I was running my engine really hard for the first time pushing it this hard. I actually left 2 black marks about 40 ft long. I turned around and was proceeding to see if it would spin the tires on taking off down hill and all of a sudden there was a weird noise and the truck engine lost all power and was rolling in gear making squalling noise (I guess the transmission since no rpm anymore). I was in disbelief and sick that all this work and money and I messed it up royally by doing something stupid. I will tell you I am a believer in prayer. I just left the house for a "quick"
run down the road but previously I noticed that my cell phone was dead and left it there to charge, not thinking about that I did this before and left and it there (mistake). For some reason we never get snow here or not even much sleet, well just as my truck broke down it started snowing extremely hard and my black truck was turning white as I realized I had no phone or wallet with me. After the battery was about dead after trying to start the dang thing so long, I saw headlights coming down the road and flagged them down and th guy stopped for me. He was nice enough to give me a ride about 2.5 miles to my house and then called a tow truck.
I checked compression highest was 243 and low-207 (this was a scary moment checking these)
I decided to pull off the distributor cap and could move the rotor around. Pulled the distributor out and found this:



What could cause this? I am very happy that it was just this but all that metal went somewhere...? I hope it didn't ruin the oil pump or camshaft.
Has anyone heard of this happening before?

I know that summit offers a melonized steel gear for crate engine roller cams but mine had the factory roller cam in it that was used with this distributor, now its the zz4 cam.
http://store.summitracing.com/partdetail.asp?part=ACF%2D10456413&autoview=sku
Robby

Been there done that, again, and again, and again...

The stock Vortec distributor has a weird non-standard diameter. Nothing aftermarket works without rigging it because all those gears are all made for classic conventional SBC/BBC distributor shafts.

The gear is available from GM without buying the whole distributor, but in my opinion it's worth buying an aftermarket distributor now that they are available. Those have standard shaft sizes.



Here's a Billet Vortec distrbutor:

What causes this? When this happened to you were you able to locate the pieces in the oil pan or were they still on the cam gear or ingested by oil pump and or screen?
I don't have a lot of excessive oil pressure (50psi max) or a high vol oil pump either.
I wonder if that plastic composite housing flexes and allows the gears to wear funny.
Robby

The gear is cast iron and intended to be sacraficial so that the steel camshaft is not harmed. The wear is caused by a lack of oiling in the area. Wear is accelerated by low-temperature oil as when a low-temp thermostat is installed.\
It is possible to improve oil oiling to the gears by grinded a very narrow and shallow channel into the plastic housing between the oil galley and the gear side.
There is a lot of lateral movement between across the surfaces of gear teeth between safts at 90 degree angles to each other like that. The missing metal is turned to dust. You're not going to find anything more than some grey goo on the drainplug magnet from this.
We;ve also discovered over the years that many of these gears came off the assembly line with poor and uneven heat treatment. This will show up as more wear on one side than the other causing the distributor to drift.

Well I guess I know what my next purchase is. Billet distributor. Otherwise I would be in the same boat.

Josh

when my truck had under 60,000kms I had random misfires on 3 cylinders. After new popets, cap/rotor wire, plugs, injector scleaning. It was discovered to be a knifeedged distributor gear that was causing my issues.

peace
Hog

You fellow gun owners know it's nothing more than a fancy term for the science of ferritic nitrocarburizing! Case hardening to the rest of the world!

Had to replace mine on the L31's 2nd intake manifold gasket change. It's a manageable task...

I'm running the new distributor that came on the HT383E (factory L31 distributor) now.

That BilleTech looks interesting, but is it worth it at $275??? James, did they fix that weakness with this billet (i.e., machine in that lube slot)??? Otherwise, what's the point because nothing else about the stock distributor is weak (barring the inherent problems with crab caps)... A melonized gear is a melonized gear regardless if it wears a GM part number or MSD, or Accel, or Mallory, etc. or has an odd shaft diameter... If they haven't improved the design, seems like the $29 gear from GM is still the way to go.

Robby, whose cam are you running and what vintage was it made? Any chance you're trying to run a billet cam with it???

Scottie wrote:

Robby, whose cam are you running and what vintage was it made? Any chance you're trying to run a billet cam with it???

It's supposed to be a factory zz4 camshaft that comes in the crate 350 engine.
I don't know what material it is made of though unfortunately .
Definitely something harder than this distributor gear!
heres what is said about it on Gilbert chevy web site: Camshaft: A new hydraulic roller camshaft (#10185071) bolsters mid-range torque and improves driveability without sacrificing peak horsepower. This dual-pattern profile has .474” intake lift and .510” exhaust lift. Intake duration is 208 degrees (at .050” tappet lift), and exhaust duration is 221 degrees.
----->Technical Notes: Distributor P/N 93440806 or melonized distributor gear P/N 10456413 must be used on all crate engines with steel camshafts.
But thats not the part # for out vortec distributors. I ordered part # 10457356 (replacement gear kit) there is a service bulletin about this replacement gear kit #77-64-04 that came out in 4-18-97.
For the time being I am going to try to make sure I know where to cut a slot in the distributor, and try to make sure there are no pieces inside the oil pump strainer or cam gear before installation. Later I will try to go with the billet aluminum one.
Robby

Robby,

That's the stock Vortec melonized gear.

A #10456413 is just the GMPP melonized gear for standard .491-inch HEI distributor shafts. In the old days, GM distributors were typically .491 or .500-inch, but then there was the .427-inch in the F-Bodies and our Vortecs. Used to be no-one but GM made gears to fit, but now most of the major companies do.

Thanks for the info!
Hopefully that one will last for a while until I get a new distributor.
Robby

Scottie wrote:

Y...BilleTech... is it worth it at $275???

Well, it's shiney, so Yes! I think so!
It has a standard shaft size that a composite gear is available for.
Also, no more broken screw ears for the cap on the plastic housing.

James B. wrote:

Scottie wrote:

Y...BilleTech... is it worth it at $275???

Well, it's shiney, so Yes! I think so!
It has a standard shaft size that a composite gear is available for.
Also, no more broken screw ears for the cap on the plastic housing.

Heavy hand James? That thought never even crossed my mind as I've never personally broke one... Now you just have to worry 'bout pulling the threads out of the billet!

Cool, composite gear! Obviously you ain't running a GM bumpstick.

James B. wrote:

Scottie wrote:

Y...BilleTech... is it worth it at $275???

Well, it's shiney, so Yes! I think so!
It has a standard shaft size that a composite gear is available for.
Also, no more broken screw ears for the cap on the plastic housing.

Put me down for (2) broke distributors. The first broke due to using the supplied screws that came with a new cap (their coated with locktite, which opened the plastic hole on the dist. too wide and snapped it off). Second one broke because I tighted it a little too snug.

Josh

For $38.08 at the dealer I got the distributor gear, and put it on and installed it in the truck. I stuck a magnet down in the hole where the distributor gear goes against the cam gear and did not find any metal shavings. I took a big funnel and stuck it in the distributor hole in the intake and poured a lot of oil down that section hoping to wash (if any) metal debree into the oil pan instead of getting b/w the new gear and cam gear and making another failure. On the side of the distributor just above the gear, I took a file and put 2 flats on the 2 round ribs just above the gear in hopes that more oil will get on the gear when in operation.
We will see how long this one lasts.
Robby

I made a sleeve & put the Comp cams polymer gear on my stock unit, No wear at all as to date. I also cut some slots in mine for oiling. The Accell dist was not available at the time, but that would be well worth the coin.

Boosted

My engine builder put this Milodon hardened distributor gear in the box of extra parts he didn't need/use. I don't know for sure if this will fit the vortec distributor or not.



Josh