MSD Distributer & gear question
 

Getting ready to install a new MSD pro-billet marine distributer into my fresh big block Chevy and I want to confirm I have the right gear for my cam. I called Isky and they said to look at the engraving on the cam but the problem is the engine shop already closed up the engine and its fully dressed and in the boat. The gear on the distributer is some melonized gear I think its cast but I am not sure if this will be ok or do I need a Bronze. Is it true if I run a composite then it doesn't matter the cam material?? I do not need something so minor taking out a new engine.

https://www.holley.com/products/igni...et/parts/85603

I have heard that ARP sell a gear that is compatible with all cams.

Did a little research and the Comp cams composite gear is compatible with most cam material but not recommended with high Vol/Press pumps which I know my engine is equipped with LOL. I'm temped to try it and have to pull the distributer in a few weeks to inspect it. I'm worried the equipped melonized gear is going to be an issue because the cam is billet. I'm playing RED OR BLACK here!

Can you see if the cam core is gold between the lobes?

If it is indeed a melonized gear, it should be fine.

FWIW every new msd I ever had my hands on had a cheap shiny black, chinese gear. For example, Cam motion cams are 8640 billet, if you run the MSD gear on them with high volume oil pump, by about 60-100 hours cam gear and dist gear will be scalloped and damaged. I usually run the cam motion gear they sell, Ive also ran melonized gears on 8640 billets, brass/bronze gears (drag race and short life stuff) and a few poly or composite gears. The few times I have ran the composite gears I break engine in on dyno with the cheap MSD before swapping it to take the sharp edges off. something else I do to ALL bbc engines is orientate the distributor to about where it goes and cut a small slit in lower distributor band directly facing where cam gear meshes to help oil the gears fwiw, Smitty

This is worth a read.

http://www.enginebuildermag.com/2009...tributor-gear/

Yeah, the info constantly contradicts itself, Comp cams statement from that article below is perfect example, contrary to THAT statement Cam motion will sell you a billet core hydraulic roller / roller cam and a matching steel gear (they dont say what gear is) and it works OK. Ive also ran the no name 60$ melonized gear from engine pro in a hot street truck on a 8640 steel roller in a SBC and timing has NOT decayed from gear wear in 10,000 miles (also modded the distributors oiling). I have put timing gun on a boat that guy said "slowed down" and timing had decayed from 34 to 22 degrees, pulled his MSD distributor out and found that chinese gear MSD uses scalloped all to hell. His engine builder screwed the pooch on that one.
THIS STATEMENT FROM THAT ARTICLE CONTRADICTS CAM MOTIONS PRACTICES: "If you have a billet steel hydraulic or solid roller cam, your two options are:
1. Bronze distributor gear

2. Composite distributor gear"

I spoke to MSD and it is confirmed melonized

I called comp yesterday I wanted to talk to them about running their composite gear and they said it is not recommended for a high col pump as it will die very quickly so I do not know my best course of action here. I cant believe something so simple is so confusing lol

something else I do to ALL bbc engines is orientate the distributor to about where it goes and cut a small slit in lower distributor band directly facing where cam gear meshes to help oil the gears fwiw, Smitty

How exactly do you do this? What exactly is getting a cut in it?

Can I tell by looking at the cam gear on the new distributer if it is melonized or a junk gear just waiting to wreck my cam and engine?

My problem is I have NO IDEA what the cam is made of I never saw it and Im waiting for my engine builder to call me to see if he remembers. Freaking Isky cant confirm their telling me to look at the face of the cam, BUDDY THE ENGINE IS IN THE BOAT!!!!!!! If I need to tear this engine apart im going to lets say not be thrilled! I wanted to toss in a composite for $143 but I dont need it wrecked in 3hrs either. If I knew it would last a season I would change it once a year and sum it up to routine seasonal maintenance> I mean its a B. O. A. T.!!

Maybe I toss in a composite and just check it every few hrs or run time but then I assume even marking the distributer I have to toss a light on it every time?

Do you or the engine builder not have the part number of the camshaft ? Was it new or is this just a freshen up ?

From his other cam thread… it’s an Isky p/n 696275284 and the grind number is RR-265/275 (per Summit).

A quick search showed that it could be built on a cast core… some suggested having it ordered on a steel core. Others commented that it needed a bronze gear or Everwear (melonized) gear. Seems it’s a bit all over the place.

I've ran melanized gears on cast iron and 8620 cams and never had any issue at all. I've ran bronze on both and always had wear. So, from experience, I'd recommend the melanized gear and not worry about it. Even if you have to buy one from someone other than MSD so you have piece of mind.

Is it a shiny black? I havent seen a new msd distributor come out of box with a good gear but maybe they changed. A real simple way to tell if any gear is wearing quickly is checking timing. Your new timing chain will settle in right away and youll have to reset timing a degree or so BUT after that it woll pretty much stay consistent.
As far as modding the lower oil band on distributor body, its exactly that. Align distributor to where you will be able to get enough adjustment either way out of body with motor at 20, 30 dgree btdc. Mark body where it touches intake, pull it back out, file or cut a small groove about .050 wide and a little deeper in lower band where it faces where cam gears meet, thats it. I do it while swapping to a good gear on the msd distributors or stock ones. Now it sprays a tiny bit of oil where the gears meet, Smitty