Started on the good head this weekend. I opened up the intake and exhaust ports a bit. Not entirely the size of the gasket. Then blended the ports back and clean up the casting. I cleaned up the guides to make the smoother. Same thing with the remaining guide in the bowl (remove them completely if possible). I didn't do a lot of work on the bowl other than feathering any sharp edges between the machining for the seat and the bowl. The Short side radius was the same.. not a whole lot of work. I think I have most of the mass work done.
I don't know if I should do any more work on the guides or the bowls. I know I still have to clean up the exhaust side some more and I haven't even started on the combustion chambers yet.
Where the bowls meet the valve seat machining there is some casting sticking out on the sides... Should I grind that down a bit?
You can see it in these two pics pretty well, on the left:
and on the right:
Some more pics, rest in the gallery mentioned above.
I made my thermostat housing high-flow when I first got the SA DIY port and polish kit and did the 99+ intake that I'm currently using. So Flash, you made it so you could remove the lifters w/o removing the head? Also Silver, you could get rid of that casting flash in the bowl area. I probably spent a total of 20 hrs on the head and intake manifold. I was/am half tempted to polish the outside of the manifold like the one Mark got(and by the way $200 was a good deal for the amount of time put into it).
Flash wrote:Need to do a little bit more rounding, of the sharp edges in the bowl area(under the valve seat) other then that, look good.
Flash
What sharp edges are you seeing? Also, in the first two pics there is that ridge like area from where the valve seat machining meat the throat.. do I bring that down or leave it?
Also, on the bowl there are little bits of the left over valve guide boss... sort of form a U.. should I completely remove those?
What I am trying to avoid is opening it up too much.
gradon wrote:I made my thermostat housing high-flow when I first got the SA DIY port and polish kit and did the 99+ intake that I'm currently using. So Flash, you made it so you could remove the lifters w/o removing the head? Also Silver, you could get rid of that casting flash in the bowl area. I probably spent a total of 20 hrs on the head and intake manifold. I was/am half tempted to polish the outside of the manifold like the one Mark got(and by the way $200 was a good deal for the amount of time put into it).
Yes, in that first pic you and see one that is done and the next cylinder that is not.........Note the yellow...thing. it is a pocket screwdriver that i bent to help figure out how much metal i could cut out of that area.
It take some time to figure out how to enlarge the hole with out finding a water jacket or getting it to thin in some area
89 XJ with 300,000 on the original eng
"I've also never completed a motor, yet. My mouth (fingers) is also writing checks my ass can't cash."
Flash wrote:Need to do a little bit more rounding, of the sharp edges in the bowl area(under the valve seat) other then that, look good.
Flash
What sharp edges are you seeing? Also, in the first two pics there is that ridge like area from where the valve seat machining meat the throat.. do I bring that down or leave it?
Also, on the bowl there are little bits of the left over valve guide boss... sort of form a U.. should I completely remove those?
What I am trying to avoid is opening it up too much.
Yes that machine part could be cut down a bit more.(ROUNDED)
This will enlarge the port!!!!..........BUT, if your "mind", is set on rounding it off and not enlarging the port you will be fine.
Your goal is to make the air entry and exit as smooth, as you can with out enlarging the port any more then necessary.
Just cutting the edge as you have done so far in the bowl area will allow it to flow better and could be good enough.........if you want to stop there.
But theres a lot more flow available on the bowl area with a little bit more time.
Flash
89 XJ with 300,000 on the original eng
"I've also never completed a motor, yet. My mouth (fingers) is also writing checks my ass can't cash."
The machined area below the valve leaves a transition step at the margin to the as cast area in the pocket, Giving it the finger, I find that ledge and sweep the grinding down into the bowl, I do not try to enlarge the area per se, but try to have a smooth radius in all directions, this will slightly enlarge the pocket in doing so, remember this area is the area for the home porter to achieve gains and screw up, go slow, sweep the radius. Feel your way. Re read the link I posted with pocket porting.
John
After thought, concentrate on cleaning up the casting, again feel your way, smooth the surface, I really do not advise changing the transition angles. just clean it up, smooth the bowl, and you will get the most from your effort.
John
Muad'Dib wrote:Im worried i wouldnt have the patience, or would mess something up.
Thats what i did with my first port job!
I suck a valve and had to have a intake and exh seat put in on one chamber. Sooooo i decide to cut the port open from the seat straight down and then round it out.
DESTROYED THE BOTTOM END and gained 1500 rpm on the top with out other change.
Needless to say theses heads slowed my Cuda by 1 full sec., even tho they rev the eng higher
Flash
89 XJ with 300,000 on the original eng
"I've also never completed a motor, yet. My mouth (fingers) is also writing checks my ass can't cash."
