Petronix Flame-Thrower

[ossieoz]

I have 2 Flame-Thrower coils. One is 1.5 ohm and the other is 3.0 ohm.

Can these be used (if a ballast resistor is used) on a Corvair?

Getting yes/no when I check out on the Internet.

Petronix says yes... but says the 1.5 is for a V8?

Any info/help appreciate


1961 Greenbrier, 1962 Rampside and 1964 Monza cab.

[66vairguy]

I'm not surprised about the Petronix confusion on the internet. I'm still amazed by the amount of incorrect Petronix information out there.

While Petronix instructions and catalog have improved, specific make information is still vague.

You may have this information - Ballast (wire) on Corvairs is 1.8 ohms (tolerance is tight). The GM coils have a broader range, but the average is 1.35 ohms for an average total 3.15 ohms. Yes the Flamethrower 1.5 ohm will work with the Corvair ballast.

The 3.0 coil is for use in cars without a ballast (wire). Sadly Petronix listed the 3.0 ohm coil for "Six Cylinder Engines" when many modern sixes in the 1960's and later used coils with a ballast resistor. So I find 3.0 coils in Corvairs that have "problems" which are usually just caused by weak spark plug firing due to the incorrect coil.

BTW - My experience with Petronix coils indicates up and down quality issues over the years. I just use a quality coil specified for a 1960's Chevrolet V8. It would be nice if all the different coils GM specified for different engines were still made, but now it is basically a one size fits all with new coils. That said I've had no issues using the Petronix Ignitor (sometimes called the Petronix I) with a stock Chevy V8 coil on non-turbo engines. With the Turbo engines moving up to a newer ignition system is suggested.

I don't recommend the Petronix II for a Corvair, as it not needed and too many issues to deal with.

[ossieoz]

I'm not surprised about the Petronix confusion on the internet. I'm still amazed by the amount of incorrect Petronix information out there.

While Petronix instructions and catalog have improved, specific make information is still vague.

You may have this information - Ballast (wire) on Corvairs is 1.8 ohms (tolerance is tight). The GM coils have a broader range, but the average is 1.35 ohms for an average total 3.15 ohms. Yes the Flamethrower 1.5 ohm will work with the Corvair ballast.

The 3.0 coil is for use in cars without a ballast (wire). Sadly Petronix listed the 3.0 ohm coil for "Six Cylinder Engines" when many modern sixes in the 1960's and later used coils with a ballast resistor. So I find 3.0 coils in Corvairs that have "problems" which are usually just caused by weak spark plug firing due to the incorrect coil.

BTW - My experience with Petronix coils indicates up and down quality issues over the years. I just use a quality coil specified for a 1960's Chevrolet V8. It would be nice if all the different coils GM specified for different engines were still made, but now it is basically a one size fits all with new coils. That said I've had no issues using the Petronix Ignitor (sometimes called the Petronix I) with a stock Chevy V8 coil on non-turbo engines. With the Turbo engines moving up to a newer ignition system is suggested.

I don't recommend the Petronix II for a Corvair, as it not needed and too many issues to deal with.

Perfect info, thanks :)


1961 Greenbrier, 1962 Rampside and 1964 Monza cab.

[bbodie52]

TO BE OR NOT TO BE... THAT IS THE QUESTION (With regard to leaving the Corvair factory ballast resistor wire in the circuit with a custom ignition system).

• NOTE: REMOVE OR BYPASS EXTERNAL BALLAST RESISTOR OR RESISTANCE WIRE WHEN INSTALLING THE RECOMMENDED FLAME-THROWER COIL.
• Do NOT remove the ballast resistor or resistance wire if the primary resistance is lower than specified or if you are using the stock coil.
• Pertronix Ignitor Operating Voltage: 8-V to 16-V DC

The Pertronix instructions are recommending a full 12 VDC voltage feed to all of their high output coils, and those listed on the chart begin with the assumption that any ballast resistor or resistor wire in the vehicle primary ignition wiring has been eliminated as a basis for the Pertronix equipment installation. If one exists, Pertronix wants it removed or bypassed. Their recommendation chart assumes that all primary current control resistance is to be provided only by their coil internal primary winding, with 1.5 ohms for a V8 and 3.0 ohms for a 4 or 6 cylinder engine. (This sets the stage for proper support of both the Flame-Thrower coil and the Ignitor distributor electronic module — providing 12 VDC for both). Pertronix then compensates for differing engine configurations (8 cylinder vs. 6/4 cylinder) by recommending different high performance coils (1.5 ohm primary resistance for a V8, and 3.0 ohm primary resistance in the coil for a 6 or 4 cylinder engine). The 1.5 ohm primary winding coupled with a V8 engine short duty cycle and 12 VDC power source produces the advertised 40,000 volt secondary output to the spark plugs. The same coil connected to a 6 or 4 cylinder engine, with its longer duty cycle, would allow excessive primary charging duration — more than needed to attain a 40,000 volt output from the secondary winding. The results would be more heat buildup within the primary coil, which could shorten the life of the coil.

Switching to a 3.0 ohm coil primary resistance coupled with a 4 or 6 cylinder engine duty cycle would reduce the current flow, but the charging cycle for the primary would be lengthened by the longer 6/4 cylinder duty cycle, which again should reach the desired 40,000 volt secondary output because of the longer duty cycle expected with fewer cylinders. The reduced current with 3.0 ohms of primary resistance would keep the coil within designed heat parameters. The factory stock design configuration that switches to a high output voltage provided by the starter solenoid during cold start cranking would not be needed, because 12 VDC would be present at all times at the new high performance coil input, providing the advertised 40,000 volt high output to the spark plugs. The Pertronix Ignitor module would eliminate concern about rapid decay of the points contacts when subjected to 12 VDC.





NOTE: IN THE ABOVE CHART THERE IS SOME ROOM FOR CONFUSION, BECAUSE UNLIKE THEIR FIRST CHART THAT INDICATES "IGNITOR ONLY", THE SECOND CHART INDICATES "IGNITOR OR POINTS" IN THE FIRST SECTION. The Flame-Thrower 3Ω coil would reduce the current that the points would be exposed to, so excessive point wear would be prevented.

Flame-Thrower II coils feature a super low resistance which make them the ideal coil for Ignitor II ignition systems as well as many other high energy ignitions. Low resistance and improved turns ratio help to produce up to 45,000 volts. This higher voltage enables you to run larger spark plug gaps for added power and better fuel economy.

These coils have internal windings that were designed to tolerate more heat with ultra-high current flow produced when coupling 12 VDC with only 0.6 ohms of internal primary resistance. The high switching current seen with such a coil would quickly destroy ignition points, and the Pertronix Ignitor internal circuitry was also not designed to tolerate this much primary current. The Ignitor II was beefed up with a switching transistor circuit and dwell control electronics that can tolerate the higher expected current when using a Flame-Thrower II coil. Connecting such a coil to a factory ballast resistor or resistor wire would not only cancel such a high output secondary voltage by reducing the primary current, but it would likely overheat the resistor wire or ballast resistor with an internal coil primary resistance of only 0.6 ohms, instead of the stock coil internal primary resistance of 1.28 - 1.42 ohms expected by engineers when they designed the factory wiring.

Of course I am making assumptions based on the technical specifications and installation instructions published by Pertronix. Many installation decisions are left to the installer, without really explaining why these different combinations of aftermarket ignition components and the variables seen in factory wiring may cause problems if the purchaser and installer doesn't understand the implications of incorrect wiring. Crane Cams, with their optical trigger ignition system, designed the electronics in the XR700 to operate with the lower expected voltage when the resistor is left in the circuit. (In fact, it can overheat if connected to 12 VDC). Their XR3000 is similar to the Pertronix Ignitor II in its high performance design that tolerates ultra-low resistance performance ignition coils.

The XR700 requires ballast resistance to limit coil current. The XR3000 is a high performance version with a computer chip that controls coil current and dwell. When installing an XR3000, all OE ballast resistance must be bypassed.

When in doubt, a phone call to Pertronix can clear things up...

Technical Assistance
440 East Arrow Highway
San Dimas, CA 91773
Phone: (909) 547-9058
Fax: (909) 599-6424

To summarize, the goal (from the Pertronix viewpoint) is to eliminate both the standard ignition points and condenser AND the stock coil AND the stock ballast resistor wire in the wiring harness. This leaves you with a full 12 VDC feeding the Pertronix Flamethrower high performance coil and the Pertronix Ignitor or Ignitor II electronic breakerless ignition module. With a six-cylinder engine in this configuration the 3.0 ohm Flamethrower coil would control its own internal primary winding current to restrict heat buildup when attached to a six cylinder engine.

It is common to tap off of the ignition coil positive terminal to power the electronics in the breakerless ignition module. That electronic circuit in the Pertronix Ignitor or Ignitor II module needs a full 12 VDC all the time. If the factory ballast resistor wire were to be left in the wiring harness, the voltage feeding the coil and the Pertronix module in the distributor would be correct for a 1.5 ohm coil (nominal 3.0 ohms total) but too low for proper operation of the electronics module inside the distributor, and a malfunction in operation could result.

This diagram shows a suggested bypass of the Corvair factory ballast resistor wire to power a 3.0 ohm coil and a Pertronix distributor module. This lets the 3.0 ohm coil take care of restricting primary current for cooler operation with the six cylinder engine, while the Pertronix Ignitor module in the distributor is happy with a full 12 VDC all the time when the key is ON.

Left-click the image to enlarge for better viewing...

[bbodie52]

If I haven't confused you already, here are a couple of other suggestions and ideas...

It is not a bad idea to relocate the coil mount position at the same time. The standard installation of the ignition coil was always mounting it directly on the right cylinder head. The cylinder head on an air cooled engine gets very hot, and a significant portion of that heat can be transferred via the coil mounting bracket to the coil itself. If you decide to replace your coil, I would recommend relocating it as shown in the pictures below at the same time.





An upgrade to a breakerless ignition system such as the Pertronix (Magnetic Trigger) systems or the Crane Cams (Optical Trigger) system is a good choice. Both have been around for many years. I tend to prefer the Crane Cams system. The Pertronix II has some known problems with a slow idle that is often found in Corvair Powerglide-based engines under load (in drive). The Crane Cams electronic module is designed to be powered with the reduced voltage provided via the ballast resistor in the ignition circuit, and may overheat if powered by a full 12 VDC. The Pertronix units require a full 12 VDC power source, bypassing the ballast resistor in the circuit.

However, there is a "new kid on the block" that in many ways supersedes the older designs. The new Stinger distributor offered by Performance Corvair (Seth Emerson) completely replaces the decades-old worn Corvair distributor with a modern design that is tuneable and includes a breakerless (magnetic pulse) ignition system in the distributor. By the time you overhaul and clean up an aging Corvair distributor and add a Pertronix or Crane Cams upgrade, you are reaching the price of a brand new Stinger distributor system. I would suggest that the Stinger distributor is a better choice.

https://www.perfvair.com/stinger-ignition-distributors/

Finally, an all-new replacement distributor for the Corvair. All-electronic High Energy ignition system included. Magnetic-pulse pickup triggers internal electronics. No ugly boxes in the engine compartment. Has Vacuum advance and adjustable mechanical advance. Complete Ready-to-Run system – Self contained. Vacuum block-off plate included for competition. Uses easily available GM parts and aftermarket accessories. Update to any 12 volt coil or add a high performance Coil. Optional cap designs and color for HEI cap or OEM style well-type cap. New 12 Volt coils available in Red, Black or Blue or Chrome! Cap clears top shroud and fan belt pulleys.

The Distributor sells for $200

Performance Corvairs / Silicone Wire Systems
Seth Emerson
3462 Kirkwood Dr.
San Jose, CA 95117

Phone: (408) 247-2237

E-mail: sethracer@aol.com

[ossieoz]

If I haven't confused you already, here are a couple of other suggestions and ideas...

It is not a bad idea to relocate the coil mount position at the same time. The standard installation of the ignition coil was always mounting it directly on the right cylinder head. The cylinder head on an air cooled engine gets very hot, and a significant portion of that heat can be transferred via the coil mounting bracket to the coil itself. If you decide to replace your coil, I would recommend relocating it as shown in the pictures below at the same time.





An upgrade to a breakerless ignition system such as the Pertronix (Magnetic Trigger) systems or the Crane Cams (Optical Trigger) system is a good choice. Both have been around for many years. I tend to prefer the Crane Cams system. The Pertronix II has some known problems with a slow idle that is often found in Corvair Powerglide-based engines under load (in drive). The Crane Cams electronic module is designed to be powered with the reduced voltage provided via the ballast resistor in the ignition circuit, and may overheat if powered by a full 12 VDC. The Pertronix units require a full 12 VDC power source, bypassing the ballast resistor in the circuit.

However, there is a "new kid on the block" that in many ways supersedes the older designs. The new Stinger distributor offered by Performance Corvair (Seth Emerson) completely replaces the decades-old worn Corvair distributor with a modern design that is tuneable and includes a breakerless (magnetic pulse) ignition system in the distributor. By the time you overhaul and clean up an aging Corvair distributor and add a Pertronix or Crane Cams upgrade, you are reaching the price of a brand new Stinger distributor system. I would suggest that the Stinger distributor is a better choice.

https://www.perfvair.com/stinger-ignition-distributors/

Finally, an all-new replacement distributor for the Corvair. All-electronic High Energy ignition system included. Magnetic-pulse pickup triggers internal electronics. No ugly boxes in the engine compartment. Has Vacuum advance and adjustable mechanical advance. Complete Ready-to-Run system – Self contained. Vacuum block-off plate included for competition. Uses easily available GM parts and aftermarket accessories. Update to any 12 volt coil or add a high performance Coil. Optional cap designs and color for HEI cap or OEM style well-type cap. New 12 Volt coils available in Red, Black or Blue or Chrome! Cap clears top shroud and fan belt pulleys.

The Distributor sells for $200

Performance Corvairs / Silicone Wire Systems
Seth Emerson
3462 Kirkwood Dr.
San Jose, CA 95117

Phone: (408) 247-2237

E-mail: sethracer@aol.com

Thanks for the info... i want to stay with points.

The reason why i’m asking about flame-thrower coil is that i bought a new coil (that doesn’t need a ballast resistor) for my 102hp... drove to a friends house about 40 miles away, put my foot to the floor and it went well :) but about 50mph and foot still on the floor it lost power. I was thinking that it might be a carb problem. Got close to my friends house and stopped at a red light... engine died and was really difficult to start again.

Drove home after a few hours at my friends place, adjusted the idle to be higher and set off home. The Greenbrier/102hp engine seemed to get worse on the way. Managed to just about get home. Pulled out a new condenser (as that was the only old bit) and attached my timing light to check everything was where it was supposed to be... nothing... not a blink from the light. Felt the coil and it was hot... switched coil and test drove the Greenbrier... blam it went like a rocket. No dead spot at higher revs and no stalling.

I must have got a bad coil... or ???

Wanted to check if i’d wear out my points early if I used the 1.5 ohm flamethrower


1961 Greenbrier, 1962 Rampside and 1964 Monza cab.

[bbodie52]

Wanted to check if i’d wear out my points early if I used the 1.5 ohm flamethrower

Not if the standard Corvair ballast resistor wire is still present in the circuit. A total of 3.0 ohms is needed — either ½ provided by the ballast resistor and ½ provided by the coil, or all of it provided by a 3.0 ohm coil. A 3.0 ohm coil coupled to a circuit that also has a ballast resistor would produce a total resistance of approximately 4.5 ohms, which would weaken the coil output to the spark plugs excessively.

BACKGROUND:

Ignition points begin to decay the moment they are placed into service. They are a basic on/off switch that carries a significant amount of electrical current. The electrical current is a product of the source voltage and the internal resistance of the ignition coil primary winding. More voltage produces more current through a given circuit resistance. Less resistance in the coil primary also produces more current flow. The higher the current that is being switched on and off by the ignition points, the greater the tendency for the points contacts to arc, burn, and pit.

A coil that produces a higher voltage output from the secondary winding to the spark plugs needs a greater current flow in the primary winding to do so. So an ultra high output coil like the Pertronix Flamethrower II is designed to run hot, to dissipate more heat without internal damage, and has a primary resistance of only 0.5 ohms. To produce a maximum output voltage to the spark plugs, it requires a full 12 VDC power source. Ignition points cannot handle such high current levels, and would quickly self-destruct. A switching circuit (breakerless electronic ignition system) that substitutes a high current capacity power transistor for mechanical ignition points is essential for such a high-powered coil.

A standard ignition circuit in a Corvair incorporates a nominal 1.5 ohm ballast resistor in the circuit to reduce operating input voltage to the standard coil, that also adds another nominal 1.5 ohms of internal coil primary resistance to the circuit (for a total of 3 ohms). This produces a coil that operates with a reduced primary voltage of approximately 7 VDC. This has been determined to produce a optimum operating engine spark plug voltage while also allowing the coil to run at a cooler operating temperature, and also extends the service life of the ignition points since the arcing and burning that occurs as the ignition points open and close to charge and discharge the coil is much-less at 7 VDC than it would have been at 12 VDC. The secondary spark voltage is lower, but acceptable for an operating Corvair engine with its relatively low RPM range and low compression ratio. (A racing engine usually runs much-higher combustion chamber pressures associated with higher compression ratios and higher rpm racing speeds. Such an engine demands higher spark plug voltages to function).

So the standard Corvair street engine (non-turbocharged) does fine with a total of 3.0 ohms in the primary circuit to limit the current in a 12 volt electrical system. ½ of the resistance (nominal 1.5 ohms) comes from the ballast resistor wire in the wiring harness. The other half of the 3.0 ohms comes from the ignition coil internal primary winding resistance. All of the 3.0 ohms could come from a 3.0 ohm coil, but such a design would require the elimination of the external primary ballast resistor wire so that a full 12 VDC is fed to the positive terminal of the ignition coil.

The use of an external ballast resistor in the primary circuit allows that portion of the resistance to be switched in and out of the circuit. This is done by the starter solenoid, which bypasses the external ballast resistor when the engine is being cranked to start the engine. This temporarily feeds a full 12 VDC to the coil to temporarily boosts the secondary voltage output to the spark plugs, which makes it easier to start a cold engine. As soon as the engine starts, the driver releases the key, which disengages the starter solenoid, which in-turn eliminates the ballast resistor wire bypass and reduces the coil primary voltage back to a nominal 7 VDC (which makes the ignition points happy).

As the points age, the continuous arcing, pitting and burning that accumulates on the contacts causes changes in dwell and ignition timing. Periodic tune-ups allows the points to be adjusted to compensate for wear and decay, to bring the dwell and timing back to desired standards. Eventually the points decay so much they must be replaced to start the process over again. An electronic breakerless ignition system eliminates the points and substitutes a transistor switching circuit that is triggered by either a magnetic pulse or an optical trigger, which does not wear and produces consistent ignition system operation, usually for many thousands of miles of operation. That is why modern automobiles no longer utilize ignition points, but substitute a computer-controlled breakerless ignition system.

For more information about ignition system contact points, see pages 8-28 through 8-30 of the attached 1961 Chevrolet Corvair Shop Manual - Section 8 - Electrical Systems

[66vairguy]

Brad - While you usually do a good job of helping out, your over supply of Petronix information was confusing and not helpful.

[bbodie52]

When I write a response it is not necessarily only written for a single reader or just the original questioner. I realize that the original questioner does not intend to install an electronic breakerless ignition system and that he will continue to use standard points. I tried to answer his question at the beginning by saying that a 1.5 ohm Pertronix Flamethrower coil. with its primary resistance a comparable match to a stock GM Delco coil (1.28-1.42 ohms), should work fine with a standard unmodified Corvair wiring harness with its integrated ballast resistor wire. This configuration will not cause premature wear of the points and will make proper use of the original factory ballast resistor bypass feature to boost the coil cranking spark plug voltage while the starter is engaged. The Pertronix 1.5 ohm coil will be operating with a total primary resistance of 3.3 ohms (Pertronix coil (1.5 ohms) plus Corvair wiring harness resistor wire (1.8 ohms)).

I assume that there are many other silent readers who might want to understand ALL of their options when considering the full Pertronix system offering and want to know why each feature is offered, what are the benefits of each Pertronix component, why the Pertronix instructions are written the way they are, and how to modify the stock Corvair ignition system to ensure the proper configuration is established to ensure that a Pertronix aftermarket system works properly. Misunderstanding the Pertronix instructions can lead to a malfunctioning system, premature component failure, etc. For those who want a complete Pertronix breakerless system, The Pertronix Ignitor electronic module coupled with a Pertronix 3.0 ohm Flamethrower coil, and a harness wiring modification that bypasses the Corvair resistor wire will get the job done.

[lostboy]

In my 1961 80hp Ive been using a 1.5 ohm with points for about 2 years and just this winter installed a Mallory Hyfire which is triggered by the points with the same 1.5ohm flamethrower and it's been great. No issues at all, knock wood.

Sent from my LG-H931 using Tapatalk

[ossieoz]

In my 1961 80hp Ive been using a 1.5 ohm with points for about 2 years and just this winter installed a Mallory Hyfire which is triggered by the points with the same 1.5ohm flamethrower and it's been great. No issues at all, knock wood.

Sent from my LG-H931 using Tapatalk

Thanks for the info Lostboy


1961 Greenbrier, 1962 Rampside and 1964 Monza cab.

[Bill MC]

The Stinger distributor made an incredible improvement in my overall performance and drivability.
Highly recommend the switch.