ADVrider

Go Back   ADVrider > Fluff > Shiny things
User Name
Password
Register Inmates Photos Site Rules Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Rating: Thread Rating: 27 votes, 4.63 average. Display Modes
Old 10-05-2012, 10:59 AM   #1336
egret
noob
 
egret's Avatar
 
Joined: May 2008
Location: Perth , WA
Oddometer: 343
[IMG][/IMG]
__________________
Mads Mikkelsen - '' I'm a beer man. I tried to drink whiskey and Scotch but I don't get it. It smells like a girl who didn't shower and just splashed a lot of perfume on . ''
Jack FM - '' Vampires , what a pain in the neck ! ''
Unknown - '' I've learned to give away not because I have too much but because I know how is to have nothing . ''
egret is online now   Reply With Quote
Old 10-05-2012, 11:57 AM   #1337
crampfan
not really a nOOb
 
Joined: Nov 2008
Location: Ozone, arkansas
Oddometer: 2,001
If you ever get a chance, you can spend days here
http://www.museumofamericanspeed.com/Default.dlp
crampfan is online now   Reply With Quote
Old 10-13-2012, 11:40 PM   #1338
Idle
Studly Adventurer
 
Joined: Jun 2011
Location: Northern California
Oddometer: 554
1000cc thumper





http://husaberg.org/forum/viewtopic.php?f=5&t=16625
Idle is online now   Reply With Quote
Old 10-13-2012, 11:59 PM   #1339
Gimpinator
Minister Funny Walks
 
Gimpinator's Avatar
 
Joined: Sep 2004
Location: Chillin' in da LB
Oddometer: 1,059
Quote:
Originally Posted by egret View Post

"Horex" VR Engine Video

This is 25 years old. Volkswagen developed their VR engines in the late eighties.

http://en.wikipedia.org/wiki/VR6_engine

BTW the ultimate expression of this technology is the Bugatti Veyron W-16 engine.

The "revolutionary" Horex engine merely adds wedged piston domes so you can have a flat cylinder head. This is a big non-no for emissions because of the large "crevice volume" above the top piston ring where lots of unburned hydrocarbons like to hide. For this reason alone no manufacturer will touch it.
__________________
"Son, I thought by now you would have run out of stupid."
Gimpinator is offline   Reply With Quote
Old 10-14-2012, 03:05 AM   #1340
pierce
Aven'Tourer
 
pierce's Avatar
 
Joined: Jan 2003
Location: S'Cruz
Oddometer: 9,975
Quote:
Originally Posted by Gimpinator View Post
This is 25 years old. Volkswagen developed their VR engines in the late eighties.

http://en.wikipedia.org/wiki/VR6_engine

BTW the ultimate expression of this technology is the Bugatti Veyron W-16 engine.

The "revolutionary" Horex engine merely adds wedged piston domes so you can have a flat cylinder head. This is a big non-no for emissions because of the large "crevice volume" above the top piston ring where lots of unburned hydrocarbons like to hide. For this reason alone no manufacturer will touch it.

well, there's some other differences in this engine from the classic VW VR6. the pistons are offset, not dead centered on the crank, so the V angle isn't as steep for the same piston spacing... yes, this means there's some inherent piston slap, but I think I read some newer toyota 4 cyl engines are using offset cranks and they apparently are getting away with this. if you time it right, the piston rod is MORE centered under the piston on the power stroke...
__________________
Experience is what you get when you don't get what you want.
pierce is offline   Reply With Quote
Old 10-14-2012, 09:01 AM   #1341
Gimpinator
Minister Funny Walks
 
Gimpinator's Avatar
 
Joined: Sep 2004
Location: Chillin' in da LB
Oddometer: 1,059
^^^^^ Offset crank.

Yes. Henry Ford did an offset crankshaft on the production Flathead V8 starting in 1932. Offsetting to the thrust side does indeed give you a bit more mechanical advantage on the power stroke, but it makes it difficult to keep the pistons from slapping.
__________________
"Son, I thought by now you would have run out of stupid."

Gimpinator screwed with this post 10-14-2012 at 11:16 AM
Gimpinator is offline   Reply With Quote
Old 10-14-2012, 10:40 AM   #1342
vtwin
Air cooled runnin' mon
 
vtwin's Avatar
 
Joined: Jan 2005
Location: NorCal
Oddometer: 6,757


__________________
"Alles hat ein Ende--nur die Wurst, sie hat zwei"
Monroe.

"You only have too much fuel if you're on fire"
unknown
vtwin is online now   Reply With Quote
Old 10-14-2012, 12:33 PM   #1343
pierce
Aven'Tourer
 
pierce's Avatar
 
Joined: Jan 2003
Location: S'Cruz
Oddometer: 9,975
Quote:
Originally Posted by Gimpinator View Post
^^^^^ Offset crank.

Yes. Henry Ford did an offset crankshaft on the production Flathead V8 starting in 1932. Offsetting to the thrust side does indeed give you a bit more mechanical advantage on the power stroke, but it makes it difficult to keep the pistons from slapping.
hmmm. thinking some more... its kinda hard to offset for power BOTH sides of a V engine unless its really asymmetrical. the drawings with the dashed lines for hte piston centerlines in that video showed both sides meeting at a point directly below the crank. to gain the thrust advantage, that virtual meeting point would need to be offset to the 'down' side of the crank...
__________________
Experience is what you get when you don't get what you want.
pierce is offline   Reply With Quote
Old 10-14-2012, 01:04 PM   #1344
Gimpinator
Minister Funny Walks
 
Gimpinator's Avatar
 
Joined: Sep 2004
Location: Chillin' in da LB
Oddometer: 1,059
Actually offsetting the crank does work fine on a Vee engine. The crank is rotating the same way for both banks, so the big end of the rod is coming over the top to the same side. Offsetting the crank over to that side that the rod big end is moving (known as the Thrust Side) will get you the mechanical advantage on both banks.

Reducing side load on the thrust side will make the pistons a bit noisier, but you can help that by offsetting the piston pin over as well. With an offset crank, there is also a bit of NVH due to the resulting uneven piston movement. This is the main reason it is not done on modern engines.
__________________
"Son, I thought by now you would have run out of stupid."
Gimpinator is offline   Reply With Quote
Old 10-14-2012, 05:36 PM   #1345
LuciferMutt
Rides slow bike slow
 
LuciferMutt's Avatar
 
Joined: Aug 2008
Location: New(er) Mexico
Oddometer: 10,572
THought you guys talking about offset cranks would find it interesting that the crank in Honda's new little CBR250R is offset to thrust side. Haven't heard about any piston slap issues with that engine yet.
__________________
You couldn't hear a dump truck driving through a nitro glycerin plant!

Badasses might screw with another badass. Nobody screws with a nut job. -- Plaka
LuciferMutt is offline   Reply With Quote
Old 10-14-2012, 06:46 PM   #1346
vtwin
Air cooled runnin' mon
 
vtwin's Avatar
 
Joined: Jan 2005
Location: NorCal
Oddometer: 6,757
Quote:
Originally Posted by LuciferMutt View Post
THought you guys talking about offset cranks would find it interesting that the crank in Honda's new little CBR250R is offset to thrust side. Haven't heard about any piston slap issues with that engine yet.

http://www.cbr250.net/forum/archive/...1005.html:deal

One of our club members has this bike and has complained of an engine rattle he claims people on the forums are talking about. He called it the "Death Rattle".
__________________
"Alles hat ein Ende--nur die Wurst, sie hat zwei"
Monroe.

"You only have too much fuel if you're on fire"
unknown
vtwin is online now   Reply With Quote
Old 10-15-2012, 07:37 AM   #1347
ttpete
Rectum Non Bustibus
 
Joined: May 2009
Location: Dearborn, MI
Oddometer: 4,927
Offset cranks have been around for over a hundred years. "Desaxe" is a term often used for the concept.
__________________
10 Ducati 1098 Streetfighter S - "Sleipnir"
09 Kaw Versys
67 Triumph Bonneville TT Special
"The problem with Socialism is that you eventually run out of other people's money" _____ Margaret Thatcher
ttpete is offline   Reply With Quote
Old 10-15-2012, 07:54 AM   #1348
LuciferMutt
Rides slow bike slow
 
LuciferMutt's Avatar
 
Joined: Aug 2008
Location: New(er) Mexico
Oddometer: 10,572
Quote:
Originally Posted by vtwin View Post
http://www.cbr250.net/forum/archive/...1005.html:deal

One of our club members has this bike and has complained of an engine rattle he claims people on the forums are talking about. He called it the "Death Rattle".

Interesting. Hadn't heard about this yet. Thanks.
__________________
You couldn't hear a dump truck driving through a nitro glycerin plant!

Badasses might screw with another badass. Nobody screws with a nut job. -- Plaka
LuciferMutt is offline   Reply With Quote
Old 10-15-2012, 10:38 AM   #1349
rotten
LOST AGAIN
 
rotten's Avatar
 
Joined: Jan 2008
Location: Soquel, CA
Oddometer: 670
I had to dig this one up, one of my favorite engine test videos.

http://www.youtube.com/watch?v=gSHToyGIxWE&t=6s

rotten is offline   Reply With Quote
Old 10-15-2012, 11:22 AM   #1350
papalobster
With Gusto!
 
papalobster's Avatar
 
Joined: Jul 2001
Location: FDL, WI
Oddometer: 12,030
You would think with all the brain power in that room, someone would have thought to bring ear plugs.
papalobster is online now   Reply With Quote
Reply

Share

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

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 On

Forum Jump


Times are GMT -7.   It's 09:24 AM.


Powered by vBulletin® Version 3.8.5
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Copyright ADVrider 2011-2014