Triple exhaust ports and what they are.

[Paulie B]

You might hear the term bein throw around with porters like Flotek who cut them into stock cylinders or you have a 240 kit with them.
Basically it's where you have 2 extra ports that flank the main exhaust port (where your pipe mounts up to your motor).
The benefits of them is they allow the exhaust to flow out of the cylinder faster which in turn draws more air from the intake hence more power.
Why am I telling you this?
Because I just came across a great picture that shows what they look like.
This has been a PB public service announcement haha
Enjoy

 

[1bad442]

nice illustartion !!! have some rep paulie

 

[darederek]

wait, how can they add these to a stock cylinder? sure dont look like they would have room to cut them in??? or do they add material to the cylinder or something?

 

[Paulie B]

wait, how can they add these to a stock cylinder? sure dont look like they would have room to cut them in??? or do they add material to the cylinder or something?

No material is added to stock cylinders.
A stock cylinder will not be able to have them as big as the ones pictured but there will be a benefit.
The picture is a CP industries cheetah cub.
They have them cast into a cylinder designed for them.

 

[Blaner]

cool, i think Graham Bell or Gordan Jennings talks about them in their two stroke tuning books. Nice pic!

 

[N8tsNastyBlasty]

every time i drill /cut triples its kinda scary.lol I dont know how big i can go but im sure im close the limit.The channels i have behind them are nowhere near this big but i find even small ones really wake up that powerband!!!!!! i wont ride w/out them!!!!! Im postin pics soon then a diy method of my own in a video on the next jug.

 

[N8tsNastyBlasty]

Here's a pic of my triples i cut my self with out any advice on how to.but like all of my disclaimers for the cynical "dont try this at home kids" I may very well end in disatrous ways.

 

[99LRDblaster]

You might hear the term bein throw around with porters like Flotek who cut them into stock cylinders or you have a 240 kit with them.
Basically it's where you have 2 extra ports that flank the main exhaust port (where your pipe mounts up to your motor).
The benefits of them is they allow the exhaust to flow out of the cylinder faster which in turn draws more air from the intake hence more power.
Why am I telling you this?
Because I just came across a great picture that shows what they look like.
This has been a PB public service announcement haha
Enjoy

I'm guessing it works and all, but I'm somewhat skeptical of the gains simply because it ultimatley is funneled all into the same typical exhaust port you begin with, giving a similar affect to putting 3 tubes up to an air intake on a carb, but it's still ultimately limited by venturi size regardless of air flow. Now I realize they are 2 entirely different scenarios and how they function, but it's just an example because ultimately the area where the pressure is exiting is still the exact same regardless of how many ports you have...1, 3, 40, whatever. I would think you would need to use a larger expansion chamber in a pipe to reap rewards from it. I can see how it would work to an extent, but I'm a bit of a skeptic and just playing devil's advocate here.

What's the theory on it?

 

[brandoz28]

its not so much size, but location

 

[Paulie B]

When the piston comes down after combustion and the ports just starts to open, thats where the benefit is. You are releasing the presure through a much larger area then just the one in the middle.

 

[sicivicdude]

The greatest amount of blow down pressure is right as the exhaust port is uncovered but before the transfers are uncovered. The exhaust port cannot be made perfectly flat topped because the rings would catch, it has to be oval shaped. By the time the piston has moved down far enough to uncover any significant amount of that oval shaped hole it's also uncovered the transfers. That's where the triple exhaust ports come in. The top of the auxiliary exhaust ports is at the same level as the top of the main exhaust port. They are opened before the transfers so they allow a bunch more scavenging to happen while the cylinder is more likely to do it.

 

[99LRDblaster]

When the piston comes down after combustion and it ports just starts to open, thats where the benefit is. You are releasing the presure through a much larger area then just the one in the middle.

Ahh ok gotcha. I was thinking it was just a size thing at first. In that case, it would be beneficial at speed to scavenge gases away an area approximately the entire size of the "regular" exhaust port while the main exhaust port is only open 25%-50% of the way. Makes sense. I:I

 

[N8tsNastyBlasty]

I know that after adding these and boysen ports my blasters got nasty faster it freaked me out at first. I had no idea how much power these little machines were hiding!!!!The first time I did it was to a junky loaner bike that i would let my friends ride with me.I didnt have much in it and decided i should at least try it. all i can say is holy crap!! heres a couple vids of my first triple ported blaster!!! <iframe title="YouTube video player" width="480" height="390" src="http://www.youtube.com/embed/aeU6lt8INPM" frameborder="0" allowfullscreen></iframe>


<iframe title="YouTube video player" width="480" height="390" src="http://www.youtube.com/embed/tCJqG1LqVaI" frameborder="0" allowfullscreen></iframe>

 

[N8tsNastyBlasty]

this is when i just guessed at port timing and didnt know the forum. hell it had the stock jets with the needle set full rich lol!!!

 

[Paulie B]

Sounds pretty heathy can you get someone to hold the camera?

 

[99LRDblaster]

YouTube - 2nd snow ride on ol blue


YouTube - 2000 faster blaster!!!!!!!



this is when i just guessed at port timing and didnt know the forum. hell it had the stock jets with the needle set full rich lol!!!

Interesting. Definitely has a totally different note to it....almost higher output dirtbike-ish sound. What did you change in terms of port timing? Wouldn't it be best to just match the top of the main exhaust port height then make a circular/oval port from the height of the top of the main exhaust port to 40ish% of the center of the main exhaust port?

 

[N8tsNastyBlasty]

I sold this one almost 2 years ago and it was a helmet cam. next time it will be on the bars. it had a motorcycle muffler i used as a silencer. It sounded hella nasty!! I kinda want to do it again.lol!!!

 

[N8tsNastyBlasty]

On this one i raised all the ports just about the width of a sharpie and had the triples just a lil higher. like i said i just guessed at it then.

 

[N8tsNastyBlasty]

Has anyone else on here cut triples other than flotek? or at least tried it? I'm kinda surprised that i havent seen anyone else's diy port pics? Honestly im not that talented i just have lots of practice drilling holes with a cordless drill.

 

[99LRDblaster]

Has anyone else on here cut triples other than flotek? or at least tried it? I'm kinda surprised that i havent seen anyone else's diy port pics? Honestly im not that talented i just have lots of practice drilling holes with a cordless drill.

A lot of people don't risk it. People find porting themselves risky enough and then find it even riskier to cut into the cylinder itself.

What did you use to curve the triples? I would think you would need some snaking tool.