backlash design could be used. Essentially, it has a second gear with one tooth less in a sandwich. Commonly found in mechanical diesel injection pump gears, where backlash would interfere with injection timing. Too costly for mass production vehicles in non critical areas.
But I don’t understand if you want it to be strong make it out of steal, and if you want it strong and silent why not just coat the steal in a rubber type coating? Just my thoughts on it
And that gear alone killed a lot of the early engines with Babbitt in the block and would lead to crank walk
80 years?? Just replace with the same part twice per century and everything is sweet ✅
Yeah he won't be doing that because of the horror stories of modern aftermarket ones being cheap crap that the teeth sheer off of after a couple hundred miles, leaving you stranded. That's why. But if you know where he can buy a many decades-old still in new condition gear that's the same quality and durability as the original that's lasted 80 years I'm sure he'd like to know where to buy them.
@@ButterfatFarmsI'm pretty sure anyone who owns an older vehicle would love to find that😂😂 there called NOS New Old Stock😂
80 YEARS?! I'd be dead by that time 😂
Interference engines?
The phenolic gear also was sacrificial so you wouldn't mess up your valves is something went wrong there.
The fiber timing gears in GM engines is a pain. I have personally had two that slipped timing and it was those stupid fiberglass timing gears. Note the replacement gears were steel. The fiber timing gears in the 68 and 69 Oldsmobile 98s were failing around 65,000 miles.
Fen-all-ic
I machine that stuff everyday.
The fiber gears in my pickup lasted almost 400k miles before they let loose and those weren't easy miles either.
phenolic ... pronounced fen ol ick .. is a compound containing a benzene ring with hydroxyl group added to one of the ring's carbon atoms.
Phenolic plastics are actually laminates of other materials glued together using a phenolic resin.
Some Volvos have these too
If had it brand new. It will be my grand children that have to walk home.
Well you have to use the aluminum one even though it make some noise
Easily the best compromise.
High temp plastitiesed material to cap the working edge of gear.
Oldsmobile used them in some of their v8s.
If only there was an aluminum timing gear with a surface coating of phenolic resin so you have a composite gear that gives you the best of both worlds. Especially if it could be recoated when the surface wears.
Aluminum teeth on a fiber hub. Like super sprox 😊
The noise isn't just the material, it's the loose tolerances around the teeth.