OST-013: Massaging a virgin ;)

[Bean]

NoHachi Wrote:Couple of questions for people in the know. But first a disclaimer: I'm asking this genuinely as someone who doesn't have the funds to send a head on a round trip to the US and have work done, but could take a risk on junking a 150euro replacement head in a diy effort. Since this thread has become an excellent primer on head work I thought that this would be a logical place for my questions:

@Bean Bandit:
In this pic (thanks for taking the time to show this):


What would be the method of choice to tackle this? Do you machine away that part of the valve seat in an attempt to blend? Wouldn't you risk ending up with a dead pocket in that location and a loss of velocity? Or do you epoxy/weld some material in?

I tried the DIY effort myself on a spare bigport I have but as I am aiming closer to 200fwhp than 160fwhp a DIY job is pushing it (i.e. wilder cams/ more rpm would be needed for similar results) - to save my parts doing a round trip I sourced everything in the US so it only needs to go one way. Still it's not cheap but no serious build is and compared to prices charged in Switzerland I'm still saving a lot.

filling it would be ideal but it's an expensive thing to do and can go very wrong if not done properly. As you can see on the sliced head pic posted by Project D there usually is a bit of material under the valve seat itself which allows a bit of blending... everything not being a perpendicular wall in the stream helps. If you look at the picture from Dan with before and after view through the intake (the one with the red arrows) you can see the same area and how it's been blended. I guess on my head which is at Loynings this process was easier and smoother to do as new and bigger valveseats are used to accommodate the OS valves.