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Distributor Gear Confusion

Discussion in 'Shop Talk' started by TexasDoc, Dec 19, 2011.

  1. TexasDoc

    TexasDoc Member

    Just replaced a flat tapped cam with a roller assembly (long story, see other thread).

    Now I have a Comp Cams XR276 roller. My distributor is a Proform HEI unit. Summit's website here says the gear IS compatible with roller cams. Proform's website here says the gear IS NOT compatible with roller cams.

    In Comp Cam's forum I asked the question: which gear for this cam? I was told I needed an Mealonized Iron gear.
    Comp Cam's video here says that for a iron cam I need a Hardened Steel gear (or a composite $$$).

    I called Summit since I bought all this from them and asked what they recommend. They said I need a Bronze gear.

    I then sent an email to Comp Cam's with the above conflicting information and was told:

    So now I am completely lost. My distributor has a steel gear, but I don't know if it is hardened steel. Proform won't answer emails. One website says I can use it with roller cams, another website says no. Summit says I need a bronze gear (I'm going to ignore this recommendation). Comp Cams tech support says I need an Iron gear. Comp Cams video says I need a hardened steel gear. Comp Cams also says that some iron gears are called steel gears as long as they are not hardened steel (in contradiction to their video) and as long as I can test it on a Rockwell tester, it will work. I don't have a Rockwell tester...... :?
  2. TexasDoc

    TexasDoc Member

    I called comp cams today. The tech guy I talked to said it didn't matter whether the gear was iron or steel, as long as it was mealonized coated. :?
  3. Reptyl

    Reptyl Member

    I've used various materials on the dist gear and the cam is the deciding factor. Here's what I know about the gear material:

    Composite gear - Works on any cam, but expensive. When building my 460W the engine builder said they don't hold up well on wet sump systems due to the load of the oil pump so we went with a steel gear. My friend's 408W stripped the teeth off of one side on a cold start up one morning at one of our Cobra runs!

    Bronze gear - Works on most roller cams and holds up okay in limited use applications. They will wear faster if using a high volume oil pump. I have used these in the past and always pull the dist every 6 months to check and normally replaced them once per year.

    Cast iron gear - I've only used them on flat tappet cams and they hold up okay with regular oil pumps. If using a high volume pump in a 351W they will wear. When they do break it makes a really nasty sound and you'll need a new motor!

    Steel gear - I'm using the Ford Racing steel gears in two roller motors with Comp Cams and so far, so good. One is a hydraulic roller and one a solid and both are steel cams.

    I'm not too familiar with the Melonizing process other than its a hardening process. I would ask Comp what material the cam is made of and choose a gear based on that info. I would also trust the mfg information over what Summit says.

  4. TexasDoc

    TexasDoc Member

    Proform tech said that as long as I didn't have a billet steel cam, the gear on it will work. I'm going to try it and keep a close eye on it.
  5. 351 stroker to 427, comp cam roller & at 1500 miles pulled motor cause cam ate Dist gear, supposedly because comp changed metals? Steel to steel now and suppose to be good ?
    Wendell / Lynn

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