Two Stroke Porting

This is mainly for the two stroke members. :sorry:
There are many places in which we can send our cylinder to and get it ported and polished. No one has the real answer as to what is the best port and polish job. Everyone has their own style of porting the cylinder. I came across a photo of a ported cylinder the other day. I still have no idea of how or where it came from. I have never seen anything like it. Any thoughts about this porting?

 
Textbook as far as I'm concerned. Only a flow bench can show actual results though.
They left the roughness of the surface but contoured the vanes and ports in a 'blunt' manner. I like it. -BIG DAN:thumb:

Hey thanks. :thumb: But, what type of power would a port job like that do. I have never seen anything like that before. Not even on smaller bores.
 

SRAD97750

Moderator
Staff member
In this photo you can see the different port timing. It acts as a supercharger, taking even more in, earlier. :thumb:

2.jpg

This is all from this TT thread.
A 2000 CR500 Cold Fusion NOS RaceBike
ENTER THE DARKSIDE -BIG DAN:thumb:
 
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In this photo you can see the different port timing. It acts as a supercharger, taking even more in, earlier. :thumb:

View attachment 22178

This is all from this TT thread.
A 2000 CR500 Cold Fusion NOS RaceBike
ENTER THE DARKSIDE -BIG DAN:thumb:

Ok thanks. That must be where I saw the picture. :redface: :smirk: Not to be a pain in the ass. I have just one more question. Do you know of any engine shop that specializes in doing a port job like that. I have always wanted to send my cylinder to Forward Motion (Eric Gore). But, as far as I know he does not do this type of porting. thanks any info will help.
 
You can do this yourself fairly easy. I'm learning the processes right now for automobile cylinder heads. Its really a crap shoot without a flow bench though. I have a friend with one though :wink:
 
This is mainly for the two stroke members. :sorry:
There are many places in which we can send our cylinder to and get it ported and polished. No one has the real answer as to what is the best port and polish job. Everyone has their own style of porting the cylinder. I came across a photo of a ported cylinder the other day. I still have no idea of how or where it came from. I have never seen anything like it. Any thoughts about this porting?



That looks to be a sx jug. They shave the reed box just a fraction to get that low end grunt. They opened up the lower ports to allow more fuel into the lower end (notice the gradual angle to create a funnel effect) and the upper port vas been bored larger with a sharper edge to allow more oxygen rich fuel (which is lighter) to turbulate and atomize quicker...

Merely speculation though as I am not a machinist..... Just a guy that likes dirt bike.......
I really fucking love dirtbikes:hug:
 
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So I am both confused and sad at the same time. I called one of the phone numbers on the GSS Race Porting web page. I spoke to the owners son. I did as his son said and called the father. I left a message. I have not got a reply yet. I hope to get a call back soon. But, I want to know if anyone knows of a shop that could kind a replicate the porting by looking at the pictures? I know there are countless shops that do porting. I also know that Eric Gore from Forward Motion is one of the best for the CR500. But, I have never seen any shop do this type of porting. Plus there is no way I am trying to do it myself. Thanks.
 
So I am both confused and sad at the same time. I called one of the phone numbers on the GSS Race Porting web page. I spoke to the owners and originator of the porting. I did as his son said and called the father. I left a message. I have not got a reply yet. I hope to get a call back soon. But, I want to know if anyone knows of a shop that could kind a replicate the porting by looking at the pictures? I know there are countless shops that do porting. I also know that Eric Gore from Forward Motion is one of the best for the CR500. But, I have never seen any shop do this type of porting. Plus there is no way I am trying to do it myself. Thanks.


You want a good port and polish job go to the people who know porting.... Eric Gore is one of the best... Call my buddy at pro circuit. Ask for Mitch and he'll port that for ya too. Get it polished, match the cases and you'll get another 10 ponies atleast.
 
You want a good port and polish job go to the people who know porting.... Eric Gore is one of the best... Call my buddy at pro circuit. Ask for Mitch and he'll port that for ya too. Get it polished, match the cases and you'll get another 10 ponies atleast.

If I am unable to contact this GSS Race Porting shop. I would have Eric do my cylinder for sure. I just saw this porting and wanted to be a little different and have it done to my cylinder. I like to be different. Plus being from CNY I'm a little off. :loco: :smirk:

If you read the CR500 section on Eric's 2 stroke services. You will see why I would choose his shop to do my cylinder. If I am unable to contact GSS.
 
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