Cast iron Dist. gear on Crower hyd. roller cam for break in

[SAcobra427]

Getting ready to fire up my all new 511 ci (BBM heads and block) that will be running a Holley EFI Sniper Stealth setup. I am also going to be using the Holley Dual Sync Dist. that goes with it but would rather just run a regular single point dist. for the initial start up just to simplify things. My question is will running the cast iron gear on the regular dist. be ok to use on the steel gear of the Crower hyd. roller cam for the first 20 or 30 min of initial runtime ?
Thanks for any help you can provide.

PS FYI, already left 2 messages at Crower about this over the last 3 weeks with no responses 

[blykins]

It won't last.  Need to use the steel gear.

[SAcobra427]

OK Brent thanks for responding ! 

[pbf777]

     Well, yeah, ..........it won't last but, it has often been practiced to initially utilize a cast iron gear on steel mechanical roller cams in order to effectively "break-in" or "work-down" the sometimes less than ideal gear surface as presented by the manufacturer prior to swapping to the as required bronze gear.     

     Trick is, knowing when to get the iron gear out before it starts shedding excessive material, perhaps then instead of providing a smoothing effect rather damaging the camshaft gear surfaces, not to mention excess particulate about in ones' oil, and this duration will vary depending on several variables in the function of the relationship.     

     Scott.

[Jb427]

I have seen cast steel gear last less then 20min running on a roller cam

[blykins]

     Well, yeah, ..........it won't last but, it has often been practiced to initially utilize a cast iron gear on steel mechanical roller cams in order to effectively "break-in" or "work-down" the sometimes less than ideal gear surface as presented by the manufacturer prior to swapping to the as required bronze gear.     

     Trick is, knowing when to get the iron gear out before it starts shedding excessive material, perhaps then instead of providing a smoothing effect rather damaging the camshaft gear surfaces, not to mention excess particulate about in ones' oil, and this duration will vary depending on several variables in the function of the relationship.     

     Scott.

Or you could just put a steel gear on from the get-go.   

[TJ]

I rate myself as a beginner mechanic and even I think swapping in a steel gear is a relatively simple and quick task...with instructions on how to get the measurement.

I have no idea why bronze gears are available.  Is there a benefit in racing?

[Falcon67]

I run all bronze on mine.  It's just easier on "short run" engines and there's no fuss about what's compatible with what.  If you order an MSD crank trigger distributor it comes with a bronze.  I ran a steel on steel in a race 393 and it chewed up both the cam and distributor gear after about 4 race weekends.  Not sure why, it just did.  Switched to bronze and haven't had any issues.  The bronze gear in the 351C door car has about 4 years of racing with a lot of passes on it and it looks just fine, very little wear. And that's running an HV pump with 72 lbs pressure cold, 60 lbs hot at 2000+.   

If it does chew up a bronze gear, you're not going to have a motor full of oil flavored with steel dirt that acts like an abrasive slurry like you get with cast or steel.  Iron/steel makes a hella mess.  And the only way to get rid of it is to pull it completely apart and wash every little piece LOL.  So best to start out with compatible materials. 

[blykins]

I have no idea why bronze gears are available.  Is there a benefit in racing?

There is none.   To be honest, I really don't know why bronze gears are available either.  They don't last long.  A steel gear on a steel cam will last forever and so will a cast iron gear on a cast iron cam.  Anytime you get a material mismatch, one side will inevitably show some wear. 

[My427stang]

I would never recommend an iron gear on a steel cam over time.  However, I also don't know how to define what that time is, because it could be an expensive experiment and have no desire to try.

I REALLY don't like bronze gears, but knowing that the dual sync has a gear that will work, and this is temporary, and you can't find a steel gear,  I'd go bronze.  However, the cost difference between steel and bronze is minimal if you can find a steel gear choice.

You may want to consider a borrowed aftermarket distributor or even purchase a used one, much easier to find a steel gear

PM me though before you mess with that dual sync, I learned a lot about them (and Holley programming/operation) on my most recent Terminator X install and would be happy to share, especially if you are going Terminator X, although Sniper is very similar.

[pbf777]

There is none.   To be honest, I really don't know why bronze gears are available either. 

     Because in some installations due to a combination of circumstances such as: deficiencies in the basic engineering from the O.E., execution in manufacture of the components in hand, the abruptness in velocity changes with greater forces presented in the more aggressive mechanical rollers, along with flexing and movement in the position of the gear relationship, vibratory effects particularly on the displacement of the lubricant, and even the fact that the lubricant is a compromise, as that which one might prefer as a "gear-lube" probably isn't going to be appreciated by the sealing rings manufacturer, add heat and other excessive loadings,..........one sometimes needs a 'softer', if only a sacrificial component in the relationship for a reasonable outcome. 

     That's why.       

     Scott.

[67xr7cat]

Bronze gears have their place. Main advantage is you don't have to worry about gear compatibility possibly damaging the cam gear.  Not all steel cams are the same material, not all cast are either.  Best way is if you know the cam material is to ask the distributor gear maker if the gear is compatable.

Bronze gears will wear out they are not a 100,000 mile solution, but properly installed can last at least a few thousand miles.  I had on last 10,000 miles. Also not all bronze gears are the same quality.

If you have a drag car and a billet steel cam bronze is a safe easy choice and provided the gear is made from ampco45 and properly installed, in that application it should last a long time.

[pbf777]

Not all steel cams are the same material, not all cast are either.  Best way is if you know the cam material is to ask the distributor gear maker if the gear is compatable.

     It is true that the camshaft cores are not all the same; problem is the so-called manufacturer who's name it on the box truly doesn't know either anymore as the cores are a buy-out from someone else manufactured where and of what?   

     Scott.

[blykins]

There is none.   To be honest, I really don't know why bronze gears are available either. 

     Because in some installations due to a combination of circumstances such as: deficiencies in the basic engineering from the O.E., execution in manufacture of the components in hand, the abruptness in velocity changes with greater forces presented in the more aggressive mechanical rollers, along with flexing and movement in the position of the gear relationship, vibratory effects particularly on the displacement of the lubricant, and even the fact that the lubricant is a compromise, as that which one might prefer as a "gear-lube" probably isn't going to be appreciated by the sealing rings manufacturer, add heat and other excessive loadings,..........one sometimes needs a 'softer', if only a sacrificial component in the relationship for a reasonable outcome. 

     That's why.       

     Scott.

Can you name a specific instance in where you have seen this as being "necessary"? 

I've never used a bronze gear on any Ford engine....hydraulic roller, solid roller, 5000 rpm, 9000 rpm, high volume pump, standard volume, I've never seen an instance where I needed bronze. 

[TJ]

I'm probably over simplifying it thinking if a ring and pinion set in a differential can push a car/truck for 100's of thousands of miles, then I expect to have a dizzy gear able to turn an oil pump for about as long.  That's why it's hard to imagine using bronze outside of racing where the engine may be torn down regularly anyway.

I can see how some guys might feel more comfortable with bronze.  I'm just inclined to only buy a cam/gear combo that will last longer. 

[pbf777]

Can you name a specific instance in where you have seen this as being "necessary"?

    Yes, in many instances over the decades.     
 

I've never used a bronze gear on any Ford engine....hydraulic roller, solid roller, 5000 rpm, 9000 rpm, high volume pump, standard volume, I've never seen an instance where I needed bronze.

     And yes, we often recommend the use of the steel gears also, but in some instances, with follow up inspections, it just isn't................happy    ; and even when installed properly!       

     Scott.

[blykins]

Can you name a specific instance in where you have seen this as being "necessary"?

    Yes, in many instances over the decades.     
 

Well that certainly cleared that up.  Much thanks.

[pbf777]

Well that certainly cleared that up.  Much thanks.

     I'm hoping I'm just misunderstanding this comment and that this isn't suppose to be a snide remark, which actually would just indicate child like behavior; and if so I would be disappointed as I felt sincerely that you were better than that?     

     As if one read my post of:
     

     Because in some installations due to a combination of circumstances............

      Particularly someone of experience would understand that there rarely is ever just one singular cause for such failures, but rather often several in conjunction, but also not necessarily for example all of those I listed, which I have attributed to such failures, but still with the same outcome as I have observed in different instances.   

      Scott.

[chilly460]

I think I’d need to hear “This is such and such core material with Rockwell such and such and no steel gear is compatible so you’ll have to run a sacrificial bronze gear”, a specific scenario, rather than a general statement.  I just don’t see why one would run a bronze gear, I’ve seen one fail in a light street use/strip scenario with a mild solid roller.  The constant wondering when it would fail seems absolutely unnecessary since steel gears are available, had one running going on 4yrs now in my car. 

How did OEM handle this with their rollers?  Cast gear on a steel core, or steel distributor gear?  Doesn’t seem like it needs to be complicated being that OEMs have run rollers for over 30yrs (granted newer engines don’t have gears).

[67xr7cat]

Not all steel cams are the same material, not all cast are either.  Best way is if you know the cam material is to ask the distributor gear maker if the gear is compatable.

     It is true that the camshaft cores are not all the same; problem is the so-called manufacturer who's name it on the box truly doesn't know either anymore as the cores are a buy-out from someone else manufactured where and of what?   

     Scott.

For sure not knowing your supply chain source is a problem in this day and age.

[67xr7cat]

I think I’d need to hear “This is such and such core material with Rockwell such and such and no steel gear is compatible so you’ll have to run a sacrificial bronze gear”, a specific scenario, rather than a general statement.  I just don’t see why one would run a bronze gear, I’ve seen one fail in a light street use/strip scenario with a mild solid roller.  The constant wondering when it would fail seems absolutely unnecessary since steel gears are available, had one running going on 4yrs now in my car. 

How did OEM handle this with their rollers?  Cast gear on a steel core, or steel distributor gear?  Doesn’t seem like it needs to be complicated being that OEMs have run rollers for over 30yrs (granted newer engines don’t have gears).

Well the day you have a steel gear on a billet cam fail and wreck that cam you may see it different.  I have NO problem with a steel gear used on a cam that is compatible with it. I can tell you when one gear is harder than the other and there is wear the harder gear will win, but if it is a close race they both may get damaged.  While you had a bronze gear fail, I've personally have seen them last 10,000 miles.  Proper install and proper material matter.  Get that wrong and it won't last.  Another question how many miles you put on your car a year?  A lot of these guys don't even put 3,000 miles a year on their cars. Do you feel pulling the dizzy once a year is too much to check the gear? 

One thing with a bronze gear it takes the wear, not the cam. If I do not know for a fact that the cam and dizzy gears are compatible I'd rather be changing a dizzy gear than a cam.

Another thing to consider a bonze gear will not wear a cam gear.  A steel one will develop a wear pattern.  Crane recommended NOT to use their steel gear on a cam that was run already with a steel gear.  Now sure guys have done this 1,000 times and got away with it, but every time you put another gear on the cam has to re-wear to it. Considering what the OP wants to do running a bronze gear on his "break in" dizzy be the way to go for just this reason. 

I'd suggest asking the dizzy gear company what cam core types they say are compatible to answer your specific example question, although here is a link to a thread where Mike Jones (7th post in thread) talks about cam core compatibility:

https://www.speed-talk.com/forum/viewtopic.php?t=59407

And here is one where Dave McLain had a steel gear fail on a steel roller cam after 3,500 miles.  Is the 8th post in the thread.

https://www.speed-talk.com/forum/viewtopic.php?f=1&t=48321

Is interesting looking at that Holley's dual sync dizzy page. Says comes with a hardened steel gear, then goes on to say bronze gears are available for billet roller cams.

https://www.holley.com/products/ignition/distributors/holley_efi_dual_sync/parts/565-205

As for the OE's keep in mind they control the cam and dizzy gear material as well as the heat treat and machining.  Using aftermarket parts not the same as OE ball game.

[Posi67]

All I have to add is that I put a bronze gear on my (not for racing) Unilite about 16 years ago and have used the same setup on 3 engines with 3 different Cams. 2 were/are Solid Rollers and one was a cast Solid. Still running to this day with no obvious issues. Granted, not a high mile car but hundreds of Drag Race passes. Never had a steel gear nor saw the need however your results may vary.   

[blykins]

Well that certainly cleared that up.  Much thanks.

     I'm hoping I'm just misunderstanding this comment and that this isn't suppose to be a snide remark, which actually would just indicate child like behavior; and if so I would be disappointed as I felt sincerely that you were better than that?     

     As if one read my post of:
     

     Because in some installations due to a combination of circumstances............

      Particularly someone of experience would understand that there rarely is ever just one singular cause for such failures, but rather often several in conjunction, but also not necessarily for example all of those I listed, which I have attributed to such failures, but still with the same outcome as I have observed in different instances.   

      Scott.

Scott, I will say that I was equally disappointed in your response.   You are a man of wordiness and I was hoping to at least get some semblance of a coincidence.  I have torn down and freshened up many Fords over the years and have never pointed a finger at a distributor gear and thought, "I need to swap that over to bronze."  So, I was very curious as to what correlation you drew; if these situations were solid rollers only, high spring pressure, low spring pressure, gear drives, etc., etc.  Equally so, you could have just said, "To be honest Brent, it's been a long time and I can't remember."  Or, you could have said, "Let me think on that one."  I saw a drip of sarcasm on your reply, and that post didn't lend itself to shining any light whatsoever.

[blykins]

All I have to add is that I put a bronze gear on my (not for racing) Unilite about 16 years ago and have used the same setup on 3 engines with 3 different Cams. 2 were/are Solid Rollers and one was a cast Solid. Still running to this day with no obvious issues. Granted, not a high mile car but hundreds of Drag Race passes. Never had a steel gear nor saw the need however your results may vary.

Dale, if it were a dedicated street car, I think it would have a different outcome. 

Even if you had the distributor in 3 different engines and put 1000, 1/4 mile passes on each, that's only the equivalent of driving 750 miles.  The bronze distributor gears will usually go several thousand miles and then they start to get sharp. 

[My427stang]

I have pulled a few home with bronze gears over the years.  Been a long while, but the last one was a buddies 68 302 Mustang, wore it off entirely the shape of the cam gear, all the way around the gear, like it was made out of soft plastic

In every case, the car was a driver. 

[67xr7cat]

I have pulled a few home with bronze gears over the years.  Been a long while, but the last one was a buddies 68 302 Mustang, wore it off entirely the shape of the cam gear, all the way around the gear, like it was made out of soft plastic

In every case, the car was a driver.

So why do you think this steel gear failed on Dave McLain after only 3,500 miles?  Is the 8th post in the  linked thread.

https://www.speed-talk.com/forum/viewtopic.php?f=1&t=48321

So why do you think I got 10,000 miles on a bronze gear?  Was a Lunati solid roller street cam back when Joe Lunati ran the place.  Was a street/strip car.  Took several years to put that mileage on it.  Used to check it once a year.  Will say the 1st one did not last long, but after learning the correct way it lasted a lot longer.

Final question, how many miles do guys on here put on their rides a year?  Am sure someone will say 20,000, but most of these cars are getting old and bet sit more than anything. the OP is building a 511ci ERA Cobra.  I'd like to know how many miles a year that car will see. 

[My427stang]

I have pulled a few home with bronze gears over the years.  Been a long while, but the last one was a buddies 68 302 Mustang, wore it off entirely the shape of the cam gear, all the way around the gear, like it was made out of soft plastic

In every case, the car was a driver.

So why do you think this steel gear failed on Dave McLain after only 3,500 miles?  Is the 8th post in the  linked thread.

https://www.speed-talk.com/forum/viewtopic.php?f=1&t=48321

So why do you think I got 10,000 miles on a bronze gear?  Was a Lunati solid roller street cam back when Joe Lunati ran the place.  Was a street/strip car.  Took several years to put that mileage on it.  Used to check it once a year.  Will say the 1st one did not last long, but after learning the correct way it lasted a lot longer.

Final question, how many miles do guys on here put on their rides a year?  Am sure someone will say 20,000, but most of these cars are getting old and bet sit more than anything. the OP is building a 511ci ERA Cobra.  I'd like to know how many miles a year that car will see.

Steve, let's take these one at the time, starting with a blanket rule we all follow (I think)...do what works for you.  I have no stock in steel gear production, but I push a few engines through, not as many as some, and my position based on experience is, I don't want to stand behind a bronze gear.

However, I will answer the best I can what my WAG is on things that I have no information, nor have I seen the parts or setup

Dave McLain is a sharp cat, but that thread doesn't say what his failure was. Without knowing, could have been anything, and a bronze could have failed as well.  I will say that I'd expect him to pay attention to details.  However, if it took out the cam, so the pin either came apart, which could easily have been a depth problem, or there was a mismatch of materials, or not sure on a 460 or 351C, but on an FE, all it takes is an unmodified ARP cam retaining bolt and you lose oil to the distributor...I bet 50% of the guys don't even look at that.  Who knows what happened .  No idea with the data we have. 

Why did yours work? No idea either.  Actually, I have not had a failure on an FE, the others were all other Fords.  However, I recently rolled into Kentucky with a u-joint falling apart, couldn't find a joint, but found a cap from another one that fit.  New rollers on a damaged joint, I was in a bind and laughed to Brent about what a hack to get home (and if I even would).  Shouldn't work, put 2500 miles on it to get to Maryland and then home after it stayed tight and quiet, got home, rollers cleaned up the joint and it looked and felt new.  I replaced them both, but could have ran it. Shouldn't happen, but did.....  Maybe the old cam / old bronze gear was a little better, maybe zinc in the oil in the old days, I wish I could give you an answer

Last, the mileage, I used to drive the wheels off my own, life got busy.  I see guys that to 2000 a year to 12000, but there are cold starts too.  My thought though is if the material is sacrificial, it is continuously sacrificial, not just all of a sudden at 10K.  I don't particularly want to push bronze into the oil more than normal wear does with other materials.

However, back to rule 1, do what works for you, you have to live with it, not the other guy.  I am all about us sharing what we do, and I have ZERO desire to be in, never mind win, a debate.  If someone comes to Nebraska....no bronze gear unless there is no other choice, and even then I am going to do everything I can to exhaust the options.  I also have a local guy that uses Eagle cranks on every FE build, not for me.  These guys are my buddies, but it doesn't mean we see and do the same thing.  I think he will see a broken crank if he starts making the power we make.  He says "I haven't yet" well, how do you argue with that, but I am not using one LOL

[Falcon67]

Previous life before serving 23 years before the IT mast was manufacturing.  Lots of precision mechanical things, power transfer, heat treat, etc.  So familiar (well, it's been a long while though) with issues of dissimilar metals running next to each other.  I've had (as noted earlier) the steel gear on billet cam fail deal.  I do not have the equipment in my shop to make failure determinations like Rockwell testing, etc.  All the install parameters were correct, not started dry, all that. The gear could have been faulty, core issue - who knows.  It passed all the static tests like every other engine build, then it just didn't last very long. I do have a budget and to lose a $300 cam after a few passes is a hit I didn't want to repeat.  I just made the call I wasn't going to put another quarter in the same Coke machine that already took my money and didn't give me a Coke.  So bronze it was - MSD I think, have to find the invoice.  It was installed on the same shaft, same installed dimension, new cam and it's been just fine.  Have no issue with yanking it out once in a while for a look.  It's actually easier to pull the distributor to pour 8 quarts into the pan vs nursing 8 quarts though a tiny baffled hole in a valve cover. There just seems to be this perception out on the internet that a bronze gear will fail before you get to the end of the block. I've got cast gears sitting around with slightly to medium sharp teeth from running with HV oil pumps on cast flat tappet cores that have less time on them than the bronze gears I'm using now and the bronze seems to be holding it's own.  It may well not be necessary but it's working in my application.  Any besides, they are kinda pretty with that shiny gold look.

[67xr7cat]

Hi Ross, good post. Think what is important here is application matters and each should make an informed decision. Falcons 67 post give some good perspective too.  When you have known parts think is fine. If is a question sometime better take the safer option. Also with some steel gears in short supply guys should not just discount bronze as an option.

I can tell you why my bronze gear lasted that long and btw that was a 351w. Devil is in the details always. As for Eagle years ago was building a 460 and my old boss said why not put a stroker in it and got out the Eagle catalog. I said guys on the internet say stay away they break. He looked at me said never had that problem been using them for years. 15 years later still does and I can tell you he has some engines making 1,000+ HP.

To me I try not to speak in absolutes. Everyone can say what does or does not work for them, but in the end the best decision is an informed decision and that is a win for everyone

[TJ]

When I think of all the places we use gears (trannies, differentials, timing gears, etc) and expect them to last indefinitely, it's puzzling why some folks just accept cam gears and dizzy gears are too difficult to match for longevity.  To me it's one of those details consumers should require in a product...gears must be compatible and should last longer than an oil change interval. 

When I suspect two components are not compatible, I look for components that are. 

Not trying to be argumentative here, I'm just puzzled.

[67xr7cat]

When I think of all the places we use gears (trannies, differentials, timing gears, etc) and expect them to last indefinitely, it's puzzling why some folks just accept cam gears and dizzy gears are too difficult to match for longevity.  To me it's one of those details consumers should require in a product...gears must be compatible and should last longer than an oil change interval. 

When I suspect two components are not compatible, I look for components that are. 

Not trying to be argumentative here, I'm just puzzled.

Race parts tend have different requirement. Guys running a solid roller on the street is kinda a misapplication. Solid roller lifters are not a 100k deal. Other issue is the aftermarket is full of questionable stuff. A lot of it is not of the quality level that OEM stuff is. For most a hyd roller from a trusted source and gear good to go.  For the rest is just racing as they say ...

Devil is in the details!

[Rory428]

All I have to add is that I put a bronze gear on my (not for racing) Unilite about 16 years ago and have used the same setup on 3 engines with 3 different Cams. 2 were/are Solid Rollers and one was a cast Solid. Still running to this day with no obvious issues. Granted, not a high mile car but hundreds of Drag Race passes. Never had a steel gear nor saw the need however your results may vary.

Dale, if it were a dedicated street car, I think it would have a different outcome. 

Even if you had the distributor in 3 different engines and put 1000, 1/4 mile passes on each, that's only the equivalent of driving 750 miles.  The bronze distributor gears will usually go several thousand miles and then they start to get sharp.

Brent, not to be argumentative, but I know that Dale does not use a tow vehicle in the pits, so between driving from the pits to the starting line, making the run, driving off the end of the track , and back to the pits, each 1/4 mile pass is easily a full mile, and that is not including the warming up of the engine, the burn out, or any other time that the engine spends running.
The new 347 SBF in my Fairmont has a billet hydraulic roller cam, so I swapped out the iron gear from MSD Billet distributor, from the old engine, which had a solid flat tappet cam, to a new bronze MSD gear. I have made 50 1/4 passes so far, after the last race in a couple of weeks, I will pull the distributor to see how the bronze gear is doing, and will report back here.

[blykins]

All I have to add is that I put a bronze gear on my (not for racing) Unilite about 16 years ago and have used the same setup on 3 engines with 3 different Cams. 2 were/are Solid Rollers and one was a cast Solid. Still running to this day with no obvious issues. Granted, not a high mile car but hundreds of Drag Race passes. Never had a steel gear nor saw the need however your results may vary.

Dale, if it were a dedicated street car, I think it would have a different outcome. 

Even if you had the distributor in 3 different engines and put 1000, 1/4 mile passes on each, that's only the equivalent of driving 750 miles.  The bronze distributor gears will usually go several thousand miles and then they start to get sharp.

Brent, not to be argumentative, but I know that Dale does not use a tow vehicle in the pits, so between driving from the pits to the starting line, making the run, driving off the end of the track , and back to the pits, each 1/4 mile pass is easily a full mile, and that is not including the warming up of the engine, the burn out, or any other time that the engine spends running.

Certainly is a valid point if the loading is the same.  But would idling down the return road be comparable to the constant oil pressure/volume loads that a street car would see?

As Ross put it, if it works for you, then it works for you.

I do think the sample size of the experiment is going to be larger for some guys than others though and we tend to stay away from the techniques/parts that give us the most burrs under the saddles.  If a guy has 1-2 engines with a specific part with no failures or a failure once every 8-9 years, he's going to look at it much differently than a guy that has 100 engines and has seen a trend over time.   Those bell curves are hard to ignore. 

[My427stang]

BTW to the OP, read this before setup

Each Holley Dualsync has it's different setup requirements.  I am not sure how it will work if you just choose "DualSync" from the drop down, but Holley told me not to in a most recent Terminator X arm wrestle on the dyno

See here
https://documents.holley.com/199r11491r8.pdf

[Barry_R]

I have built a reasonable number of FE engines for several years - personal and customer - and have a fair amount of history to base my thoughts upon.

Before the melonized steel gear was available, the only option was bronze if you were going to run a roller cam - so that's what we all ran.  I put many thousands of street miles and track passes on a single bronze gear on my car for years.  It held up fine, but numerous friends had premature wear issues on their's.  Could have been a combination of correct assembly and simple good luck on mine.  Race car guys were far more concerned with short term success and power gains than long term gear life.  The bronze gear was viewed as a sacrificial and maintenance item - if it lasted a long time it was an unexpected bonus.

When Ford went to roller cams in 1985, they also went to steel distributor gears on the 302.  They were not available for other engines yet, but the OEM design and metals selection was an obvious choice and the aftermarket took notice of both the hydraulic roller benefits and the gear issue.  One cam manufacturer (CMC) went so far as to design a two piece cam that had a separate cast gear section on a steel roller core to insure compatibility with existing cast gear ignitions. 

OEM development continued with the release of induction hardened ductile iron cam cores.  These would still be compatible with hydraulic roller lifters, but were lower cost in manufacturing.  Several aftermarket companies went to these cores on milder cams in order to get the lower cost and more profitable package.  But this introduced yet another cam material into the market.  It's important to note that camshafts are sourced from one supply chain, while the distributor gears come from multiple unrelated manufacturers.  This is very different than rear end gears or transmission gears where all the mating parts come from a single (often OEM connected) source and are often pre-run to insure compatibility.

For street flat tappet applications the cast cam/cast gear is the obvious choice.
For street/street race oriented roller builds I will use the melonized steel gear in the majority of applications.  Experience has proven that they do work.  My observed failure rate is "zero".
On a pure race roller cam application I can still find a place for a bronze gear.  They are also a proven technology in that environment, and the expected periodic inspection is not a big deal for a racer.

[jayb]

I have used one bronze distributor gear in my life, on a mild Crower roller cam that I installed in my 68 Shelby back in about 1985.  The gear wore away to almost nothing in 2000 miles.  Pulled out the roller cam and went back to flat tappet in that 428.

On the other hand, I've installed over a dozen steel gears on roller cams in the last 20 years, and never had a failure.  They do show signs of wear, but none have ever failed despite thousands of street miles and lots of trips down the track.

I can see where, on a dedicated drag car, a bronze gear may make sense and work fine.  But all my cars are street/strip, even my 8 and 9 second Drag Week cars.  I would not trust a bronze gear on any street application.  I have read about people who have had good luck with bronze gears on the street, but I think they are in the minority.  I personally wouldn't risk it...

[Falcon67]

Brent, not to be argumentative, but I know that Dale does not use a tow vehicle in the pits, so between driving from the pits to the starting line, making the run, driving off the end of the track , and back to the pits, each 1/4 mile pass is easily a full mile, and that is not including the warming up of the engine, the burn out, or any other time that the engine spends running.
The new 347 SBF in my Fairmont has a billet hydraulic roller cam, so I swapped out the iron gear from MSD Billet distributor, from the old engine, which had a solid flat tappet cam, to a new bronze MSD gear. I have made 50 1/4 passes so far, after the last race in a couple of weeks, I will pull the distributor to see how the bronze gear is doing, and will report back here.

This is a real thing - if you are at Texas Motorplex, or pretty much any "quarter mile" track that only runs 1/8 mile unless it's a national NHRA event, you're gonna drive a while. A friends 5.72 in 1/8 door car at TM will use nearly 3 gallons of methanol per pass - drive to staging (staging lanes to burnout box is nearly 1000'),  race 660', coast/drive another 1/8 mile (unless you miss the first turnout then it's ANOTHER 1/8 mile)  then drive back to the pit.  I made 11 passes at the finals and used right at 10 gallons of VP 110.  That's nearly double what I'd use at the home track for two days of bracket racing.  Just to say - yes, lots of places race cars get driven a lot.  Not even my dragster get's towed anywhere - I drive it.  For something like a 3 day weekend of racing like the Texas Tripple Tens, I'll carry either a pony 30 gallon drum or partner with someone else on a full drum of methanol.  You'll be putt-putting around a lot at a big track.

I do think the sample size of the experiment is going to be larger for some guys than others though and we tend to stay away from the techniques/parts that give us the most burrs under the saddles.  If a guy has 1-2 engines with a specific part with no failures or a failure once every 8-9 years, he's going to look at it much differently than a guy that has 100 engines and has seen a trend over time.   Those bell curves are hard to ignore.

100% agree - my sample size of one or two is not ever meant (and I try not to state as such) to be a definitive representation of the quality or fitness of an item for a particular purpose LOL. 

[67xr7cat]

BTW to the OP, read this before setup

Each Holley Dualsync has it's different setup requirements.  I am not sure how it will work if you just choose "DualSync" from the drop down, but Holley told me not to in a most recent Terminator X arm wrestle on the dyno

See here
https://documents.holley.com/199r11491r8.pdf

Ross do you know if the OP can use the dual sync to trigger a msd 6 box or similar? I know it is a hall effect output so I'd think it would work.

Of course he would have locked out timing, but since he is just trying keep the initial start up simple think that be his easiest solution since the dual sync already has a steel gear, plus it then would avoid any possible wear in issues.

[My427stang]

A dual sync puts out two signals, cam and crank.  However, even though the cam signal might be able to be used, it's designed to be indexed at 50 BTDC and even if you indexed it differently, you'd have no advance and the output is not a ground, its a square wave 1/2 volt, so I don't think so. 

The Sniper system is pretty easy, I'd just set it up and go

[SAcobra427]

OK Thanks everybody for your opinions on this and after talking with Ross I have decided to just go with the Dual Sync from the start. Hopefully it goes as easy as it sounds.

[cammerfe]

I understand your thinking, but a ring and pinion are a matched set, already mated to each other. A cam and a diz gear are coming from widely divergent backgrounds, so more care in putting them together is called for. Bronze is chosen due to properties that make it most likely that it will be sacrificial. It probably makes sense to ask the cam supplier for suggestions as to a gear source.

KS

[My427stang]

OK Thanks everybody for your opinions on this and after talking with Ross I have decided to just go with the Dual Sync from the start. Hopefully it goes as easy as it sounds.

Bravery counts in bench racing.....

Happy to review the file before start if you decide you want me to

[SAcobra427]

[/img]OK Yes!  I will take you up on that Ross
Thanks so much.

[TJ]

I understand your thinking, but a ring and pinion are a matched set, already mated to each other. A cam and a diz gear are coming from widely divergent backgrounds, so more care in putting them together is called for. Bronze is chosen due to properties that make it most likely that it will be sacrificial. It probably makes sense to ask the cam supplier for suggestions as to a gear source.

KS

Yeah, I figured that's the case with a ring/pinion and I appreciate BarryR shedding some light on the topic.  My point was gears are everywhere and they last a long time.  Also, as a customer I know while roller cams are relatively new to FE's, they are far from new to engines.  I expect the metallurgy should be well figured out.  So like you said, makes sense to ask the cam supplier for a gear source.  If they can't recommend one I'll go some place else. 

This is a great forum for FE's.  I tend to think buying decisions are influenced here.  I'd like to steer manufacturers toward sensible solutions.  I wouldn't settle for a sacrificial gear. I'll sell my truck or swap in an ecoboost before I did that.  Maybe get a flat tappet cam, but ida know...I really like my roller.

[cjshaker]

OK Thanks everybody for your opinions on this and after talking with Ross I have decided to just go with the Dual Sync from the start. Hopefully it goes as easy as it sounds.

Okay, now that all that is settled.....about that avatar....

[shady]

Sure beats a car pic. At first glance I thought it was my wife, but when I finally looked up, the hair was the wrong color.

[Falcon67]

Google's AI image search apparently has a sense of humor. 

[pbf777]

When Ford went to roller cams in 1985, they also went to steel distributor gears on the 302.

     This is true, except for a short period in the early production when Ford actually utilized bronze gears!  I always wondered who was responsible for the durability testing on this engineering?  Well anyway, that didn't last long (pun intended) and Ford had to scramble to develop the steel driven gear.     

     Scott.

One cam manufacturer (CMC) went so far as to design a two piece cam that had a separate cast gear section on a steel roller core to insure compatibility with existing cast gear ignitions.

     We used to see these most commonly on the big-block Chevy's in the race boats; apparently as the boats when leaving the water, exposing the props, the engines would flare up in R.P.M.'s, then re-entering the water would snap the R.P.M.'s back down, this raised havoc with the bronze distributor gears making for very unreliable service.     

     Scott.