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Username Post: Comp Cams Composite distributor gear 12140 missing roll pin hole one side        (Topic#375181)
toro455 
"9th Year" Gold Supporting Member
Posts: 1310
toro455
Loc: Western NY
Reg: 06-15-02
06-10-24 06:22 PM - Post#2870758    

Unfortunately I bought it almost a year ago. I bought Comp Cams PN 12140 Composite distributor gear for BBC and SBC. The project got behind and I just took a close look at it tonight. I slid it over the distributor shaft and couldn't understand why I couldn't rotate it to a position where I could see the light through the shaft...

It turns out they only drilled it on one side as opposed to drilling through for the roll pin. Does anyone know if this was a Quality Control issue or intentional?

I searched online and nobody seems to know for certain. I bought it a year ago so no chance to return it. If I read it correctly one owner drilled his and somehow elongated either the shaft or the hole...not good.

Thanks,
Scott



 


ss3964spd 
"6th Year" Gold Supporting Member
Posts: 4672
ss3964spd
Loc: Fairfax, Va
Reg: 12-21-00
06-11-24 07:11 AM - Post#2870768    
    In response to toro455

Intentional or not, if the hole doesn't go all the way through, once the gear is installed there'd be no way to remove the roll pin if needed.

Dan

If I recall correctly my memory is excellent. My ability to access it is not.


 
toro455 
"9th Year" Gold Supporting Member
Posts: 1310
toro455
Loc: Western NY
Reg: 06-15-02
06-11-24 10:47 AM - Post#2870774    
    In response to ss3964spd

Dan,
Exactly, as you wrote, it's needed if you ever want to remove the roll pin. I was wondering if the one I received was a mistake or that's the way they make them; with the intent of having the customer drill them. I posted a question on Amazon and someone else mentioned they had to drill theirs as well.

Thanks,
Scott



 
ss3964spd 
"6th Year" Gold Supporting Member
Posts: 4672
ss3964spd
Loc: Fairfax, Va
Reg: 12-21-00
06-11-24 01:14 PM - Post#2870777    
    In response to toro455

Does the hole not go into the other side of the gear at all, Scott, or maybe it just doesn't go all the way through?

I don't recall if the interference fit of the roll pin is in the gear hole itself, in the distributor shaft hole, or both. I believe both.

Dan

If I recall correctly my memory is excellent. My ability to access it is not.


 
toro455 
"9th Year" Gold Supporting Member
Posts: 1310
toro455
Loc: Western NY
Reg: 06-15-02
06-13-24 06:51 PM - Post#2870842    
    In response to ss3964spd

It doesn't go through at all.

I thought about it and maybe they felt the mold core would need to be tapered to pull it or optionally they would need to pull separate pins from opposite directions and neither option was great. A taper would cause slop and there would be a better side to insert the roll pin from (slightly larger side). Two separate cores and there might be a mismatch; although they could have bored a pilot for both sides while building the mold... anyway it needs to be drilled. I'll do it slowly, create a small pilot with the size which can guide on the shaft, and then remove it and step the size up to just barely under the final diameter (if I have a drill just under). Doing it like that I guess the roll pin will be tight on both sides.

Scott





 
IgnitionMan 
Valued Contributor
Posts: 4081

Reg: 04-15-05
06-17-24 12:47 PM - Post#2870951    
    In response to toro455

Some of the holes in some distributor shafts are NOT cut on the center of the shaft, so, some, not all gear makers drill both sides of the gear for the pin.

Procedures, find if the shaft is a .491, or .500 diameter, and fit the gear to the shaft.

Align the gear hole with the shaft hole, drill the second gear hole, deburr, press pin in place.

GM shafts are usually dead center, aftermarket shafts can be off to one side quite a bit.

Why in the world are you using a junk pile composite plastic gear n the first place?



 
toro455 
"9th Year" Gold Supporting Member
Posts: 1310
toro455
Loc: Western NY
Reg: 06-15-02
06-17-24 02:06 PM - Post#2870955    
    In response to IgnitionMan

Thanks IgnitionMan,
It's a 0.500" shaft and a Hyperspark distributor. The method you described is how I planned to do it if I indeed use it; I may not (on the fence).

The reason I was thinking about using it is roller cam shaft gear compatibility. From what I found there are 2 only two materials which should be considered. The first is melonized and the second composite.

I also have a Howards' Cam distributor gear I can use. It was advertised, I think by Summit Racing, as melonized . It didn't say what the material was on the package and so I called the Howards Tech line. The person did say that PN gear I have is the gear they use on all of their roller camshafts but he also said it goes through a coating process but it's not melonized.. So I don't know exactly what it is.

I'm really just trying to do everything as correct as possible but I rarely change distributor gears. Based on what I've read one weak point of the Chevy engine design is the distributor housing sits on the intake and that has more variation than if it sat on the block (like an Oldsmobile as an example). I understand it's import to shim it for the proper end play (timing consistency and durability). I was going to try to do that by installing and checking shaft movement. I was also planning to check the gear pattern with some gear marking grease.

Any suggestions regarding the details are appreciated. My thought was that people who had issues with the composite gear may not have shimmed them properly. Not that anyone ever wants debris in an engine but changing a distributor gear is a lot less involved than changing a cam and thus the one main reason for proper material selection.

Thanks,
Scott



 
IgnitionMan 
Valued Contributor
Posts: 4081

Reg: 04-15-05
06-28-24 10:41 AM - Post#2871314    
    In response to toro455

"Melonized" is simply a coating for a stock gear that will be used on a stock hard chromed Chevrolet ROLLER CAM. As I stated, it is a COATING, nothing more.

Is the cam a steel cam that is HARD CHROMED? If not, then, rollers and some special steel flat tappet cams would use a SACRIFICIAL gear, BRONZE, and will usually live 5K miles, before it needs to be replaced. Bronze gears are usually for special performance roller cams used in 1/4 mile race engines ONLY.

The reason the stock type Chevrolet cams are hard chrom4ed, is they need the extra coating to help allow the rollers on the lifters live long and not destroy themselves.



 
toro455 
"9th Year" Gold Supporting Member
Posts: 1310
toro455
Loc: Western NY
Reg: 06-15-02
06-29-24 08:03 AM - Post#2871335    
    In response to IgnitionMan

The cam is a Comp-cams part. I asked them a lot of questions but it's been years now as the project got behind. I have the notes, on the cam, somewhere.

I also did a research on the compatible gears. If I can attach a word document or pdf I can attach it.

I remember reading, as you mentioned, bronze basically has no business in a street engine.

I found this on the Comp Cams site:
"Most street roller and hydraulic roller camshafts are made from an austempered material which is compatible with the standard gear; however, COMP Cams® composite distributor gear is the best choice."



 
65_Impala 
Very Senior Member
Posts: 5025

Reg: 12-29-02
07-02-24 07:24 AM - Post#2871399    
    In response to IgnitionMan

A Melonized gear is not coated. It's a hardening treatment.




 
IgnitionMan 
Valued Contributor
Posts: 4081

Reg: 04-15-05
07-04-24 03:51 PM - Post#2871462    
    In response to 65_Impala

Here we go again, I WORK IN THE DISTRIBUTOR FIELD, HAVE FOR 50 PLUS YEARS.

One of the options I have for gears is to send them to a company in Los Angeles, and HAVE THEM "MELONIZED" COATED.

Gee, that would make them....wait for it, the truth is coming, COATED, not a metal gear, but.....YET AGAIN, COATED.

"Melonized" coatings are to help acclamate the gear to a hard chromed camshaft, such as ALL factory stock GM hydraulic roller cams.

If some screwball tried to make a gear solely from Melonized, it would not last trying to put the holder pin into it.

Of course, there are other..... opinions, and those have been shot down along the way, just like other misleading info on just about everything.



 
toro455 
"9th Year" Gold Supporting Member
Posts: 1310
toro455
Loc: Western NY
Reg: 06-15-02
07-05-24 12:02 PM - Post#2871490    
    In response to IgnitionMan

Ignitionman,
I was under the impression that it was basically a nitriding process which is a chemical reaction between the treated base material and what the material is exposed to. I don't know if melonizing in fact falls under that same category and only the process is different but that's what I thought.

I have read that melonizing leaves a dimpled appearance though and that does sound more like a coating but maybe that's where confusion comes from.

I've heard people refer to the results of nitriding as a coating but I believe that's technically incorrect.

I found a good explanation of why a nitriding treatment may make sense on a distributor gear here:
https://fractory.com/nitriding-explained/
"Nitrided parts have high surface hardness coupled with a ductile core. The combination of these properties provides a wear-resistant surface with a flexible core that can handle impact loads much better than a hard material."

Here's a pretty thorough description of the melonizing process. I can also see the name is a registered trade mark"
https://www.northeastcoating.com/salt-bath/enginee...

"During Melonizing® a nitrocarburized layer is formed consisting of the outer compound layer (ε-iron nitride) and the diffusion layer thereunder. The formation, microstructure and properties of the compound layer are determined by the base material. The compound layer consists of compounds of iron, nitrogen, carbon and oxygen. Due to its microstructure, the compound layer does not possess metallic properties. It is particularly resistant to wear, seizure and corrosion, as well as being stable almost to the temperature at which it was formed. Compared with plasma or gas nitro-carburizing, compound layers with the highest nitrogen content can be obtained by Melonizing®. Layers with a high nitrogen content give better protection against wear, and in particular corrosion, than those with a low content."



 
65_Impala 
Very Senior Member
Posts: 5025

Reg: 12-29-02
07-06-24 06:57 AM - Post#2871505    
    In response to IgnitionMan

Melonize isn't a thing. Melonize doesn't exist as a substance. you can't make something out of Melonize. You can't coat a surface with Melonize. "YELLING" in capitol letters and claiming to be an expert doesn't change this fact.

Melonziing is a high temperature hardening process, a form of nitrocarburizing. It's not a coating. It changes the iron gear properties both at the surface and below the surface. In the context of distributor gears it's used to harden the surface of the gear to make it compatible with the camshaft.

A coating over the surface only would be completely useless because once the coating wore off the hardened or billet steel roller crankshaft material would begin rapidly wearing the softer iron gear metal.

https://en.wikipedia.org/wiki/Ferritic_nitroca rbur...



 
IgnitionMan 
Valued Contributor
Posts: 4081

Reg: 04-15-05
07-06-24 01:57 PM - Post#2871521    
    In response to 65_Impala

CORRECT, claiming to be an expert, of which, YOU always do, especially whenever you read ANYTHING I post, is not good.

Now, in the 50 years I have worked on distributors, fixed them while on loan from Chevrolet Skunkworks to Delco-Remy for the large cap HEI's, and doing the conversions I invented, I have had the same person in So. Cal., "Melonized" coat over 200 distributor gears, to work with stock GM hydraulic roller cams, which are hard chromed, from the factory.

The person that does my coating is the one that GM used decades ago to do the "Melonized" coatings for race gears GM used in their face shops, including Skunkworks. He coats them.

But, who is anyone to doubt the infallable, total knowledge of 65_Impala, after all, he has been everywhere, knows everything, no question,

and, hates everything I write, for whom knows why. Frankly, I have been totally fed up with his BS for the time I have been on this board. Very, very, very seldom, he does come up with a some what coherent answer, but not often.

I prefer, and will continue to work from my own real life, hands-on, did it myself experience.

Anyone pulled a "Melonized" gear out of an engine for what ever reason lately? If so, please look at the tooth contact areas on the gear teeth very closely, and let us know what you see.



 
65_Impala 
Very Senior Member
Posts: 5025

Reg: 12-29-02
07-06-24 04:08 PM - Post#2871524    
    In response to IgnitionMan

You can quit insulting me. I posted a link to an 3rd party explanation of the process. You are trying to push the wrong information down everyone else's throats via belittling other forum members, "expert" claims and yelling in capitols.

If you're trying to claim the black wearing off is the melonize being gone then you're simply wrong. It could be something like a black oxide layer wearing off. Or it's simply the surface getting polished by the cam gear. That's certainly not a thin melonize coating wearing off, because melonize isn't a coating. The gear is still case hardened where it's shiny. There is depth to the hardening below the top layer of the metal. The hardening process is explained on Wiki following the link I posted, for anyone who wants to read about it.

A melonized gear has gone through a case hardening process. Melonize is the name of the process. Period.



 
IgnitionMan 
Valued Contributor
Posts: 4081

Reg: 04-15-05
07-07-24 09:24 AM - Post#2871548    
    In response to 65_Impala

"It's probably something like a black oxide layer wearing off."

You don't know??? EVERY "Melonized" coated gear I have ever seen is not black color, but a ruddy brown.

The lines on the contact paths are the "Melonized" coating has done its job, cushioning the tooth mesh for match in, coating worn away.

Keep going, maybe one day, you will actually post factual info, and stop harassing others (Yes, I am NOT the only one he regularly attacks for no apparent reason).





 
65_Impala 
Very Senior Member
Posts: 5025

Reg: 12-29-02
07-07-24 10:55 AM - Post#2871554    
    In response to IgnitionMan

  • IgnitionMan Said:
Keep going, maybe one day, you will actually post factual info, and stop harassing others (Yes, I am NOT the only one he regularly attacks for no apparent reason).






Grow up. You were told you're wrong on the internet, and you are 100% wrong.

Melonizing is a hardening process, which alters the structure of the surface of the original iron gear. Nothing is coated onto the surface of the gear. I posted a link explaining the process. There are 2 other links in this thread also explaining it.

Post a creditable link that backs up your coating claims.




 
IgnitionMan 
Valued Contributor
Posts: 4081

Reg: 04-15-05
07-10-24 08:03 AM - Post#2871631    
    In response to 65_Impala

Keep going, you make one great point, you are wrong.

I have had a bunch over 100 gears "Melonized" COATED for units I have done for all sorts of people, by the person that did/does them for Chevrolet Racing, of which I also worked in the past,

But, YOU know more than all those people, and insist on harassing me, calling me a liar, even when YOU are proved dead wrong, which you have milked for years now.

The OP was interested in a composite gear, plastic, just like the ones on Slant 6 MOPAR engines, that crack and split regularly.

Go find someone else to call a liar for absolutely no reason, your 15 minutes are long used up.



 
65_Impala 
Very Senior Member
Posts: 5025

Reg: 12-29-02
07-10-24 01:41 PM - Post#2871645    
    In response to IgnitionMan

Post proof or STFU already.

I didn't call you a liar. I just posted what the melonizing process really is.

Here is the link again, and a quote this time.

https://en.wikipedia.org/wiki/Ferritic_nitroca rbur...

  • Quote:
Salt bath ferritic nitrocarburizing is also known as liquid ferritic nitrocarburizing or liquid nitrocarburizing[12] and is also known by the trademarked names Tufftride[3] and Tenifer.[13]

The simplest form of this process is encompassed by the trademarked Melonite process, also known as Meli 1. It is most commonly used on steels, sintered irons, and cast irons to lower friction and improve wear and corrosion resistance.[14][15]

The process uses a salt bath of alkali cyanate. This is contained in a steel pot that has an aeration system. The cyanate thermally reacts with the surface of the workpiece to form an alkali carbonate. The bath is then treated to convert the carbonate back to a cyanate. The surface formed from the reaction has a compound layer and a diffusion layer. The compound layer consists of iron, nitrogen, and oxygen is abrasion resistant and is stable at elevated temperatures. The diffusion layer contains nitrides and carbides. The surface hardness ranges from 800 to 1500 HV depending on the steel grade. This also inversely affects the depth of the case; i.e. a high carbon steel will form a hard, but shallow case.[14]





You not knowing or understanding something doesn't make you a liar, it just means you don't know which causes you to post wrong information.



 
IgnitionMan 
Valued Contributor
Posts: 4081

Reg: 04-15-05
07-11-24 09:38 AM - Post#2871668    
    In response to 65_Impala

Well, it has finally come down to the end.

A LONG time ago, I promised myself that I would never engage in any sort of battle of wits and intelligence, with ANY UNARMED PERSON.

The biggest one of those persons, posted all this drivel, and not for any other reason than to continue harassing and attacking me.

Time for me to stop trying to overcome his never ending attacks, and monumental postings of completely incorrect and wrong "gospel".

I have other more worthwhile things to do than do my truth and honesty side of that battle of wits he insists on perpetrating.

Too bad, some others have truly gained from what I have added on these boards, and that was/is my ONLY intention.

That battle of wits NO-ONE here needs, nor wants, so, I will go elsewhere, and help those elsewhere with the truth, and no attacks from that person that has absolutely no wits, no intelligence, no clue, so it does not continue to interfere with the good people that want the right answers, help.

Take care, all.





 
65_Impala 
Very Senior Member
Posts: 5025

Reg: 12-29-02
07-11-24 12:49 PM - Post#2871669    
    In response to IgnitionMan

I've never seen another poster on the internet cry victim so much. It's impressive.

You can't go anywhere else. Every other internet forum has banned you due to your behavior.



 
bobb 
Super Senior Member
Posts: 6683

Loc: paradise
Reg: 09-05-03
07-16-24 07:54 AM - Post#2871821    
    In response to 65_Impala

uh, time will tell.

70 L camino, grampa engine, g-force 5 spd, road rage suspension. Pray first before all else fails.


 
Magnetocheck 
"2nd Year" Silver Supporting Member
Posts: 481
Magnetocheck
Age: 69
Loc: Charlotte, NC, USA
Reg: 09-05-22
07-16-24 11:22 AM - Post#2871831    
    In response to bobb

I left this forum once because I couldn't take all the arguing BS from old farts who forgot to eat their bran in the morning before posting, I came back this month to see if anything had improved. I see it hasn't so I'm out of here for good. Where are the moderators who are supposed to monitor bad behavior?


Bob
'65 Impala SS 396 Convertible
Member, National Impala Association


 
65_Impala 
Very Senior Member
Posts: 5025

Reg: 12-29-02
07-16-24 08:25 PM - Post#2871851    
    In response to bobb

Tell what exactly?

The process is well documented. There is no coating, it's a trademarked hardening process. Don't want to be told you're wrong, then don't post wrong information on the internet.

It's rather important to get this right when a damaged cam could result from wrong information. The OP posted that he was told by Howards that the gear he had was costed and not melonized, but the cam calls for a melonized gear. Then, Mr. Wrong tells him a melonized gear is just coated, which is 100% wrong. I don't want wrong information causing the OP to use the wrong gear. Do you?

I have seen his banned profiles on other forums and years ago had a moderator from one personally message me to tell me he was banned for attacking other members, and not for trying to sell services without paying to be a vendor. I'm not just making that up either.




 
rcr3 
Site Ambassador -"20th Year" Gold Supporting Member
Posts: 3993
rcr3
Age: 72
Loc: MANHEIM PA. U.S.A.
Reg: 11-24-02
07-17-24 05:33 AM - Post#2871860    
    In response to Magnetocheck

  • Magnetocheck Said:
I left this forum once because I couldn't take all the arguing BS from old farts who forgot to eat their bran in the morning before posting, I came back this month to see if anything had improved. I see it hasn't so I'm out of here for good. Where are the moderators who are supposed to monitor bad behavior?




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toro455 
"9th Year" Gold Supporting Member
Posts: 1310
toro455
Loc: Western NY
Reg: 06-15-02
07-17-24 06:29 PM - Post#2871873    
    In response to 65_Impala

  • 65_Impala Said:
...The process is well documented. There is no coating, it's a trademarked hardening process....

It's rather important to get this right when a damaged cam could result from wrong information. The OP posted that he was told by Howards that the gear he had was costed and not melonized, but the cam calls for a melonized gear....




65_Impala,
I believe the Howard's Tech was referring to a surface hardening using an alternative Nitriding process but not technically according to the method associated specifically with the registered trademark. Summit Racing is using the term Melonized like Band-Aid (Adhesive strip?) or Kleenex (facial tissue).

Part of the issue discussing this is that some refer to the process as coating probably because it's easier for many people to comprehend despite being technically incorrect (coating would add thickness but Nitriding or melonizing does not; rather it results in a harder outside surface based on conditions and chemical reaction). As you pointed out I wrote "coating" above but, thinking back, I don't know for a fact that was exactly what the tech said. If he did he may have simply said it to avoid having to explain that the net effect was equivalent and that technically he cannot refer to the process as melonization due to the specific trademarked method. I know enough to know a Nitriding process is not a coating process but I'm also accustom to people occasionally, technically incorrect, referring to it as a coating... ironically I may have slipped myself if that exact wording did not come from the tech (I don't know now).

I'm convinced that the Howards gear is an alternative, but essentially equivalent, process. I have basically made up my mind to not use the composite/polymer gear only because to shim it properly I would need to install it at least twice. In doing so I was concerned installing the roll pin multiple times may impact the fit of the pin to gear. I'm not lucky enough to have the proper end play before measuring and checking the pattern on the gear.

Scott






 


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