Flat plane crank RV8
Discussion
It's been done before but machined from billet so it's expensive.
Also, you can't get proper balancing with a flat plane crank but people do seem to rev them without their engines falling apart. I was going to rotate the journals on my crank patterns to enable a flat plane version to be produced but it's not viable unless I sell several castings.
Boosted.
Also, you can't get proper balancing with a flat plane crank but people do seem to rev them without their engines falling apart. I was going to rotate the journals on my crank patterns to enable a flat plane version to be produced but it's not viable unless I sell several castings.
Boosted.
Why bother?
A cross plane crank is smoother and can still make decent power.
There is nothing magical about a flat crank and it's relationship to power though you could argue, in extremis, that a flat one will rev a bit higher. The real difference is in the exhaust system. With a flat crank you treat each side as a four which makes for relatively easy exhaust packaging. With a cross plane crank you can still get a high power exhaust system. In most cases the solution, which can produce good power, is to connect cylinders at 270 degrees apart which results in 1-3/2-4 on one side and 1-2/3-4 on the other side. The best layout, but very difficult to package, is to connect cylinders 180 degrees apart which results in cylinders 1 & 4 on one side being connected to cylinders 2 & 3 on the other side. The result is a complicated mass of curly pipework sometimes reffered to as a "snake pit" system. Check out the original Ford GT40 for an example.
Perhaps you'd be better off thinking about an exhaust system?
A cross plane crank is smoother and can still make decent power.
There is nothing magical about a flat crank and it's relationship to power though you could argue, in extremis, that a flat one will rev a bit higher. The real difference is in the exhaust system. With a flat crank you treat each side as a four which makes for relatively easy exhaust packaging. With a cross plane crank you can still get a high power exhaust system. In most cases the solution, which can produce good power, is to connect cylinders at 270 degrees apart which results in 1-3/2-4 on one side and 1-2/3-4 on the other side. The best layout, but very difficult to package, is to connect cylinders 180 degrees apart which results in cylinders 1 & 4 on one side being connected to cylinders 2 & 3 on the other side. The result is a complicated mass of curly pipework sometimes reffered to as a "snake pit" system. Check out the original Ford GT40 for an example.
Perhaps you'd be better off thinking about an exhaust system?
Wasn't the Repco-Brabham V8 a Rover based-flat-plane-crank engine? Obviously in a single seater the desire to rev' and make lots of top-end power is more desireable than on a road engine.
I think I read somewhere that a company in America produce flat-plane cranks for Rover/Buick V8s - I'll check my 'favourites'.
I think I read somewhere that a company in America produce flat-plane cranks for Rover/Buick V8s - I'll check my 'favourites'.
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