Recent Topics
1998 Olds 88-3800 engine
by ET16
09/01/14 06:20 AM
ATF Change (4T65E-HD) - What to do?
by tony1679
09/01/14 05:16 AM
Popular Science article in 1976 on synthetic oils
by Apollo14
09/01/14 03:05 AM
9/1-10/5 Pep Boys Sales Ad
by tenderloin
09/01/14 02:21 AM
To Buy the Jug, or use another weight?
by Timo325
09/01/14 02:00 AM
8/31-9/7 Pep Boys Sales Ad
by tenderloin
09/01/14 01:57 AM
weedeater one we261
by turbodieselfreak
09/01/14 01:42 AM
Engine rebuild durability?
by PandaBear
09/01/14 01:31 AM
FRN is back
by larry007
09/01/14 12:41 AM
Who makes TrueGard brand?
by Datsyuk
09/01/14 12:38 AM
Pennzoil Platinum 15w50 Pallet 125 boxes/ 6qt
by Datsyuk
09/01/14 12:26 AM
8000 H&K G36 Assault Rifles
by Merkava_4
08/31/14 11:42 PM
Newest Members
DennisWaller, DMackey, Mambo_Dave, 2165, JohnSawyer
51160 Registered Users
Who's Online
40 registered (BISCUT, 3800Series, andyd, 05LGTLtd, 2009Edge, 4 invisible), 665 Guests and 369 Spiders online.
Key: Admin, Global Mod, Mod
Forum Stats
51160 Members
64 Forums
218608 Topics
3447064 Posts

Max Online: 2862 @ 07/07/14 03:10 PM
Donate to BITOG

Topic Options
#3312352 - 03/14/14 11:23 PM Crankshaft Design
MolaKule Offline


Registered: 06/05/02
Posts: 14395
Loc: Midwest
_________________________
"IDIOTITiS: Causes the brain to shut down and the mouth to keep talking. Thousands affected. Best defense, slap and run." Donald Duck smile

Top
#3312367 - 03/14/14 11:59 PM Re: Crankshaft Design [Re: MolaKule]
Shannow Online   content


Registered: 12/12/02
Posts: 26336
Loc: a prison island
That's a lot of information in a small space, thanks.

Top
#3312379 - 03/15/14 12:22 AM Re: Crankshaft Design [Re: MolaKule]
expat Offline


Registered: 05/12/09
Posts: 3795
Loc: Canada
Thanks for posting.

But to put things in perspective:

Austin Seven two bearing crankshaft:

http://www.a7c.co.uk/parts/BB1photo.jpg

Amazingly they will run 6k rpm

Top
#3312388 - 03/15/14 12:37 AM Re: Crankshaft Design [Re: MolaKule]
edhackett Offline


Registered: 06/09/03
Posts: 1526
Loc: Sequim, WA
Here's Alfa Romeo's take on a 4 cylinder crank from the mid 50's through the end of production of the Alfa designed engines.



Ed
_________________________
Never attribute to engineers that into which politicians, lawyers, accountants, and marketeers have poked their fingers.

Top
#3312418 - 03/15/14 01:46 AM Re: Crankshaft Design [Re: MolaKule]
Shannow Online   content


Registered: 12/12/02
Posts: 26336
Loc: a prison island
Quote:
There were some initial problems with bolt-on counterweights, which resulted (as one Formula One designer told me) in "several deep holes being dug in the surface of a few racetracks". There are tensile and fatigue stress issues, as well as the inevitable fretting between contact surfaces and the requirement for highly developed fastener technology.


Having observed more than a couple of high cycle fatigue failures of turbine blades, with horizontal shaft rotating equipment, there is obviously a 2g difference in the centripetal acceleration at 12:00 versus 6:00.

Most of the genuine high cycle fatigue (calc'd at 170x10^6 cycles from crack to failure in most) ones that I've seen have ultimately failed at around 6:00, as evidenced by trajectories and consequential damage.

Top