dirty white boy Posted May 23, 2009 Share Posted May 23, 2009 (edited) i've been reading up on different flywheels and i was told that the 70 was lighter (19lbs) than the others at 23lbs. is this the case? do you think that a 4lb difference is worth the effort or should i be looking at an aftermarket one? a guy on craigslist said he weighed it at 19lbs....$100 Edited May 23, 2009 by dirty white boy forgot something Quote Link to comment Share on other sites More sharing options...
blue72 Posted May 23, 2009 Share Posted May 23, 2009 I haven't heard this one before. AFAIK all 225mm S30 coupe flywheels are 23.1lbs and cast with "E30". Of course, I haven't personally dismantled any series one cars. The light 225mm flywheel came on manual trans equipped 810 and 910 Maximas. It weighs 17.6lbs and is cast with "Y70". I've got one in my car now. Quote Link to comment Share on other sites More sharing options...
dirty white boy Posted May 23, 2009 Author Share Posted May 23, 2009 here are the pics of it. it may belong to someone on hybridZ Quote Link to comment Share on other sites More sharing options...
zcarnut Posted May 27, 2009 Share Posted May 27, 2009 i've been reading up on different flywheels and i was told that the 70 was lighter (19lbs) than the others at 23lbs. is this the case? From what I have read and been told by knowledgeable individuals, only the first 1,000 (or so) 240Z’s had the 8.0 kilogram (17.6lb) flywheel. The change to the heavier flywheel (the 11 kilogram, or the 24.2 lb one) occurred when Nissan experienced breakage issues with the early crankshafts that had only six counterweights. This resulted in serious harmonic vibrations at engine speeds over 6000 rpm which lead to the failure of dampers and flywheels. Nissan “fixed†the problem by replacing the crankshaft with one that used eight counterweights. They also changed the flywheel to the heavier one and I believe that even the damper was replaced with a re-designed one. If you have seen a copy of the very early printing of the 240Z parts manual, it does indeed have different part numbers for the associated (the crankshaft, the damper and the flywheel) parts. The above part changes occurred beginning with engine serial number L24-3606, which would have been around mid-January in 1970. Later on, during the “second life†of the L24 engine in the Datsun 810 and the later Nissan Maxima, the usage of lighter flywheel was re-introduced. BTW, the fact that some of the 240Z used the 17.6 lb flywheel has been used by some of the more clever ITS racers to justify using the Y70 flywheel as a performance advantage. Quote Link to comment Share on other sites More sharing options...
woldson Posted May 29, 2009 Share Posted May 29, 2009 Sooo not all the l series engines have the same crank,,,,, interesting. Quote Link to comment Share on other sites More sharing options...
dirty white boy Posted May 30, 2009 Author Share Posted May 30, 2009 (edited) zcarnut's post was pretty in-depth....i asked the guy does it have a y70 and he says it has an a3 on it. anything special? Edited May 30, 2009 by dirty white boy error Quote Link to comment Share on other sites More sharing options...
zedsn Posted June 3, 2009 Share Posted June 3, 2009 Why not just buy a new aluminum flywheel for under $300? The stock pressure plate will work just fine with the aluminum flywheel. I bought a fidanza and like it very much. Quote Link to comment Share on other sites More sharing options...
blue72 Posted June 3, 2009 Share Posted June 3, 2009 zcarnut's post was pretty in-depth....i asked the guy does it have a y70 and he says it has an a3 on it. anything special? He could be reading it wrong. I've got two E30 flywheels (for sale, shameless plug) sitting 20' from me. Aside from JAPAN E30, one also has W 276A stamped on it and an M as well as a 5 cast into it. Ask him for some good quality photos if you can. Quote Link to comment Share on other sites More sharing options...
dirty white boy Posted June 3, 2009 Author Share Posted June 3, 2009 to answer zedsns's question......i did think about the fidanza but at 10 or 11 pounds i think it may be too light for the street from reading through the posts. i've also found a guy to lighten mine for $85-$150 at GM Tooling in gwinnett co. ga. he said he would get it down to 17 lbs. although, i have a 2+2 and a coupe flywheel. should i use the 240mm for the larger surface area (but more weight of the pressure-plate) or go with the 225mm for the lighter weight pressure-plate. i also have a centerforce (stage 2 i think with the weights on the pressure-plate for the 225mm) although i don't want the hard clutch all the time on the street so i don't think i'll use it. Quote Link to comment Share on other sites More sharing options...
zedsn Posted June 4, 2009 Share Posted June 4, 2009 I put my aluminum flywheel on this spring when I changed out my auto trans and put in a 4 speed setup and couldn't be happier. You can run a stock cluctch but the clutch surface is also larger so you can run a wider disc and pressure plate if you choose as well. Quote Link to comment Share on other sites More sharing options...
woldson Posted June 4, 2009 Share Posted June 4, 2009 Make sure they take the weight on the outer diameter as much as possible. Don't be afraid of going lighter, I'm at 17lbs or so with the turbo fly in my na. I can start off in second with out a hitch. GET the flywheel AND pressure plate balanced once weight is removed. You won't believe how much soother the car will run. The fly will have to be balanced anyway due to casting irregularities after lighting. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.