Melonized or Composite Distributor Gear

[Tom Katzenberger]

Guys,

I have an oil pump on my 455 which puts out a little over 10% more volume. The question I have is: should I use a melonized Dist. gear or composite dist. gear and does anyone know where I can source a very good melonized gear? Also, I am using a Comp Billet cam part #4241311.

Thanks in advance,
Tom K.

 

[Wally]

Melonized gear...https://dickmillerracing.com/product/dmr-29423/

 

[Tom Katzenberger]

Wally,
Thank you very much. I did just order 2 gears from Josh at CamGear.com. i really appreciate you reachi g back and now we have two sources as a community.

Take care , stay healthy and hopefully we'll see you in Oklahoma.

Tom K.

 

[tmsnyder]

Guys,

I have an oil pump on my 455 which puts out a little over 10% more volume. The question I have is: should I use a melonized Dist. gear or composite dist. gear and does anyone know where I can source a very good melonized gear? Also, I am using a Comp Billet cam part #4241311.

Thanks in advance,
Tom K.

Just for documentation purposes, Tom, you said that BOP Engineering told you their composite gear was not recommended for high volume oil pumps?

 

[Tom Katzenberger]

Todd,

I see where BOP Engineering now says their gear is good for High Volume and high pressure oil pumps.

Below was the guidance I was following. There are several threads on line of BOP composite failures when they were used with High volume or high pressure oil pumps. Maybe the composite material has changed for the better.

Below is AI's response that I included in my decision to use the melonized gear:

Using a composite distributor gear with a high-volume oil pump is strongly discouraged. The increased rotational load and torque required to spin a high-volume pump can cause a composite polymer gear to quickly strip, shear, or melt. [1, 2]

Key Risks and Compatibility

• Extreme Load: High-volume and high-pressure oil pumps dramatically increase the resistance on the distributor drive gear. Composite gears (made of carbon-polymer or nylon) are sacrificial and designed to yield to prevent camshaft damage, but this makes them too weak to handle heavy pump loads. [1, 2, 3]
• Oil Viscosity: Combining a high-volume pump with thick racing oil (e.g., 20W-50) multiplies the shear load. [1, 2]
• Intended Purpose: Composite gears were originally designed for NASCAR applications where the distributor spins the ignition but does not drive the oil pump. [1]

Solutions for High-Volume Pumps
If you require a high-volume oil pump, upgrading your distributor gear to a hardened, wear-resistant material to withstand the high torque is necessary. [1]

• Melonized/Parkerized Steel Gears: The industry standard for standard and high-volume applications using cast-iron or steel billet camshafts.
• Hardened Steel Gears: Often used for street and strip applications where a melonized gear isn't compatible with certain aftermarket billet camshafts. [1, 2, 3]

That said, we do live in a low RPM environment. Many do use Rotella 15-50 oil. My oil pump volume is only 10% over OEM. I think we are in the gray area and I could go either way. I do like the idea of losing the composite gear in lieu of loosing the whole cam. I think I may later switch the gear and keep a spare on hand. I will keep my eyes and ears open to see how we are doing with these new cams and composite gears as time passes.

Take care,
Tom