DIY porting

[blowit]

Guys, we have had so many guys ask and have replied too many times. Thought it warranted it's own topic.

 

To port yourself, you do NOT need any specific tools but ones that will work for you and obtain a certain goal. What I mean is after you know how much material it to be removed and at what level of finish, you can select what tools you want to use. Some guys use air tools, some guys use electric, some guys use a wood chisel, does not matter as long as you know what needs to be done. You should understand what you are doing BEFORE cutting!

Porting was originally concepted by engineers to change optimal power characteristics to tailor power in a certain area without having to recast a cylinder. The actual tuning of engines from the basic concepts IS brass balls engineering but some of the best porting masters have learned through many hours of studying, trying, and failing. Absolutely anyone with capacity and desire to port an engine, can do so with success. The key is in the homework. This seems to be where most will fall short in that by simply looking and measuring ones work, they can simply "duplicate" it or guess on the measurements and "that's about right" theories.

 

There is a ton to be learned in porting and it can be fun and rewarding. The biggest to note here is learn. I will say this, if you are not good at math, things can get tricky and confusing fast. Engine porting is about 95% math. Hell, engines in general is 98% math. After all, do you think the OEMs just "guess" on the size of a bore, stroke, rod, comp ratio, etc? Learning the basics just makes you more educated when assessing porting.

 

"Porting" or port flow and timing are things that should be look at both together and separate. The idea is to get more dense fuel/air in the combustion chamber without losing a bunch out the tail pipe. This all works off port flow in CFM, CMPM, pr whatever volume you wish. Obviously, longer you leave the door open, the more you can get through it in a given about of time. The key is how long is too long? These are questions that only math can answer. By guessing at porting, you can leave yourself wondering, "what did I do right", or worse yet, "what did I do wrong".

 

Timing is one thing, individual port flow is another. Understanding port flow has less to do with engines and more to do with understanding sonic and subsonic air. For these concepts, we HIGHLY recommend starting with fluid dynamics and aerodynamics books. Some of the theories seen in old engines are considered "old school" by todays standards due to better test data and testing methods. Simply understanding flow means you can actually improve an engine by simply helping ports to flow better.

 

I will not drag this one out as I am hoping others will elaborate but the one thing you cannot have too much of is EDUCATION. Read it and understand it. If you think any porting expert got there by guessing, you are wrong. Sometimes it does take trial and error to prove a theory. We call that R&D. It takes time and expense. For anyone wanting to port their own engine, please understand that you can do it, but guessing will get you no where. There are a few amature porting guys here that actually know what is going on. Props to them for learning it.

 

To anyone looking at learning porting, understand that it is NOT an "art" as some people call it but an expertise in an area few choose to learn. After all, find me some true art that had an intended goal when it was concepted. Porting is math and physics and it can be learned. I recommend to anyone looking to understand porting, get books! This will certainly lead you down the path of success and understanding.

 

 

Brandon

[wesw]

post some of your work

[brian]

Brandon,

I think it's cool that you posted this. I like to see people being encouraging.

Too often, on this topic especially, some guys can get quite discouraging.

 

And I also agree that education is the key to everything we do. Some

things just take a lot more education than others.

[dajogejr]

Brandon...

Your post sounds more like a college degree and less like tested by fire methods.

 

Math and physics are a GREAT place to start, and I agree...no one can have too much education.

 

But that's like saying you can get a piece of paper from some university saying you know how do a job. Yet a seasoned veteran in the field will tell you experience is key...

On that note, I'll take street smarts over book smarts any day.

 

Knowledge and Wisdom are two totally different things. Just because something works on a sheet of paper or on a computer doesn't mean it works as you think it will in the real world.

 

Back to porting...

I think I've always portrayed the message of...if you want to try it out, go for it. But be prepared to fail. Without experience...it's 100 times easier to ruin a set of cylinders than it is to make them better.

 

However, those that are the best at it have probably ruined more cylinders than most people will ever see.

 

Reading up on and educating yourself on the matter at hand only goes so far...and it's a starting point.

But no builder built a record setting engine or a track record holder their first time out by reading a book and using a calculator...

 

Maybe I'm taking all this to the extreme...but I like to think I'm "keeping it real".....

[2strokespirit]

to me... a GOOD CLEAN port job is an ART!!!! I do not say you cannot do it yourself or learn to do it, I am sure a lot of us can master the art of porting and be an artist..... and I am SURE that most of us can not master it, thats why there are just a few big names if it comes to porting..and not everyone and their bro can port... Practice makes perfect and it costs $$$$$ if you fail. :thumbsup: BUT I agree, try it out if you want to.

[blowit]

to me... a GOOD CLEAN port job is an ART!!!! I do not say you cannot do it yourself or learn to do it, I am sure a lot of us can master the art of porting and be an artist..... and I am SURE that most of us can not master it, thats why there are just a few big names if it comes to porting..and not everyone and their bro can port... Practice makes perfect and it costs $$$$$ if you fail. :thumbsup: BUT I agree, try it out if you want to.

 

 

Basically what was said above is cutting on ports while having no idea what is is you are even cutting on, why, or what it does, is certain for disaster. An understanding of the concepts is a much safer approach. If you can't tell, we prefer to do things by the numbers because numbers do work. I guess in some other work we do, "that's about right" causes aircraft to fall from the sky. We don't leave much to chance. This also does not mean you need a degree in physics just to port cylinders but the more you know, the more armed you are.

 

 

Brandon

[FireHead]

There is a ton to be learned in porting and it can be fun and rewarding. The biggest to note here is learn. I will say this, if you are not good at math, things can get tricky and confusing fast. Engine porting is about 95% math. Hell, engines in general is 98% math. After all, do you think the OEMs just "guess" on the size of a bore, stroke, rod, comp ratio, etc? Learning the basics just makes you more educated when assessing porting.

 

"Porting" or port flow and timing are things that should be look at both together and separate. The idea is to get more dense fuel/air in the combustion chamber without losing a bunch out the tail pipe. This all works off port flow in CFM, CMPM, pr whatever volume you wish. Obviously, longer you leave the door open, the more you can get through it in a given about of time. The key is how long is too long? These are questions that only math can answer. By guessing at porting, you can leave yourself wondering, "what did I do right", or worse yet, "what did I do wrong".

 

Timing is one thing, individual port flow is another. Understanding port flow has less to do with engines and more to do with understanding sonic and subsonic air. For these concepts, we HIGHLY recommend starting with fluid dynamics and aerodynamics books. Some of the theories seen in old engines are considered "old school" by todays standards due to better test data and testing methods. Simply understanding flow means you can actually improve an engine by simply helping ports to flow better.

 

I will not drag this one out as I am hoping others will elaborate but the one thing you cannot have too much of is EDUCATION. Read it and understand it. If you think any porting expert got there by guessing, you are wrong. Sometimes it does take trial and error to prove a theory. We call that R&D. It takes time and expense. For anyone wanting to port their own engine, please understand that you can do it, but guessing will get you no where. There are a few amature porting guys here that actually know what is going on. Props to them for learning it.

 

To anyone looking at learning porting, understand that it is NOT an "art" as some people call it but an expertise in an area few choose to learn. After all, find me some true art that had an intended goal when it was concepted. Porting is math and physics and it can be learned. I recommend to anyone looking to understand porting, get books! This will certainly lead you down the path of success and understanding.

Brandon

Word. Good post!

 

If I may add a few things:

 

1.) You cannot create port work that is worth a crap by copying what you see in pictures.

 

2.) You cannot call anything that has a CNC machine involved an "art". :thumbsup:

[2strokespirit]

Basically what was said above is cutting on ports while having no idea what is is you are even cutting on, why, or what it does, is certain for disaster. An understanding of the concepts is a much safer approach. If you can't tell, we prefer to do things by the numbers because numbers do work. I guess in some other work we do, "that's about right" causes aircraft to fall from the sky. We don't leave much to chance. This also does not mean you need a degree in physics just to port cylinders but the more you know, the more armed you are.

Brandon

 

 

....did I say something wrong?? I said go on and try it out, do a search on the site of all the DIY porting and you will see, I always said DO IT YOURSELF IF YOU CAN!!

[Bansh-eman]

although i did not read this whole post, i would have to say i disagree in saying that ANYONE can do it, its is without a dought a form of art. just because you read and understand literature dosen not me you have the capabilities to create the correct angles and have a steady enough hand to cut things. yes education is a tool envolved in doing it right but theres more to it then simply reading and understanding dynamics.

 

to anyone willing to learn i give all the props in the world but i cant afford to ruin motors the learn, or buy the tools for that matter.

[FireHead]

although i did not read this whole post, i would have to say i disagree in saying that ANYONE can do it, its is without a dought a form of art. just because you read and understand literature dosen not me you have the capabilities to create the correct angles and have a steady enough hand to cut things. yes education is a tool envolved in doing it right but theres more to it then simply reading and understanding dynamics.

 

to anyone willing to learn i give all the props in the world but i cant afford to ruin motors the learn, or buy the tools for that matter.

dought........................really? :biggrin:

[dajogejr]

Basically what was said above is cutting on ports while having no idea what is is you are even cutting on, why, or what it does, is certain for disaster. An understanding of the concepts is a much safer approach. If you can't tell, we prefer to do things by the numbers because numbers do work. I guess in some other work we do, "that's about right" causes aircraft to fall from the sky. We don't leave much to chance. This also does not mean you need a degree in physics just to port cylinders but the more you know, the more armed you are.

Brandon

 

I agree, Brandon...I didn't want you to think I was being critical, and I might have read into what you said too much.

 

General basics and understandings are a great place to start, I agree. But I'd prefer someone with actual experience vs a motor that is theoretical, like numbers and figures punched into a computer to tell you what a motor "should" make.

Not that a computer program or modeling isn't a good place to start, I just think there's more to finishing and fine tuning than what they can tell you. What works on a screen or paper doesn't always work in the sand, dirt or on pavement.

 

That's like saying my motor put out a gazillion HP on a dyno, I should beat everyone, right?

 

NO....it's setup and getting that power to the ground. Knowing how to ride doesn't hurt either...

[Machwon]

Here's some experiences I've had as a DIY who started almost 17 years ago. At first It was very crude with the porting tools and it was tough not to rush it, My power improvements were great in the mids but falled way short on top. My experience grew greatly by purchasing a cylinder from a big name Co, spending money on the software and eventually seeing many different cylinders ported by big name companies.

 

Understanding trigonometry and math will be a very important to getting good results.

Operating a porting tool does become the "art" of the job, Starting out you tend to make things more uneven than what you started with and you easily lose control of the tool in the corners. Computer programs are awesome but can be misleading on the power numbers. However, it is an undispensable tool for evaluating different combinations of stroke, rod and power spread combinations. You will likely make mistakes at first as I wished I had some of the first cylinders back. I've ruined cylinders but only by hitting the water jackets on some extreme builds. Usually worst case port jobs sent to me now will look hacked up, but still usually can make a decent drag port cylinder. The devil eventually comes in the details as anyone can dimensionally match other porting, but this still won't run as good. Pictures do very little for ones exerience. Viewing a good ported cylinder, evaluating it mathmatically and taking good notes is what you need.

 

It has been a great overall experience porting cylinders and I still love to do it. I do well over 100 cylinders each year now. I won't rush any cylinder out that I do, but my skill at porting has improved so greatly that I have probably cut my time in 1/2 to do a decent pair of cylinders. As I aged I will have to say that I can't port for more than 2 hours at a time as my hands now will get numb. Fortunately I still have my 20/20 eye sight.

[jmd0346]

I think i could port jugs and be good at it. The problem is I dont have the extra jugs to learn on.lol Im not screwing mine up making trial runs.

[Toybreaker]

I think i could port jugs and be good at it. The problem is I dont have the extra jugs to learn on.lol Im not screwing mine up making trial runs.

 

That is why you start with your friends bikes!

[2strokespirit]

That is why you start with your friends bikes!

 

 

:yelrotflmao: