AU Cam

[Norton]

Hi All,

Just a quick question regarding cams.

What's the difference between "Billet" & "Re-Grind".

I keep seeing references to "No Billets available for the AU". I'm looking to get a Crow Cam for my car in the next month, will I be able to get a Billet and if I can't is a re-grind ok?

Norton

[Racecraft]

a billet cam refers to the block of steel it is turned from. It is a new cam machined out of a large lump of steel..
A regrind they just change the profile of a factory cam by machining it.. A regrind cam needs shims where as a billet won't.. I think that is right

THere are no billets available in Australia atm, last I heard the guy from Sure Cams was sourcing the billet blocks in the USA and wasn't expecting anything to be on the shelves before June

I wouldn't get a regrind myslef but others have and are happy with them..

[JefXR8]

Ive been wondering that question myself

[LOWAU]

The only issue with regrinds are that you have to add shims to your rocker arms, and that *might* get more noise from the valve train, going billet eliminates that factor.

[Norton]

Originally Posted by LOWAU

The only issue with regrinds are that you have to add shims to your rocker arms, and that *might* get more noise from the valve train, going billet eliminates that factor.

Why do you have to add shims??

I am still a little confused the the difference.

Are there any good websites that explain the difference or even show pics?

I would assume that they are both milled out of the same material.

Regards

Norton

[jonbays]

The billet just has the original base circle dimemsion and better valve actuation angles. both will need shims but the regrind needs significantly more.

No need to worry both are ok

[FS5]

when they they do a regrind ,like jonbays said the grind what they can out of the base circle to alter lift and duration .then you ad shims to make up for what was grinded out.
lets just say you have a stock au cam and all you want is 2mm more lift at the valve .they will grind 1mm off the base cicle of the cam lobes .then you will have to ad a 1mm shim behind the HLA's.with the 2 to 1 rocker ratio on au's you get the 2mm lift at the valve.
regrind cams are good its just the shims ,what some manufacture's supply aren't up to the task .if you do decide to go a regrind ,i'd get some shim's made up to the specific height required .

one thing that confuse's me is why do you need shims on a billet cam ,other than the factory ones .shouldn't they all be based on the same base cicle?

[XR6-VCT-2000]

From what i remember from the metal trades, 'Billet' refers to a 'Bullet Proof' lightweight metal/ not as such that is actually boolet proof , but a very very hard metal. Im assuming a billet cam would be alot more solid , weight less and have less wear compared to a normal cam / thats is if what they are refering to as a billet cam ? .

[Casper]

Originally Posted by XR6-VCT-2000

From what i remember from the metal trades, 'Billet' refers to a 'Bullet Proof' lightweight metal/ not as such that is actually boolet proof , but a very very hard metal. Im assuming a billet cam would be alot more solid , weight less and have less wear compared to a normal cam / thats is if what they are refering to as a billet cam ? .

Normal falcon cams are billet cams. Its only after they have be reground that they become a "reground" cam

[xr8ute]

Camshaft cores can be made from different materials.

As spring pressures increase, the camshaft core is more prone to flex/vibration, which is obviously not a good thing for the valvetrain...

I believe the most common OEM hydraulic cams, and the cheaper aftermarket hydraulic cams, are made from a SADI core (not sure what that really means though?).

The better (i.e. stiffer) cores are made from steel...


Not sure if/how this relates to "billet" cams. Maybe a SADI core is cast, and a steel core is cut from a big square "billet" of steel?

[BLACKAUXR8]

have you tried sourceing a te50 cam. My mate got one for his eb xr8 and it is wicked. idles nice and sounds tough. It is a good basic cam upgrade

[XR6-VCT-2000]

Originally Posted by Casper

Normal falcon cams are billet cams.

Ty, thats new news to me, i didn't know the AU's had a factory released billet cam in them. cheers.

Originally Posted by Casper

Its only after they have be reground that they become a "reground" cam

In the case of any cam , i think thats pretty obvious ! :

[Mr_4.0]

nearly ALL ford cam for a ong time have been billet from the factory.