dart blocks and r/s ratios

[integrawhat]

im goin BIG boost so im pretty much decided on a dart block my only confusion is in witch one to choose they are the same price and they offer a b18 with either a standard 81.5 bore or a 84mm bore and they have a b20+ block with a 226mm deck height and 84mm bore. i kinda just assumed it would be obvious to get the higher displacement but i am unasure about r/s ratios and what specs i should go with in regards to crank and rods. im goin to run high boost so i want to know what a strong r/s ratio would be. im kinda hopin you guys with more experience could help me with r/s. thanks

[turboEKhatch]

Rod/Stroke ratio means dick all in 99.9% of motor builds. Period, amen. A longer rod theoretically means better flow on the intake because the piston accelerates quicker from TDC, pulling more air in through the valve(s), but the difference it makes on a street engine is so tiny it's not worth designing your motor just to get rod/stroke ratio X.

What it comes down to is people have made 1000 horsepower on B-series blocks with sleeves. Dart blocks are expensive, and you have zero need for a tall deck motor unless you plan on running a 95mm or longer stroke, which really is completely overkill for a street turbo motor.

[Ace$nyper]

Originally Posted by turboEKhatch

Rod/Stroke ratio means dick all in 99.9% of motor builds. Period, amen. A longer rod theoretically means better flow on the intake because the piston accelerates quicker from TDC, pulling more air in through the valve(s), but the difference it makes on a street engine is so tiny it's not worth designing your motor just to get rod/stroke ratio X.

What it comes down to is people have made 1000 horsepower on B-series blocks with sleeves. Dart blocks are expensive, and you have zero need for a tall deck motor unless you plan on running a 95mm or longer stroke, which really is completely overkill for a street turbo motor.

You are 110% correct.

You know your shit