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J

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Discussion Starter #1
fancy brake discs and standard discs... is there anything differant in the materials used???

speaking to a guys at work and he nestled an idea in me head...

what's to stop me getting a new pair of standard discs... and angle grinder... and making some carefull 1mm deep groves in a disc... hey presto.. grooved discs... all the benifits and not the silly cost???

i knwo it's gotta be done right and no silly deep cuts etc.. but just an idea

obviously grooving deep will weaken the discs. i'm the site the grooves were about 1 - 2mm deep on me black diamonds i had on me xr2, that 1mm grooves should be fine.

are fancy discs made out of a more solid material? to make the disc stronger so the grooves don't weaken them? would this honestly make much of a difference if any on standard dics to the strength.

ideas please guys!

J
 
M

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Discussion Starter #2
J
i know that "proper" drilled discs are moulded that way cos if you drill standard discs they are weakened quite a bit. Maybe grooved discs have to be moulded that way too for the same reason ???

Marlon
 
J

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Discussion Starter #3
aye but the drilled bit really does weaken the disc as it goes all the way through... the drilled bit is only a groove... surely when you wear the disks thin it's weaker than a few grooves... but still well within safety limits?

???

j
 
W

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Discussion Starter #4
Don't know about this but I used to be a metalworker so............when you cut into metal you cut through its molecular structure or "grain" thereby weakening it.

Marlon is right when he talks about the castings being made with the holes integral to the disc. This will maintain the structure and strength. I would imagine the grooves would have be cut in exactly the right place or you would alter the balance and get hotspots again weakening the disc.

Just my 2p :D

wrinx
 
J

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Discussion Starter #5
Mmmm im not convinced...i thought they were drilled after..i know crank shafts are cut and drilled after casting.
 
W

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Discussion Starter #6
But crankshafts and camshafts are cast in the rough shape first. Personally, I wouldn't want to mess with brakes in this way.

wrinx
 
J

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Discussion Starter #7
not all discs are xdrilled and grooves as part of the casting... i'm sure black diamond do their after the disc has been made.

one thing i have seen on a lot of xdrilled discs is fracture marks from the holes, and i've heard about some discs shattering because of the fractures.

i had black diamond combi's (xdrilled and grooved)on me old xr2, thos were getting small fracture marks on them only after 1 yr of use.

the grooved area were fine and showed no signs of stress.

I've never heard/seen any probs from grooved discs...

i know i would have to keep even balance and spacing and take mega care when making the grooves...

as the groove would still be within the safetey limits (as in brake discs worn down) i would expect the metal still to be as strong and not have gone through and 'stonger' layers.

what i mean is.. discs can be worn down to 1.5mm - 2mm each side max and still be ok. I the groove was only 1mm deep, surely there would still be within the solid metal integrity limits.

hmmm... not sure...

i need new discs for the front soon... thinking about doing some diy stuff... i'm very competent with a grinder and will make a jig... gotta wait and see i guess.

jimybob/wrinx/anyone!!!... whaddya reckon??

any brake guru's about??

j
 
W

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Discussion Starter #8
Used grinders alot in me previous life, that'd have to be some jig :D

The balance issue still worries me, removing slightly more metal or in different profile (as the disc wears) to the other side could cause vibrations and problems later.

Do you know anyone with access to a CNC milling machine who could do it for you?

wrinx
 
J

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Discussion Starter #9
yes i do as it happens!

i'll have a word and see what they reckon!

good man!

i was gonna do the rears this weekend... and monitor them carefull for anything going weird... if it plays up then it's only pennies 12 quid per disc

hmmm...
 
J

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Discussion Starter #10
personaly i wouldnt f*u*k with my life in this way, millions are spent perfecting jigs and designing new brakes ,half an hour and a grinder wont do.!!!
 
J

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Discussion Starter #11
well,

fek it...

decided to some to me senses... no need for it, gonna get fancu discs i guess... oh well!

rgrds

J
 
J

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Discussion Starter #12
one more point..you could fail your mot for doing it,the manual says that any modification likely to weaken or cause premature wear to any component IS a reason to fail.
 
J

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Discussion Starter #13
fair enough... i'm not doign it anyways...

just checkin really if it was possible.. just gonna get new proper discs :)
 
7

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Discussion Starter #14
Forget drilled discs. For my 75 3.0 I went with BIG non-drilled brakes. 302mm from a Toyota Supra and Wilwood calipers. BTW, they were cheaper than standard Alfa parts. Total cost was about UKP400 including CNC machninig adaptors, carbon pads etc.

But the 155 has big discs already, my 155 V6 has ok size disc, 284mm. Maybe you should think about getting 4-pot calipers from a GTV V6 or Fiat Coupe 20V Turbo.
 
J

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Discussion Starter #15
wont work the pads are too big,you would need the correct size disc as well.
 

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HI JIMYBOB, THANKS FOR ALL MAN.
REGARDS
JORGE wink
 
J

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Discussion Starter #18
just to let you know...

alfasalv - www.alfasalv.co.uk - are selling CAR (italian people) crossdrilled/grooved/vented discs (click on the go-goodies then scroll down) for my car (2.0 16v ts - 1977 - the 285mm ones) for £42 each... that's the same price more or less for standard discs from you local motor factor people... bargain!

might be cheaper still for the other 2.0 8v, 1.8 16v because they are smaller discs???

rgrds

J
 
T

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Discussion Starter #19
Jason:
Where the heck did you get you'r hands on a 155 2,0 TS 16v FROM 1977?????Must be a very early prototype :D :D :p
 
J

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Discussion Starter #20
well... i was gonna edit my post... to make you look foolish.. but no... i thought i'd better not..

:D :D

J
 
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