Boost Bottle Building 66 or 80cc?

[Lazy Dog]

I'm working on building some boost bottles for some friends and myself and came to a small problem.

I understand the difference between the 66cc and 80cc rating based on where and how it's measured. Problem is technically there both correct it is a 66cc and 80cc engine. But depending what number you work off of the bottle size will be the right size or too big/small.

So does anyone know what number should be used for the the bottle volume. Is the head volume counted?

 

[Al.Fisherman]

I'm working on building some boost bottles for some friends and myself and came to a small problem.

I understand the difference between the 66cc and 80cc rating based on where and how it's measured. Problem is technically there both correct it is a 66cc and 80cc engine. But depending what number you work off of the bottle size will be the right size or too big/small.

So does anyone know what number should be used for the the bottle volume. Is the head volume counted?

All (5) my engines are 66cc. Everyone has a boost bottle I made. All internal volume is 66cc. For low end/idle I feel they work, although others will disagree.



Each rounded cap holds 5cc, for a total of 10cc. Schedule 40 (56cc) is used. If you want the bottle shorter use Schedule 20 (larger diameter cylinder)

 

[Basement Cat]

Honestly boost bottles do not add performance to an engine. Most of the time any gain in power is a placebo effect. If you want to build something that might actually help then look into helmholtz resonators.