[Camaro_Nut2001]

Well, I finally got the courage to start porting on my "062" Vortecs. I'm gonna fully port the exhausts and just barely clean up the intake ports along with gasket matching the intake and heads. I'm cutting the guides and seats, pulling the pressed in studs, tapping and installing shoulderless screw studs (gonna run self-aligning rockers so I don't have to cut the stud boss) and hope for the best. I think I am done with the carbide cutters on the first head and ready to do the final finish on the exhaust ports with cartridge rolls. Here are a few pictures. Please let me know if you think I'm headed in the right direction, completely off base or just plain ruined this head already. If I haven't ruined the head, please give me your advise on how i'm doing and any tips you have. Thanks, Ted.
http://www.hotrodders.com/forum/atta...1&d=1357179111
http://www.hotrodders.com/forum/atta...1&d=1357179111
http://www.hotrodders.com/forum/atta...1&d=1357179111
http://www.hotrodders.com/forum/atta...1&d=1357179111
http://www.hotrodders.com/forum/atta...1&d=1357179111

[hcompton]

If you run the bit back and forth it will dig a hole and cut too deep on the outsides. Ends with a crown in the middle.

Sanding rolls will help smooth out the pinch points around the guiides. Might need to tear some off to get into the deepest part. Take your time and use smooth cuts agasit the direction of the bit. Dont use die grinder air power does not have good tq and will stall the bit and dig a hole when it does. Electric is much easier to control and produces a smoother finish. But dremel is not going to cut it you will need something with a hp rating and works at low and fast rpm.

Focus on just removing the ruff casted surface and leaving a smooth cut finish. Hanging the shape is not always the best idea. Usally the shape is made with a purpose in mind and is not easy to redesign with just cutting the port and not adding metal back in. This basic clean up will net you a real 3-5 percent increase.

Also changing the shape of the port can really mess up swirl porting and other flow devices that will actually hurt flow when the air is moving at hundreds of mph thru the port.

[Camaro_Nut2001]

Originally Posted by hcompton

If you run the bit back and forth it will dig a hole and cut too deep on the outsides. Ends with a crown in the middle.

Sanding rolls will help smooth out the pinch points around the guiides. Might need to tear some off to get into the deepest part. Take your time and use smooth cuts agasit the direction of the bit. Dont use die grinder air power does not have good tq and will stall the bit and dig a hole when it does. Electric is much easier to control and produces a smoother finish. But dremel is not going to cut it you will need something with a hp rating and works at low and fast rpm.

Focus on just removing the ruff casted surface and leaving a smooth cut finish. Hanging the shape is not always the best idea. Usally the shape is made with a purpose in mind and is not easy to redesign with just cutting the port and not adding metal back in. This basic clean up will net you a real 3-5 percent increase.

Also changing the shape of the port can really mess up swirl porting and other flow devices that will actually hurt flow when the air is moving at hundreds of mph thru the port.

First off, thank you for the advice. Do you think I have hurt the flow on these exhaust ports? Like I said earlier, i'm not gonna do any cuttin on the Intake ports. I'm tryin to get these ports to look just like the ones in David Vizards book and it looks like he cut alot of the guide to make a smooth area completely around it and blended it into the exiting port. I have been using my die grinder cut down to 30psi. I'm gonna try to get to Lowes tomorrow and get a light dimmer to use with my electric die grinder as its way to fast if plugged into an outlet, 25,000 rpms if i'm not mistaken.

[techinspector1]

Originally Posted by Camaro_Nut2001

25,000 rpms if i'm not mistaken.

Put on your big boy pants and use both hands.....

[Camaro_Nut2001]

Originally Posted by techinspector1

Put on your big boy pants and use both hands.....

Well I would if I could but I have a problem, big boy britches dont fit me due to me not havin much of a butt. I mean flat, flat as a flitter! Not only that but i'm kinda, sorta not comfortable with the way that thing jumps around and slings cartridge rolls apart. By the looks of what I have done so far do you think I need to cut a little more with the carbide cutters or go with 80 grit rolls?

[1Gary]

Aleast read this link and consider building it.A good tool to have in any hot rod shop.







Flow Bench

[F-BIRD'88]

Looks fine. You can thin and streamline that big fat valve guide boss some more. So the air can go around it.

[Camaro_Nut2001]

Originally Posted by 1Gary

Aleast read this link and consider building it.A good tool to have in any hot rod shop.







Flow Bench

Thanks for the link. I have done a little reading on home flow benches and plan to do alot more. If I can, or better said, when I can, get this porting trick down pat I want to build a flow bench. Right now i'm just doing my best to not ruin the heads, lol. That Vizard feller has a heck of alot of talent when it comes to making power and he has a section in one of his books on building a flow bench. I think with more reading, and I read some and glanced some at the article you posted, I can build a pretty accurate one by combining information from both articles. Thanks again for the link!

[ap72]

Why not the intake ports? That's where most of your gains will be made.

[hcompton]

Flow bench is not as useful as it might seem. Yes it helps and good bench numbers equal good hp numbers if everything else is right. But remeber the first thing they tell you when using a flow bench is its only about 1/4 the speed and pressure of a running engine. The real engine will force air thru the head much faster than a small vacum can. So yes they work but can lead to poorly ported heads if you do not understand flow to begin with.

Air flows down the center of the port. the air along the walls is moving very slowly and not really where the largest flow comes from. but air moving down the center of the port can reach and exceed the speed of sound. Your goal as a porter is make the port flow enough air to get close to the speed of sound as possible without going past the mark becasue air get tubulent after that. But until it reaches that speed it will increase in flow to the cylinder as the speed increases. Until you reach the tipping point where the air get turbulent. Since the flow bench cant actually push air with that much pressure most of the time you need to calculate the port size and shape. and when that i done it is almost always smaller than the one you have in front of you to cut.

Here is what I use to port heads. this is a little small for the job with cast iron car heads but will work. But its amazing on alum car and bike heads. If you want it perfect this or a tool like it is the only way to go.

K.SRH440, Industrial Kit with heavy duty shafting, 115 Volt

Foredom has been making precision tools for many years and a lot of professional use them. Price sucks and they dont go on sale. This would produce much better results for your money spent than a flow bench. Now both should solve a whole lot of problems. But most head porters make there own tools. Or use tools they have had for years to do certain parts of the heads.

If you want to become a master at porting best to go to the junk yard and buy about 20 heads off anything and start cutting. Eye and ear protection is very important. Your not a porter until you been to the hospital to get a burning hot peice of metal removed from your eye. Also is a really good way to remeber to where your safty glasses. One trip to the hospital and you never forget again.

[Camaro_Nut2001]

Originally Posted by F-BIRD'88

Looks fine. You can thin and streamline that big fat valve guide boss some more. So the air can go around it.

I was hoping you would chime in. After comparing pictures of mine and some of Vizards I don't think i'm ready for the cartridge rolls yet, lol. When you say streamline, do you mean taper the guide boss into the runner? Also, I read somewhere about not taking very much at all from the back side of the boss. I have looked at your profile pictures and didn't find any but do you have a picture or two of a completed exhaust port that you have done? Am I right by not messing with the intake bowl? I really do value your knowledge.

[Camaro_Nut2001]

Originally Posted by ap72

Why not the intake ports? That's where most of your gains will be made.

Well now, maybe I need to reconsider as everything I have read thus far says that on the Vortecs the intake side is close to impossible to improve and I figured with my very limited knowledge on porting I would be best to leave them be. What were you thinking needs to be done on the intake side?

[Camaro_Nut2001]

Originally Posted by hcompton

Flow bench is not as useful as it might seem. Yes it helps and good bench numbers equal good hp numbers if everything else is right. But remeber the first thing they tell you when using a flow bench is its only about 1/4 the speed and pressure of a running engine. The real engine will force air thru the head much faster than a small vacum can. So yes they work but can lead to poorly ported heads if you do not understand flow to begin with.

Air flows down the center of the port. the air along the walls is moving very slowly and not really where the largest flow comes from. but air moving down the center of the port can reach and exceed the speed of sound. Your goal as a porter is make the port flow enough air to get close to the speed of sound as possible without going past the mark becasue air get tubulent after that. But until it reaches that speed it will increase in flow to the cylinder as the speed increases. Until you reach the tipping point where the air get turbulent. Since the flow bench cant actually push air with that much pressure most of the time you need to calculate the port size and shape. and when that i done it is almost always smaller than the one you have in front of you to cut.

Here is what I use to port heads. this is a little small for the job with cast iron car heads but will work. But its amazing on alum car and bike heads. If you want it perfect this or a tool like it is the only way to go.

K.SRH440, Industrial Kit with heavy duty shafting, 115 Volt

Foredom has been making precision tools for many years and a lot of professional use them. Price sucks and they dont go on sale. This would produce much better results for your money spent than a flow bench. Now both should solve a whole lot of problems. But most head porters make there own tools. Or use tools they have had for years to do certain parts of the heads.

If you want to become a master at porting best to go to the junk yard and buy about 20 heads off anything and start cutting. Eye and ear protection is very important. Your not a porter until you been to the hospital to get a burning hot peice of metal removed from your eye. Also is a really good way to remeber to where your safty glasses. One trip to the hospital and you never forget again.

Now that sounds like just what I need!! I like the foot controller and really really like the flexable shaft idea. I never knew this tool even existed. Thank you for showing it to me! I do plan to get into porting heads as I have several friends that race, I build and tune their carbs, and its something I can do sitting down for the most part. I have several pairs of safety glasses and am a firm believer in them. When I get in from the garage tonight I'm gonna do some more reading on this tool and may just order me one. For everything that comes with it, $355.00 is kinda cheap. I paid almost $200.00 for my 8pc. carbide cutters.

[Camaro_Nut2001]

WOW, nice work AP72. Thank you for posting the pictures.

[ap72]

that's actually about half way through, its also very important to blend the chamber in with the top cut of the valve job- which can be very tricky. I also didn't thin the guide any in that pic, typically I do thin it some but not as much as a lot of people do.

Just blending in the bowl cut and the top cut of the valve job on those heads will pick up 15 cfm, that area is very critical, and very tricky and time consuming as you do not want to nick the valve seat. smoothing out the short turn a little can help too, just don't get carried away. In general the areas closest to the valve seat are the most important. Also, enlarging the pushrod pinch a little and getting a nice and even contour on the roof will help with higher rpm power.