I was just curious when it is necessary/recommended to run a bronze distributor gear? Also what are the benefits?
Thanks smile.gif

I just read an article in CHP March 2000 last night. Must look it up, if you want me to.

Roughly the bronze dist. gear is used on the more hardened type of camshafts and is the one that is meant to be sacrafised (wear out) if one will.

The old normal stock type camshafts go with the iron distributor gear. Modern roller types go with bronze.
Third party : depends on material type.

Rob

The latest thing is a "Poly" gear ($100 :eek: ) will work with any cam and not put shavings/powder in your oil.

All-billet cam cores (typically solid rollers) require bronze or the new polymer gears.

OEM hydraulic roller cams most often require melonized iron distributor gears.

Iron cam cores (most hydraulic and solid flat tappets) can use an iron distributor gear.

The waters can be muddied a bit as some manufacturers offer their rollers with pressed on iron gears, in which case you can run an iron distributor gear.

The reason for the different gear requirements are based on the composition and hardness of the cam core and gear on the cam. For example, an iron distributor gear on a billet roller cam will eat the gear up in no time flat, while an iron distributor gear may go 150K+ miles on a hydraulic flat tappet (iron core) cam.

Iron gears are long wearing and will not "pollute" the oil with debris. A bronze gear is a maintenance item and will wear out, an unfortunate side effect is bronze particles circulating in your oil. However, bronze is rather soft and it is very unlikely to damage anything. The new polymer gears are supposed to do away with that problem, but they're fairly new and they don't have a real track record yet.

Keep in mind that even if you use the right gear, you will still eat things up if the distributor isn't installed at the correct height. Aftermarket intakes, decked blocks, etc, can all contribute to this problem. I ate a distributor gear last year because I changed intakes and neglected to check the height of the distributor. It was too high, and the distributor and cam gear were destroyed after only 2500 miles, and the debris generated took all my bearings with it.

Troy

thanks for the explanations guys. graemlins/thumbsup.gif

Gokou - I feel for you. I had a 331 that ate up a couple cam shafts a while back. Luckyily 2 years later I was able to get it rebuilt and will be throwing it back into my car hopefully tomorrow. graemlins/hurray.gif

Thanks