[wakesupremo]

I have read quite a lot regarding distributor drive gears and roller cams. Is it a necessity to change to a poly gear or the 'new ' melonized gear with a roller cam? I have an MSD pro billet. What do I need?

[Formulajones]

Yes, unless the cam company offers a cast gear on your roller cam.
Some offer that option. Best to ask them what the core is so you can choose the right distributor gear. They'll make recommendations as well.

[wakesupremo]

Thanks. I have looked through my box of receipts and found the cam card supplied with the cam. Theres no mention of dizzie gear, the cam is a Comp 51-000-13. I have contacted Comp but no reply as yet.

[Tim Corcoran]

You will need either a brass, melanized or composite gear. I always use the BOP composite gear for my roller cams.

[Steve C.]

Part number 51-000-13

The number 13 is the core code number.

It's not listed here on page 2

https://issuu.com/cpg-development/do...ster_catalog/8


.

[indymanjoe]

Is this the part? wow!

https://butlerperformance.com/i-3164...ributor%2Bgear

or

https://butlerperformance.com/i-2445...ributor%2Bgear

[rolling money pits]

First one is polymer, for the Olds 403

Second is basic bronze, for Pontiacs.

Both for factory size distributor shafts.

[Steve C.]

Composite Distributor Gear for Pontiacs

PDG37 Pontiac Composite Distributor Gear (.491).................... $139.99
PDG38 Pontiac Composite Distributor Gear (.500).................... $139.99
PDG39 Pontiac Composite Distributor Gear 455SD/RAV (.491) $199.99

https://www.bopengineering.com/A_Pon...lvetrain.shtml



.

[grivera]

Originally Posted by wakesupremo

Thanks. I have looked through my box of receipts and found the cam card supplied with the cam. Theres no mention of dizzie gear, the cam is a Comp 51-000-13. I have contacted Comp but no reply as yet.

I’m not aware of any comp cams Pontiac HRs that have the cast iron gear them. Seems they are all steel.

[Tim Corcoran]

This is the one you need

BOP Pontiac Polymer Dist. Gear, .500 For MSD BOP-PDG38

Its also listed on the Butler website

[Cliff R]

I've used both bronze and BOP gears and only had issues early on before I figured out that Comp Cams sometimes uses a "chain saw" to machine the distributor drive gear teeth on their steel roller camshafts. Yes, missed one that has rough as a corn cobb and it chewed up my BOP gear in less time that it took to type this!

Since that little learning experience I started using a fine jewelers file and removing all the sharp edges from the drive teeth then bead blasting them wth ultra-fine glass beads. Never had any issues since.....

[wakesupremo]

Thanks for all the replys.

[RocktimusPryme]

Can a Melonized gear be used on an aftermarket roller cam ( I assume ground on a billet core)

Ive always been a bit hazy on that, I know they were made to work with OEM roller cams, but I was never sure if they would work with an aftermarket roller.

This is of particular interest to me because my bronze gear is looking a bit thin, and these just became available for .500 distributors

https://pontiacspeedshop.com/howards...sktMECOoLgNSXk

I have another bronze gear I can throw on, but Im curious if this would be worth the purchase.

I asked about it and was told "Morel gave their blessing for use on Howards 1055 Roller Cams.." Which is good, but maybe those cams have a different gear on the cam than a Comp, so I would like to know how the group at large feels.

Side note: My single complaint about my Hyperspark is that the .500 shaft seemed a bit thicker than that. Two separate MSD bronze gears did not want to go on.

[gtospieg]

You should ask Comp Cams(maybe your cam doesn't require a special gear)...but I think the melonized gears can be used on anything.

[Formulajones]

The eom crate engines like the gm 502 for example (I have one) use steel roller cam cores with melonized distributor gears. So I tend to think a billet core would be acceptable. I typically use melonized gear on all the roller cam cores but I always ask the manufacture at time of purchase to be sure.

[RocktimusPryme]

I can give comp a call. I didn’t buy my cam, and the guy that did is unfortunately passed. So I never had the chance to ask but I’ll see what they say and report back.

[GoatZillaRacing]

Comp Cams recommends these too. They actually say not to use a composite gear with a high pressure pump. I've never had a composite gear fail but I must admit, these feel safer to install and they are more affordable too.

https://pontiacspeedshop.com/howards...ributor-gears/

[wakesupremo]

I asked comp tech department and they sent me a very informative video of the different cams and core material. It does in fact, state that they recommend a polymer gear for all of their cams but, definitely on any roller cam.

[Dragncar]

Originally Posted by GoatZillaRacing

Comp Cams recommends these too. They actually say not to use a composite gear with a high pressure pump. I've never had a composite gear fail but I must admit, these feel safer to install and they are more affordable too.

https://pontiacspeedshop.com/howards...ributor-gears/

Can we get those in .491 ?

[chuckies76ta]

Couple of links with info.
https://help.summitracing.com/knowle...SR-04904/en-us
https://www.northeastcoating.com/salt-bath/engineering