35% Lost to Cooling and Lubrication

Engine Efficiency

Thermal Efficiency

35% lost to cooling and lubrication 35% lost to exhaust gas 5% loss in engine friction 10% loss in power train friction

End result %15 of gasoline power is applied to wheels!

Volumetric Efficiency

Amount of air that fills the cylinder VS how much can it hold?

Variables include intake, exhaust, and valve timing and sizes.

Other types of engine designs;

Atkinson Cycle Engine

Uses the idea that the intake valve is left open longer - past BDC compression. When used with a variable valve timing system, it allows control over engine displacement!

Highway = 2.0 L

WOT or high load = 2.5 L

Advantage, efficient Disadvantage requires variable valve timing and extra hardware.

Two Stroke Engines.

Every TDC stroke is a power stroke.

Advantage - more power per RPMs. No Valves.

Disadvantage - VERY dirty engine to run. Loud. Smoky. Poor cold running since engine runs so rich. Wastes fuel since some of it blows out the exhaust with each stroke No low RPM torque

Diesel Engines

Uses more fuel than air

1 All are injected Needs glow plugs to pre-heat fuel when cold Runs on compression, has no ignition system or spark Can run on Kerosene, Corn Oil, Peanut Oil. Uses a fuel pump to act as speed of engine

Advantages - Very efficient with the fuel it uses. Very high torque.

Disadvantages - “soot, noise” Water in fuel Dirt in fuel Vibration Thank GM….

Modern diesels are far better at being clean, and low noise generators.

Some diesels are as fuel (MPG wise) as a Hybrid, and do so w/o the electric motor and battery! Up to 60 MPG!

Rotary Engine

Felix Wankel Two Cycle design, however has no pistons and valves.

Uses two plugs per rotor Very high power w/small displacement Very high and never ending HP curve Limited only by speed of external engine parts

Advantages - 3 total moving parts!

Disadvantages - Seems to get 20 MPG Apex seal failure 60K miles Fairly dirty, older ones used 4 converters, inline…!

Miller Cycle

Similar in design and idea to the Atkinson cycle engine

Uses a super charger as well as the modified intake stroke of the Atkinson cycle

Stratified Charge Engine

Uses both a rich and lean mixture in the same cylinder More of a cylinder head design

2 Your Honda engines were like this. Uses a 3rd intake valve to do this.

Motor oils

API SAE What it does

S/C ratings Synthetic oils 5w30 vs 10w40?

What does that mean?

Oil Pump Filters Pressure Relief Valve Bearings Oil Level Pressure Gauge

Water Cooling Systems T-stats Water Pumps Coolant Types Radiator Heater Core Hoses Pressure Cap 190~210 deg F.

Add Ons:

Oil Pressure Gauge Oil Temperature Gauge Oil Cooler Lower Temperature Thermostat Deeper core radiator More cooling fans

3 Oil Pressure Tests:

Why? Oil Pressure warning system/gauge Engine Knocking or noise

Check oil level Quality Last oil change? Filter brand? Grade of oil?

Locate oil grades and quantities Locate and test oil pressure sender circuit

How they work: Switch is grounded to engine block when pressure is low, completes ckt and turns on warning light.

How to test. Jump sensor wire to ground with engine running, and check status of warning light. Check sensor resistance between sensor output and ground. Resistance should change when engine is started.

Remove sensor Install pressure gauge MAKE SURE THREADS ARE THE SAME!!!

Start engine Check for leaks Check hose Routing around hot engine parts!!! Warm up engine to operating temp (Use Thermo gun, or wait until cooling fans cycle once) Run engine at 2000 RPM. Measure pressure at idle and 2000 rpm Check with specs in Mitchell’s On Demand.