Any suggestions on how I am porting these heads?

Just getting started. Knocked out most of one of the heat bumps, nice slow transition on the inside of the curve, knocked down most of the valve hump but leaving the round hole round at the valve.

Not going all out but want to open the flow and clean it up...

 

Looks fine, just don't remove too much off the inside radius, concentrate on the roof and walls. All you need to remove off the floor is the rust.

 

I don't know about the GT heads, but the thing they say on any head is to NOT grind the floor.
You can smooth it, but don't reshape or enlarge it.
The roof is priority for most Fords, then the bowls, and finally the walls.
The exhaust can be mirror polished, but the intake must have some texture left.

 

Ask someone better then me on that style head, but,,, before you go to far you may want them magnafluxed. Be a shame if theirs some cracks with that nice work your doing. Does look nice from pic's, keep them all the same

 

Dont do any more to the floor.Dont open the ports to match gaskets either.(it will cause reversion)Thats very bad.The roof looks good though.I would definitely get the heads magnafluxed before you go any further.You could be grinding on a dead horse if there are any cracks in them.Try to work the transition where the seat meets the chamber(usually has a small sharp ridge where they meet)blend that out.If you get the valves done ask if they can do a 4 angle.That extra back cut on the seat and valve really wakes up the flow around the valves.Good luck,have fun.

 

Put a gasket up to that head and scribe a line around the inside of the gasket. Then port it to that line. Blend your grinding in about 3/4 of an inch into the runner and you will have a 90% porting job. The last 10% is for guys with flow bemches.

 

I will gasket match and clean up the intake. That is the easy part.

I feel a ridge when I put my finger in and it starts to curve down, that is where I am focusing now. Other than that, just cleaning up and smoothing out the top where the smog bump is.

Am I OK to knock off some of the valve guide as long as I don't get into the actual hole? I am trying to smooth that out a little but not change the shape of the valve guide hole. Afraid that would mess stuff up.

Other than that. I have taken a good bit of material out. You can actually look into the top and see right out the bottom about 30-40% of the opening... Trying to make it as smooth and straight a shot as possible.

Got a broken intake stud. Don't have acetylene, so I might take it to the local shop and let him get that stud out, magnaflux it. Should I have him take .010-.015 off the bottom?

 

There's nothing wrong with gasket matching other than it gives some goofy flow characteristics. Normally the gasket is larger than the rest of the port, so as the air flows through the intake, it slows down at the gasket, then speeds back up again in the head. Not the worst thing in the world though. A forward facing step in the flow path is worse than inconsistencies in port velocity. The best thing to do is figure out which one is the bigger (the intake or the head) use it as a template and port the smaller one to match it. When I gasket matched and pocket ported my last small block it went from a 14.7 to a 13.7 over night. These were on cast iron vortec heads. (yeah I know, chevy stuff, but whatever.) When you make a template, include the bolt holes in the template so you can line it up. Color the face of whatever you're going to grind with a magic marker, then use a center punch or awl to scribe a line. Works like a charm and it's cheaper and easier to use than bluing.

The air needs a straight shot at the head of the valve. That's why you don't grind the floor. Grinding the floor, makes the air flow over the valve sideways and then it just slams into the cylinder wall and, well.... it's just not so good. That's why your high performance heads will have raised ports. Here I'll attach a crappy picture to show what I'm talking about.

The top picture shows you what a crappy port looks like. It's pretty flat and the air has to make a big bend right before the valve. You can "fix" this a little bit by pocket porting the area that the last blue arrow is pointing at. It makes the area under the seat a little thin here though. A good rule of thumb is to not grind away any metal under the seat, but if you have to, I'd leave at least .250"

The bottom picture shows what a raised port looks like. The air doesn't have to make a big bend before the valve and just flows nice and straight down into the cylinder. You can see that if you grind on the floor all you're doing is making the air at the floor make a big bend to get through the valve. It's also the same reason why grinding on the roof of the top section will help air flow.

That's head porting basics in 30 seconds.

When you get into some serious head porting, epoxy is your best friend.

Are you using a double cut burr on those heads? What shapes do you have?

 

I tend to just smooth the valve guide. Some guys grind it all the way off. Which is fine, but it just makes the valve a little less stable as it's trying to seat itself.

 

Thanks for the GREAT pics and suggestions...Just the stuff I was looking for

 

Hows It Going Did It Turn Out Ok

 

The one I have been working on looks good. Just need to polish it up and move on to the next one.

 

Gasket matching isn't just for the intakes. You should do that on both ends of the head (intake and exhaust) and on the manifold and headers. Any turbulence that is introduced by unmatched surfaces reduces the flow. Remember that the gasses from the exhaust are expanding and need room to do that. The intake needs a bit of a funnel to get the velocity up to make it past the valve. Gasket matching gives you 90% of the increase in flow that you are going to get from your porting job.

 

Gasket matchng isn't going to get you 90% of the added flow on the exhaust side. Removing the Thermactor bump, widening the walls and raising the roof and blending the bowls are where it's all at on the exhaust side. Matching the gasket there is only the starting point.

 

I found out the hard way that this is all I need to do on the Exhaust side...