IdahoKidd Posted December 13, 2009 Share Posted December 13, 2009 I am installing the 5 speed (81 zx) behind the turbo motor(83zx) into my 77z. I have both the original turbo flywheel and and aftermarket lightened one (aluminum). I have searched (aluminum flywheel) and came up with lots of information as to what parts mix and match, but my question is, what are the pros and cons? This is going to be a daily driver, not much into street racing, track racing, etc. Lots of rural crooked Idaho roads with lots of hills. Should I stick the aluminum flywheel into my 240 instead and keep the steel one on the turbo? I also have an limited slip r200 with 4:56's I can slip into either car as well. (Currently in the 240, which came with the flywheel and an l26 carbed motor). Thanks! Leonard Quote Link to comment Share on other sites More sharing options...
aarang Posted December 13, 2009 Share Posted December 13, 2009 Put in the aluminum one. I regretted not doing it sooner in my heavier ZX turbo. No problems on the street. Makes the car seem more responsive. Quote Link to comment Share on other sites More sharing options...
johnc Posted December 13, 2009 Share Posted December 13, 2009 Its a good thing. Quote Link to comment Share on other sites More sharing options...
FlatBlack Posted December 13, 2009 Share Posted December 13, 2009 What is the size of the flywheel? I am running a single piece 225mm Lightweight flywheel made for a KA24E, with no problems [but a slipping N/A OEM KA24 clutch]. I ran it on my N/A setup for over a year and it didn't start slipping the clutch until after a couple of months of boost and my young-and-dumb heavy right foot. If it is 225mm, I'd go ahead and say leave the flywheel on the 240Z and buy a 240mm Fidanza for the turbo car. I'm ordering mine this week and running a 280ZX Turbo/zenki 300ZX Turbo clutch. If the issue is steel vs. lightweight, I would definitely recommend the latter, it feels much much better. Quote Link to comment Share on other sites More sharing options...
stravi757 Posted December 13, 2009 Share Posted December 13, 2009 Heys guys I was wondering. Is it fine just just throw on a lighter fly wheel? My first thought is that you would have to get the whole crank rebalanced if you put a lighter fly wheel on. Does it not affect the balance? Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted December 14, 2009 Share Posted December 14, 2009 Externally balance engines, like ours, stay balanced as long as each component you add is already balanced. Quote Link to comment Share on other sites More sharing options...
MAG58 Posted December 14, 2009 Share Posted December 14, 2009 Externally balance engines, like ours, stay balanced as long as each component you add is already balanced. Internally balanced? If you'll notice on our cars, there is no indexing pin or offset bolt circle like an American V8, meaning it can be oriented in any direction. This is usually a sign that each part is balanced individually. Some fly-by-night shops that treat the L series like a V8 however are sometimes tempted to re-balance by taking material out of the flywheel. That said you should be fine just swapping your flywheels, but if the motor is apart, getting the bottom end balanced is always a good idea. Quote Link to comment Share on other sites More sharing options...
letitsnow Posted December 14, 2009 Share Posted December 14, 2009 Go with the one for the larger clutch disk, if they're the same, go with the lighter one. Internally balanced? If you'll notice on our cars, there is no indexing pin or offset bolt circle like an American V8, meaning it can be oriented in any direction. This is usually a sign that each part is balanced individually. Some fly-by-night shops that treat the L series like a V8 however are sometimes tempted to re-balance by taking material out of the flywheel. That said you should be fine just swapping your flywheels, but if the motor is apart, getting the bottom end balanced is always a good idea. Most(chevy, no idea about ford or mopar) v8's are internally balanced, some however, put the end counterweight on the flywheel, but they are still internally balanced. The only externally balanced sbc is a 400. Quote Link to comment Share on other sites More sharing options...
MAG58 Posted December 14, 2009 Share Posted December 14, 2009 True, but many other V8's are externally balanced. The Ford's come to mind. Below is an aftermarket balancer for a 302. I speak from experience when I last got my mini crank balanced by some yay-hoo's at a 'respected' shop around here and they asked for the flywheel (which is lapped onto the crank with only one giant bolt at the end) and the not thinking anything of it, I gave them both to them and they ended up taking material out of everything but the crank! Needless to say I was not happy. Quote Link to comment Share on other sites More sharing options...
letitsnow Posted December 14, 2009 Share Posted December 14, 2009 This is starting to go away from the original topic, but is that really externally balanced or is it the end counterweight? 1 piece RMS chevies have a big chunk of steel welded to the flexplate, but they are still internally balanced. I'm defining internally balanced as being able to change the balancer and flywheel without taking it to a machine shop for rebalancing. I'd call what that shop did to your mini externally balanced, hopefully you got them to fix it. Quote Link to comment Share on other sites More sharing options...
MAG58 Posted December 14, 2009 Share Posted December 14, 2009 I've always viewed an 'externally balanced' engine as one that uses weights outside the engine crankcase to assist in balancing the reciprocating assembly. I view an internally balanced engine as one that does not have any offset weight added to either the damper or flexplate/flywheel. That would mean that they have neutral balance, or that they are in balance without the other components of the reciprocating assembly. Quote Link to comment Share on other sites More sharing options...
Kash Posted December 15, 2009 Share Posted December 15, 2009 For a street car with 50% or more city driving, keep it OEM...currently running a Fid'z and it requires a little too much attention around town. Quote Link to comment Share on other sites More sharing options...
Gcontrol Posted December 15, 2009 Share Posted December 15, 2009 For a street car with 50% or more city driving, keep it OEM...currently running a Fid'z and it requires a little too much attention around town. What do you mean by too much attention?? What are the issues that you have with the flywheel? Quote Link to comment Share on other sites More sharing options...
CamH Posted December 15, 2009 Share Posted December 15, 2009 What do you mean by too much attention?? What are the issues that you have with the flywheel? I think he probably means that it makes it a little harder to take off from a stop, because the engine will want to rev up much faster, and also has less rotational mass which makes it easier to kill. Quote Link to comment Share on other sites More sharing options...
Kash Posted December 16, 2009 Share Posted December 16, 2009 I think he probably means that it makes it a little harder to take off from a stop, because the engine will want to rev up much faster, and also has less rotational mass which makes it easier to kill. That's it, too easy to stall in stop and go traffic, especially if it is your second car and the other car is also a stick with a dual mass flywheel. Quote Link to comment Share on other sites More sharing options...
LamboZ Posted December 16, 2009 Share Posted December 16, 2009 On a turbo motor you do want a heavier flywheel. It will bring boost on sooner with a heavier load on the motor. It most likely won't do much to your engine if your running a factory to smallish turbo. A light flywheel will make for a more rev happy fun daily motor though. I have a 8lb with a very heavy duty clutch, so it makes for a race car feel that some ppl don't like but I enjoy it. Quote Link to comment Share on other sites More sharing options...
aarang Posted December 16, 2009 Share Posted December 16, 2009 It took me all of three minutes to get used to my aluminum flywheel and new clutch while driving on the street. As far as the heavier flywheel being better for a turbo... there are a few old threads that have debated that! Quote Link to comment Share on other sites More sharing options...
Tony D Posted December 17, 2009 Share Posted December 17, 2009 I don't own a Z Car with a stock weight flywheel, an can't imagine a situation short of the wife's Navara going rock climbing in compound low where I'd want a stock weight flywheel! That goes for VW's and Corvairs I own. I've had lightened flywheels in everything since 79! The following generalities are true: having a stock 3.36 gear will make it harder to launch. having a stock L24 with no torque will make it harder to launch than a larger engine. having any turbo or L28 is childs play, even at 3.36... If you can't hold a car on a hill with a clutch, likely you will have an issue launching the car with a lighter flywheel. I have no problem holding my car on a hill with a light flywheel...My son doesn't stall the car either, and that was his first learning experience. Matter of fact, he thinks the wife's Navara 'is really mushy' on the engagement compared to the light flywheel and clutch setup he learned on in the Z. Quote Link to comment Share on other sites More sharing options...
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