OK, so here is a pic of a nylon, a bronze and a steel slant six dizzy gear all in a row.

http://s785.photobucket.com/user/67dart ... sort=3&o=0

Dimension wise, # teeth and pitch, the bronze and steel Aussie gears are the same as the nylon gear except, as many of you know, the shaft hole is a bit smaller to fit the Aussie Bosch type distributor shaft (I have a separate post on those, I'm curious if anyone uses them).

I've been reading up on the posts about these gears, also on other blogs, and I've read all kind of fantastic "facts" e.g. the bronze gears only last 3000 miles, the steel gears will destroy your camshaft unless it's billet, nylon gears are crap, etc. etc.

Q1: Do the Aussie's only run steel and bronze gears? Q2: If the answer to the first question is "yes" then do they use different camshafts as well? Q3: Were the Aussie SL6's fitted with distributors after they arrived in Australia or were they all manufactured there or what? (oops that was more than one question). Q4: What's the story on cam to gear material choices? Q5: why can't/shouldn't I use a bronze or steel gear on my distributor?

thanks all,

Brian

P.S. sorry about the Al vs Fe question, I own that mess...I'll send Motrin to anyone with a headache from that.

_________________
https://tinyurl.com/yynpj4v2

Those metal pinions are pretty, for sure. Here's the thing: the nylon distributor drive pinion, properly installed on the distributor, gives decades of reliable service. How do you imagine improving on that?

_________________
一期一会
Too many people who were born on third base actually believe they've hit a triple.

I'm still shell shocked from my second distributor/cam/oil pump gear shredding which, I'm fairly confident after having read multiple posts and discussing with a few folks, happened because of cam walk and not because of the nylon gear going prematurely. I'll install a cam button to address that possibility, but...

That said, I can't keep out of my mind the possibility, however remote, that the nylon failed first, causing an ill-timed denotation, and that shredded the cam/pump gears. Entertaining that thought for a moment, wouldn't using a more robust and well tested (in Australia I presume) material on the dizzy drive gear also be prudent? Hence my question about their purported use of steel gears on their distributors.

My knowledge of materials science tells me the following things. Nylon is softer, but also that means it'll give more if there are misalignment issues in the gear meshing, so it's safer at least for that reason. Bronze is, though harder than nylon, softer than the cam/pump gears, so if not meshed properly would wear out much faster than nylon or steel. Steel, if not meshed properly would wear out the cam/pump gear potentially. Seems to me if there are no issues with mesh, i.e. one meticulously checks the engagement pattern and its proper/good, the steel gear would be the safest bet, though we are talking about 3 variables (3 gears all meshing properly together) so there's that factor. Once again, I'm contemplating trusting my (soon to be) freshly rebuilt SL6 on a $2 nylon gear that twice I've pulled out shredded along with my cam/pump gears.

If it's really the cam walk, and I think it is, then I'm OK. I checked the dizzy shaft play etc, all tight tolerances, very little play, no signs of wear on the nylon gears prior to the catastrophic events with two different distributors, no signs that the rotor jammed. I'm using a very high quality cap and button. I plan to go forward with nylon again, but I wanted to see the bronze and steel gears for myself, and find out if anyone knows if Australia uses these regularly, if they have issues with them or if anyone else has experience with them.

brian

_________________
https://tinyurl.com/yynpj4v2

and/or a bad cam worm.
Correct.
Nope. That didn't happen. It just plain didn't, any more than a purple-and-green unicorn threw a strawberry red Samsonite Silhouette suitcase crammed full of $10,000 bills through my front window (and believe me, I've checked).
...and if the distributor locks up for any reason (and there are several), the damage is limited to the engine stopping and the need to repair or replace the distributor. Replace that nylon pinion with a metal one, lock up the distributor, and the damage gets quite a lot more extensive and expensive.

You really are overthinking this and worrying far too much about things that don't actually happen, while disregarding things that do.
No, you're not. You're contemplating trusting a nylon pinion. That's it. If it fails, the engine stops running and you need a new pinion. That's it.
The shredded nylon pinion is a symptom, not the cause.
Steel drive pinions were standard equipment on certain Australian-built distributors. They work fine.

_________________
一期一会
Too many people who were born on third base actually believe they've hit a triple.

That should be on a T-Shirt!

_________________
1964 Dart GT

I was overthinking, I just needed somebody to say so....

I've not had anyone, or anything, throw a suitcase full of bills through my window either...but we can dream can't we?

brian

_________________
https://tinyurl.com/yynpj4v2

It'll have to wait until after I'm done printing up the A purple-and-green unicorn didn't throw a strawberry red Samsonite Silhouette suitcase crammed full of $10,000 bills through my front window (and believe me, I've checked) shirts.

_________________
一期一会
Too many people who were born on third base actually believe they've hit a triple.

The Aussie slants that I've seen had the steel gear,that's not to say ALL had it,...I've never looked at every single slant distributor over here. They were used with the local manufactured Bosch distributors used on most for local content laws of the time. The Aussie Hemi engines ran the same nylon gear as the USA slants,they last years, You can buy a steel or bronze gear from the so called experts over here,but in reality all you are doing is making a bunch of I'll informed bogans rich by buying anything from them and encouraging them to spin more BS....save your money...they already have a refrigerator full of beer and all the crack they need without any more financial input from the healthy US to Aus exchange rate these days!
From what I've seen your nylon gear DID fail first...that's how you discovered the problem when the engine ran rough wasn't it? But it didn't CAUSE the failure it was the poor victim, just like you would be if you believe the spin and bought a bronze,steel,titanium,carbon fibre,sintered snot or any other type of drive gear other than the stock nylon type....imagine,your new sintered snot distributor gear will last forever,impervious to all wear and threats,it's like a cockroach in a nuclear blast....so what's happens? You get to drive another few hours before the same problem raises its head and the oil pump gear fails, your engine has zero oil pressure and hopefully you notice it early enough to not totally ruin your engine......but that dist drive gear is perfect....what a great investment that was! So why did it fail? Cam walk? Really,the cam should be thrust against the block's face due to the normal operation of the lifters and the thrust from driving the oil pump. Hemi engines did have similar issues as the slant oil pumps and the cams would walk,but once again it was usually the result of a problem not the actual cause. Most of these engines had wiped lobes and low oil pressure upon inspection. Before you button up your engine pull the cam gear slightly off its thrust face and then rotate the engine and you should see it move rear wards. I've read here someone had issues with a roller timing set with a mismatched gear causing poor alignment and making it move forwards and hitting the timing cover.... It's worth checking. In all reality you are probably just the unfortunate victim of a bad cam with an incorrectly machined oil pump drive gear. Just grab a good used cam,lifters and oil pump as a matching set,maybe consider the mod to provide extra oiling to the drive gear... Then get the cam ground to your choice of specs,get the lifters faced and check the oil pump and assemble it all up and hopefully enyoy years of trouble free nylon gear driven distributor motoring, cheers.

Rough doesn't begin to describe the detonations in my system when this happened...it literally sounded like a double barreled 12 gauge going off with both barrels. The first time it was under the hood (I figured I'd find a hole in the block and a rod stuck in the fender well), in this more recent event the fuel detonated well back into the exhaust system, it exploded under me...that's why I'm gun shy. I had taken this slant through its courses, logged ~10k miles on it through all kinds of tests, grandma mode, high speed, hard acceleration, city traffic, 2 hour long highway drives, before this happened...I wasn't expecting it (either time).

What are the chances it'll happen to me three times? That sound you hear is me knocking on wood....and getting ready to fab my cam button and possibly an oiling tube...

Oh well, the Phoenix shall rise from the ashes yet again, ever better this time!! Can't wait.

brian

_________________
https://tinyurl.com/yynpj4v2

Whew! That has to be the longest spelling I've ever seen of "H-E-M-I-P-E-R-F-O-R-M-A-N-C-E".
SHHHH!!!! Quit givin' away my best go-fast secret, dangit!!!

_________________
一期一会
Too many people who were born on third base actually believe they've hit a triple.

Naw. It was just that a spark went off when an intake valve was open, and that made the fuel/air mix in the intake manifold go BOOM!
A spark went off when an exhaust valve was open, and that made the fuel/air mix in the exhaust system go BOOM!

_________________
一期一会
Too many people who were born on third base actually believe they've hit a triple.

Also, another thing: Make sure you're using a good quality nylon pinion. It's easy to get garbage made in finest my brother-in-law got special deal on material that looks like same, I make distributor pinion for you, package with your brand, hundred percent, I give you deal, you sign here now! Chinese "quality".

_________________
一期一会
Too many people who were born on third base actually believe they've hit a triple.

[quote="SlantSixDan"]

Whew! That has to be the longest spelling I've ever seen of "H-E-M-I-P-E-R-F-O-R-M-A-N-C-E".

[quote]

Yep...that's half of the "professionals" I was thinking of...we have another "Star" performer in another state as well. I trusted them...once....what a mess..
You would be better buying Prochump parts than paying 5 times the price for the same part wrapped in their own packaging, that way,your only wasting 20% of your hard earned cash!

Ohgawd, yeah, "ProComp", yet another pretend-brand of rubbish from China. No engineering behind it, just pure low-fi copycat knockoff lookalike junk. And yet, people spend money hand over fist on it and get on the internet and congratulate themselves on what a smart decision they made.

I don't know which "Star" outfit you refer to. Blue Star Spares was one of my go-to sources in Australia for many years, but they've had that "temporarily closed" notice on their front page for months now, and that doesn't seem to bode well. I recall there was another group calling itself something similar to Blue Star, don't really know much about them. Then there was GPRS, who have some interesting products on their website but never answer email or phone calls.

_________________
一期一会
Too many people who were born on third base actually believe they've hit a triple.

Boy, ProComp, What a bunch of garbage. Bought two nitrous plate systems from them. Was really cheap, but figured I could get a couple of parts out of the "kit'. If anybody put one of these kits on their engine, I don't think the engine would even start. I will say when I contacted them to complain, about the quality, they gave me a full refund, including shipping both ways.

_________________
Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225