Distributor Gear For My Comp Roller Cam

[petew]

Looks like the gear that came with my Pertronix D133700 distributor will not work on my Comp roller cam .
The distributor shaft is .500
What are you guys running for this combo ?

[chilly460]

The installation PDF states they run a steel gear.  Generally, that should be compatible with a roller core, are you running a billet core that won't work with a steel gear?

[blykins]

If it's a roller cam, as Chilly says, it needs to be a steel gear.   No bronze, no cast iron.

[petew]

The installation instructions for the Pertronix D133700 read " Flame Thrower Billet distributors come with hardened steel distributor gears which SHOULD NOT be used in applications with a billet camshaft . Consult camshaft manufacturer for distributor gear compatibility "
Comp says that they want a melonized gear on it.
I haven't been able to locate a Ford .500 id melonized distributor gear . The Comp 410M it a .500 id melonized gear but Comp says it won't work , they did wish me luck thought ....

Pertronix says the gear is hardened to 45c Rockwell .

[blykins]

I sell hundreds of cams a year, most are ground by Comp, and all FE roller cams are billet steel. 

I always recommend steel gears and I always use steel gears on the engines I build here.

I’d run a steel gear.

[petew]

Well Brent based on your experience that is good enough for me .

[petew]

It is interesting though , I tried to press the Comp tech guy on the steel gear that the distributor came with and get a yes or no answer about using it .
All he would say is that they want a melonized gear to be used .
Felt like I was talking to a damned lawyer not a tech guy for a camshaft company.
Anyway I sure appreciate the response and will run the steel gear that came with the distributor.

[RustyCrankshaft]

I am running several Pertronix distributors on hyd rollers Brent and Powell have ground for me (in FE's and 2 brand X bigblocks) and not had any issues with them. My picked is driven several days a week and gets a lot of miles put on it with the stock Pertronix steel gear. I've had it out to inspect and based on that I'd say that gear would run 150k miles no issue at all or more.

[My427stang]

I have a few of those out there on long haulers, no issues. The cheaper one that looks like a stocker has an iron gear.

[chilly460]

I have a few of those out there on long haulers, no issues. The cheaper one that looks like a stocker has an iron gear.

I just bought the "as cast" Pertronix for my 352 and it came with a steel gear.  Mine is not the RTR, not sure if other models come with iron gears.  I was going to run an OEM with a Pertronix and steel gear, but by the time I bought those pieces it was only a few bucks more to go with the new Pertronix distributor. 

[My427stang]

I have not used one of the stock look in a few years, but at the time they were all cast but listed as hardened. If they changed it and they have a steel option that’s awesome, but be sure it is what you think it is.

[chilly460]

I have not used one of the stock look in a few years, but at the time they were all cast but listed as hardened. If they changed it and they have a steel option that’s awesome, but be sure it is what you think it is.

I was surprised when I saw that they spec'd it with a steel gear, and checked several places because I figured it could be a misprint.  I'll get a pic of the gear, it's fully machined so I believe it's steel but I can't confirm.  I will call Pertronix today and see if whoever I speak to has a clue, vs just reading off the same specs I can see in the catalog. 

[petew]

The tech guy at Pertronix that I spoke to was good and knew the product . He actually admitted the I was not the first to call with this question and was frustrated that Pertronix had not addressed the issue.
In reality it seems that their instructions may be the issue .  Appears that they may just be covering their ass and putting the final gear decision in the cam manufacturers lap .

[Joe-JDC]

If you take a fine file and drag it across the barrel of the distributor gear, a sintered iron/iron gear will mark.  A hardened steel gear will not leave witness marks.  That has been used for determining compatibility since the first HO roller camshafts came and folks started installing carbs and manifolds with different distributors.  Try it and you can tell the differences.  Joe-JDC