Engine firing orders

[wizzer]

Do manufacturers choose a firing order for a specific reason?

Surely if you change the crank positions you can have any firing order you want? Why do some V8's fire alternatively and others fire twice on one bank, then once on the other and then reverse this order until all 8 cylinders are fired.

 

[TCJBOLDIE]

A flat plane crank may have something to do with the firing order

 

[obi_waynne]

The firing order is also designed to make the engine smooth. If all the power went to one end of the crank and then the other end you'd get strange vibrations which would cause problems. Heat dissipation is another reason why adjacent cylinders are not fired after each other.

Manufacturers take a lot of time to work out the best firing order for each engine design, and it's not something an end user should play with.

Your example as @TCJBOLDIE says has to do with flat plane vs cross plane cranks. This firing order is the best way to deliver smooth power on a cross plane and gives an engine that lovely burble.

 

[TCJBOLDIE]

IIWC when Sir Jack Brabham built his first V8 race motor that was based on an alloy production block st he used a flat plane crank and had the exhaust exiting from the centre of the V so the cylinders exhaust system could be paired according to the correct firing order for the best power output.

Found a pic 4you
https://www.google.com.au/search?q=pics+of+repco+brabham+motor&tbm=isch&imgil=snuegxDLKAEVMM%3A%3BgmOj5kJ9gEvisM%3Bhttps%253A%252F%252Fprimotipo.com%252F2014%252F08%252F07%252Frb620-v8-building-the-1966-world-championship-winning-engine-rodways-repco-recollections-episode-2%252F&source=iu&pf=m&fir=snuegxDLKAEVMM%3A%2CgmOj5kJ9gEvisM%2C_&usg=__8Vk8Lit7TEUlutWN3iVpx83Vouc=&biw=1680&bih=926&ved=0ahUKEwjRo-KVu5PUAhXCp5QKHaNbByQQyjcIOg&ei=tDcrWdH5CMLP0gSjt52gAg#imgrc=Ft8ofODjKir1aM:

 

[wizzer]

Thanks guys for another informative answer.