I ordered a new HEI off ebay. After I got it coming I read somewhere about the gears on the dist being hard. I drilled a small spot on my new one and it easily started drilling a hole. So my question is what should I do?
My jeep is a 77 with the sure enough junk prestolite dist. I have been a dirt track racer since I was 15 and the HEI has always been the bomb, thats why I went with it for the 258 but didnt do alot of research before I ordered it.
Ebay, 'China' specials, are usually have WAY too much advance, so be aware you may have to trim back the timing curve a little...
As for gear, if it drills easily, then it's probably OK for a 258 with factory ductile iron camshaft.
It was the V-8 versions that had REALLY hard gears, and went on the already hardened camshaft V-8 drive gears that were the biggest issue.
Since we blew up the story on the forums, and named names, about the rotten gears, the market has improved, and the old gears have filtered though the system.
Since you race, you know the signs of detonation, so you will know if you have too much advance or not.
You still see one once in a while eat up a V-8 drive gear, but not like it was, two or three every week...
It's not practical to change the camshaft when you need a distributor change, so I make sure I use a SOFT ductile iron gear as not to upset the camshaft wear pattern.
Once the camshaft 'Clearances' the softer ductile iron distributor gear, the wear will stop and you have another matched set...
That's why I warn about the cheap 'China' steel gears, they aren't quite 'Steel' or 'White Metal', and they aren't exactly soft enough to call 'Cast' iron.
What happens is, China and other third world countries are still using straight hard carbon to make 'Steel' with,
Not graphite you see most commonly used in America for carbon content in steel,
(Hard carbon is cheaper and easier to make, usually a waste product of some other manufacturing process)
That old hard carbon is hard to control, doesn't mix well with the iron, and you get hard spots, or just an overly hardened gear since they don't seem to have a grip on the concept of proper 'Quenching' to control hardness...
And some of the 'Foreign' gears are just plain made WRONG, wrong tooth pitch, wrong tooth profile, wrong material, wrong install height, ect.
You get what you pay for, and in this case, the extra gear cost for a properly made one is well worth the next 100,000 miles of use!
I found a good use for those hard gears! They make good drill stops!
You drill through your intended material and the drill isn't going any farther!
Might cost you a drill sharpening, but you won't screw up what's below it, and when they are slipped over the drill for a depth stop, the chuck isn't going to wear them even with repeated use. They are hard as a rock!
Roller cams are usually STEEL, and I mean real, hard steel.
You have to use something that will 'Sacrifice' to the camshaft or you will be changing camshafts quite frequently.
Bronze is a sacrificial solution to the issue.
Not a long term 'Fix', but a short term one.
Since the camshaft WILL eat the bronze gear up, you WILL have to keep an eye on it and change it as necessary.
Bronze gears are a stop gap fix when you are running a roller camshaft in an older carbureted engine you are trying to squeeze some extra horse power but don't want to fork over for fuel injection... And ignition control...
When we use roller camshafts in the race cars,
That's when we go to crank triggers, coil packs, and let the computer control timing since they are fuel injected anyway.
No distributor, no distributor drive gear issues...
I know people will argue with this, but it's pretty basic stuff...
Nothing like sheering off the distributor gear with a 'Racing' oil pump and roller camshaft, and trying to figure out what you are going to do next to solve the problem.
That leads to a VERY expensive external oil pump to take the load off the distributor shaft/bronze gear since you can't run a steel gear on a steel roller camshaft,
And you have to have high oil pressure...
You find yourself spending money on the oil pump instead of switching out the camshaft or buying fuel injection with computer ignition control and coil packs...
msd uses iron mellonite gears in all their distributors, its suppsose to be good in all applications. they still recommend the use of bronze gears in full roller hydraulic cams though.
Ever rub one of those gears with a real fine sandpaper?
The sandpaper gets 'Slick'... Strangest thing you will ever see! Freaked me out entirely when I was trying to gain 0.002" clearance for the housing...
They 'Self Lubricate' to an extent (Graphite in the steel),
Not saying you don't need oil, you most CERTAINLY DO NEED OIL, but they don't gall up right away and start eating on the camshaft gear.
They are also soft and easily conform to the camshaft gear teeth...
They are about $50-$60, but when all else fails, use the best and pray for rain!
my 70 el camino i built had a hydraulic roller camshaft in it with an msd probillet distributor. i called msd to see about a bronze gear and the said the part number i had was able to be used with the camshaft and require a bronze gear. something about they changed in the gear material that wouldnt tear the camshaft gear up. they used the term iron mellonite.
I'm almost ashamed to admit how much $$$ I have in an old AMC 360. But very proud of the dyno numbers! Forged this, roller that, New Comp 292, etc..
Then I buy the cheapest HEI, even w/$$ left in the budget. Had to spend the $55 (MSD iron gear p/n8005?) just so I could sleep at night. Penny wise, pound foolish, that's me. But I got a FREE HEI ignition wire "kit". Special HEI wires are needed?? Cut to fit, then install the ends. Came out really nice though. CRT, on epay claims to have the right gear.
Luckily, this backwater town has a good old fashion speed shop w/a carb guru that has a Sun Dizzy machine. And knows how to use it! He made my built, dual quad, 401 Buick Nailhead scream. After I THOUGHT I had it dialed in pretty well. The dyno guys were good, but once road worthy, and I hit the exhaust shop around the corner from him, he's my 1st stop. Then the Chassis dyno.
EDIT: "Nothing like sheering off the distributor gear with a 'Racing' oil pump" J-Hammer. Maybe somebody will come up w/an affordable, easily installed, Dry Sump Oiling system. (Now that is good comedy humor for us AMC guys!)
I've also learned that sometimes... when people don't agree with you .... its best to hold them down and kidney punch them till they agree with you
Last edited by hutch1200; 12-07-2013 at 01:34 PM..
Reason: Add porn link
We have a bunch of 'Internet Experts' that 'Claim' huge numbers on everything they do...
Even though we are basically working with 'Tractors' here, they recommend roller camshafts, aftermarket heads, huge tube headers, ect.
None of which make power down where we use it in CJs, on highway or trail.
If you have to have a rev kit, roller camshaft, $4,000 worth of head/valve work, ect.
You are NEVER going to reach the RPMs required for that stuff to make power in a CJ unless you are at the race track.
And taking a CJ to a 1/8 or 1/4 mile track is like trying to race a house, just about as aerodynamic...
Claims... Are all lies.
PROVE IT ON THE TRAIL.
Get 22 miles to the gallon highway with no driveability problems and still have a capable trail rig,
Now that impresses me and a 'Dyno' or all the speed shop parts in the world can't duplicate that!
I see HUGE tires on aluminum rims, with no rock scratches, no paint chips, ect.
And the guy goes on and on about his 'Rig'...
Every bolt on 'Bling' part Quadratrac sells, but hasn't been out of his back yard with it...
He can't turn, he can't get up to speed, he can't control it at speed, gets 4 gallons to the mile, but still recommending that crap to everyone...
Give me a back yard built dual purpose CJ that WORKS any day!
Mall crawlers give me the runs.
I see guys every weekend we are at the ORV park, polite CJs, YJs, TJs that are VERY capable, and didn't come on a trailer!
They drive in, they wheel all day, they don't throw mud everywhere, they don't have open exhausts annoying the crap out of everyone, and they have a good time!
That's my kind of guy!
I also see the guys show up with big diesel trucks pulling big trailers, backing off big tires...
They are usually back on the trailer in short order with something broke.
Then there are the guys that show up at an ORV ride with some stupid class/bracket time on the windshield...
They are ALWAYS broke in the first hour, if it gets off the trailer at all...
I'm not impressed...
The one thing I like to see come in on a trailer is some little 'Tractor' that just can't be stopped!
Trees, rocks, ledges, he doesn't care!
Low center of gravity, good wide axles, good ground clearance, tires he can control, and a crawl ratio that will let him change the rotation of the earth if he gets a good hook and he's off to the back country, trail or not!
These guys are easy to spot, they usually don't have winch cable pulled and wrapped around the front bumper, if they have a need for a winch at all!
Unlike the 'bling' and 'Race' bunches, these guys will stop, give you a beer while they are pulling you out of some bottomless pit that is consuming your Jeep in a rapid manner...
Articulation of a lizard and sure footed as a mountain goat!
When you talk to them, you get answers like "Axles? Tractor, Steering? Fork Lift. Transfer case? Rock Truck..."
If you are going to build a 'Dedicated' off roader, these guys make the grade in my book!
It's not what you buy, how much you spend, it's what you build yourself and how well it works!
If you spend $12,000 and wind up with a garage ornament, then you blew it.
If you spend $12,000 and wind up with something that can drive through your house, basement and all, then you WIN!