> jumpsuit steve wrote:
>
> > LSLB RXb wrote:
>
> > -------------------------------------------------------
>
> > is this with a stock length conrod or the longer conrod cause 1.3mm
> btdc
>
> > would be different if it was the 75mm conrod vs the 85mm conrod.
>
> rod length should not affect timing in a significant way.
>
> http://www.torqsoft.net/piston-position.html
>
> crank angle difference between 75mm and 85mm rod with 40mm stroke @
> 1.3mm btdc is .23 degrees.
>
> piston position difference @ 18.5 deg is 1.302mm - 1.271mm = .031 mm
> aka .0012"
still makes a difference :)
I just really am lobbying for people to report timing on setups in degrees so the information can be compared across platforms. we can start to make gains on timing approximation from setup to setup if we use like terminology.
so to say:
If an adequately aircooled 10,000 rpm 40mm cylinder/pipe setup on a 40mm stroke need to be timed at 15º BTDC, does an adequately aircooled 10,000rpm 38mm cylinder/pipe setup on a 43mm stroke need to be timed the same?
and what about
if an adequately aircooled 10,000 rpm 47mm cylinder/pipe setup on a 40mm stroke need to be timed at 13º BTDC, does an adequately aircooled 10,000 rpm 45mm cylinder/pipe setup on a 43mm stroke need to be timed the same?
if you aren't reporting in degrees, it just sort of makes it harder to ask those semi-difficult questions.
thanks for that calculator tho, that thing rocks.