Missed out on the one Pete had up for sale and i'd like to change afew more bits and pieces on my car to get the bhp up abit.
Any ideas where to buy one from now PSD has ceased trading?
Jon, you don't need to buy a lightened flywheel, although specific racing lightweight ones are available - at a premium! Their life span isn't the same as an O.E. part either.
Any decent engine machine shop will be able to lighten your existing one. Looking at the back of the flywheel, material is removed from inside the outer "hub" part of the flywheel, adjacent to the ring gear land.
Obviously you shouldn't remove too much material because it can weaken the structure of the flywheel itself. However, the machine shop should (hopefully!) have plenty of experience in this type of work and know what is a "safe" amount to machine off.
Last time I had one done they only charged me 1 hour labour - £30 or so IIRC?
It won't make any extra power having it done, but it does help the engine rev up quicker improving throttle response and reducing the rotating mass.
PeteG40 has one for sale.
its sold
Dont forget they need to be balanced on a crank too - if unbalanced will shake the shit out of the engine
pete
they need to be balanced but it doesn't have to be done on the crank (although in an ideal world you'd get the whole assembly balanced as one). PSD just used to supply the flywheels ready to bolt on.
yeah but they balanced em on a stock crank, which was better than not... or was steve telling porkies?
Quote from: PeteG40 on January 06, 2009, 10:55:37 PM
yeah but they balanced em on a stock crank, which was better than not... or was steve telling porkies?
in retrospect probably the later
Are you sure VW assembled the whole crank and flywheel and balanced it as a whole? For every single engine they made?
It's the ideal situation but I doubt it was done at the factory and also, who does that after changing a clutch? A new cover plate and clutch plate adds to the rotating mass too and can upset the balance as much as a flywheel.
well vag probably didnt - but then they probably designed them uniformly enough to not need balancing, as clutches would be i dare say. But skimming some metal off the back of a flywheel might upset its original balance....
Not saying it would if done uniformly, but it might.
yeah the engineering shop should certainly balance the flywheel when they've done it but I don't think it's necessary to get the whole crankshaft assy balanced which is what I thought you were saying.
The cranks are balanced individually from the factory, there are drilled holes in the counter balances where they've taken metal out to balance it.
i was saying balance on a crank - apparently psd used to... i dunno i'm an engineering newbie
psd never asked me to send them my crankshaft when I bought a flywheel from them. Totally pointless doing it on another crankshaft.
unless each std crankshaft was same balance..
well they are all supposed to be balanced so should be the same but there will be tolerance levels meaning small differences between different ones, and then take wear into account.
oh well at least we had a debate about it
haha
Steve used Julian Godfrey's for lightening and balancing PY flywheels, cranks etc.
Unlike Steve and PSD they have a very good reputation in motorsport and if your into your Fords you maywell have heard of them.
I had mine done a little while back, just dropped it in and it was done within a week even though they said it would probably be two weeks...Cant remember how much it cost but it wasnt too dear.
Hope this helps
Pete, to get everything dynamically balanced you need all rorating mass attached to the crank. So thats cam belt pulley, aux drive pulley on one side, then the flywheel and clutch on the other side (not sure if they just do the cover plate). Then you need the conrods and pistons to work out their weight (and ideally match them evenly) so you know how to to load the crank.
Quote from: PeteG40 on January 07, 2009, 09:54:03 AM
well vag probably didnt - but then they probably designed them uniformly enough to not need balancing, as clutches would be i dare say. But skimming some metal off the back of a flywheel might upset its original balance....
Not saying it would if done uniformly, but it might.
When a flywheel is lightened, it is machined uniformly. It's not a case of drilling holes like on a crank's counter balance weights. This reduces the likelyhood of upsetting the balance.
However, a decent machine shop with modern equipment will be able to machine and balance parts to closer tolerances than VW did at the factory during mass production.
Ideally you would have the flywheel balanced after it's been lightened, but then ideally you'd have the whole rotating mass dynamically balanced. All depends how far you want to go.
Yeah Dan, the full balance is crank pulley, crankshaft, flywheel and clutch cover. The clutch plate doesn't get balanced. Weight matching pistons and rods is going into blueprint territory, good but expensive due to the time it takes.
i went along to a engineerin shop. they do this at a charge of £50
he explained a little to me statin that he wouldn't be balacing it up because it has already been done my the manufacter.
also told me that in an example not g40 specific that if my flywheel were to be say.. 8kgs he would roughly be able to take it to 5kgs without takin to too far so that it would need a re balance and possibly weaken the structure of it.
^ this aint my words just quoting but sounds legit ? :^)
Using those figures that's over a 35% reduction in weight which seems a lot to me. Maybe he's right though, it's just I get a bit frightened when I think of exploding flywheels! :o
i really really dont know so i'd be lyin to agree
but i dont know wat psd take off g40 flywheels?
and wat does our one weigh standard?
he maby just makin examples haha ? but thats jst a figure that he quoted that stuck in my head
I have a standard G flywheel and a "psd" l+b flywheel so i'll check the weight of both and post it up tomorrow eve if i get the chance..
awesome thanks :)
maby it will give me an indication to advise the engineer on my specific flywheel..
i dont want him choppin out half the weight and tellin me he does it all the time on subaru's coz :| scary wobble wobble thud clutter bang = :@ angry terry
Quote from: jez1272gt on January 14, 2009, 10:25:42 PM
I have a standard G flywheel and a "psd" l+b flywheel so i'll check the weight of both and post it up tomorrow eve if i get the chance..
Yeah, that would be good to find out.
Well in my experiance of engineering i`d have thought that they would machine the part mentioned earlier in this post and this would possibly be done in a big lathe wich with a 4 jaw
indepedant chuck and what they call a wobbler wich would ensure that its running uniformley without wobbling like a warped disc (brake) to ensure a perfect grip in the chuck.
There are several machines capable and as i remember i`ve seen it done on verticle boring lathes as well.
I have to say that if you ballance a flywheel then its ballanced regardless of the crankshaft.
I`ve seen cranks being ballanced many times in the past and it was never done with the flywheel attatched.
Basically, if you have your crank lightened and ballanced then the flywheel as well, then the hole assembly is ballanced.
If you have just the flywheel done then it goes on the standard crank then it will behave as it did before.
Albeit of course that it will rev quicker as mentioned because of there being less mass to turn.
I think if i remember correctly that at least 1 bloke i knew (now retired) used to surface grind the clutch plate face 1st because of the wear/grooves incurd by the clutch plate.
Tho they wear mostly uniform due to being encased in the bell housing and mostly free of debris and shite like a brake disc.
I would of thought that there would be a modern engineer G40 owner on here who can shed some light on this and how exactly its done these days tho engineering basics are the same.
Modern machinary these days tends to have incredibly accurate measuring Vernia Technology
on board and the components come off the machine ballanced after machining.
Many of you will have seen the Bugatti Veyron engine block being Machined on a 5 axis CNC machine on youtube, out of a solid Alloy block.
How many engineer`s Jobs as that gobbled up.
Hi time we got one of those funded by lottery money for the club. LoL.
Regards, Fred.
haha yeah we'll have to sell a lot of tins of charger lube and toothed belts before we can buy a 5-axis CNC mill. When that day happens we'll machine up some nice alloy blocks for g40s.
And some Lovely cylinder heads Paul.
Unfortunately the scales i had in mind to weigh the flywheels werent man enough for the job so i'll post up the weights when i next go up my mates workshop....
Just under 1kg came off my fly wheel.
1kg is bugger all tho :^)
every little counts lol
Yeah, but you still need some inertia for hill climbs and have you seen the mess made when a fly wheel shatters?
The flywheel only needs inertia to help give a smooth idle on a road car engine. Ideally it should be as light as possible. On race spec engines the flywheels are very light indeed, inertia is not important here as idle speed is often so much higher.
Deffinately agree with Nick on lightening a standard flywheel too much though. An exploding flywheel will burst through a bellhousing and then through a bulkhead or tranmission tunnel (depending on engine configuration) with ease. :o Very messy indeed.
oh dear. my car dont idle anyways with that cam.
So has anyone come to the best conclusion as to wats best to lighten the fly wheel by?
or we still waitin to hear wat the psd one weighed in at ?
so, are we basicly saying.
get the crank balanced etc with out having the flywheel done at the same time. But its ok to fit a lightened and balanced flywheel at a later date?????