Sorry trev, your right on that one! Static balancing is only used when the distribution of mass is known or can be measured without dynamically mving the system. Its hard to put what is going on in a cylinder into words!! Little animations make things so much clearer! From what they tried to teach us, a six usually has its journals spaced 120 degrees apart to make it balance the primary forces of piston motion. The secondary force as I said acts perpendicular to the direction of travel of the piston which can cause a "rocking" moment inside the engine. That's why sometimes masses which counter-rotate to the direction of crankshaft movement are used, to correct this. Someone told me that the 2.6l astron engines have such an arrangement, can anyone confirm this.
Daniel Kroehn Datrats, quality Datsun performance parts www.Datrats.com.au ----- Original Message ----- From: "Pooley, Trevor" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Wednesday, November 14, 2001 10:00 AM Subject: RE: V-6 or 4cyl? > Daniel, > > My understanding of engine balancing is that only the rods and pistons are > statically balanced. The reciprocating parts are dynamically balanced. > > I found this link about L6 harmonics. > http://www.zhome.com/ZCMnL/tech/harmonics.htm > > I know from people in my club that a good quality aftermarket crank front > pulley is a must for L6 race engines as the harmonics are great enough to > destroy the std front pulley or even snap crankshafts. > > The last time I saw a pic of an L6 crank it was not mearly an extended L4 > crank with journals 180deg apart. Although I can't remeber the exact > configuration at the moment. > > Regards > Trev > > > -----Original Message----- > From: Daniel Kroehn [mailto:[EMAIL PROTECTED]] > Sent: Wednesday, 14 November 2001 9:51 > To: [EMAIL PROTECTED] > Subject: Re: V-6 or 4cyl? > > > It hard to get your mind around this shit, I just had a three hour exam on > balancing and the like at uni yesterday. Its not static balancing like when > you get the pistons, rods, crank, flywheel combo balanced, its all about the > dynamic balancing where froces from the piston firing create forces and > moments which lead to imbalances inside the engine. Can someone tell me why > the secondary forces in a 6 completly cancel out as I'm not 100% clear on > why, I guess I'm picturing it as a four only with two more cylinders(hence > primary force cancelation). > > Daniel Kroehn > Datrats, quality Datsun performance parts > www.Datrats.com.au > > ----- Original Message ----- > From: <[EMAIL PROTECTED]> > To: <[EMAIL PROTECTED]> > Sent: Wednesday, November 14, 2001 8:20 AM > Subject: Re: V-6 or 4cyl? > > > > Even if your engine is built by Swiss watchmakers with no expense spared, > you cannot escape the unbalance caused by the engine configuration. > > But of course if the engine has been manufactured to sloppy tolerances > then it will be much worse than an engine built by our Swiss mates. > > Nick > > > > > > From: "mark krawczuk" <[EMAIL PROTECTED]> > > > Subject: Re: V-6 or 4cyl? > > > Date: 13/11/2001 21:39:44 > > > To: <[EMAIL PROTECTED]> > > > > > > hi, so what if their un balanced, anybody doing up a high performance > > > engine always gets the engine full ballanced........................ > > > > > > > > > > > > > > > > > > mark k > > > > > > ----- Original Message ----- > > > From: <[EMAIL PROTECTED]> > > > To: <[EMAIL PROTECTED]> > > > Sent: Tuesday, November 13, 2001 2:30 PM > > > Subject: RE: V-6 or 4cyl? > > > > > > > > > > Beautiful... :) > > > > > > > > -----Original Message----- > > > > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] > > > > Sent: Tuesday, 13 November 2001 13:15 > > > > To: [EMAIL PROTECTED] > > > > Subject: Re: V-6 or 4cyl? > > > > > > > > > > > > The theory behind engine configuration is about balance and packaging > > > > > > > > A 'V' engine (except v12) is fundamentally unbalanced. i.e they shake > and > > > > vibrate because all the rotating and reciprocating components are not > > > fully > > > > balanced. > > > > V engines are compact, this is their advantage. > > > > > > > > An in-line four cylinder also unbalanced - but you can add two balance > > > > shafts to compensate > > > > > > > > straight 6 engines are fully balanced for most harmonics, that is why > BMW > > > > still use them when a v-6 would be lighter, cheaper, and more compact. > > > > > > > > Flat 'boxer' engines are fundamentally balanced and use a very short, > and > > > > therefore stiff, crankshaft. > > > > This is why Subaru and alfa-sud engines are so smooth and responsive > > > > compared with inline fours. > > > > > > > > Straight 8's are fully balanced but the crankshaft is long and not > > > > torsionally stiff and you'd need a long engine bay to fit it all in > > > > > > > > PS just because some engines are smoother than others it doesn't mean > that > > > > they can't go just hard > > > > > > > > Nick > > > > > > > > > > > so can you explain why? > > > > > > > > > > > > Drag cars are v-8's because noone makes straight 8's... > > > > > > > > > > > > If your theory is true why aren't all motors Vees? > > > > > > What about the boxers? > > > > > > > > > > > > > > > > > > > > > > > > -----Original Message----- > > > > > > From: James Marmont [mailto:[EMAIL PROTECTED]] > > > > > > Sent: Tuesday, 13 November 2001 12:08 > > > > > > To: '[EMAIL PROTECTED]' > > > > > > Subject: RE: V-6 or 4cyl? > > > > > > > > > > > > > > > > > > no way!!!!!! Thats why all top fuel drags are "V"s > > > > > > > > > > > > -----Original Message----- > > > > > > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED]] > > > > > > Sent: Tuesday, 13 November 2001 12:42 PM > > > > > > To: [EMAIL PROTECTED] > > > > > > Subject: RE: V-6 or 4cyl? > > > > > > > > > > > > > > > > > > that's just for space reasons I thought... > > > > > > > > > > > > > > > > > > -----Original Message----- > > > > > > From: James Marmont [mailto:[EMAIL PROTECTED]] > > > > > > Sent: Tuesday, 13 November 2001 11:20 > > > > > > To: '[EMAIL PROTECTED]' > > > > > > Subject: RE: V-6 or 4cyl? > > > > > > > > > > > > > > > > > > the "v" says it all > > > > > > > > > > > > -----Original Message----- > > > > > > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED]] > > > > > > Sent: Tuesday, 13 November 2001 11:32 AM > > > > > > To: [EMAIL PROTECTED] > > > > > > Subject: V-6 or 4cyl? > > > > > > > > > > > > > > > > > > Hey All, > > > > > > > > > > > > Does anyone know whether it is the number of cylinders or the > capacity > > > > of an > > > > > > engine that determines it's torque? > > > > > > > > > > > > That is would a 2l V6 have more torque that a 2l 4 cyl?? > > > > > > > > > > > > Iggy (dreaming again) Sandejas > > > > > > Sydney NSW > > > > > > Datsun 1600 FJ20t > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > This message was sent through MyMail http://www.mymail.com.au > > > > > > > > > > > > > > > > > > > > > > > > > > > > > This message was sent through MyMail http://www.mymail.com.au > > > > > > --membersozdat------------------------------------------------------- OZDAT Mailing List Please Note:- Send (un)subscribe requests to [EMAIL PROTECTED] Send submissions to [EMAIL PROTECTED] No unauthorised redistribution of this email http://www.ozdat.com/ozdatonline/index.htm http://www.ozdat.com/ozdatonline/listindex.html http://www.mail-archive.com/[email protected]/ ---------------------------------------------------------------------
