Melonized Distributor Gear Source

-
RustyRatRod said:
This explains how to tell if a gear is melonized.

[/URL][/URL]
Click to expand...
That's an interesting read, but not super helpful.

Kern Dog said:
Cast steel?
I have only heard that mentioned once before.
What components are made this way? I’m primarily familiar with cast iron and forged steel.
Click to expand...
That's what I read when I searched this site. Ken from Oregon cams even said this in an email a while back: "The factory OE roller cam cores are made out of cast steel, fairly durable but not the best. We can regrind your cam core but you have to be careful of the spring pressure, not much over stock. It is better to make a new cam out of billet steel if you are going to use a lot of spring pressure."

DMC_78 said:
This is what the cam looks like. I can’t tell what it is made from. He definitely said the HUG6215 was not needed though.

View attachment 1716356473
Click to expand...
That looks like a billet to my untrained eye.

Bobzilla said:
Remember, when you call and ask for technical advice they, any technical help line personal at any company, will give you an answer whether they know the correct answer or not.
Click to expand...
It's like that with online forums too.
 
For those who don't know what the Melonite/ Salt Bath Nitriding process is I'll provide some details. Melonite is actually a registered trade name metal finishing surface enhancement process, or Salt Bath Nitriding. Which is the same process as and its synonymous trade-name, Tuftriding, as in what have been done to crankshafts for 60 plus years that involves immersing parts in a nitrogen-bearing Melonite specific salt solution. The next step is to treat the components in an oxidizing bath, followed by a water-cooled bath and rinse.

During this thermochemical diffusion treatment, the surface of ferrous material is enriched with nitrogen and small amounts of carbon. Melonite processing changes the microstructure of the material surface providing greatly improved wear resistance, excellent corrosion resistance, improved surface fatigue resistance, and frictional properties and creates a black finish that helps reduce drag, increase lubricity, and improve strength and corrosion resistance for long-term durability.

For what it's worth to know it's a very low cost process when done in quantity, but the aftermarket sellers make it out to be black magic and charge accordingly.

Tom
 
Last edited:
The article in post #20 is interesting & informative....but I would not the mothod mentioned to determine melonized or non-melonized.
Mancini had the mel gears & Lunati sold them as 'Everwear gears'. The cam in post #24 has some pretty seriously shaped lobes & I doubt the core would be cast.
 
Hughes likes to stick it to you when you buy one. A couple years ago they were 190.00, now they are 265.00 or more. I'm glad I'm about done buying hot rod parts. I have enough **** for what I have and that's it :lol:
 
I'm wondering if you can send your stock gear in and have it nitrided? It's done with gun parts all the time.
 
GGress said:
I'm wondering if you can send your stock gear in and have it nitrided? It's done with gun parts all the time.
Click to expand...
Absolutely. The company doing it know what the gears need if you can provide material specs, but the cost for a one off job is very high. If you’re going to do it, do a bunch so you can resell and recoup cost. Otherwise buying from Howard’s is probably cheaper.
 
The 'gear' in a Pontiac engine is on the dist shaft. I had mine nitrided to use with a billet steel roller cam about 7 years ago. Still looks great, no wear. And the gear was off a Chinese HEI.
 
GGress said:
I'm wondering if you can send your stock gear in and have it nitrided? It's done with gun parts all the time.
Click to expand...

Very much depends on the alloy. Different materials can react differently. The process occurs at 1075-1100 degrees for about an hour. Cast iron or ADI will probably take it well, but some tempered steels or case hardening alloys can turn butter soft in the core at those temps.
I've always assumed the cost of a melonized gear was mostly in the cost of the steel gear, assuming it was steel.
Houston plating and MMI trutec have always given me good results. A one off can be mixed with other parts to keep the cost down, but no guarantee it doesn't get lost in the tank. If I was going to try it I'd get a handful done and then cut a few in half and core test the hardness. If it's above around 40ish on the RHC scale it would probably be OK. Surface hardness takes a different test and can be done to confirm the nitride did it's job. Minimum lot charge is usually at least $150, but that was before the crazies took hold, might be different now.
 
You must log in or register to reply here.
-

Back
Top