5 replies to this topic

[OO7]

It seems that a theoretical 90 degree V24 engine has two possible crank configurations:

1) A dual V12 crank, like the following pattern:


Arms 1 & 2 are at 0 degrees and correspond with cylinders 1-13 and 12-24.
Arms 3 & 4 are at 60 degrees and correspond with cylinders 2-14 and 11-23.
Arms 5 & 6 are at 120 degrees and correspond with cylinders 3-15 and 10-22.
Arms 7 & 8 are at 180 degrees and correspond with cylinders 4-16 and 9-21.
Arms 9 & 10 are at 240 degrees and correspond with cylinders 5-17 and 8-20.
Arms 11 & 12 are at 300 degrees and correspond with cylinders 6-18 and 7-19.

2) The crank arms will look like spokes 18, 1 and 2 in the image. Where the spokes intersect will be the crank centre.


Arms 1 & 2 are at 0 degrees and correspond with cylinders 1-13 and 12-24.
Arms 3 & 4 are at 30 degrees and correspond with cylinders 2-14 and 11-23.
Arms 5 & 6 are at 60 degrees and correspond with cylinders 3-15 and 10-22.
Arms 7 & 8 are at 180 degrees and correspond with cylinders 4-16 and 9-21.
Arms 9 & 10 are at 210 degrees and correspond with cylinders 5-17 and 8-20.
Arms 11 & 12 are at 240 degrees and correspond with cylinders 6-18 and 7-19.

Both crank (1) and (2) appear to be equally balanced in the first order (initially at least) and move their respective cylinders equally in relation to each other i.e both cranks will place cylinders at both ends of a bank in the same position. This is unlike flat-plane and cross-plane cranks for V8 engines, in which only the flat-plane crank matches cylinders end to end in a bank.

I'm thinking if however crank (2) will generate second order vibrations as in a flat-plane V8 crank?

Does anyone know why the following WR12 cranks are different?





The first two look more robust and have typical 'uniform' counterweights, while the third has pieces cutout of some of the counterweights?

Obi

[macoran]

Originally posted by Obi Offiah
It seems that a theoretical 90 degree V24 engine has two possible crank configurations:

1) A dual V12 crank, like the following pattern:


Arms 1 & 2 are at 0 degrees and correspond with cylinders 1-13 and 12-24.
Arms 3 & 4 are at 60 degrees and correspond with cylinders 2-14 and 11-23.
Arms 5 & 6 are at 120 degrees and correspond with cylinders 3-15 and 10-22.
Arms 7 & 8 are at 180 degrees and correspond with cylinders 4-16 and 9-21.
Arms 9 & 10 are at 240 degrees and correspond with cylinders 5-17 and 8-20.
Arms 11 & 12 are at 300 degrees and correspond with cylinders 6-18 and 7-19.

2) The crank arms will look like spokes 18, 1 and 2 in the image. Where the spokes intersect will be the crank centre.


Arms 1 & 2 are at 0 degrees and correspond with cylinders 1-13 and 12-24.
Arms 3 & 4 are at 30 degrees and correspond with cylinders 2-14 and 11-23.
Arms 5 & 6 are at 60 degrees and correspond with cylinders 3-15 and 10-22.
Arms 7 & 8 are at 180 degrees and correspond with cylinders 4-16 and 9-21.
Arms 9 & 10 are at 210 degrees and correspond with cylinders 5-17 and 8-20.
Arms 11 & 12 are at 240 degrees and correspond with cylinders 6-18 and 7-19.

Both crank (1) and (2) appear to be equally balanced in the first order (initially at least) and move their respective cylinders equally in relation to each other i.e both cranks will place cylinders at both ends of a bank in the same position. This is unlike flat-plane and cross-plane cranks for V8 engines, in which only the flat-plane crank matches cylinders end to end in a bank.

I'm thinking if however crank (2) will generate second order vibrations as in a flat-plane V8 crank?

Does anyone know why the following WR12 cranks are different?





The first two look more robust and have typical 'uniform' counterweights, while the third has pieces cutout of some of the counterweights?

Obi

Wouldn't a real W12 have three banks of cylinders ?
Looking at the VW block I would still consider it a V12 arrangement, but with twin row cylinders.

What block is the other crank from ?

[OO7]

Originally posted by macoran


Wouldn't a real W12 have three banks of cylinders ?
Looking at the VW block I would still consider it a V12 arrangement, but with twin row cylinders.

What block is the other crank from ?

Yes another W12 configuration would be to have 3 banks of 4 cylinders. The WR12 is basically a double V or VV configuration.

I don't know from what block the V12 crank came from.

Obi

[macoran]

Does anyone know why the following WR12 cranks are different?





The first two look more robust and have typical 'uniform' counterweights, while the third has pieces cutout of some of the counterweights?

Obi [/B][/QUOTE]

I am still a bit confused about:
The first two look more robust and have typical 'uniform' counterweights, while the third has pieces cutout of some of the counterweights?

Which do you consider as being the first two, and which the third ?

[OO7]

Originally posted by macoran
I am still a bit confused about:
"The first two look more robust and have typical 'uniform' counterweights, while the third has pieces cutout of some of the counterweights?"

Which do you consider as being the first two, and which the third ?

The first two are the top image followed by the large middle image. The third is the WR12 crank in the bottom image. It is the crank on the left in the third picture with two cranks displayed.

Obi

[Powersteer]

V24, I would absolutely love that but then again there an oil crisis and a recession coming last I heard.