Guys , I just built a 383 and I’m using a accel hei distributor, I’m running a Gm 383 crate camshaft and understand that I should be using a melonized distributor gear. When I read the description for identification of a melonized gear it doesn’t appear that I have one . I have like a machine finish. I have several late model HEIs and none have that melonized finish. Should I buy a different distributor gear for my 383. Thanks

 

Which Accel HEI distributor are you running? I need the part number. I also need to know if it has a 0.491 or 0.500 distributor shaft diameter. I can probably figure this out from the part number. Some aftermarket large cap internal coil HEI distributors used the standard GM shaft diameter of 0.491 and some used the bigger shaft diameter of 0.500.

Unlike what the Internet says, not all melonized distributor gears have a dapple textured finish. Some are smooth.

Which GM 383 cam do you have? Part number.

 

Large cap hei .500
https://www.jegs.com/i/COMP-Cams/249/410M/10002/-1

 

.490

 

I'd trust that Summit SUM-850468 distributor gear at $19.99 about as far as I could throw his 383 stroker engine. Made in a 3rd World sh*thole country by people that think melonizing is boiling the gear in a pan on a stove in used bath water with some rock salt thrown in. That gear is also for a 0.430 distributor shaft diameter.

Summit Racing claims these two 0.491 & 0.500 melonized distributor gears are Made in the U.S.A.

This would be the correct Summit Racing house brand gear for a 0.491 distributor shaft diameter. Summit Racing SUM-850466-M Summit Racing™ Distributor Gears | Summit Racing

This would be the correct Summit Racing house brand gear for a 0.500 distributor shaft diameter. Summit Racing SUM-850467-M Summit Racing™ Distributor Gears | Summit Racing


Summit Racing claims these two Comp Cams 0.491 & 0.500 melonized distributor gears are Made in the U.S.A.

This would be the correct Comp Cams gear for a 0.491 distributor shaft diameter. COMP Cams 412M COMP Cams Melonized Distributor Gears | Summit Racing

This would be the correct Comp Cams gear for a 0.500 distributor shaft diameter. COMP Cams 410M COMP Cams Melonized Distributor Gears | Summit Racing

I'd trust that Comp Cam gear about as far as I could throw his 383 stroker engine too. Probably made in the same places by the same people as the Summit Racing cheap distributor gear but marked up for a crazy profit margin by the Wall Street bankster gangster private equity fund that runs the Comp Group. The same people that brought you defective flat tappet lifters made in a 3rd World sh*thole country built from recycled pot metal and machined by hand with rocks and sold to you for good money that failed and destroyed many people's engines.

The Comp Group and the Holley Group both should have been sued into bankruptcy from massive class action lawsuits. Holley mainly for their POS Holley Sniper EFI throttle body injection systems and the many other POS parts they sell under the brands of formally great companies they have bought and ran into the ground.

What does "Made in the U.S.A." mean anyways?

#1 What you think it means.
#2 Assembled in the U.S.A. for components made elsewhere and put into a box that was Made in the U.S.A., and did that in the U.S.A., with a sticker stuck on the box that was Made in the U.S.A.
#3 They took the foreign made part and put it into a box that was Made in the U.S.A., and did that in the U.S.A., with a sticker stuck on the box that was Made in the U.S.A.

 

Apparently there's some ridiculous law that states that if a certain amount of the product like the application of stickers as you mentioned, and the packaging is made in said country then they can legally mark the entire thing as being made in that country. I learned this with the fancy and expensive carbon fiber Italian bicycles. They're all for the most part out of Taiwan. They get painted and packaged in Italy. That gives them enough to legally stick a made in Italy label on the bike. Fortunately Taiwan has a very good carbon layup. But regardless it's disingenuous. Years ago someone told me that all the Snap-On tools marked Snap-On USA were made off shore. The American stuff was marked Snap-On U.S.A. All of it was sold as made in the USA. Not sure if that's accurate but I wouldn't have a hard time believing it.

 

That was a quick search
look at gm 10456413 .500 or 19052845 .490 I think that’s the p/n

 

If it's a steel cam then a nitrided steel gear is required. "Melonizing" is term thrown about and it's not apples to apples. This is what @Airwolfe was referring to with the "salt water bath".
I contacted several manufacturers on this very subject and when they were queried on whether their "melonized" gear could be used on a steel cam, the answer was no. If you go through some of the distributor gear Q and A at Summit, my question will be in there asking about this.
There's a coating process and then there's a heat treated process. And a steel cam needs a steel gear. Some prefer composite as I've heard about good results with that as well.
For the record, the gear for my billet cam was $90 USD. I purchased it directly from the cam grinder. (Jones Cams)

Below is what came on the Pertronix distributor I purchased.

https://www.summitracing.com/parts/pnx-d671002

 

Your Accel HEI distributor may or may not have a melonized distributor gear. Of the 5 Accel large cap HEI distributors they have for sale from $125.75 to $171.95 nowhere do they mention "Melonized", "Melonite", or "Melonite/QPQ processed". They just mention "High-Quality Distributor Gears". If it doesn't have one of those Melonized gears and it eats the distributor gear all that metal runs through the engine's oiling system and everything the oil touches in the engine.

Seeing the price of those Made in China Accel HEI distributors one has to wonder just how much of a "High-Quality Distributor Gear" can you get when for twice the money or less you can get the entire Accel HEI distributor for what a quality "Melonite/CPC" processed distributor gear costs.

MELONITE / QPQ



A melonized distributor gear at first will appear like any normal iron gear. But if you look closely, the melonized gear (left) offers a mottled appearance on the collar while a standard iron gear is smooth (right). (Image/Jeff Smith)

I believe MSD Pro Billet HEI distributors use the 0.500 distributor shaft and the Accel HEI distributors use the 0.491 distributor shaft.

I would trust a Genuine GM melonized steel distributor gear to run against a Genuine GM cam gear on a Genuine GM 5150 alloy billet steel roller camshaft.

For $77.79 from Rock Auto plus tax and shipping the GM part is worth a lot of "peace of mind" over a Hung, Flug, Dung Made in China gear on the Made in China Accel distributor. Don't forget to use one of the Rock Auto promo codes posted on the Rock Auto Promo Code thread here on the forum for a discount.
GENUINE GM Original Equipment 456652 - Roll Pin, Distributor Gear
GENUINE GM Original Equipment 19432310 - Hardened Distributor Gear For .491" Shaft - (Old Style HEI , Coil In Cap) For Use With Roller Cams


GM GENUINE 19432310

Description

This melonized steel gear is required on all GM Performance Parts crate engines with a 5150 alloy billet steel roller camshaft.
If engine is assembled not using this melonized steel gear it may affect your GM Performance Parts crate engine warranty.
0.491 inch shaft size for use on old style HEI distributors with coil in cap.

I don't see any reason why someone couldn't run this gear on an older points and condenser Chevy distributor with a 0.491 shaft if for some ignorant reason someone wanted to do so.

 

I have both in my bin of extra parts. Both from GM. The melonized gear does have a "mottled appearance on the collar".

Fred

 

The GM "Melonized" distributor gears come in a smooth appearance on the collar and a "mottled appearance on the collar" version. Both versions are "Melonized" but the earlier version got the "QPQ" treatment on the entire gear and collar and the later version only got the "QPQ" treatment on the gear portion.


GM Genuine Parts 10456413 Distributor Gear.


GM Genuine Parts 19432310 Distributor Gear. (1)

GM Genuine Parts 19432310 Distributor Gear. (2)


.
The gear on the top 10456413 was used in 1987 to 1991 C4 Corvettes with the computer controlled large cap HEI distributor with a 0.491 diameter shaft.

The gear below it 19432310 replaced that gear 10456413 at some point in time when it was discontinued. Maybe GM switched suppliers for the gears, or their supplier changed the manufacturing process for the gears. You will notice they aren't exactly the same gear. The smooth finished gear has the groove machined into the collar and the other one doesn't. I assume the new supplier saw no need to do the "QPQ" treatment on the collar and only did it to the part that matters. The actual gear teeth.