I know it might not be the most popular approach but I am porting my own heads. I'm building a "torque monster" 383 with a 220'ish cam, 11:1 compression, headers and cat back. The goal here is to produce a decent increase in flow so the peak HP isn't killed by overly restrictive heads. I want to keep the port volume reasonable so the midrange torque and throttle response are maximized. I've tinkered around with porting quite a few times and have a couple of in depth books ( one from David Vizzard) that spell out some of the theory and practical application involved in porting SBC cylinder heads. Anyhow, I figured a few people on here might be interested in some info. on my project as this is something that can be done by someone with a moderate degree of mechanical skill and fairly inexpensive tools. I'll be carrying these to have them flow tested in a week or two when they're done and will post flow charts afterwards.
Here are a couple of pics that were snapped this evening. This is the rough in stage so the finish has high and low spots and is generally coarse. The ports started out with stock volumes of around 165 cc's for the intake ports and 63 cc's on the exhaust side. I'd estimate total metal removal at around 75% complete and the port volumes as shown are about 175 cc's intake and 68 exhaust. It looks like port volumes will end up around 180 and around 72 exhaust if I stay with the stock valve sizes. I'll probably be going to 2.0 and 1.56" valves which should put final port volume around 185 cc's intake and 75 cc's exhaust. All this detail on port volume is not meant to imply that volume is the best indicator of port improvement but from the testing and theory I've seen indicate that if metal is removed from the right areas then port volume increase is tied to the improvement in flow. You can also find flow charts floating on the web for various port volumes that give you a rough idea of where to stop if you know what flow range you're looking for.
The way I approached this was to remove the material from higher velocity areas of the port that see the most flow in order to get the largest flow increase from the least amount of metal removed. The port floors were by and large left alone because they have a pretty smooth radius as cast. The port roof ( especially in the bowl area) is where the flow is concetrated so this is where most of the material was removed. A good "port bias" was established to promote good port swirl ( the sides of the bowl are angled to direct the flow toward the center of the cylinder and the outside half of the bowl is widened more as it sees more flow ).
The bulk of the material removed came from the bowl area from just above the seats to about 1.5" into the port where the roof meets the bowl radius. The area on either side of the valve guides was widened and deepened a good bit, more was done here on the cylinder wall side of the ports to establish the port bias. The bowls were deepened ( or raised) a good bit, this is visible in the troughs on either side of the guides) and a nice smooth arc was formed into the roof of the port. The guide bosses were slimmed down as much as possible and streamlined into a teardrop shape to smooth the airflow over them.
A relatively small amount of material was removed from the straight section of the intake ports. The port runners are narrowerat the roof than the floor. The roof of the port was widened by a few millimeters in the area where the port curves in to clear the pushrod and the roof was gradually raised as you go deeper into the port to make a straight shot at the top of the bowls. The side of the port roof next to the pushrod was raised a little closer to level.
For people who are skilled/educated in this area feel free to contribute constructive criticism or general comments concerning the general approach or port form. I still have some material left to remove and have flexibility to make changes. It might be fun to discuss some of the theory involved.
Regards, Michael

http://home.comcast.net/~grammerman/...haust_bowl.jpg

http://home.comcast.net/~grammerman/...l_rough_in.jpg

http://home.comcast.net/~grammerman/...rt_runners.jpg

 

What tooling are you using?

 

I have some open cut 1/4" shank carbide burrs and use a pneumatic die grinder. PIcked them up off of ebay for about $15 apiece, they work well on aluminum without clogging. Standard shapes, cone, ball and flame.
Regards, Michael

 

It looks like the flutes are too aggressive and/or you are exerting to much pressure.

Not trying to be an ***, just pointing out anything I can to help you out. The cuts should not be a rough as that looks.

 

i agree

 

I agree too, wouldn't want anyone to think that this would be a proper finish to leave in the ports when done. Since I'm grinding 15-20 cc's of metal from each intake port I opted to remove most of the material with fast cutting aluminum burrs. If you were just cleaning up the bowls and blending things a little you wouldn't want to use a burr this coarse. The finished ports will be much smoother, I may not have been clear enough about that when I said the ports were in the rough in stage with a coarse finish. Fine cut burrs and some WD-40 will be used to finish the ports once the ports are close to final shape. Doing the rough in on aluminum with the fine burrs made for ferrous materials is much slower but a good idea if you don't know exactly where you're going with the shape. I'm around 15 minutes of cutting per intake port, it would take closer to three times as long to rough the ports in with the fine burrs. It is important to keep these aluminum burrs moving, if you let them sit still very long you might find some water

 

If you are still looking for pistons, I have a set of 11.1 Forged J&E SRP pistons for a 383 I will cut you a deal on.

 

a Chisel

 

You wouldn't joke about that if you'd seen some of the home port jobs that I have had to fix

 

I was so scared when I was porting my TrickFlow heads, I took my time. I put about 30 hours into porting and polishing them. Looks like you've done alot of research. Good luck and I hope they turn out nice.

 

This may be another one for ya to fix.

 

way to be constructive....... at least he's spending time to try to help others out

 

Usually people will read up on something before they start,if ya DON'T KNOW.

From What I have seen of these heads,they will be ruined from lack of knowledge and the willingness to do port work without that knowledge.

Ya can't help others with NO info/background/experience as the picture indicate.

I am trying to let the guys with NO experience know, that head porting is an art and best left to those that can do it. If ya don't agree that's fine.
This sight has always been about the right info and doing it correctly.
I won't let the wrong info be spread as Gospel. I WILL try to set the info straight so newer guys don't think that cobbled up is correct.

Substandard work has NO place in the performance arena.

 

Racerdude, I can understand how you might be afraid to port heads or might warn all others from doing it. A man's got to know his limitations. Making blanket statements that confer the notion that any port work by anyone who is not a pro with years of experience is destructive or will ruin the heads doesn't hold up to the sniff test. I wonder how many porting "experts" there would be to send your stuff to if everyone followed your advice. As for not having info., David Vizzard's research is pretty highly regarded by quite a few engineers who spend their time testing and developing automotive cylinder heads.
You show a lack of general porting knowledge and competence by making a big deal about a rough port finish. Either that or you just have an axe to grind and don't mind screwing up a potentially informative thread. I suspect the latter. If you had any detailed criticism or anything remotely intelligent to say about the port form shown in my pictures or the changes I made then somebody might be in danger of mistaking you for a person who knows what they are talking about or who really gave a rip about correcting faulty information.
You saw the original post with the photos and you read the description that said the finish had high and low spots and was coarse because the port was in the rough in stage. Everyone else did too, and they saw the next couple posts where it was spelled out very clearly that this was not a final finish and would be smoothed out toward the end of the process. Have you ever bored and honed a cylinder? If your work is consistent with the screwy logic you use to discredit others here then you probably went at it with 600 grit stones from the very start. You wouldn't have any need for a more aggressive and efficient tool like a boring bar to start the process. You must have heard of them, it's the tool that leaves lots of evil, incompetent, rough looking tooling marks in the cylinder bore ( which will wind up very smooth in the end) as it does the bulk of the material removal and dimensional work. Check Amazon.com, they have some good info. on metal machining that might educate you on this sort of stuff. PM me and I'll send you some links.
Porting is not magic or black art as you are trying to pass off. Producing the absolute max. results for a NASCAR engine requires years of research and experience but a basic street port job is a completely different animal. Someone who is not skilled with their hands and tools can easily make a mess though, don't get me wrong. You pick up some good books that are readily available and have detailed dimensions and views of the port forms required. Next you spend a good amount of time studying the info. before you start cutting. If developing a solid understanding of the airflow dynamics is over your head then put down the data and hand off the heads to someone who can. If you understand what's happening and if you have the manual dexterity required you copy the models carefully and conservatively and make a nice improvement. Maybe not optimal or perfect, but for a reasonable investment of time you can realistically produce a very tangible improvement and save a good bit of money. As a bonus you get the satisfaction of accomplishing a challenging goal.
It used to be that well researched and developed information wasn't available and well meaning dummies would go in and hog out the ports and just add useless volume and produce angles and arcs that made the port work against itself. Those dummies are still around but for those with a reasonable degree of technical sophistication and skill with their hands this is a reasonable project, IF you take the time to educate yourself. David Vizard says as much in his books, but I'm sure racerdude knows much more than he does about porting. Just ask him, he'll tell you so.
If anyone wants to steer the discussion away from superstition and references to voo doo and black magic I'd appreciate it. Quite a few of us might actually learn something from a real discussion rather than agenda driven slop slinging.

 

Yea I saw it wasn't finished.
By the time ya get them smooth when the flow comes past the pushrod pinch it won't have enough velocity to fill the cyl.
So much for the SMALL port theory.
Just don't want the less inexperienced to mistake you for somebody that knows anything about porting work.
Ya know that Vizard's books are from the '60's and are in reprint.
I have done heads before for customers sprint cars but don't find it to my liking. It takes me too much time to duplicate the ports and get the ports equal in flow.
I pay the experts to do it and there are plenty around but only a few that really know what they are doing.

You might want to consider that too.
Just because you are a noob don't think ya are talking to one.

Ya got to be smarter than the iron.