Dizzy shot out on the Chevy big cap points to Hp Hei just an info difference in Hp wise. 

Is there really a performance difference between stock points vs HEI, and an aftermarket HEI ignition system? Readers were curious, so we procured the necessary distributors and headed to Westech Performance for some dyno Points vs HEI testing.

Points vs HEI For this points vs hei test, we used Westech's resident mule motor, "Pepe," a 350-cube small-block, to test the power output of each ignition setup. The small-block was a fairly stout performer equipped with 9.6:1 compression, a Comp Cams 292 hydraulic cam, AFR 190 Street aluminum heads, an Edelbrock Victor Jr. intake, and a Holley 750-cfm carb. The advance curve on each distributor was set up exactly the same: 24 degrees internal mechanical advance (all in by 3,000 rpm) and 12 initial internal advance to generate a total ignition advance of 36 degrees BTDC. To ensure accurate results, the distributor's supply of incoming power voltage was carefully regulated, the engine coolant temperature was the same for each dyno pull, and each ignition setup was tested back-to-back no less than three times.

Pro Opinions
Performance Distributors says:
"We recommend converting to an electronic ignition on a musclecar engine over a point-type ignition system for several reasons. The first is reliability, as electronic ignitions are virtually maintenance free. Also, HEIs allow full alternator voltage to go through the ignition system, which with our 50,000-volt coil allows larger plug gaps for better combustion and more power.

Another benefit is simplicity-our DUI distributors are a drop-in installation with a one-wire hook-up. No external components are necessary thus eliminating messy wiring in the engine compartment. Most of all, our distributors are custom-curved for each specific customer's engine so engine-damaging detonation is eliminated, and it gives the most efficient combustion possible."

Accel Says:
"Replacing a points distributor with an electronic unit is typically done for reliability. From a performance standpoint, a lower rpm (less than 5,500 rpm), low-compression (less than 9.0:1) engine will work OK with points. For supercharged, nitrous, high rpm, or high-horsepower (over 400 hp) applications, an electronic distributor, CD box, coil, and spiral core wire set is the hot ticket. An aftermarket CD ignition delivers a tremendous amount of energy to the plugs and prevents fouling. Remember that an ignition system functions as a system-the distributor, coil, spark plugs, and wires all have to be in great shape to deliver the maximum spark energy. If one component of this system is weak, upgrading other areas is futile."

MSD says:
"Accurate and reliable ignition triggering is an important part of performance, and breaker points can be a weak point. You also need to consider the condition of the rest of the distributor. Even if the points are set precisely, your timing can be all over the map due to a worn shaft or bushings; plus, the centrifugal advance is probably not the most accurate. In a budget pinch, a points distributor will get you through but only to an extent. Although you can run an MSD ignition box with a points distributor, if you're increasing cylinder pressures, improving induction, or raising the rpm range, you're also increasing the need for not just a powerful spark but an accurate and reliable spark as well. In short, an electronic distributor and ignition should be on top of your "improve and replace" list in your quest for more power."


Points Stock HEI Performance Distributors HEI
RPM HP Torque HP Torque HP Torque
3500 241.2 362.0 238.3 357.6 244.1 366.3
3600 249.7 364.2 248.0 361.8 247.9 361.7
3700 258.2 366.5 258.2 366.6 257.8 365.9
3800 265.5 367.0 264.9 366.1 266.6 368.5
3900 276.5 372.3 273.9 368.9 274.5 369.6
4000 282.5 370.9 282.2 370.5 283.1 371.7
4100 289.5 370.9 287.3 368.0 290.2 371.8
4200 295.8 369.9 293.1 366.6 297.4 371.9
4300 309.0 377.4 302.7 369.7 307.0 375.0
4400 320.3 382.3 313.2 373.8 318.7 380.4
4500 328.8 384.9 324.7 379.0 331.6 387.0
4600 337.2 385.0 338.7 386.8 337.4 385.2
4700 349.3 390.3 348.9 389.9 348.5 389.4
4800 356.8 390.4 356.9 390.5 359.7 393.6
4900 372.1 398.8 369.0 395.5 371.6 398.3
5000 378.2 397.3 380.6 399.8 378.8 397.8
5100 391.0 402.6 389.8 401.4 389.9 401.5
5200 402.5 406.5 399.2 403.2 399.7 403.7
5300 406.6 403.0 402.7 399.0 404.9 401.2
5400 412.1 400.8 406.6 395.5 407.8 396.6
5500 412.3 393.7 414.2 395.6 414.9 396.2
5600 422.6 396.3 418.4 392.4 419.2 393.2
5700 425.7 392.2 423.8 390.5 426.9 393.3
5800 431.0 390.3 430.7 390.1 432.2 391.4
5900 432.1 384.6 428.4 381.3 436.2 388.3
6000 428.1 374.8 427.0 373.8 428.4 375.0
6100 433.5 373.3 427.6 368.1 429.6 369.9
6200 432.2 366.1 432.2 366.1 428.4 362.9
6300 438.1 365.2 437.5 364.8 437.1 364.4
6400 436.3 358.1 436.3 358.1 443.0 363.5
6500 435.7 352.0 435.7 352.0 438.6 354.4
6600 433.4 344.9 435.3 346.4 442.0 351.7
6700 444.1 348.1 446.0 349.6 452.8 355.0
6800 444.8 343.5 444.8 343.6 451.0 348.3
6900 424.2 322.9 417.9 318.1 417.6 317.9
7000 391.1 293.5 384.9 288.8 387.0 290.4


Sources


Westech Performance Group, THE Dyno Center

Performance Distributors - Performance Distributors


The test engine was a stout 350 small-block using traditional aftermarket bolt-on parts. During all testing, the engine was run with Hooker 1 3/4-inch headers (that fit a '67-'69 Camaro), Flowmaster mufflers, and 92-octane pump gas.


Usually, the leaner the fuel mixture is the more power the engine makes-albeit at the risk of destructive detonation. A fatter air/fuel ratio is safer but delivers slightly less power and more easily fouls spark plugs. Before testing began, the engine was jetted to deliver a real-world air/fuel ratio of about 12.9:1 rather than a race-type, extremely lean ratio of about 13.4:1.


After jetting was completed, a fresh set of Bosch platinum spark plugs was installed moments before distributor testing began. Fresh plugs, gapped at the factory recommended settings (0.035-inch, points; 0.045-inch stock HEI; 0.055-inch Performance Distributors HEI) insured that no distributor setup was unfairly saddled with a set of fouled plugs.


For all distributor tests a set of Performance Distributors Live Wires 8mm spark plug wires were used to eliminate variables and prevent any misfiring mishaps.


<strong>Test 1: Points Distributor</strong><br /> We first tested a brand new, stock breaker points distributor with a traditional vacuum advance mechanism and adjustable points. Factory specs call for between 28 to 32 degrees of dwell, so we set our dwell in the middle at a real-world 30 degrees. Lower dwell, which also means less point gap, tends to help prevent the points from floating and mistriggering at high rpm but generates a less powerful spark.


Although there are lots of aftermarket "hot" coils available, for a fair comparison we used a brand new, stock GM Delco Remy coil during testing.


Power output between distributors was expected to be very close, so Westech Performance owner, John Baechtel, closely monitored engine stats during testing to ensure consistency. Each dyno pull cycled the engine between 3,500 and 7,000 rpm with Baechtel keeping a close eye (and keen ear) out for the presence of high rpm ignition misfire. All three distributor setups did misfire (points and stock HEI around 6,400 rpm; Performance Distributors HEI at 7,000 rpm) during testing which affected power output-but hey, that's what our real-world testing was trying to identify. The points distributor generated a peak 444.8 hp at 6,800 rpm.


<strong>Test 2: Stock HEI Distributor</strong><br /> HEIs are a direct bolt-in for traditional GM small- and big-block V-8s (there are also four- and six-cylinder versions) but sometimes present a distributor-to-firewall clearance problem due to their larger diameter. Cap size is larger for two reasons: to space out the terminals to help prevent misfire and to house a built-in coil and module. Many older musclecars have either a ballast resistor or special resistance wiring reducing voltage delivery to the coil. When retrofitting an HEI to an older musclecar, you must ensure that the HEI is powered by full charging system voltage.


HEI distributors deliver more spark energy, but to take full advantage of the extra zap requires widening the spark plug gap. Since we were using a stock HEI for this test, we gapped the plugs at a stock gap of 0.045-inch. Afterward, we dyno tested the setup and found that the stock HEI produced 446.0 hp-about 1.2 more hp over the points distributor setup. We also made a few pulls with the same 0.035 gap as with the points distributor, and the results were essentially identical as with the 0.045 gap.



<strong>Test 3: Performance Distributors HEI Distributor</strong><br /> Time for the big firepower-an aftermarket hi-po HEI distributor. We installed a Performance Distributors Street/Strip HEI (PD also offers a special, hotter spark Racing HEI under PN 127211) that delivers a hot 50,000 volt coil and a special cap/rotor combo. PD claims their Street/Strip HEI is good for 7,000 rpm which is almost true-ours crapped out at 6,900. Most stock HEIs deliver about 30,000 volts output and typically begin misfiring above 6,000 rpm.


Performance Distributors recommends that the plug gap be opened up to 0.055-inch (which we did) to take full advantage of their Street/Strip HEI. After double-checking the timing, the Performance Distributors unit churned out a peak 452.8 hp-6.8 hp more than the stock HEI, and 8 more hp than the points setup.


<strong>Plug Wire Test</strong><br /> We got to wondering if there is really any difference between stock and aftermarket plug wires. To find out, we dyno-tested our mule engine with two sets of wires: new stock replacement 7mm plug wires and aftermarket 8mm wires. With the points distributor setup, we back-to-back dyno-tested each set of wires three times and found there was a difference: The stock wires produced a peak power of 441.3 hp, while Performance Distributors Live Wires delivered 444.8 hp-a 3.5hp increase. If you're running a hotter ignition (such as an HEI or an aftermarket ignition box) there may be even more of a difference because more spark energy will be shuttled through the wires. Cruddy wires with carbon-core conductors provide more resistance (and get even worse with age), while aftermarket spiral-metal-core units won't bottleneck the juice
Orich

 

Thanks Orich.
I can sure think of bolt-ons and simple mods that can get more than 6 horse at 5000 rpm.

But nonetheless..

Thanks

 

I thought 11.5 HP with wires was quite nice for the performance HEI setup. For me there was some other benefits for switching, idle smoothed out, acceleration was quicker and more crisp, slight increase in fuel mileage, and no crappy points and condenser any more.


I went originally with the DUI, which made a nice difference for me. I ran into the issue of the distributor hanging over the temp sensor though, and of course I needed to run a longer sensor, plus I needed 2 sensors. Pulled the DUI and put a Pertronix whole billet distributor in, and it was a nice unit as well, along with their wires and coil. When I went to the MSD Atomic EFI, I wanted to also control the timing via the computer and unfortunately couldn't use the Pertronix, so I had to switch over to the MSD pro billet unit with a phasable rotor and a MSD 6AL box. Really nice to adjust the initial, vacuum advance, ported or non ported and centrifugal all by the handheld now.


I have a couple distributor setups for sale now ..

 

I always carried my points just in case of petronix failure, as many cautious people do. But I've never heard of anyone needing to put them back in. I got 5 years and 40,000 miles on the last truck before I sold it and didn't have to look at a huge ugly chevy thing when I opened the hood.

 

to each their own ,

 

I don't have a Pertronix, although, I did install one in a '67 Mustang that belongs to a guy in a neighboring town.

If I did have one, I would just carry a spare Pertronix module in the glove box. It would be far simpler to swap out than trying to fumble with and set up points --since it seems many unfortunate circumstances with old engines happens after the sun goes down and you can't see what you're doing under the hood.

 

Carrying a spare is great insurance that you will never need it,lol. When I did my first conversion from points on my trusty old 72, I used all Duraspark II components and mounted 2 modules on the fender just in case. Of course it never needed the second one.