Re: Viking Engine?
Posted: Fri May 30, 2014 1:05 pm
Several things that everyone should keep in mind when reading specifications about engines.
First you need to compare engine weights that are ready to fly, that includes alternators, starters, exhaust, intakes, carbs, ignitions, oil, oil coolers, (radiators and water for liquid cooled). Remember water at 8lbs per gallon can really add weight. Many manufacturers list their engine weights for a basic engine, no fluids and no "accessories".
Another item to check is what RPMs do the engines make their claimed horsepower, some engines claim their horsepower at numbers like 3400+ rpm, which is going to be hard to obtain statically with most props.
Finally, propellors are matched to an aircraft, engine, and mission. A propellor that works great on something like a Pietenpol probably isn't going to work as well on a Panther with the same engine. And of course a prop for cruising, won't necessarily be the best for high speed or climbs. Finding the right prop can be a real challenge, and take a lot of time and money to optimize performance.
Unfortunately, there is a tendency for many people to exagerate higher performance for their car, airplane or boat on the internet, than they really can do. So check around and compare.
First you need to compare engine weights that are ready to fly, that includes alternators, starters, exhaust, intakes, carbs, ignitions, oil, oil coolers, (radiators and water for liquid cooled). Remember water at 8lbs per gallon can really add weight. Many manufacturers list their engine weights for a basic engine, no fluids and no "accessories".
Another item to check is what RPMs do the engines make their claimed horsepower, some engines claim their horsepower at numbers like 3400+ rpm, which is going to be hard to obtain statically with most props.
Finally, propellors are matched to an aircraft, engine, and mission. A propellor that works great on something like a Pietenpol probably isn't going to work as well on a Panther with the same engine. And of course a prop for cruising, won't necessarily be the best for high speed or climbs. Finding the right prop can be a real challenge, and take a lot of time and money to optimize performance.
Unfortunately, there is a tendency for many people to exagerate higher performance for their car, airplane or boat on the internet, than they really can do. So check around and compare.