Recent Topics
Reviews of the "high mileage " oils
by edwardh1
55 minutes 45 seconds ago
Your Synthetic Engine Oil vs NASCAR Synthetic Oil
by bigt61
Today at 05:37 AM
Advice on Situation
by The Critic
Today at 05:01 AM
Formula Shell 5w+10w30, Home Depot $1.98 quart
by Gasbuggy
Today at 02:49 AM
The attack of the fridges!
by Toaster_Jer
Yesterday at 10:54 PM
P 135 code oxygen sensor heater element
by turtlevette
Yesterday at 10:34 PM
PPPP 10W-30 Formulation Change?
by john_pifer
Yesterday at 10:10 PM
97 Maxima stalling, sputtering when engine is hot
by zorobabel
Yesterday at 09:04 PM
2011 Suzuki S40
by Papa Bear
Yesterday at 08:57 PM
Ready for Winter Maintenance
by Farmer
Yesterday at 08:39 PM
opinion of carquest full synethic 5w30
by ted s
Yesterday at 08:36 PM
Mann W 811/80 Oil Filter - Hyundia/Kia OEM?
by knerml
Yesterday at 08:36 PM
Newest Members
EFIfiveoh, Localhero800, Bill98z3, Alex_Wills, RobV
59419 Registered Users
Who's Online
43 registered (4WD, 2015_PSD, BigCahuna, AirgunSavant, bbhero, 97f150, 9 invisible), 976 Guests and 15 Spiders online.
Key: Admin, Global Mod, Mod
Forum Stats
59419 Members
66 Forums
255967 Topics
4206668 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: 17504
Loc: Iowegia - USA
Mr. Rodgers did not adequately prepare me for the neighbors in my neighborhood. smile

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

Registered: 12/12/02
Posts: 34121
Loc: Oz
That's a lot of information in a small space, thanks.

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

Registered: 05/12/09
Posts: 5131
Loc: Canada
Thanks for posting.

But to put things in perspective:

Austin Seven two bearing crankshaft:

Amazingly they will run 6k rpm

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

Registered: 06/09/03
Posts: 1788
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.

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

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

Registered: 12/12/02
Posts: 34121
Loc: Oz
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.