Engine

From Velocity Aircraft Wiki
Jump to: navigation, search

Here are some engine-related builder's tips.

Engine Installation Pictures

V8 Engine      V6 Engine      Subaru Engine      Franklin Engine      Mazda Engine

Engine Tutorial

A Simple Tutorial on Aircraft Engines (or the only thing between you and the ground)

Over the many years I spent building my Velocity I have either talked to a lot of builders or overheard comments about aircraft engines. I have heard or know most of the misconceptions and old wives tales about them. Most of all it has become obvious that many builders don't understand aircraft engines, engine documentation and most of all what a rebuilt engine is. To begin, if you know nothing about aircraft engines or their operation I strongly recommend you get a book on engines and read it. "Bingelis on Engines" is a good start and will probably save you its cost in time and money many times over. Most currently available aircraft engines are neither sophisticated nor use high tech materials. They are basically 1930-40's class truck and tractor parts. Another thing that is often misunderstood is an engine series. I will use Lycoming as an example, however, it applies to all makes. All of the engines in a series are not alike, for example the O & IO-360 series of engines vary radically in internal construction including such things as crankshafts, induction systems, oiling systems, etc. Additionally, engine manufacturers have and do make OEM engines that may be a price compromise and this may impact their durability. Lycoming made an O-320 with a dual magneto single drive for Cessna 172s that is known for poor durability. Forget all of the horror stories about engine failures and especially rebuilt engines and remember that the most destructive thing to the engine is the operator.

All new Lycoming and Continental engines are used when you get them, they go through dynamometer testing to ensure proper operation and construction. A new engine can be purchased through a kitplane manufacturer at very attractive prices not a lot more that a QUALITY rebuilt engine. A factory REMAN can be considered equivalent to a new engine, is a little less expensive and does come with a new logbook. Now on to rebuilt engines and my basic rules to remember.

1. Don't buy an engine without a log book except as a core for rebuilding. 2. Don't buy a rebuilt engine without a logbook, work order (list of exact things done including AD compliance), and anything sent out for rebuilding should have the yellow tags. The log book should be signed by the re builder including their FAA certificate number. 3. Never buy a takeout engine without a logbook under any circumstance. 4. Before you buy a used engine put down a small refundable deposit and take the log book to a reputable A&P to examine and advise you about the engine purchase. The few dollars spent here can save you a huge amount of money in the long run. 5. The Golden Rule - No Log Book RUN, don't walk, it isn't an aircraft engine, it is a boat anchor!!

Now lets look at overhauls. An overhaul in FAA terms can consist of nothing more than new GASKETS & SEALS so now you see why the work order is important. Keep in mind that the following four overhauls must use certified parts and parts certified for the specific engine.

1. Factory Reman - Can only be done by the manufacturer and is equivalent to a new engine. 2. Top Overhaul - basically a valve job but can include new rings and or pistons. The Crankcase is not opened and the bearings and camshaft and other internal parts are not inspected. 3. Overhaul - this is where the problems can really begin since it can range from all new parts to gaskets and seals. This is where it gets tricky and you want to understand exactly what you are getting. Now you understand why the work order and log book are so important. 4. Service Level Overhaul - this is the lowest form of an overhaul and it says that as long as the parts are within factory tolerances (there may only be another hour or less of life remaining) they can be reused.

Lastly we have the "Non Certified or Experimental Aircraft Overhaul". Here anything goes including parts from other than the same model, less that minimum tolerances, uncertified parts, the list goes on. This does not mean that you can't get a good non certified engine, however, you better buy it from a reputable rebuilder and you should know what you are buying.

This little tutorial wouldn't be complete without a war story. About 3 weeks ago I saw the rod end cap from a Lycoming IO-360 C1D6 just like mine. The cap rather than being concave was convex and the lower half of one cylinder was gone along with a large piece of the crankcase. The newly rebuilt engine (about 200 hours) had been rebuilt with a crankshaft ground three thousands of an inch undersize and standard size bearings used. Needless to say the engine pounded itself to death. This was a certified rebuild and was "a really good price". The FAA has pulled the rebuilders ticket and every engine he has rebuilt will have to be torn down at the owners expense. If you don't know about engines ask or hire a professional to help you, it may save your life. Jim

Motor-Driven Fuel Valves

POLLAK® MOTOR-DRIVEN FUEL TANK SELECTOR VALVES @ J. C. Whitney For fuel-injected systems operating up to 65 psi. Designed to prevent returning fuel to incorrect tank. Weatherproof fiberglass-reinforced nylon valve body. Valve grounds to frame. Meets or exceeds DOT standards. Fits 3/8" I.D. fuel hose. Recommended fuse: 10 amps. Can be wired so original dash gauge indicates fuel level in either tank. Includes: switch, faceplate, wiring connector, instructions. Hoses not included—order separately. 2 styles: 3- or 6- port. 6-port valve required on vehicles with 3 lines attached to fuel pump. For 12-volt systems.

SKU Description Unit Price 81ZX2705U Electric Fuel Tank Selector Valve, 6-port, Motor-driven Unit Price 52.95

Jim_Agnew_2 at Yahoo dot Com

Motor-Driven Valve


POLLAK® 3-PORT SOLENOID-ACTUATED FUEL TANK SELECTOR VALVE @ J. C. Whitney

I do not recommend this valve due to its inability to maintain position without power!!!

For systems operating up to 8 psi. Fits 5/16" I.D. hose. Recommended fuse: 1.0 amp. Weatherproof fiberglass-reinforced nylon valve body. Valve grounds to frame. Meets or exceeds DOT standards. Can be wired so original dash gauge indicates fuel level in either tank. Includes: switch, faceplate, instructions. Hoses not included—order separately. For 12-volt systems.

SKU Description Unit Price 81ZX2686W Electric Fuel Tank Selector Valve, 3-port, Solenoid-actuated Price $36.9

Motor-Driven Valve

Prudhomme Air Cleaner

Here are some pictures of Jean Prudhomme's circular air filter installation.

Exhaust

This section is for builder's tips and tricks related to exhaust.

Ferrell Exhaust Augmentors

Here is a gallery of my exhaust augmentation system. Basically, I didn't want to disturb the airflow around the airplane. This system does that, plus I get the "jet" of exhaust creating a small amount of thrust, and the augmentors aid cooling by creating (hopefully) a small suction of the cowling and expelling the cooling air out the prop circle (and cooling the exhaust air). Here is a article on augmentor design.

Prudhomme Aft-Facing Exhaust

Here are some pictures of Jean Prudhomme's conversion from a stock "down/rooster-tail" exhaust to an aft-facing one.

Ferrell LightSpeed Ignition

Here are some pictures on how I mounted my dual Lightspeed Engineering Plasma III, direct-crank-sensor ignition system. The controller boxes are mounted on the cold side of the firewall, with the sensor wire coming in the copilot electrical duct, and the coil output wires go out the pilot side duct.
Brett Ferrell, N44VF