- Joined
- Aug 7, 2014
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I am building a twin in-line engine and having machined the cam shaft blank I studied the profiles before progressing further.
To my eye, the drawing is wrong. The shaft will rotate CCW looking rearwards from the front and the lobes themselves, positioned at 0 - 90 - 270 and 0 degrees, looks as though the cam should be rotating in the CW direction.
If I were to build the cam as shown, then the forward inlet opens at 0 followed by the exhaust at 90 degrees (180 crankshaft degrees) thus the exhaust would be open during the compression stroke. It is a similar situation for the rear cylinder lobes.
I think the lobes should be 0 - 270 - 90 - 0. Can I solicit some thoughts on the cam lobes just to be sure I am right - or wrong maybe.
Steve
To my eye, the drawing is wrong. The shaft will rotate CCW looking rearwards from the front and the lobes themselves, positioned at 0 - 90 - 270 and 0 degrees, looks as though the cam should be rotating in the CW direction.
If I were to build the cam as shown, then the forward inlet opens at 0 followed by the exhaust at 90 degrees (180 crankshaft degrees) thus the exhaust would be open during the compression stroke. It is a similar situation for the rear cylinder lobes.
I think the lobes should be 0 - 270 - 90 - 0. Can I solicit some thoughts on the cam lobes just to be sure I am right - or wrong maybe.
Steve