I am building a database, and PoA user’s input is required. So, a very important measurement, albeit under utilized, is the Cylinder Index. The Cylinder Index, (CI for short) is a measure of one's Otto Cycle machines (4 stroke), Clerk and Day cycle (2 stroke), Wankel engines (rotary), Brayton/Juul (6 cycle), and continuous combustion (gas turbine, rocket). Before we continue, we must pay homage to Joe Soucheray, for giving us such Garage (Hangar) Logic. The basic CI interpretation is simple: How many reciprocating cylinders does one keep that turns that reciprocating motion into useable rotary work. “Useable,” in this instance, shall always be defined by the very user of the cylinder. Very easy examples to follow: I am the soul keeper of a Chevy V8 that powers my RV. Therefore, I have a CI of 8. Or: I am the soul keeper of 13 leaf blowers for my noise making business. Therefore, I have a CI of 13. And: I am the soul keeper of a museum of 7 Felix Millet motorcycles, 2 are daily demonstrators, 5 are on display. Therefore, I have a CI of 35. These simple rules are no longer simple in this modern age of word definitions, concern for the engines that do not provide current work, and a compensation values for non-reciprocating ICE’s. Thus, we must place a few rules to keep the CI trending towards relevance. To make my DB relevant, some extra simple rules must first be defined. Rule 1 Keeper: A person who manages, or looks after the cylinders. If the responsibility is shared by other keepers, the CI value must be divided by the number of individuals who are also keepers. Example: My boat charter fleet has 156 cylinders with 5 mechanics including myself. Therefore my CI is 31.2*. Rule 2 *Well, since we cannot have anything but integers, the .2 must be rounded down to 31, and the spare single CI (1) vanishes and cannot be counted, ever. Fractions will always be rounded down. Rule (exception) 3 Wankel type engines: These peculiar ICE’s are a special case. Usually two lobes and their associated elliptical cylinder are fused together. A ratio must be used to compensate for the eccentricity of the cylinder, and that ratio is 1:1.2. Therefore, if one has a Mazda with the Wankel engine, the CI value will be 2.4. Again, the integer rule applies here. Rule (exception) 4 Rocket engines: Since they are an ICE, usually in cylinder form, (and without getting into the Newton formula for a conversion factor for hangar type discussions) the CI will simply be the length of said rocket propulsion system. Ex: My BigBertha Amateur Built solid fuel rocket is 3.5m tall. The engine system is .5 meters long. Therefore, my CI = .5 x (the number of expendable, single use, propulsion systems one is the keeper for + re-useable systems). Yes, this one gets a bit labor intensive. Rule (exception 5) Turbo-propeller engines. The layman in the hangar would logically assume that this CI is 1 per engine. However, this is where the exception of equivalent horse power (not torque!) must be assessed. The *rated* HP of the turbo-propeller engine shall be divided by 100 to reveal an equivalency measure for an accurate CI. Example: Draco has a 680 SHP continuous combustion engine. Therefore, it has a CI of 6.8. Again, applying the integer rule, it must be rounded down to 6. This is a much higher value than 1, and is considered a gesture of “good will.” Be thankful for this exception, turbo-prop keepers. Rule 6 Jet: The number of combustion chambers shall determine the CI without a conversion factor. The 4 combustion chambers shall be: Can, Cannular, Annular, or Double annular. Ex: My wife flies an ME-262, and I am the menchaniker for the 2 on the wings, and the 2 on the hangar floor. My CI is 24. Or: My Premiere 1 has a CI of 4. Sorry, no additive or multiples for “coolness” or “yeahbuts.” Rule 7 Electric engines (motors) are out right NA. Common commentary is important for leading the DB inputs. Remember, there are no rules for for currently “non-working” cylinders - only useable. Owner vs. Keeper, an important distinction. Others shall remark on the suitability of another’s CI if warranted, (or not). Under no circumstances shall one’s CI be influenced by another if the accuser's CI is greater than the defendant's, regardless of the veracity of the influence, unless warranted. CI to Vehicle ratio is a value that has no real value, unless it can be valued by others. The goal of the DB is to determine a logical “awesomeness [term in progress]” value. Where is the cross-over from one level to another? Where is the line between “not enough” and “whoa dude, have you seen a mental health professional about this?” This is the real unknown that needs a definition. My CI: 37 Truck +8, Jeep +6, RV +8, B24R +4, her car +4, KLX300 +1, RC engines +5, broken weed whacker +1.