Valve velocity

[Matt Cole]

Anyone know what target valve velocities would be inlet and exhaust? 70,80,90 m/s?

[Andrew Cooke]

no idea what you're trying to do, but you could work out what they are from the cam profile and rpm

[Matt Cole]

Ha thanks Andy. I'm thinking of a bit of DIY head work. ;) I think you know the cams I'm going to use?

As you know the megane head has a strange port shape due to the injector angle. Theres plenty of meat in the way and needs to be removed and matched to my manifold. From there I was thinking of saving myself a fortune and look at valve seat and port shaping etc.

I then thought what the hell am I trying to achieve and, hence my question.:scratch:

[Andrew Cooke]

are you talking about port velocities, or valve velocities?

DIY porting is more likely to make things worse than better, there is a reason why modern engines make so much power. Any improvements will be within 1/4" of the valve seats, and be detail stuff.

[Matt Cole]

are you talking about port velocities, or valve velocities?

DIY porting is more likely to make things worse than better, there is a reason why modern engines make so much power. Any improvements will be within 1/4" of the valve seats, and be detail stuff.

Ok. I guess a specialist may be the best option. I do think that the meg head could be vastly improved as it seems a fairly rough casting.