I've just been puting together some camshaft details for a friend and I thought I'd post some of what I said here:
The details of my 504's camshaft:
Wade grind number 112
Maximum lift at cam follower: 0.285" (7.2mm)
Lift at TDC on number 1 inlet follower: 0.039"
inlet opens 22 degrees before TDC
inlet closes 63.5 degrees after BDC
exhaust opens 63 degrees before BDC
exhaust closes 23.5 degrees after TDC
So by common cam timing terminology this cam would be called a 22/63.5 63/23.5
the inlet duration would be 265.5 degrees (22+180+63.5)
the exhaust duration would be 266.5 degrees (63+180+23.5)
the valve overlap would be 45.5 degrees (22+23.5)
this is not very wild by comparison with:
the 505 STI and GTI have a 20/60 60/20 cam
BMW 2002 Tii 18/66 66/18
the 2 litre Cortina 18/70 64/24
the 1.6 GT Cortina 27/65 65/27
the Renault 12TS/GL 22/62 65/25
the Renault 16TS 21/59 59/21
the Renault 17TL 24/68 68/24
the Renault 17TS 40/72 72/40 (quite wild)
Alfa Romeo Alfetta 1.8 litre 41/60 62/25
Michael Loney's hot 404 44/74 74/44 (very wild, 88 degrees of overlap!)
Michael Loney's cam had about 0.300" of lift, which isn't large, but it is probably as much as is practicable in a 504 engine. The rocker ratios on the 504 engine are somewhere around 1.1:1 or 1.2:1 (does anyone know which it actually is?), which isn't large, so the most lift possible at the valve is somewhere around 0.355" (9mm). On other engines it isn't uncommon to have performance cams with valve lifts as high as 12mm.
There are a number of 504 TI cams, but the 504 timing is difficult to compare with the above cams because it is measured from the time the valve is 0.7mm (0.028") from the seat, until it reaches that point again, whereas the 505GTI is measured at 0.35mm of lift (and I think most cams are measured at something similar to 0.35mm -can anyone confirm this?). Because of this 0.7mm reading, these official 504 TI cam figures look tamer than they actually are:
Their actual timing may be as much as 16 degrees more on each figure,
which is something like:
The 1.8 litre injected 504 has a maximum lift at the cam follower of around 6.82mm (0.272"). This is an average figure (It's actually 6.79mm inlets, 6.86mm exhaust). I'm not sure about the lift of the 2 litre TI cams.
The 404 and 1.8 504 cams have a maximum lift of around 6.18mm (0.247")
Their timing is officially 0.5/35 35.5/10, but it may actually be as much as 16/51 51/26
The early (round port) 2 litre carb 504 has this timing 1/36 33/5.5,
but again it may actually be as much as 17/52 49/21
I'm not sure of the timing of the later square port carburettored engines.
There was a variety of other tamer and more restrictive cams fitted to anti-pollution
carby 504s in the US (e.g. -4/34 34/-4). I think the restrictive cam timing and low compression are the main things which hold the 504 engine back, but I guess they're ideal for abusive environments like Africa and the Middle East.
Using the 8.8:1 pistons and 0.5mm shaved off the head (which is typical for old heads which have been shaved a few times) gives a compression ratio of around 9.2:1 (same as 505 STI). So basically every half millimetre adds about 0.4 of a ratio point to the compression of a 504. Shaving anymore than 1 millimetre off the head may necessitate shortening of the pushrods, to allow for valve adjustment and to avoid the rockers hitting the rocker cover.
Here's the phone number and address for Wade Camshafts:
Wade Camshafts Pty. Ltd.
113 Dryburgh St
Ph: 9328 4001
FAX: 9329 8318