A Detailed Guide: What To Watch Out For When Swapping Power Valve Components Between 200 and 220 Cylinders
Posted: 11:04 pm Jan 17 2024
Having swapped my 220 kips power valve components to a 200 cylinder, I ended up finding something unexpected that could help someone in the future. The subvalves are inserted in from the top of the cylinder followed by the guides or bushings. The bushings are designed to support each subvalve and keep them from moving up and down from engine vibrations.
I found that the bushings on the 220 are .9mm (17.6mm) taller than the ones on the 200 (16.7mm). So, if you go to use the 220 bushings on a 200 cylinder, they will stick up above the cylinder and the entire power valve system will be locked up after tightening the cylinder head on. You can remedy this by removing material off the 220 bushings but I decided to use the correct part.
On the other hand, if you use the 200 bushings on a 220 there may be excessive up and down movement on each subvalve.
The way to tell the difference is by looking for a groove around the center of the bushings. The 200 bushings have a groove and the 220 don’t. Also, if you look at parts diagrams they are a different part number.
The 200 bushings dimensions are listed next to the part number as 6x15x17.2mm yet that is incorrect based on the 2 sets I got a hold of. The actual measurement is 6x15x16.7mm. No one has shed light on the difference between the bushings as far as I can see.
Lastly, It is known that you never want to mismatch a 200 and 220 main valve to your cylinder. If you have a 220 cylinder use the 220 main valve and vice versa. If not, you will have a clearance issues between the main valve and the piston or you will not be fully closing off the exhaust port at lower rpm’s. Hopefully this helps someone in the future.
I found that the bushings on the 220 are .9mm (17.6mm) taller than the ones on the 200 (16.7mm). So, if you go to use the 220 bushings on a 200 cylinder, they will stick up above the cylinder and the entire power valve system will be locked up after tightening the cylinder head on. You can remedy this by removing material off the 220 bushings but I decided to use the correct part.
On the other hand, if you use the 200 bushings on a 220 there may be excessive up and down movement on each subvalve.
The way to tell the difference is by looking for a groove around the center of the bushings. The 200 bushings have a groove and the 220 don’t. Also, if you look at parts diagrams they are a different part number.
The 200 bushings dimensions are listed next to the part number as 6x15x17.2mm yet that is incorrect based on the 2 sets I got a hold of. The actual measurement is 6x15x16.7mm. No one has shed light on the difference between the bushings as far as I can see.
Lastly, It is known that you never want to mismatch a 200 and 220 main valve to your cylinder. If you have a 220 cylinder use the 220 main valve and vice versa. If not, you will have a clearance issues between the main valve and the piston or you will not be fully closing off the exhaust port at lower rpm’s. Hopefully this helps someone in the future.
