A aviation & planes forum. AviationBanter

If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Go Back   Home » AviationBanter forum » rec.aviation newsgroups » Home Built
Site Map Home Register Authors List Search Today's Posts Mark Forums Read Web Partners

light twins?



 
 
Thread Tools Display Modes
Prev Previous Post   Next Post Next
  #11  
Old August 7th 05, 08:48 PM
Jim Carriere
external usenet poster
 
Posts: n/a
Default

Gordon Arnaut wrote:
For example, most V-8 engines come with a harmonic balancer, even though
they have four power pulses for each crankshaft rotation. That's because
there is enough flex in the crankshaft that the crank can begin to resonate
at some rpm within the operational range.


Actually, V-8s have a harmonic balancer because they would otherwise
have a first order imbalance. The physics explanation is pretty long
and doesn't make a lot of sense anyway, but it's because the
crankpins are 90 degrees apart (inline fours don't have this
imbalance because the pins are in pairs 180 degrees apart, but they
have second order imbalance instead... that is what a pair of balance
shafts cures) and the mass on the ends of those crankpins (rods and
pistons) flinging around are at different distances along the
crankshaft. Also, the harmonic balancer on a V-8 is two weights, one
on each end of the crankshaft. A lot of people don't realize there
are two weights, not just the one on the front of the engine.

Harmonic dampers are a different animal. They will smooth out power
pulses on any engine configuration. Harmonic balancers have nothing
to do with power pulses and everything to do with complicated
vibration of large pieces of metal moving back and forth in different
directions and different places.

I think the terms balancer and damper are confused with each other
because they look almost the same- a big part attached to the front
of the crankshaft to make the engine smoother.
 




Thread Tools
Display Modes

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

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Diesel aircraft engines and are the light jets pushing out the twins? Dude Owning 5 October 7th 04 04:14 AM
The light bulb Greasy Rider Military Aviation 6 March 2nd 04 01:07 PM
Light Twins - Again - Why is the insurance so high? Doodybutch Owning 7 February 11th 04 09:13 PM
Light Twins. How soft??? Montblack Owning 19 December 3rd 03 11:38 PM
Light Twins. How soft??? Montblack Piloting 19 December 3rd 03 11:38 PM


All times are GMT +1. The time now is 08:27 AM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
Copyright ©2004-2025 AviationBanter.
The comments are property of their posters.