Past
Technical Articles
Arranged by Date (Most Recent
First)
Accurate Measurement Device
Engine Analysis Software
Over the years, we have developed The Engine Analysis Software and the limiting factor was ALWAYS the difficulty of measuring all the dimensions super accurately.
Bill McGraw developed a device to measure the head clearance accurately, and that was incorporated into our measurement system at that time. That worked for us, along with dial calipers and a high intensity light to see when the ports closed. One-day, Norris Sparks, our Dyno machinist and part of our development group decided that the measurement system was not as accurate as he wanted. SO…he came up with a different approach. He, being a machinist, knew that a height gauge would be ideal IF a system could be developed to be able to measure the port heights in a liner. He decided that the way to do it was to make a stem that would accurately snag the port. Following is the height gauge with the special stem installed. Following is the stem, highlighted for clarity.
Using this system, we were able to get accuracy to 1/2 thousandth. That was fantastic! Better than that, we were able to measure a complete engine and document it into The Engine Analysis Software in less than 5 minutes with +/- 1/2 thousandth accuracy. We have found additional uses for the depth gauge. We measure the TDC position of the engine with the liner installed, the head projection, top of liner/top of piston difference, etc.
This depth gauge can be purchased from any machine supply store for about $500. Norris has found it as an import at Precision Industrial Tool & Supply, Inc. (800-433-7487) for $149.00. It is 12" model #EHG-605 The pin is an EX4 hard pin with a ground flat area of about .015"
Other notes for EAP Registered Users: Brian Callahan and I have developed a little auxiliary spreadsheet program to calculate the exhaust port area. This is an input item in the newest version of EAP for calculating the ideal tuned pipe and time area calculations. The spreadsheet is included in the current copy of the EAS.
Other images that may spur your imagination are located at http://rc-engine-analysis-software.com/images/liner.gif andhttp://rc-engine-analysis-software.com/images/nrpiston.gif and http://rc-engine-analysis-software.com/images/osmixture.gif
This technical notes paper is dedicated to Ken from Ashville, NC. (probably not useful to him!)
The Perfect Liner Finish The finest way to brreak in a nitro rc engines for performance and longivity.
Squish Velocity as a Component of Head Design A very helpful discussion of Squish Velocity (MSRV).
Fuel Mixing for Model Engines A very helpful spreadsheet (Excel) for mixing fuel.
Model Engine Bearing Installation Easy installation of Model Engine Bearings.
Engine Analysis Program Measurement Use of a height guage for precise measurement.
Recent Tid-Bits Several findings from dyno testing and on-water testing.
Compression Ratios Re-visiting Compression Ratio.
How Our Dyno Works An “in depth” abstract on the workings of our Inertial Dyno by Brian Callahan.
Exhaust Timing A current look at our opinion on Exhaust Timing and Port Configuration.
Pipe Length #4 of 4 How to accurately determine Tuned Pipe Length – Part 4 and Summary
Pipe Length #3 of 4 How to accurately determine Tuned Pipe Length – Part 3
Pipe Length #2 of 4 How to accurately determine Tuned Pipe Length – Part 2
Pipe Length #1 of 4 How to accurately determine Tuned Pipe Length – Part 1
Bits & Pieces Bits and Pieces of information gathered from Dyno Testing.
After Run Lubrication of Model Engines A must read for all modelers!
Report on Building Our Inertial Dyno – Brian Callahan This paper is a Graduate Level paper prepared by Brian Callahan for his Graduate work at the University of Michigan. Easy to read and provides a lot of useful information.
Inertial Dynamometer
This Tech Note discusses the recently completed Inertial Dynamometer.
Engine Blueprinting #5 (Final Assembly)
This Tech Note discusses the
clean up and final assembly of the engine.
Engine Blueprinting #4 (Rotor/Crank TIMING)
This Tech Note discusses the
timing of the Crank Induction or Rotor Assembly.
Engine Blueprinting #3 (Rotor/Crank FITTING)
This Tech Note discusses the
proper fitting and maintenance of the Rotor Assembly.
Engine Blueprinting #2 (The Exhaust Port
- Shape & Timing) This
Tech Note discusses the shape of the exhaust port and some other important information.
Engine Blueprinting #2 (Engine Measurement and Fitting) This
Tech Note discusses to correct measurement methods, for the model
engine, to input the data into "The Engine Analysis Software".
Combustion Chamber (Head) – Squish Velocity
This article deals with squish velocity in technical terms.
Combustion Chamber (Head) – Shapes
Several shapes of combustion chambers and their application.
Combustion Chamber (Head) – Squish Band
This will show you the correct squish band shape, percentage,
etc for our high nitro engines.
Tuned Pipes & How They Work
Do you need a simple explanation of how tuned pipes work – then
this is for you.
Engine Timing
What is the correct timing for your engine? This will help you
decide.
Engine – The Fit – Piston
Part #2 of The Fit covering the Piston.
Engine – The Fit – Liner
Part #1 of The Fit covering the Liner.
Engine – Compression Ratio
This is the first Tech Article and maybe the place where you
can make the most gain in performance. You MUST have The Engine
Analysis Software for this to be meaningful to you.
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