Visit this link and tell me what you think. Somehow, I don't believe that everyone who has had their heads ported and polished is lying through their teeth... http://www.mototuneusa.com/think_fast.htm
Power User
Teaching quads a lesson
Visit this link and tell me what you think. Somehow, I don't believe that everyone who has had their heads ported and polished is lying through their teeth... http://www.mototuneusa.com/think_fast.htm
I'm back in the USSR...
Power User
Got the holeshot
I think he absolutely 100% correct about how people think...
2-stroke lover
Power User
The day begins with 3WW
Well their not necessarilly "lying." The other guys that port differently have found a method that they like. This guy has found his.
Its all about trial and error. This guys seems to have found something that works. Ive read half way through, Im going to sign up for his newsletter.
Pretty interesting stuff.
My feedback: http://www.3wheelerworld.com/showthr...k-for-ATC-Eric
Survivor! TF: 07, 08, 09, 10, 11, 12, 13 Sandpuppies: 07, 08, 09, 10, 11, 16, 17, 18 Imperial Invasion 09, 10, 11, 13, 15, 16, 17, 18, 19, 20
Everything Big Bore on FaceBook
Power User
4 Wheels? Huh?
but.... he said he was useing stock carbs on his bike
i can see a stock carb not likeing a huge ported head
if he is right why dont the nhra top fuel cars use stock heads....lol
hes right to a point but nothing is always right or true
80s......185 atc, Yamaha tri-moto 200, 85 200x with tons of work
90s......89 Suzuki quad racer 250 (raced 250 A class for 6 years, late 90s.. custom framed 250x with long travel shocks and a built 350x motor.... built Honda 110
00s...... chomeoly framed 350 RX with all the goodies (thanks to my bro)
2012.....Replaced the 350x motor for a 444cc YZ426
WWW.HREATV.COM
Power User
Roostin Away
I believe what he says It true. Velocity speeds up the air flow & kinda acts like a supercharger. If you pulled air through a paper towl tube the velocity would stay the same In & out. If you pulled air through a transmission funnel, the velocity would be much higher, your scooping alot of air & forcing It through a small opening.
83 ATC 60-R Cr60 converted with Zinger parts.
83 ATC 70.
83 Tri zinger
ATC 85-R Cr85 engine on shortened 86-R frame.
ATC450AF
86 310-R Drag racer
440 snowmobile powered custom built.
87 Cr 500 Converted to Drag racer
Power User
The day begins with 3WW
I look at my V-Force reed cage and understand what this guy is getting at. The intake side of the cage is real small, smaller then a stock cage. It helps to icrease velocity.
My feedback: http://www.3wheelerworld.com/showthr...k-for-ATC-Eric
Survivor! TF: 07, 08, 09, 10, 11, 12, 13 Sandpuppies: 07, 08, 09, 10, 11, 16, 17, 18 Imperial Invasion 09, 10, 11, 13, 15, 16, 17, 18, 19, 20
Everything Big Bore on FaceBook
Someone put sand in my panties.
Roostin Away
its totally true, it isnt necessarily "smaller" ports, but correctly shaped and sized ports. if you canoe down a river, where the river get narrow, it speeds up right? well, thats how an intake port is supposed to work , and when the air is going fast right the at the narrow part, the valve opens and the air "rams" itself into the cylinder. the key to head porting is making this theory work its best.
1985 Honda ATC250R drag trike with s/t kit and full drag CR hybrid motor and drag chassis...
1986 Honda ATC250R daily rider fully modded engine, +4 swinger,etc...
1997 Polaris Storm 800 triple, boyesen reeds, dg individual silencers, 240 studs, 123mph on radar...
R.I.P. Hey Ron Racing-GIT IT RAG!
Got the holeshot
Oh Boy !!!!
"07" DR650 Suzuki Dual Sport
Trikein' Away
Teaching quads a lesson
I just read a little part of it.
"Then some of the charge gets pushed back out of the cylinder and into the port as the piston returns up the bore during the intake charging phase."
"It gets worse !
On a carbureted bike the reversing charge will create an effect called double carburetion, which means the mixture will become even richer with fuel as it passes back over the main jet nozzle for a second time."
Ok now to test this theory take off your air filter and place a piece of paper over it If its blowing back out the carb then it will blow back onto the paper pushing it away from where the filter should be. BUT i have never seen this happen. Also with the increasing RPM's the more air is sucked so his theory of blowing back through the carb is even less effective. The only way this would work is if the valves arnt sealing.
Now im not saying everything hes saying is crap I do belive a high velosity port can be good. Some engines i port that way. Some i dont it depends on what they are looking for. In my experiences You will get more torque with a high velocity porting and high hp with BIG porting.
Diffrent strokes for diffrent folks Good porting is good porting who gives a *Edited**Edited**Edited**Edited* how its done, there is not right or rong if it runs good. He found what works for him but i will guarintee it wont work for everyone.
First Time Rider
Arm chair racerNew to the board
These images seem relevant to this topic:
04' vs. 05' CRF250R
05' vs. 06' YFZ450
Always finding new and exciting ways to not give a hoot in hell
Catch me if you can
Those are some very interesting pictures there GPRacer.
R.I.P. Hey Ron Racing-GIT IT RAG!
Got the holeshot
yeah they are ... i'm wondering when i do the opposite to all the stuff i do ...Originally Posted by Billy Golightly
"Compared to them Pics"
Why is it FASTER ? ... HUMMMM
"07" DR650 Suzuki Dual Sport
Got The Holeshot
Arm chair racerJust too addicted
www.3wheeler.org
* * * Nothing scares me more than someone who knows, with certainty, what is best for me * * *
First Time Rider
Arm chair racerNew to the board
I like Jennings' book a lot. But I sure would like to see a new edition.
Always finding new and exciting ways to not give a hoot in hell
Catch me if you can
Jennings book is great, but its about 30 years out of date
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