Hi all

I worked from 1968 to 1993 on Rotary Engine

One item always eluded me and that was working out the CR and for purely
academic reason I would like to complete this program, I would be grateful
if you could give me some worked examples data.
R'=R+a : e : B : Radial flank clearance : Width clearance & finally rotor
pocket volume.

In my worked example based on the Norton Rotary

R'= 71.5 mm e= 11.6 mm : B=68.2 mm : Flank Clearance = 0.5 mm : side
clearance = 0.15 mm , the compression ratio's ranged from 7.5 to 1 & 9.2 to
1 do you have any examples that also include combustion pocket size, or
could you please measure the rotor pocket volume, and tell me the alleged
CR.

We used to measure this for D.Garside and I would give him the volume of a
Plasticine by filling pocket, scrape around the flank with a steel rule, and
then measuring the fluid displacement,



It is possible that no two formulae give the same results.

I have worked out the flank clearance Volume, but just need some actual
rotor pocket volume, and the R'=R+a : e : B= width and the : posted CR

Example R'= 10.5 cm : e=1.5 cm : B or width 7 cm

Raw CR = Best possible ie, no combustion pocket or flank clearance = CR
18.29 to 1

Flank Clearance = 0.050 cm = CR = 15.41 to 1

As above but with volume in rotor pocket = 35 cm  = CR = 8.66 to 1

If flank clearance set to zero and pocket volume = 35 cm = CR = 9.41 to 1

But you should include for the pocket volume and the spark plug/s recess and
also the Land clearance, sometimes called top land clearance in piston
engines.

And the only way to test the program is by having as many types of engine
data and Chamber Volume and CR

Bob Rowley

Tamworth

UK

The volume varies with the year. A rotor I have
here in my office is 10 mm deep. Mean width is 48
mm and it is about 77 mm long. CR is roughly 9.6.
Housing width is 80 mm.

You can download Kenichi Yamamoto's book "Rotary Engine" from this
web site. It contains most of the dimensions on the Mazda rotary.

http://foxed.ca/foxed/index.php?page=rx7manual

Here are a couple of excerpts.

Other info is scattered throughout the tech papers on our site.

Paul Lamar