I have searched and couldn't come up with a definate answer for my combination.

I have a 2 pc rms 383 with a Comp XFI 280 retro-fit hyd roller cam. I'm getting ready to order a new big-cap TPI distributor from Davis Unified Ignition and it asks which distributor gear is needed. I'm not sure if I need the stock, melonized, or composite gear. I know Comp Cams recommends the composite gear but at over $100 is it really necessary?

In the Comp general tech section, they state:
"Most street roller and hydraulic roller camshafts are made from an austempered material which is compatible with the standard gear; however, COMP Cams® composite distributor gear is the best choice."

I had a big cap TPI dist with stock gear on an older XE retro-fit hyd roller and it was fine. At least, I never noticed any abnormal wear. My distributor grew legs and is now missing and I need to replace it but I'm not sure which gear it had, stock iron or melonized? I'm not sure if Comp's description of a standard gear is the iron or melonized gear.

Since my distributor is missing I can get the DUI ready to drop in for $295 with the coil and all. To replace from Napa I'd still need cap, rotor, coil, and the small harness that plugs into my TPI harness. I also can't find a used one anywhere.

Which gear do I need for my setup? Is the composite gear really worth the $100+ price tag?

Thanks for any advice that can be given.

 

I've run both a ZZ4 cam and an XFI-268 using the stock distributor gear with no problems.

Hope this helps!

 

That's what I was thinking, too. I know the dist gear is the same for all the big cap HEI both for TPI and earlier. I just couldn't remember or find out if the "stock" gear was cast iron or melonized.

I'll just get the stock gear when I order. Thanks for the reply.

 

I see that comp says " "Most street roller and hydraulic roller camshafts are made from an austempered material which is compatible with the standard gear; however, COMP Cams® composite distributor gear is the best choice."Well, the most worries me a lot.

Some roller cams are made of billet steel, not cast iron, this steel is not compatible with your stock distributor gear, if you run them together, it will not only eat up the distributor gear, but the cam gear will be destroyed as well. This is why people use bronze gears, they will not harm the cam gear, but will wear out leaving trace particles of bronze in your engine, so, because of this they built the composite gears, these gears will last way longer than bronze, and put way less shavings in your engine, but they obviously cost more.

Now if the cam IS compatible with the stock gear, use it, there would be absolutely no use for the high dollar gear, the stock gear is made to never wear out, if it is not compatible with stock, then you HAVE to order a cheap bronze gear that will wear out, or a composite gear which will last substantially longer.

 

Years ago when I was running the retro-fit XE hyd roller cam, Comp said they pressed on a cast iron gear on their hyd roller cores and that a stock gear could be used. In the newer catalogs, it has the quote I posted in my first post. I never could find out if Comp quit using the cast gears on their hyd roller cores. I just bought my new XFI 280 a few months ago and never thought about looking at that before installation. Sure they are going to push the hi dollar gear LOL

I know it's better to replace a $100 dist gear than to replace a cam and any damage it can do to an engine (bearings, crank, cam, etc...) but then again, I'm not made out of cash. If the stock gear will work then I'd like to be able to use it.