Guilty as charged, I am supposed to be working - but it is more fun to follow these threads :)
Regards, Nick > > From: "Daniel Kroehn" <[EMAIL PROTECTED]> > Subject: Re: V-6 or 4cyl? > Date: 15/11/2001 13:04:42 > To: <[EMAIL PROTECTED]> > > I never thought of about the engine been a degree of freedom all by itself. > Hey Nick, are you by chance a mech engineer? I've just read a few of your > posts and noticed you mention a alot of things I've been learning about this > year at uni. > > Daniel Kroehn > Datrats, quality Datsun performance parts > www.Datrats.com.au > > ----- Original Message ----- > From: <[EMAIL PROTECTED]> > To: <[EMAIL PROTECTED]> > Sent: Thursday, November 15, 2001 12:31 PM > Subject: Re: V-6 or 4cyl? > > > > Yeah, I suppose that you are limited with the flywheel if you still want > to run a starter motor and idle below 1500rpm. > > The stock clutch and flywheel is about 20Kg from memory. What kind of > weight are you talking about (~5Kg?) > > In first gear it works out something like 1Kg from the flywheel is > equivalent to 5Kg from the car. I suppose that when people are putting > carbon fibre here there and everywhere saving a couple of grams of rotating > mass is helpful. > > > > When modifying the crank you could consider the aerodynamics of the > spinning crank. You could ground the counterweights to a knife edge, polish > etc.. Use a scraper and windage tray. Gotta be good for 5Hp or more. > > > > > > The rules don't generally allow it, but I have been thinking of an engine > brace that stops the engine rocking, or solid engine mounts. > > By removing that degree of freedom you would increase the sensitivity to > throttle response so you can open up earlier in the corner without > wheelspin. > > When you are chasing the ultimate I reckon this is an overlooked area. > > > > Nick > > > > > > From: "E Smith" <[EMAIL PROTECTED]> > > > Subject: RE: V-6 or 4cyl? > > > Date: 15/11/2001 13:03:04 > > > To: <[EMAIL PROTECTED]> > > > > > > Nick, > > > When you have already lightened the flywheel to maximum with a > reasonable > > > safety factor so it will not self destruct, the next thing to go are the > > > counterweights and a reduced balance factor. Its one of those things > where > > > you take of more and more till it goes bang, then back of a notch or > two. > > > > > > Cheers, > > > Feral Errol > > > mailto:[EMAIL PROTECTED] > > > http://www.datrats.com.au/ > > > > > > -----Original Message----- > > > From: [EMAIL PROTECTED] > > > [mailto:[EMAIL PROTECTED]]On Behalf Of > > > [EMAIL PROTECTED] > > > Sent: Thursday, 15 November 2001 12:36 PM > > > To: [EMAIL PROTECTED] > > > Subject: Re: V-6 or 4cyl? > > > > > > Errol, > > > > > > I am guessing that the only reason to chase smoother engine running is > to > > > remove the high frequency vibrations. > > > This means that you can rev higher for longer before connecting > > > rod/piston/big-end bolt fatigue failures occur. > > > And if your engine can rev 500 rpm more than the opposition, you can get > 500 > > > revs worth of power by changing cam profiles etc... > > > If you are rev limited, then I suppose the only advantage is increased > > > reliability > > > > > > If you want to reduce rotational inertia you are better off lightening > the > > > flywheel. > > > > > > I wish that my engine was as well built as a race engine, an 8,000rpm > > > pick-a-part L20 mmm... > > > > > > Nick > > > > > > > > From: "E Smith" <[EMAIL PROTECTED]> > > > > Subject: RE: V-6 or 4cyl? > > > > Date: 14/11/2001 21:12:38 > > > > To: <[EMAIL PROTECTED]> > > > > > > > > Yep Daniel, > > > > The Mitsi Astrons use counterbalance shafts. They have counterweights > that > > > > must be timed to knock out some of those secondary forces???? > > > > If people are looking to stretch the grey matter in engine designs, > how > > > > about looking at the balance factors in engines. The balance factor is > the > > > > ratio of the conrod and piston assembly masses compared to the crank > > > > counterweight mass/es. A balance factor of unity would in theory have > > > > minimal secondary force losses except at 90 degrees and 270 degrees > crank > > > > rotation rotation from TDC where the rod design causes some losses. I > have > > > > seen race Datto engines running balance factors as low as 30 percent > to > > > > reduce rotational inertia. This is a testament to the strength of > their > > > > basic design. People overseas are doing some interesting things with > > > balance > > > > as most of the secondary forces are energy that is lost and wasted. > > > > Any though or LOL's???? > > > > > > > > Cheers, > > > > Feral Errol > > > > mailto:[EMAIL PROTECTED] > > > > http://www.datrats.com.au/ > > > > > > > > -----Original Message----- > > > > From: [EMAIL PROTECTED] > > > > [mailto:[EMAIL PROTECTED]]On Behalf Of Daniel > Kroehn > > > > Sent: Wednesday, 14 November 2001 11:43 AM > > > > To: [EMAIL PROTECTED] > > > > Subject: Re: V-6 or 4cyl? > > > > > > > > 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 > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > This message was sent through MyMail http://www.mymail.com.au > > > > > > > > > > > > > > > > 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]/ ---------------------------------------------------------------------
