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

[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....