ninjette.org

Go Back   ninjette.org > General > General Motorcycling Discussion

Notices

Reply
 
Thread Tools
Old October 14th, 2017, 09:13 PM   #41
JacRyann
ninjette.org certified postwhore
 
Name: Jonathan-Philippe
Location: SF Bay Area
Join Date: May 2017

Motorcycle(s): CB125T, Ninja 250R street, Ninja 250R race, pregen EX250F bike-in-a-box#1 & 2, VF500F, EX500R, CBR600RR

Posts: A lot.
MOTM - Nov '17
Quote:
Originally Posted by Triple Jim View Post
That's either a 250 or 350
Nope, it's a 3-cyl 750 2-stroke. 250 per cylinder qualifies for ninjette status?
JacRyann is offline   Reply With Quote




Old October 14th, 2017, 09:16 PM   #42
Ram Jet
ninjette.org certified postwhore
 
Ram Jet's Avatar
 
Name: Bill
Location: Port Huron, Michigan
Join Date: Mar 2017

Motorcycle(s): 2007 Kawasaki 250 Ninja, 1982 Honda Ascot FT500

Posts: A lot.
Quote:
Originally Posted by Triple Jim View Post
That's either a 250 or 350, and appears to be built for its look, rather than performance. Things like Emgo pod filters, tires chosen for their vintage appearance, and low-end expansion chambers give it away. I like the one I had the opportunity to do the exhaust system for a lot better. It's an S3 with a highly modified H1 engine and a lot of real performance mods. Admittedly the airbox wasn't back on yet, and I've probably posted it before, but:
Have you ever read "Two Stroke Tuners Handbook" by Gordon Jennings? He does a mind-blowing dissertation on expansion chamber design. I fool around with model airplane engines and they sell after market chambers for these little engines. I just smile and shake my head. Ain't no way they put any of Jennings theory to work. I'm sure they just make them to look cool. By the way after Gordon's fist ride on an H1 he said "He had to beat-down the goose bumps with a hammer"

That gas tank on the Jac Ryan photo looks a-lot like a 73' 500 tank.

Bill
__________________________________________________
Insanity: doing the same thing over and over again expecting different results each time.
Ram Jet is offline   Reply With Quote


Old October 14th, 2017, 09:21 PM   #43
Ram Jet
ninjette.org certified postwhore
 
Ram Jet's Avatar
 
Name: Bill
Location: Port Huron, Michigan
Join Date: Mar 2017

Motorcycle(s): 2007 Kawasaki 250 Ninja, 1982 Honda Ascot FT500

Posts: A lot.
Quote:
Originally Posted by JacRyann View Post
Nope, it's a 3-cyl 750 2-stroke. 250 per cylinder qualifies for ninjette status?
I note the owner has a solid functioning brain. No 5 1/2" rear tire. I used to run 4.10's front and back on my 500. He needs Uni air filters. Nice bike and a-lot of work.

Bill
__________________________________________________
Insanity: doing the same thing over and over again expecting different results each time.
Ram Jet is offline   Reply With Quote


Old October 14th, 2017, 09:30 PM   #44
Triple Jim
Guy Who Enjoys Riding
 
Triple Jim's Avatar
 
Name: Jim
Location: North Central North Carolina
Join Date: Jul 2016

Motorcycle(s): Ninja 250

Posts: A lot.
MOTM - Aug '17, Aug '16
Quote:
Originally Posted by JacRyann View Post
Nope, it's a 3-cyl 750 2-stroke. 250 per cylinder qualifies for ninjette status?
I've owned an H2 since 1978, and trust me, that's not a 750 and it's not a 500. They have nine horizontal fins on their cylinders. The 250s, 350s, and 400s have seven fins on their cylinders, although the bottom one is hidden in your photo. A 400 has very square looking heads. The photo below is of me on my H2 a couple years ago. You can count fins if you like.

Ramjet, yes, the Jennings and Bell books are old staples of tuning.

Correction: I don't have any S1 cylinders here, but I thought they were externally the same as S2 cylinders. They're not, S1 cylinders have six fins, and other photos of that triple, like the one on the right below, on http://notyouraveragebikes.com/ clearly show six fins, so that's definitely a 250 triple. I guess that might qualify it as a Ninjette, but it was rated only 28 hp at the crank, so somewhat less power than our 4-stroke 250s.

At about $7,300 US, I doubt if it will sell very soon: http://notyouraveragebikes.com/our-b...h250caferacer/
Attached Images
File Type: jpg jims_h2_killboy_gamma_800.jpg (93.5 KB, 7 views)
File Type: jpg not_your_average_bikes_s1_engine.jpg (195.6 KB, 1 views)

Last futzed with by Triple Jim; October 15th, 2017 at 07:11 AM.
Triple Jim is offline   Reply With Quote


Old October 27th, 2017, 04:49 AM   #45
maverick9611
ninjette.org guru
 
maverick9611's Avatar
 
Name: Michael
Location: Augusta,Georgia
Join Date: May 2017

Motorcycle(s): 2008 exploited 250r

Posts: 475
ok guys, here is the end result. if anybody wants all the details let me know. thanx member jacryann for the help. long stacks is what i wanted but you loser your taper. here is the final price quote from steel dragon

Hi Michael,

Price for a set of (2) aluminum stacks, 2.5" long, machine finish, is $60.00 + $25.00 programming fee = $85.00. Shipping is additional; if you're in the US, it would be between $6.65 and $8.35, USPS Priority Mail. Polished finish would be an additional $2.50/stack.

Just let us know if you're good with everything- if so, we would need your shipping address and which finish you would prefer. For payment, we send a PayPal invoice to your email.
__________________________________________________
"trying not to get old"
maverick9611 is offline   Reply With Quote


Old October 27th, 2017, 07:59 AM   #46
Racer x
ninjette.org certified postwhore
 
Racer x's Avatar
 
Name: Eric
Location: Iowa City
Join Date: May 2009

Motorcycle(s): 2008 Kawmeracchi 350 2010 Project X

Posts: A lot.
Blog Entries: 54
MOTM - Feb '16
I users the stacks for a long time. They look cool but donít really help topend power. I got the best power from just using nothing. But that was on the dyno. I am not sure but I think the right side will go lean with stacks or open carbs when traveling at speed. I use pods on the street to keep dirt out. But for the track I take them off.
__________________________________________________
Top speed 123.369mph. Ohio mile
Worlds fastest 250 ninja
Racer x is offline   Reply With Quote


Old October 27th, 2017, 08:05 AM   #47
maverick9611
ninjette.org guru
 
maverick9611's Avatar
 
Name: Michael
Location: Augusta,Georgia
Join Date: May 2017

Motorcycle(s): 2008 exploited 250r

Posts: 475
Quote:
Originally Posted by Racer x View Post
I users the stacks for a long time. They look cool but donít really help topend power. I got the best power from just using nothing. But that was on the dyno. I am not sure but I think the right side will go lean with stacks or open carbs when traveling at speed. I use pods on the street to keep dirt out. But for the track I take them off.
thanx for sharing mr. X. i will try them with ram air socks. still going to get innner screen installed too. some say donít might upset air but if i run them naked it will have some protection. here is my zrx stack screen
__________________________________________________
"trying not to get old"
maverick9611 is offline   Reply With Quote


Old October 27th, 2017, 10:47 AM   #48
jkv45
Rev Limiter
 
jkv45's Avatar
 
Name: Jay
Location: WI
Join Date: Jul 2013

Motorcycle(s): '06 SV650n, '00 SV650n project, '00 Derbi GPR, '64 CA77 Dream 305, '70 CL450 Scrambler, numerous dirt bikes

Posts: A lot.
MOTM - Oct '16
That's gonna kill the flow...
jkv45 is offline   Reply With Quote


Old October 27th, 2017, 06:24 PM   #49
Racer x
ninjette.org certified postwhore
 
Racer x's Avatar
 
Name: Eric
Location: Iowa City
Join Date: May 2009

Motorcycle(s): 2008 Kawmeracchi 350 2010 Project X

Posts: A lot.
Blog Entries: 54
MOTM - Feb '16
It might actually cause the airflow to straighten out. Less volume but better flow caricteistics. It would be fun to see a color computer program of pressure with different screen size.

I love the look of the stacks and have used them. But don’t have any real information or knowledge that can add to the conversation. What I have read is the original intention of a big long funnel comes from dragsters. Now I could be and probably am wrong but what I read was the high over lap camshafts caused pressure to go the wrong way and fuel was splashing back out of the intake track. The long tubes coughs the fuel droplets and when the throttle was whacked open all the fuel that was splashing out of the intak went into the engine. Call the myth busters
__________________________________________________
Top speed 123.369mph. Ohio mile
Worlds fastest 250 ninja
Racer x is offline   Reply With Quote


Old October 27th, 2017, 06:57 PM   #50
Ram Jet
ninjette.org certified postwhore
 
Ram Jet's Avatar
 
Name: Bill
Location: Port Huron, Michigan
Join Date: Mar 2017

Motorcycle(s): 2007 Kawasaki 250 Ninja, 1982 Honda Ascot FT500

Posts: A lot.
Quote:
Originally Posted by Racer x View Post
It might actually cause the airflow to straighten out. Less volume but better flow caricteistics. It would be fun to see a color computer program of pressure with different screen size.

I love the look of the stacks and have used them. But donít have any real information or knowledge that can add to the conversation. What I have read is the original intention of a big long funnel comes from dragsters. Now I could be and probably am wrong but what I read was the high over lap camshafts caused pressure to go the wrong way and fuel was splashing back out of the intake track. The long tubes coughs the fuel droplets and when the throttle was whacked open all the fuel that was splashing out of the intak went into the engine. Call the myth busters
Like this?

Bill
Attached Images
File Type: jpg Crower_Injectors.jpg (44.4 KB, 0 views)
__________________________________________________
Insanity: doing the same thing over and over again expecting different results each time.
Ram Jet is offline   Reply With Quote


Old October 27th, 2017, 07:20 PM   #51
Racer x
ninjette.org certified postwhore
 
Racer x's Avatar
 
Name: Eric
Location: Iowa City
Join Date: May 2009

Motorcycle(s): 2008 Kawmeracchi 350 2010 Project X

Posts: A lot.
Blog Entries: 54
MOTM - Feb '16
Yup, Is that an old Hilborn system?
__________________________________________________
Top speed 123.369mph. Ohio mile
Worlds fastest 250 ninja
Racer x is offline   Reply With Quote


Old October 27th, 2017, 07:30 PM   #52
Triple Jim
Guy Who Enjoys Riding
 
Triple Jim's Avatar
 
Name: Jim
Location: North Central North Carolina
Join Date: Jul 2016

Motorcycle(s): Ninja 250

Posts: A lot.
MOTM - Aug '17, Aug '16
With two different lengths to make up for the two different intake runner lengths of a big block Chevy. (although this set looks a little on the overly different side)
Triple Jim is offline   Reply With Quote


Old October 27th, 2017, 08:19 PM   #53
Ram Jet
ninjette.org certified postwhore
 
Ram Jet's Avatar
 
Name: Bill
Location: Port Huron, Michigan
Join Date: Mar 2017

Motorcycle(s): 2007 Kawasaki 250 Ninja, 1982 Honda Ascot FT500

Posts: A lot.
Quote:
Originally Posted by Ram Jet View Post
Like this?

Bill
Most likely. It's just a photo I pulled searching "fuel injected small block Chevy photos". Many "roundy round" oval track cars ran very long velocity stacks for probably a good reason. Formula 1 cars have/had an affinity for velocity stacks also. According to Gordon Jennings "Two Stroke Tuner's Handbook" the long velocity stacks tend to eliminate secondary intake tract resonances that upset proper fuel metering. Short velocity stacks may look cool but may in fact interfere with proper fuel metering. Bottom line is you are hard pressed to beat the O.E.M airbox/air filter set-up.

Bill
__________________________________________________
Insanity: doing the same thing over and over again expecting different results each time.
Ram Jet is offline   Reply With Quote


Old October 27th, 2017, 08:49 PM   #54
Triple Jim
Guy Who Enjoys Riding
 
Triple Jim's Avatar
 
Name: Jim
Location: North Central North Carolina
Join Date: Jul 2016

Motorcycle(s): Ninja 250

Posts: A lot.
MOTM - Aug '17, Aug '16
Right Bill. Tony Nicosia told me that for the H1 and H2, you can't beat the stock airbox setup if you're using anything close to the stock carb size.
Triple Jim is offline   Reply With Quote


Old October 28th, 2017, 01:08 AM   #55
Mohawk
ninjette.org guru
 
Mohawk's Avatar
 
Name: Chris
Location: Bristol, UK
Join Date: Feb 2016

Motorcycle(s): ZZR250, VFR800

Posts: 317
Every engine has an ideal stack length for maximum torque=power at X rpm. Shorter stacks move power up the rpm range & longer ones move it down. You need to tune the intake pulse for your required use. This can be done with intake length & exhaust primary length.

The Ninja 300 & Versys-X 300, share the same engine, but the versys makes more torque lower in the rpm range & overall but loses out on max hp to the ninja. All achieved with intake & exhaust header lengths.

For maximum power you need an airbox & velocity stacks, plus ramair if you can get it. My 800 gained 5hp with no other mods other than moving the same filter to the top of the airbox, rather than sandwiched in the middle, so the volume never changed, but the still air area above the v-stacks doubled !!! 5hp from just moving the filter location ! You need as big an airbox as possible after the filter. Minimum size should be 10x the engine capacity, there do not appear to be any gains past 20x which is usually very hard to package on a bike. So a 250cc would need 2.5L minimum & 5L maximum. Obviously the larger the engine the harder it is to package the larger airbox.

YMMV
Mohawk is offline   Reply With Quote


Old October 28th, 2017, 02:03 AM   #56
Ram Jet
ninjette.org certified postwhore
 
Ram Jet's Avatar
 
Name: Bill
Location: Port Huron, Michigan
Join Date: Mar 2017

Motorcycle(s): 2007 Kawasaki 250 Ninja, 1982 Honda Ascot FT500

Posts: A lot.
Quote:
Originally Posted by Mohawk View Post
Every engine has an ideal stack length for maximum torque=power at X rpm. Shorter stacks move power up the rpm range & longer ones move it down. You need to tune the intake pulse for your required use. This can be done with intake length & exhaust primary length.

The Ninja 300 & Versys-X 300, share the same engine, but the versys makes more torque lower in the rpm range & overall but loses out on max hp to the ninja. All achieved with intake & exhaust header lengths.

For maximum power you need an airbox & velocity stacks, plus ramair if you can get it. My 800 gained 5hp with no other mods other than moving the same filter to the top of the airbox, rather than sandwiched in the middle, so the volume never changed, but the still air area above the v-stacks doubled !!! 5hp from just moving the filter location ! You need as big an airbox as possible after the filter. Minimum size should be 10x the engine capacity, there do not appear to be any gains past 20x which is usually very hard to package on a bike. So a 250cc would need 2.5L minimum & 5L maximum. Obviously the larger the engine the harder it is to package the larger airbox.

YMMV
Great perspective. Velocity stake length may be a-bit more complicated than you have described as cam timing and valve overlap are big players too. I have a Honda FT500 single and have kept the airbox intact. It's a wonderful design but the airbox takes up about as much space as the engine itself. The airbox on the Ninja and my Honda serve a multitude of purposes and I'll admit it's tempting to free-up a-lot of internal frame space but I think it's unwise to remove it. Don't anybody get mad. I'm just vomiting my opinion. I tend to trust Kawasaki engineers and if there was not a good reason for the design it probably wouldn't be there.

Bill
__________________________________________________
Insanity: doing the same thing over and over again expecting different results each time.
Ram Jet is offline   Reply With Quote


Old October 28th, 2017, 04:55 AM   #57
Racer x
ninjette.org certified postwhore
 
Racer x's Avatar
 
Name: Eric
Location: Iowa City
Join Date: May 2009

Motorcycle(s): 2008 Kawmeracchi 350 2010 Project X

Posts: A lot.
Blog Entries: 54
MOTM - Feb '16
I have been modifying the 250 engine for almost ten years. I think the stock airbox has a lot of merrit. If it could be improved and I have not tested it but the metal flame guard and snorkel removed is about it.
__________________________________________________
Top speed 123.369mph. Ohio mile
Worlds fastest 250 ninja
Racer x is offline   Reply With Quote


Reply




Similar Threads
Thread Thread Starter Forum Replies Last Post
[motorcycle.com] - Variable Intake Velocity Ninjette Newsbot Motorcycling News 0 March 13th, 2017 03:50 PM
Velocity Stacks in airbox/stock filter Ducati999 General Motorcycling Discussion 7 September 4th, 2014 02:49 PM
Velocity CC Cowboy General Motorcycling Discussion 21 June 3rd, 2014 08:03 PM
[superbikeplanet.com] - More IOMTT On Velocity/Discovery Ninjette Newsbot Motorcycling News 0 March 19th, 2014 01:20 PM
[topix.net] - Honda Stacks the Deck for Motocross of Nations, but Dungey Still Rides Ninjette Newsbot Motorcycling News 0 September 22nd, 2010 12:40 PM


Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


Motorcycle Safety Foundation

All times are GMT -7. The time now is 06:02 PM.


remote server monitor
Powered by vBulletin®
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
User Alert System provided by Advanced User Tagging (Lite) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Except where otherwise noted, all site contents are © Copyright 2016 ninjette.org, All rights reserved.