hi need help on a new hei for the chevy motor in the cj8 scrambler
i heard some bad things
found this one and just dont know if it would be ok for not does anyone know if it is ok or which one is thanks
The 'Bad Things' are with the HEI Distributors that are made from 'China' parts imported from wherever, slapped together by guys advertising on E-bay and the '4 wheel drive' sites...
The AMC/Jeep gears in particular were killing engines right and left,
Then along came the $100 to $150 HEI clones that had shafts and housings too long that were jamming up oil pumps....
And yes, it's still an issue with the cheap HEI clones you get...
The only SAFE HEI clones are from DUI and MSD, and both are over $300 each.
(You get what you pay for...)
Since yours is a CHEVY ENGINE,
I would walk into the local discount place and ask for a distributor from a '79 Chevy Impala with 305 or 350 V-8 engine,
Then I'd put a premium cap, rotor and coil on it,
And top it off with a set of MSD spark plug wires.
I prefer the cut to fit wires so they actually do what I want them too,
But there are just LOADS of Small block Chevy versions of the wires out there.
Personally, If I were buying 'Cheap' wires, I wouldn't buy anything cheaper than AUTOLITE wires (Around $45) and the MSD wires are only $60 and will be MUCH better wires...
this is what they say about it
Fully CNC machined and polished housing with adjustable vacuum advance.
Everything this day and age is CNC machined.
Even China uses CNC machines because they work 24 hours a day, 7 days a week, never call in sick, never need a brake, never get hungover, and never screw up the cut....
And all you need is one unskilled monkey to load/unload the machine when the batch is done machining...
What I want to know is,
What tooling did they use?
What are the tolerances?
What was used for bearings/bushings?
Is it factory blue print sized, or is there large tolerances there also?
They don't tell you what the housing is made from....
We know it's aluminum, but is it run of the mill bar stock,
OR is it a good, void pressed, Forged aircraft or aerospace grade aluminum.
Polishing covers a LOT of evils, including cracks!
Is the shaft hardened and centerless ground?
Is the advance head indexed properly?
Can you adjust the centrifugal advance without removing the shaft and advance head from the housing?
Just a few of the questions I have for the CLONES when they make claims...
Each distributor has a 50,000 volt Super Coil to insure accurate and reliable timing to 7,500 RPM.
The HEI distributors, by definition, have a single spark, and the SPARK ENERGY of that spark relies directly on the saturation time the coil gets.
NO SINGLE SPARK HEI COIL IS GOING TO BE RELIABLE AT 7,500 RPM FOR 50,000 VOLTS!
There simply isn't enough saturation time for that to happen!
HEI coils (early E-core coils) have quicker saturation times than canister coils, but they are still at the mercy of the TIME the module switching transistor allows it to charge, and that time decreases as RPM INCREASES!
I still have yet to see ANY IN CAP HEI COIL that doesn't start loosing spark energy between 2,500 RPM and 3,000 RPM...
No matter what the 'Claims' are or how glossy the print ad is!
The 4340 Chrome moly gear will work with cast or billet cams.
Now, the factory used a ductile Iron gear, not a steel gear of any kind, much less a HARD STEEL GEAR!
I haven't hear of these HEI CLONES tearing up CHEVY engines, but they have played hell with the AMC factory camshaft gears and oil pumps!
True spark alignment for instant throttle response.
First of all, Throttle Response has to do with the interaction between the fuel ratio, the RPM capabilities of the engine (Weight of the rotating mass, balancing, compression, ect.) and the advance curve.
You can EASILY tune a factory distributor for a faster advance curve but if you don't have the engine getting enough fuel FAST ENOUGH,
And a light enough, close enough to balanced rotating mass, the engine simply isn't going to rev up quickly or smoothly...
One other thing you might want to know...
Most engines will rarely see operation above 5,000 RPM for more than a few seconds.
EVERY factory distributor is capable of operation at or below 5,000 from the factory...
If you are going to flash above 7,500 RPM,
Or operate for long periods above 5,000 RPM,
You want ROLLER BEARINGS instead of the bushings these HEI Clones have...
SO! READ UP AND REMEMBER THIS!
Up to 5,000 RPM long duration operation,
Or 7,500 RPM flash RPM, the factory distirbutor will do you as good as the 'HEI CLONE' distributors will...
Remember, reman factory distributors are between $50 and $100 and come with LIFETIME warranties!
*IF* you use the factory GM HEI Distributor,
And use a CDI MODULE (Capacitive Discharge Ignition) module instead of the HEI module in the distributor,
You can increase the spark energy to the plug a bare minimum of 500% and up 1,000% depending on what kind of spark energy you are getting at your 'Redline' RPM...
And these modules start at about $139 from Summit.
500% increase for $139.... Yes, it's true and the HEI Clone guys would rather you didn't know about it!
Works with the stock, factory style distributor just fine also!
Summit SUM-850602 - Summit Racing Street & Strip® Multi-Spark Digital CD Ignitions
MSD Ignition 6200 - MSD 6A CD Ignitions
Getting the coil out of the distributor cap will allow you to use a LARGER coil with better winding ratio, that will give you MUCH BETTER, MORE USABLE SPARK ENERGY.
MSD Ignition 8401 - MSD Modified HEI Dust Covers
You can effectively DOUBLE your usable spark energy by simply using a REMOTE coil instead of the small, poorly designed HEI 'In-Cap' coil...
MSD Ignition 8227 - MSD Blaster TFI Coils
The distributor advance and triggers are all about the same,
It's the COILS AND MODULES that make the differences, so don't get suckered by 'Shiny' when what you need is USABLE SPARK ENERGY!