Head porting

[fallen_one]

I'm going to do a bit of porting work with my head and manifolds. Not just porting but rather smoothing, removing of imperfections and intake manifold port/gasket matching(leaving exhaust head-to-manifold steps along). I've never done porting work before, thus I have a couple of questions. Maybe any professional could give me some advice.

1. I want to remove these casting marks:

I have a dremel, but it lacks of working bits, just drum sanders and couple of orange stones. I've tried them but they almost don't cut aluminum at all. What cutting bits should I buy? And what polishing bits for exhaust channels and combustion chamber?

2. I'm going to smooth sharp transition edges

but as you can see from another angle

valve seats are not flush with surface and form sharp edges themselves. Can I smooth these edges or I'll just ruin valve seats in this case?

3. And the last quick question: have I ruined the valves or a piece of fine grit emery paper could help:

?



P.S. Any help will be greatly appreciated, but please, don't advise me to find a reputable workshop with flowbench. I have no racing proven engine builders nearby. An ordinary workshop won't succeed with this work much better than me, cause they also will do it for the first time.

[compactfean]

First off I commend you for doing your homework. I can tell by the direction you're going with this you already know about flow vs velocity and what excessive porting can do. So to start..... You will probably get the best results excactly how you're doing it. The bits you have are actually for finishing. What you want to start out with is dye grinder bits. Be very careful though and take little off at a time and keep all transitions blended. After you get the shape you want then use the barrel sanding cartridges. I used the kit from summit racing for port and polishing and it has a wife variety of grits and sizes. Be EXTREMELY careful around the valve seats and do not, by any means, nick the seats. BUT you can shape close to them id you have a steady hand. (masking the valve seats is a good idea)
As for your valves, they are fine. If you want to shape the valves smoother that's fine BUT DONT TOUCH THE SEAT AREA. That surface rust can be cleaned up with some scotch brite. When your done, hand lap the valves with valve lapping compound. Look for any of the compound that didn't make contract with the valve, or the valve seat. Keep lapping until the valve and the seat have a perfect match. I personally think that polishing is over rated. You will get more benefits from glass bead blasting all the ported serfaces (except valve and its seat). This worked so well for me I literally felt a difference in my butt dyno.

[fallen_one]

Thank you for your help.
Could you comment the 4th image? How to improve flow in those places? Actual intake valve seats form sharp edges and restrict flow, I've been told not to touch seats but I don't see how to improve flow there without seats modification. Or should I leave it as is?

[compactfean]

From the looks of it, you should be able to port that without an issue. The only way you will be able to tell if you can port that area is to use the valve lapping compound and see where the clave seats and avoid that area.