zep Posted June 14, 2007 Share Posted June 14, 2007 Hey guys, recently got my flywheel lightened, and they took a huge amount of meat off it. Now I showed the pic to the OzGemini forums and some guy started having a go at me about safety etc. He seemed adament that it will destroy itself. He's got me freaking out a bit, how common is this really? And with a flywheel which has been lightened by a proper engine building shop (equipped with american 8s all over the place) and fully balanced should I be too worried. The Ozgem guy said I should run a scatter shield, can you even get these for four cyclinder cars, and should I bother? Cheers Quote Link to comment Share on other sites More sharing options...
EURON8 Posted June 14, 2007 Share Posted June 14, 2007 not 100% on this but i have a feeling that: light weight flywheel + heavyduty clutch + high revs = BOOM!! duck for cover!! (in some cases) Happens alot wit rotarys. Im sure someone will shot me down but meh thats what ive heard. Quote Link to comment Share on other sites More sharing options...
thegreatestben Posted June 14, 2007 Share Posted June 14, 2007 I would say read less forums, more factual information. Forum stories are the worst for this sort of thing. Might be some smart cunt that actually knows a thing or two on here but its hard to know who that is in this situation. Quote Link to comment Share on other sites More sharing options...
blakamin Posted June 14, 2007 Share Posted June 14, 2007 Has happened, can happen... pretty ugly when it does... (only ever had one go in a v8 tho) Quote Link to comment Share on other sites More sharing options...
peteretep Posted June 14, 2007 Share Posted June 14, 2007 it happens when the factory flywheels are lightened too much, they get heat related problems from the lathe or something, similar to problems that happen with skimming brake disks(the can warp). and thats why people get billet stuff? just from what i understand, look into it Quote Link to comment Share on other sites More sharing options...
Spencer Posted June 14, 2007 Share Posted June 14, 2007 Yea as above has happened, would never do it on my, car mate got a billet one made up for $400 well worth the investment Quote Link to comment Share on other sites More sharing options...
mikuni Posted June 14, 2007 Share Posted June 14, 2007 I talked to the guys from ATL Balancing yesterday about this very same thing as I dropped my flywheel off to be balanced. The have done a lot and said they have never had one shatter/explode/whatever. He suggested that each one is cast, and that at times a poor casting could be lightened, resulting in weak areas. You can usually tell how good the casting is by looking at the flywheel. If it has holes drilled around the meaty sections, which is lightening from the factory, then the casting was unbalancing originally and had to be balanced straight when it was new. If you get one that is cast exactly right and was not balanced, it is likely to be of a higher quality. Well, thats straight from him and I know little about it other than that. And the fact that I'm getting mine lightened soooo much that we will find out very soon if its a bad thing or not. I have also seen one explode at summer nats afew years ago. Needless to say the results weren't pretty, but it was a rotary revving over 10krpm and dropping the clutch for the launch down the strip, so I'm fairly certain mine won't face that same abuse. Not to mention, it was probably a standard flywheel lightened down to around 10lbs, so it probably wasn't the strongest thing in the first place. Quote Link to comment Share on other sites More sharing options...
WDE_BDY Posted June 14, 2007 Share Posted June 14, 2007 DELETED Quote Link to comment Share on other sites More sharing options...
mikuni Posted June 14, 2007 Share Posted June 14, 2007 That one wasn't a factory lightened one but actually an aftermarket flywheel. Was the bolts holding the clutch on that let go apparently.You can't compare to rotaries, the revs they pull cause a massive amount of stress. If its been done professionally and your not reving the tits of it I wouldn't worry at all. There are many other things likely to go wrong long before your flywheel explodes. Callum Oh did you see it too? It was green but I can't remember if it was an rx3 or rx323 haha... I've got pics somewhere though. So was the flywheel ok and it just lunched the clutch plate etc, or did it take the whole lot when the clutch let go? I actually asked about this because those bolts are pretty small and mine looked pretty old and shit I agree on the revs thing, plus with the ultra light fylwheels that rotarys run I've heard the forces of just revving up and down can put heaps of stress on those components? Either way zep, it sounds like the 6 grand that a g161 can pull and a moderately lightened flywheel should be ok Quote Link to comment Share on other sites More sharing options...
Ogre Posted June 14, 2007 Share Posted June 14, 2007 talked to gman bout thins in depth b4.he had one explode racing on manfeild, bits went everywhere, throught gearbox tunnel bounced off dash and embedded in his leg, another went throuh door. I wouldnt be worried tho, seems its just the luck of the draw, and if your getting somone who knows what they are doing and your not taking a ridiculas amount outa it and being balanced well then it will be fine. Quote Link to comment Share on other sites More sharing options...
WDE_BDY Posted June 14, 2007 Share Posted June 14, 2007 DELETED Quote Link to comment Share on other sites More sharing options...
EURON8 Posted June 14, 2007 Share Posted June 14, 2007 Oh did you see it too? It was green but I can't remember if it was an rx3 or rx323 haha... I've got pics somewhere though. If its the one im thinkin of it was a green rx3 coupe. (YBNVD ??) and that car is the reason Why rotaries are now required scatter blankets at all drag events. Apparently flywheel hit a skyline in the carpark Quote Link to comment Share on other sites More sharing options...
mikuni Posted June 14, 2007 Share Posted June 14, 2007 Oh yeap, I'll track down the pics I got of it later is I can be arsed. Pretty impressive though, massive hole in bonnet and smashed to pieces bellhousing. Not something you want to happen thats for sure. Its a grose thought, that pieces can come into the cabin after seeing the damage that occurs. Quote Link to comment Share on other sites More sharing options...
sholdowa Posted June 14, 2007 Share Posted June 14, 2007 There's a bloke called Graham Bahr over on turbosport.co.uk wrote a fair bit on it. In short, it seems that if the pressure plate is heavier than the flywheel tself, then strange thinge happen, which is not a good idea at all. Don't even pretend to understand why, but I listen and believe! Quote Link to comment Share on other sites More sharing options...
mikuni Posted June 14, 2007 Share Posted June 14, 2007 hahaha that does make sense but holly shit!! Have you lifted a flywheel and a clutch individually before? Flywheels are fucking heavy and clutch plates aren't soo much, so I guess people must have been running extremely light flywheels for that to occur. I don't think that would be possible on a piston engine either, which is the other reason this phenomena only usually occurs on rotarys or race cars. Apparantly the rotation of the rotor itself actually has enough inertia to allow for a smaller flywheel to be used. Again I stand to be correct on that, but thats how I understand it to be. The other point to mention now that we are also talking about clutch plates is that they should be ballanced when doing the flywheel, because lightening the flywheel will make it more prone to being put off ballance by the clutch assembly (heavier/stronger flywheels will not be as susceptable to this because the ratio of the weight balance is more in their favour i would guess). The guys at ATL said its actually relatively common for the clutch assembly to be slightly off ballance, so they suggested giving that to them to ballance on the flywheel also, which I'm doing. Quote Link to comment Share on other sites More sharing options...
Guest sexychevette Posted June 14, 2007 Share Posted June 14, 2007 Oh did you see it too? It was green but I can't remember if it was an rx3 or rx323 haha... I've got pics somewhere though. If its the one im thinkin of it was a green rx3 coupe. (YBNVD ??) and that car is the reason Why rotaries are now required scatter blankets at all drag events. Apparently flywheel hit a skyline in the carpark Was the pressure plate that flew over the grandstand. Theres a few videos on youtube of exploding flywheels edit mostly dragracing with hardcore clutch dumping which does it i think Quote Link to comment Share on other sites More sharing options...
Gaz Posted June 14, 2007 Share Posted June 14, 2007 If they do a full balance like they did on mine then they should do the clutch plate etc anyways. Place I went to took a fuck load off my flywheel and said itll be sweet. Guess it depends alot flywheel to flywheel. They race boat engines so I guess they know with thier high RPM all the time. Didnt actually ask why it was sweet tho.. should have. Was a lime green RX3 and sure it was the 4nRnats, but prob wrong. Was there.. parts went everywhere, shit on track, messy. Reason for scatter blankets indeed. Was brought in before 1year. Scatter blankets, good idea, wrap round ya box, look to be made of same stuff or similar to a strop. Not so great for everyday driving or track as they tend to stop alot of heat escaping down the tunnel. Quote Link to comment Share on other sites More sharing options...
Guest sexychevette Posted June 14, 2007 Share Posted June 14, 2007 Was an rx3 coupe in the mazda savanna metalic green. Last time i saw the car he still had the hole in the bonnet Quote Link to comment Share on other sites More sharing options...
Unclejake Posted June 14, 2007 Share Posted June 14, 2007 Mk1 Cortina billet steel flywheel and baby clutch FTW. Quote Link to comment Share on other sites More sharing options...
davidian Posted June 14, 2007 Share Posted June 14, 2007 ^choice. youd wonder how it gets any friction just from looking at it 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.