Ignition Protection, it’s all about safety!

Many of our customers give us a curious expression when we mention that our late model Delco starters are “Ignition Protected”. Confusion only grows when we mention that the starter they purchased at their local auto parts dealer is more than likely not ignition protected, and really shouldn’t be used on their Atomic 4. While it’s true that keeping flammable fumes out of your engine compartment is the surest way to prevent an explosion, ignition protection is a very effective and inexpensive way to prevent an explosion in the event that gas fumes ever fill your engine compartment without you being aware of them.

As an Atomic 4 owner, it is to your benefit to understand what ignition protection is all about.

Ignition Protection came on the scene in 1978, when the Coast Guard began requiring that all spark producing equipment used on marine engines comply with “SAE J1171”, a very specific protocol for spark producing components, which on the Atomic 4 includes the starter, alternator, distributor, and electronic fuel pump. All of these components when sold by Moyer Marine, whether through our catalog, or on a rebuilt engine are ignition protected, either by the manufacturer, or as a modification done by Moyer Marine (as in the case of Delco starters).

For the purposes of this tech tip, we’ll be focusing on late model Delco starters, in the hope that you’ll be able to transfer the knowledge to other spark producing components. 

You may also find Ignition Protection easier to understand if we look at what happens inside a starter without Ignition Protection in the event that undetected gas fumes (for whatever reason) have built up, until reaching an explosive mixture within an engine compartment … 

… Gas fumes within the engine compartment will find their way into the interior of the starter motor through the open nose cone. Then, during starter operation, sparks from the brushes will ignite the explosive mixture within the motor section of the starter. Whenever such an explosion occurs inside a non-ignition protected starter, the flame pattern will quickly escape through the open nose cone and ignite the explosive atmosphere within the rest of the engine compartment with devastating results. 

The underlying concept of ignition protection is to control an explosion inside the starter, preventing it from igniting fumes in the engine compartment.

SO HOW IS IGNITION PROTECTION DESIGNED INTO A STARTER?

The first step is to install a steel disk between the motor and nose cone. A brass bushing in the center of the steel disk creates a partial seal around the shaft of the armature. We also install a rubber gasket between the solenoid and nose cone, and a hard rubber grommet around the electrical lug between the solenoid and starter motor.

NOTE: These modifications do not stop, but only slow the escaping gasses during an explosion within the starter, so that the flame pattern will cool off below the ignition point and not ignite the explosive atmosphere within the engine compartment itself.

Below, two late model Delco (pre-1978, non-ignition protected) starters on the way to our rebuilding shop. Both will be modified and sold as rebuilt starters in accordance with regulation “Marine SAE J1171”.

THE SAE J1171 TESTING PROCESS

Before we could label or market any starter as being ignition protected, a sample of the starter, along with a detailed report of how it was modified, had to be submitted to an independent testing laboratory for a thorough (and very expensive) functional test as follows:

1) The starter to be tested is equipped with a fitting and tubing to supply an explosive mixture inside the starter. 2) The sample starter is then mounted inside a strong steel chamber (the approximate size of one of our engine compartments). This chamber is in turn filled with the same explosive mixture being supplied to the inside of the starter.
3) The starter is then operated until an explosion is confirmed to have occurred inside the test starter. To pass the test for Ignition Protection, the overpressure and flame pattern of the explosion within the starter must be released without igniting the explosive atmosphere inside the steel chamber itself. This part of the test is repeated 50 times.

You may notice if you purchased a late model Delco starter from Moyer Marine, it will be labeled “Marine SAE J1171”. This label is required by the Coast Guard on all Ignition Protected equipment. 

We hope you now have a better understanding of Ignition Protection and what’s behind “Marine SAE J1171”… It really is all about safety! 

The underlying concept of ignition protection is to control an explosion inside the starter, preventing it from igniting fumes in the engine compartment.