EmptorMaven

Most modern cars have engine control computers and sensors that can tell not only whether your current tank of fuel is contaminated but also whether you would benefit from higher-octane gasoline. Yet few (if any) cars readily communicate those data to the driver. Why not?

Many car engines are designed with higher compression ratios that require “premium” gasoline for optimal performance. These cars can still run on lower-grade fuel: They rely on knock sensors to detect the failure of low-octane fuel to resist detonation and can retard ignition timing to counteract it. However this timing adjustment reduces engine efficiency and power, so typically drivers want to avoid it. (Conversely, higher-octane gasolines are sometimes sold at such a premium to regular that their higher cost might outweigh the efficiency benefit to engines tuned for them.)

But gasoline octane rating is not the only factor that determines safe engine timing. Air density, which decreases with altitude and temperature, also affects detonation. Fuel that works great in summer or mountains may bog your car down in cold or sea-level conditions. Only your engine knows for sure whether it’s running optimally, or whether it would benefit from a bump in your fuel tank’s octane.

Apparently some aftermarket engine computer interface devices (e.g., the ScanGauge or the DashHawk) can allow a driver to monitor engine timing retardation in realtime. Ideally manufacturers should convert these data into useful dashboard information. Perhaps something like, “Your current fuel is handicapping the engine. Increase tank octane by 2 for optimal performance in current conditions.”

Cleaning primer pockets of fired cases is part of the ritual of preparing accurate, reliable reloads.

RCBS sells a $15 Primer Pocket Brush Combo (Part #9574) for this purpose, consisting of a threaded handle and two threaded stainless steel wire brushes for each primer pocket size.  It is the first tool in the following photo:

The second tool shown is Lee’s $2 Primer Pocket Cleaner (Part #90101).  It is just a small blued steel cylinder with a squared-off blade on one side for small primer pockets and on the other side for large ones.

The following picture shows eight large-primer cases.  The left two have not been cleaned, showing the importance of this step of brass preparation.  The top three were cleaned with two twists of the RCBS tool, and the bottom three with two twists of the Lee tool.  I thought the RCBS would be more comfortable and easy to use, but after prepping a batch of brass I became much more concerned about what it was doing to my primer pockets:  As you can see the steel brushes leave noticeable gouges in the brass.  In contrast, the Lee tool keeps the pocket face square and relatively unscathed.

I can’t see any good coming of marring primer pockets to this degree.  Especially over repeated uses the RCBS brush is removing measurable amounts of brass, and if you didn’t need it the first time it will almost certainly be needed on subsequent cleanings since the primer pocket floor is no longer flat enough for a tool like Lee’s to make full contact.  Therefore I recommend against the RCBS tool. Lee’s much cheaper tool is a perfectly functional solution to primer pocket cleaning.