johnlaudano
Well-Known Member
- Joined
- Jan 17, 2011
- Messages
- 99
- Reaction score
- 129
I ran the engine again withe a reduced-size venturi of 6mm. it didn't make a difference in mixture sensitivity but it seems to allow more variation in fuel tank height without consequence.
I checked the valve timing and was very disappointed to learn of my great error in planning and design. I think the main problem was that both intake valves were open simultaneously which disrupted intake of fuel mixture. The secondary problem was excess valve lift. had i superimposed the cam diagram of the second cylinder onto that of the first cylinder during the designing, the trouble would have been avoided. There's always next time. But it does run and will work in the boat. The checked rpm rang was about 1000- 6000. low end can goes down with reduce ignition timing but throttle response is poor.
Attached is the cam diagram showing the current condition. Does anyone have examples of cam charts for various engines related to performance? or, suggestions for cam timing for a good idle and good low-end torque?
I checked the valve timing and was very disappointed to learn of my great error in planning and design. I think the main problem was that both intake valves were open simultaneously which disrupted intake of fuel mixture. The secondary problem was excess valve lift. had i superimposed the cam diagram of the second cylinder onto that of the first cylinder during the designing, the trouble would have been avoided. There's always next time. But it does run and will work in the boat. The checked rpm rang was about 1000- 6000. low end can goes down with reduce ignition timing but throttle response is poor.
Attached is the cam diagram showing the current condition. Does anyone have examples of cam charts for various engines related to performance? or, suggestions for cam timing for a good idle and good low-end torque?
