Upon my recent return to the forum, I saw gggGary's post "Port-n-Polish" thread Here.
Obviously it caught my interest. gggGary was kind enough to send me an orphaned head to experiment
with as I worked on ways to develop the xs650 head two years ago. He paid the shipping and wouldn't accept
reimbursement. I was extremely grateful as that head was instrumental in my experimentation. I learned a great deal.
Eventually developing the D45F head for Wannabriden in a long lost thread here.
The beginning of the thread is fraught with some mistakes and errors which I acknowledged and corrected.
It documented the entire journey of me building my flow bench and learning to use it.
I also covered basic porting tenents and philosophy as well as the math that is used in the process of identifying the port charcteristics necessary to fullfill an engines requirements based on it's volumetrics.
Everything is there, warts and all. I had and still have zero interest in posturing or seeking accolades posting up gaudy numbers.
My only interest was in developing a fully active port that was designed for his motor (700cc with a shell cam).
The final result was an extremely efficient port which I exceeded my expectations at the beginning of the process.
When testing a head the numbers are what they are and they dictate what needs to be done.
Most people are only aware of CFMs. Of all the testing done CFMs are the LEAST IMPORTANT.
I cannot stress that enough. The CFM simply need to provide an engine with the amount of air required by the engine's volumetrics.
The closer the CFMs are to the volumetric requirement the better. Too much results in loss of effieciency in the low to mids.
Too little with take power from the top. The engine specs determine "The Goldilocks Zone" where air flows most efficent.
There is no such thing as a one size does it all.. (Go Big
). There is ALWAYS a trade off unless the port is matched to the volumetrics.
The key element in porting is raising the VELOCITY within the port as evenly as possible throughout the port. That is what's MOST important.
It is critical to understand your riding style and intended use as well as the engine combination.
(Cam, Stroke, Bore, Power/Torque Curves, Valve Size, Etc.) when porting a head IF you are seeking to OPTIMIZE your Performance and Power.
Like everything else in life you do the best you can with what you got. There was a time when I had nothing more than a die grinder,
then I added a large commercial vacuum and some string and flowballs. Now I have a bench that will pull 28" of depression, and digital test
equipment, manometers, calibration plates etc. But I'm off track.. back to the Madness head
As I said, I was and am very grateful to gggGary for his part in aiding my testing, so I reached out and offered to test his head for him.
No charge of course and I finally kinda sorta got to reimburse by paying that shipping return to him.
I thought it might provide some information he could use. Since I am writing this, he clearly was interested and accepted my offer.
I have been porting a couple of car heads most recently and once he said yes I changed my fixture back to the XS650 setup in order
to be ready for testing upon the head's arrival. I know he is trying to get Madness back together so I told him it would be a week or less and it was.
I will say that I did this as a favor to return a favor, I had no intention of making this posting.
I had told gggGary that I would provide him with all the test results and he could do as he wished with them.
He made it clear that it was his desire that I post the findings. I'll admit that I was somewhat reticent, because I did not want any kind of appearance
that I am degrading someone's efforts or hard work. I am fully aware that I hurt another member's feelings when I did the posting 2 years ago.
That bothered me a great deal as that member was the very inspiration for me to do what I am doing with these heads.
It is a very difficult thing to maximize the efficiency of a port without having access to test equipment, That is just reality.
So the "bottom line" as they say is.. the numbers are what the numbers are...
That could almost be a direct quote from gggGary in our discussion about me presenting this data for the forum.
I am still making charts and such to present the data in a way that it can be followed and understood. That should start coming out this weekend.
Since my testing fixture had been changed for larger auto cylinders and placed back, I will also be retesting (in case that skews any numbers)
my 100% stock head as well as the head I pocket ported to verify/reestablish a baseline and a comparison to have some context for the results.
gggGary can be persuasive, but I ultimately decided to go forward with this posting because I think there are many people curious about pocket porting,
and I feel the information could provide them some insights on what they can expect as well as some hints on how to proceed should they give it a go.
I won't leave you totally hanging, I think that gggGary did pretty well. He had already completed the head when I reached out
and we never discussed what his expectations were, beyond just telling it like it is. That is what is going to occur.
The tests I performed are as follows:
CC'ing the Chambers, Intake Ports and Exhaust Ports.
Mapping the Intake Ports and Measuring the Cross Sectional Area (CSA)
Flowballs for Port Activity
Smoke testing for Seperation of Air in the Port
CFMs
Velocity Mapping of the Port (the MOST important!)
Sooo Vroom Vroom
Hopefully someone finds it useful...
Rick
Obviously it caught my interest. gggGary was kind enough to send me an orphaned head to experiment
with as I worked on ways to develop the xs650 head two years ago. He paid the shipping and wouldn't accept
reimbursement. I was extremely grateful as that head was instrumental in my experimentation. I learned a great deal.
Eventually developing the D45F head for Wannabriden in a long lost thread here.
The beginning of the thread is fraught with some mistakes and errors which I acknowledged and corrected.
It documented the entire journey of me building my flow bench and learning to use it.
I also covered basic porting tenents and philosophy as well as the math that is used in the process of identifying the port charcteristics necessary to fullfill an engines requirements based on it's volumetrics.
Everything is there, warts and all. I had and still have zero interest in posturing or seeking accolades posting up gaudy numbers.
My only interest was in developing a fully active port that was designed for his motor (700cc with a shell cam).
The final result was an extremely efficient port which I exceeded my expectations at the beginning of the process.
When testing a head the numbers are what they are and they dictate what needs to be done.
Most people are only aware of CFMs. Of all the testing done CFMs are the LEAST IMPORTANT.
I cannot stress that enough. The CFM simply need to provide an engine with the amount of air required by the engine's volumetrics.
The closer the CFMs are to the volumetric requirement the better. Too much results in loss of effieciency in the low to mids.
Too little with take power from the top. The engine specs determine "The Goldilocks Zone" where air flows most efficent.
There is no such thing as a one size does it all.. (Go Big
). There is ALWAYS a trade off unless the port is matched to the volumetrics.The key element in porting is raising the VELOCITY within the port as evenly as possible throughout the port. That is what's MOST important.
It is critical to understand your riding style and intended use as well as the engine combination.
(Cam, Stroke, Bore, Power/Torque Curves, Valve Size, Etc.) when porting a head IF you are seeking to OPTIMIZE your Performance and Power.
Like everything else in life you do the best you can with what you got. There was a time when I had nothing more than a die grinder,
then I added a large commercial vacuum and some string and flowballs. Now I have a bench that will pull 28" of depression, and digital test
equipment, manometers, calibration plates etc. But I'm off track.. back to the Madness head
As I said, I was and am very grateful to gggGary for his part in aiding my testing, so I reached out and offered to test his head for him.
No charge of course and I finally kinda sorta got to reimburse by paying that shipping return to him.
I thought it might provide some information he could use. Since I am writing this, he clearly was interested and accepted my offer.
I have been porting a couple of car heads most recently and once he said yes I changed my fixture back to the XS650 setup in order
to be ready for testing upon the head's arrival. I know he is trying to get Madness back together so I told him it would be a week or less and it was.
I will say that I did this as a favor to return a favor, I had no intention of making this posting.
I had told gggGary that I would provide him with all the test results and he could do as he wished with them.
He made it clear that it was his desire that I post the findings. I'll admit that I was somewhat reticent, because I did not want any kind of appearance
that I am degrading someone's efforts or hard work. I am fully aware that I hurt another member's feelings when I did the posting 2 years ago.
That bothered me a great deal as that member was the very inspiration for me to do what I am doing with these heads.
It is a very difficult thing to maximize the efficiency of a port without having access to test equipment, That is just reality.
So the "bottom line" as they say is.. the numbers are what the numbers are...
That could almost be a direct quote from gggGary in our discussion about me presenting this data for the forum.
I am still making charts and such to present the data in a way that it can be followed and understood. That should start coming out this weekend.
Since my testing fixture had been changed for larger auto cylinders and placed back, I will also be retesting (in case that skews any numbers)
my 100% stock head as well as the head I pocket ported to verify/reestablish a baseline and a comparison to have some context for the results.
gggGary can be persuasive, but I ultimately decided to go forward with this posting because I think there are many people curious about pocket porting,
and I feel the information could provide them some insights on what they can expect as well as some hints on how to proceed should they give it a go.
I won't leave you totally hanging, I think that gggGary did pretty well. He had already completed the head when I reached out
and we never discussed what his expectations were, beyond just telling it like it is. That is what is going to occur.
The tests I performed are as follows:
CC'ing the Chambers, Intake Ports and Exhaust Ports.
Mapping the Intake Ports and Measuring the Cross Sectional Area (CSA)
Flowballs for Port Activity
Smoke testing for Seperation of Air in the Port
CFMs
Velocity Mapping of the Port (the MOST important!)
Sooo Vroom Vroom
Hopefully someone finds it useful...
Rick
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I found his original post interesting when he first did it. Even though I’m kind of out of the game anymore, I still find engine building and performance modifications to be interesting . I’ll admit that much of the technical data kinda sails over my head, but I enjoy seeing the process and head porting has always intrigued me , because so much of it that folks like our Gary did, is just sort of of intuitive. Remove obstructions and smooth the way, it’s all kind of voodoo science. But to get into actively reshaping ports and scientifically collecting data….well that’s entering into factory race efforts domain. The XS650 motor has always seemed to me to be a difficult motor to coax big power out of. The old flat track racing pioneers in the 70’s and the one off factory racing heads that guys like Kennedy Robert’s used, used to fascinate me as a young man….still does. 
