How do you equally space the cylinders of a 7 cylinder radial engine?

Answer 1

It is true. You could divide 360 degrees by 7, but then you have to measure angles :/ If you measure the circumfrence of your circle and divide that by 7 then you can equally space your cylinders.
There is a simple formula:
measure the diameter of the circle (d), then circumference (c) is:

c=pi*d

then arc length (a) is:

a=c/7=pi*d/7

Answer 2

As previously answered, 360/7. It doesn't have to come out evenly to be machinable.

And in response to the "Why 7?" comment: Radial engines (still used on airplanes today with a few new designs still coming out) run smoother with an odd number of cylinders. So there are/have been radial engines with 3, 5, 7, 9 and more cylinders.

There are a few Curtiss C-46 Commandos flying from our local airport with 2000-hp 18-cylinder radial engines (two banks of 9 cylinders). 60+ year old design still flying.

Answer 3

Very carefully! %-)

Just because we use 360 degrees for a circle doesn't mean a radial engine has to have a number of cylinders that's a factor of 360.

For 7 cylinders, you just make them 360/7 = 51.42857142857... degrees apart. No different than making cylinders in a 6-cylinder radial engine 360/6 = 60.00000... degrees apart.

Answer 4

Instead of having a in-line six cylinder engine you have a seven cylinder in-line engine. You start with the first cylinder in the center and place one on each side evenly spaced and continue with two more on eash side spaced the same distance apart as the first three.

Answer 5

Why 7 cylinders? but if you must I would look at the length..
___________________
| 1 | 2 | 3 | 4 | 5 | 6 | 7 |

My question is how would they all work with each other and not pop a cork?

So you're then saying
.......(1).......
..(2).......(3).
.......(4).......
..(5).......(6).
.......(7).......

hmmmm?