OzVMX Forum

Clubroom => Tech Talk => Topic started by: vmxrider on April 29, 2016, 03:15:23 PM

Title: 2 stroke vs 4 stroke big end size
Post by: vmxrider on April 29, 2016, 03:15:23 PM

Maybe a silly question, but why do 4 strokes have much larger big ends/crank pins than equivalent capacity/horsepower 2 stroke big end. I think Husky's might be the exception.

Title: Re: 2 stroke vs 4 stroke big end size
Post by: shelpi on April 29, 2016, 03:53:23 PM

purley a knee jerk reaction answer IMO because a 4 stroke is spinning more junk over
now thinking about it are they always?? some 4 banger little ends are smaller and dont run a bearing :o

Title: Re: 2 stroke vs 4 stroke big end size
Post by: Lozza on April 29, 2016, 05:06:18 PM

Quote from: vmxrider on April 29, 2016, 03:15:23 PM

Maybe a silly question, but why do 4 strokes have much larger big ends/crank pins than equivalent capacity/horsepower 2 stroke big end. I think Husky's might be the exception.

Higher cylinder pressures

Title: Re: 2 stroke vs 4 stroke big end size
Post by: vmxrider on April 29, 2016, 07:37:01 PM

Thanks Lozza, back to school for me :-[