Roller cam materials and melonized distributor gears [Archive] - Chevelle Tech

: Roller cam materials and melonized distributor gears


gibbons
Jan 10th, 11, 4:53 PM
Another dumb question: What is a factory zz502 cam made out? I think I recall from porosity issues that tappet cams are cast iron in general(?) And rollers in general are billet steel(?) And the zz is?

It seems there is always talk of distributor gears associated with roller cams. I heard that you need a melonized gear with a zz502 cam. MSD says all their gears are melonized so I would be good to go with their 8365 pro billet HEI. BUT, being a good boy and using the search function first, I found a post from Wolfplace from 2004 where he said that MDS distributors have problems with GM rollers.

So where are we today, could an out of the box MSD HEI (with a supposed melonized gear) drop in a zz crate without gear confrontations?

This all escalated from the simple desire for a rev limiter... :clonk:

cstraub
Jan 10th, 11, 5:14 PM
A bronze gear will work with any cam core.

A melonized gear will work with a core with an induction hardened gear.

You factory cam will work with a melonized gear. MSD's stuff is .501" diameter. GM's stuff is .491".

Dave427
Jan 10th, 11, 6:13 PM
Like Chris mentioned your GM HEI has a .491" shaft and the MSD stuff has a .500 shaft.
So if it was me I would go to the GM store and get a melonized gear and hone it out to .500" then you will be safe.
The GM part # is 10456413

cstraub
Jan 10th, 11, 6:26 PM
Like Chris mentioned your GM HEI has a .491" shaft and the MSD stuff has a .500 shaft.
So if it was me I would go to the GM store and get a melonized gear and hone it out to .500" then you will be safe.
The GM part # is 10456413

They are available in .501". PM me or Wolfy for them.

wildman926
Jan 10th, 11, 7:37 PM
Is this just related to GM roller cams?

dreis454
Jan 10th, 11, 7:59 PM
Another dumb question: What is a factory zz502 cam made out? I think I recall from porosity issues that tappet cams are cast iron in general(?) And rollers in general are billet steel(?) And the zz is?

It seems there is always talk of distributor gears associated with roller cams. I heard that you need a melonized gear with a zz502 cam. MSD says all their gears are melonized so I would be good to go with their 8365 pro billet HEI. BUT, being a good boy and using the search function first, I found a post from Wolfplace from 2004 where he said that MDS distributors have problems with GM rollers.

So where are we today, could an out of the box MSD HEI (with a supposed melonized gear) drop in a zz crate without gear confrontations?

This all escalated from the simple desire for a rev limiter... :clonk:
No the MSD pro billet HEI does NOT have a melonized gear,you must install one.

MSD suggested THIS one for me http://www.summitracing.com/parts/MSD-8561/ I am running the 8365 Dist. & the ZZ502 cam.

chrispicide35
Jan 10th, 11, 8:42 PM
Lunati may have solved this problem with the everwear dist. gear, the gear is compatible with 1050, 5150, 5160, 8620 and 8660 roller cams, Read on:

http://www.lunatipower.com/ProductGroup.aspx?id=243&cid=43

.500 gear...$49.95 At summit:

http://www.summitracing.com/parts/LUN-89026LUN/


Here is an article for a distributor mod to oil the gears, it may be a good idea for whatever gear you decide.

http://www.hotrod.com/techarticles/roller_cam_installation_tech/photo_09.html

It sounds like a great idea and i wonder if any/or how many people have tried this. Engine builders lets hear what you think of this. i cant see how it would hurt.

gibbons
Jan 10th, 11, 10:22 PM
Oh man, this is getting into an ugly topic again! Like which oil pan :)

The MSD guy I talked to seemed pretty sharp. For what it's worth, he assured me that their gears are now melonized and described surface hardening that entails. Another TC member sent me note about his experience with an out of the box MSD distributor on his 502 and he sounds like he's doing fine.

Anyway... I got myself worked into a frenzy on this one, just like I do with everything and end up paying 5X what in originally scoped. I am still monkeying with other winter projects, I think I will let this one sink in. An option is the 8501 kit, which has the new HEI processor with rev limiter and better coil (plus cap and button) that will bolt onto my GM unit that I know works. I wouldn't have the bearings and groovy stuff the MSD has, but I don't race and only drive 800 miles a year.

OK, the big FYI question: Is the zz502 cam billet steel or cast?

Vegas69
Jan 10th, 11, 11:39 PM
A bronze gear will work with any cam core.

A melonized gear will work with a core with an induction hardened gear.

You factory cam will work with a melonized gear. MSD's stuff is .501" diameter. GM's stuff is .491".


A bronze gear will work with any cam gear but it won't last on any camshaft. It needs to be checked on a regular basis. Like every 500-1000 miles. I would highly reccomend against running one on the street. It's a race car ONLY part.

Gibbons, GM recommends a melonized gear. End of story.

The factory cast cams had a cast iron gear and you could run a cast iron distributor gear.

Many roller cams are and were made from billet steel. A cast iron distributor gear is to hard and could sacrifice the cam. Most run a bronze gear.

My personal preference is a billet steel cam with a press on cast iron gear with a melonized distributor gear.

dreis454
Jan 11th, 11, 9:04 AM
OK, the big FYI question: Is the zz502 cam billet steel or cast?

Steel Billet.

Dave427
Jan 11th, 11, 11:26 AM
Seriously if its all about a rev limiter why don't you just add the module to the 502 distributor and you will bwe finished.
There is no power gain here, by adding the MSD unit.
The best thing about the MSD unit is the timing curves can be adjusted a bit easier.


Dave

Steve439
Jan 11th, 11, 6:00 PM
Here is an article for a distributor mod to oil the gears, it may be a good idea for whatever gear you decide.

http://www.hotrod.com/techarticles/roller_cam_installation_tech/photo_09.html

It sounds like a great idea and i wonder if any/or how many people have tried this. Engine builders lets hear what you think of this. i cant see how it would hurt.

I cut the groove on my MSD after learning about it here.
I don't see any wear on the gear so it didn't hurt...
I'd definitely do it again on any engine I build.

cstraub
Jan 11th, 11, 6:07 PM
A bronze gear will work with any cam gear but it won't last on any camshaft. It needs to be checked on a regular basis. Like every 500-1000 miles. I would highly reccomend against running one on the street. It's a race car ONLY part.

Gibbons, GM recommends a melonized gear. End of story.

The factory cast cams had a cast iron gear and you could run a cast iron distributor gear.

Many roller cams are and were made from billet steel. A cast iron distributor gear is to hard and could sacrifice the cam. Most run a bronze gear.

My personal preference is a billet steel cam with a press on cast iron gear with a melonized distributor gear.

Gear lash. Most wear on rollers comes from improper amounts of lash between the dist. gear and the cam gear. We are asking these to mesh at 90. When John Reed came out with oversized cam gears after chasing phasing issues with with ignition units one can now get gears to set the proper lash. If you check the lash and set it up correctly you would be surprised how many thousands of miles a bronze gear will run.

Vegas69
Jan 11th, 11, 10:21 PM
I got 2,000 out of mine before it thrashed the bearings and left me on the side of the road. :D I'll put that down as one of the many lessons learned in life. ha ha Engine builder put a bronze distributor gear on a press on cast iron cam gear. Of course I run a melonized and ablocked bypass on my new engine but did a boat load of research after it happened. They have their place, just not in a street car. IMO

lemonice
Jan 13th, 11, 5:14 PM
i just called my dealer here in leesville louisiana and that part# 10456413 is $70. plus tax. wow.

70 SS 454
Jan 15th, 11, 12:10 AM
ken

i have the msd digital e curve 8394
look at it if you are going to a new distributor

absolutely the best $350 i have spent
enabled me to try MANY curves by simply changing dip switch settings once the total was set to 38*

has integral rev limiter
http://www.summitracing.com/search/?keyword=digital%20e-curve&dds=1

sent you an email

rich

edit: additional expense i just thought of is external blaster 2 coil, epoxy filled msd 8222
http://www.summitracing.com/parts/MSD-8222/
and a manifold mount bracket -- i have a used chrome (Decent but not perfect ) bracket i will send you if you go this route

i think i also have a oil filled blaser 2 8202 if you want it
i ran one for many years
burnt a hole thru the tower (unrelated to oil fill)
so i replaced it only to go to the 496 a few months later so this one has less than 2000 miles i would guess (wnet to the epoxy filled with the new engine simply because i was redoing everything else)

email me

gibbons
Jan 15th, 11, 3:52 AM
Yeah, that e-curve would be really cool! I looked at it but then started adding things up, dist $375, coil $50, for-sure-melonized-gear $42, wires with plug boots (not hei boots) on both ends $75. Add some shipping and other incidentals, and it's pushing $600 vs $220 for the cool MSD module, cap, rotor, coil, and button. I'm slowly running out of tolerance for spending!

I don't really have a way to test the effects of ignition settings, so I am going to go off of what I have seen on this site, and run with it:

total advance 38 (I am at 4200' elevation so my compression is lower)
centrifugal advance all in at 3000rpm
initial advance 16
vacuum advance about +16 to give me 54ish at cruise
vacuum advance starting at 8in-hg, all in at 16in-hg

Something like that, if there isn't any obvious pinging. The e-curve is cool, but I can all the stuff above mechanically.