yves norton seeley
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- Joined
- Feb 13, 2014
- Messages
- 897
Yves - when you make your dial indicator brackets to measure valve lift at TDC - be sure you only turn the crank in the direction of running rotation when you get close to TDC - if you turn backwards it will give you false reading.
Porting is just as important or more important than installing big valves and as Nigel said - with the bigger valves the port floor curve leading to the valve (and the sides of the bowl) must be re-shaped. The FA ports can use some cleaning up around the guides as well. For a 920 the ports could be improved a bit for more flow to keep up with the increase in volume.
see this FA porting video and pay close attention from 6:20 to 7:20
see the template at 6:40
Hi Jim, I first want to tcheck the cam timing, I don't understand your camshaft timing video: When you are at TDC with the valves in balance, the inlet is underway to open and the exhaust is underway to close, so if I understand I must turn the crank clockwise to have the mesurment for the IN valve and counter clockwise to have the mesurment for the exhaust??
Thanks
Yves