Camshaft casting number identification?

[SouthSwedeSpider]

Does anyone know if it is possible to identify a camshaft's specifications from the casting numbers? Is there a list or something? I would like to verify that my cams are stock, the car is garaged a bit away right now but I had some pictures of the engine where it's possible to see the exhaust cam number which appears to be 4?34832 (2nd digit blurry at the pic). Anyone that knows if this is a stock cam for a 2 liter f.i. 1980 engine? Is it correct that the stock cam specs for this engine are timing 5/55/55/5, lift 9,9 mm?

[So Cal Mark]

a casting number won't guarantee that a regrind hasn't been done

[SouthSwedeSpider]

Get your point but I don't think its likely that the cams have been reground since the engine seems to be stock otherwise, and pretty untouched. Is it possible to see if they have been reground just by looking at them, or do they have to be taken out and measured?

http://spiderpics.tradgardsmedia.se/#0.9

Sorry, couldn't figure out how to paste pictures directly into the post.

[Daniel]

Here you go Bjorn



If you were wondering the differences in Lobe profiles for better performance or MPG etc
Fiat didn't really make any changes to the Cams during most of the run on Spiders the best Cams
Performance wise were the early 1438s and that is it . Some may believe or say the 1608 cams were
the best stock Cam but i am sure none of the people who believe this have measured them ! if they
had done so would be disappointed to find they are just as normal or the same as the others

Daniel

[Daniel]

BTW i posted a easy to use Photo Share link if you want to use it or give this a shot again

http://fiatspider.com/f08/viewtopic.php?f=18&t=12141


Daniel

[ace124]

The casting number is just that, a casting number. From there cams were ground to whatever the specification called for. The casting number you mention is also the same as a set of Abarth cams i have stamped abarth after grinding to their specification, i.e 11mm lift and close to 300degrees duration.
There are 3 lobe widths in the fiat range, none guarantee grind. The early narrow lobe type as in the AC or AS spider. The mid width as in the 124 BC/CC/CSA etc 1600 and 1800 engines, and the late wide lobe types.

Having spent many hours measuring the different profiles on hand, i can say that AC and BC 1400 and 1600 cams are IDENTICAL.
As are most late model wide lobe cams. They are all around 9.55 mm lift and timed 26/66 66/26 when measured @ 0.5mm gap.
Some of the mid width cams are 9.7mm lift and offer a bit more duration.(Fiat 132)
The highest duration fiat factory cam (exc the 125 130 Tc which i have not personally seen) is indeed the mid width type from the 124 CC coupe. These are advertised as 15/55 55/15, but this is at 0.8mm gap so in effect if you chech them at 0.5mm then they are actually very close to 30/70 70/30 and they have 9.9mm lift.
The 1608 cam thing is a myth. If people take the time to measure they will see.
Having said that, the difference in performance between the 26/66 and 30/70 (0.5mm gap) cams is not noticable on the road. Maybe on an accurate dyno that replicates runs to the nearest HP, you may see 3-4 hp at a guess.

[ventura ace]

. . .Having spent many hours measuring the different profiles on hand, i can say that AC and BC 1400 and 1600 cams are IDENTICAL.
As are most late model wide lobe cams. They are all around 9.55 mm lift and timed 26/66 66/26 when measured @ 0.5mm gap. . . .

Hello ace124,
I've checked several stock camshafts as well and concur with your findings (that they are all identical in timing), but my measurements are a bit different than your numbers. I find the lift to be close to 9.55mm as you suggest. But, I see the timing of 26/66 to be at around .019 - .020" valve clearance, and close to the 15/55 timing at .050" clearance. Do you mind reviewing your numbers again, ---- of course, I could be wrong . . . .

Alvon

[ace124]

Hi Alvon, the 272 degrees duration and 9.55mm figure i got from both 124 AC, BC and 2l 131 cams was with 0.5mm clearence or 0.20'. Looking at the Fiat Factory service manual they get the same figure with the same clearence of 0.5mm.
The 124 CC cams are definitely close 30/70 70/30 and 9.9 mm lift when measured at a clearence of 0.5mm. The 15/55 figure is with 0.8mm clearence.
As far as im aware Fiat never quoted timing figures in factory manuals with 0.050' (inch) clearence. This equates to 1.27mm clearence and appears in no literature ive seen anywhere other than from aftermarket cam makers.
I guess there will always be a little give and take due to wear.
Maybe the US spec cams were different? i dont know as ive not measured them.

Lets see what others have come up with with respect to numbers.

[SouthSwedeSpider]

Sorry for not totally following you cam gurus here. I'm not really familiar with how to interpret the figures, but I assume that to be able to compare timing and duration, this must be measured at the same clearance (or...?). From what I have read in Phil Wards Twin cam book http://www.amazon.co.uk/Twin-Cam-Italia ... 210&sr=1-2, the stock 2 liter cam timing is 5/55/55/5, but it does not state at what clearance. So, if I should change to e.g. Mark A's FI performance cams which are stated as 28/66/66/28, are these figures at the same clearance as the stock cams, and what performance gains could I expect in that case? I drive mainly in the rpm range of 2000-5000, I'm not using it as a track racer but merely to pass other drivers on narrow countryside roads. As with all things there is a downside as well I guess, will there be power/tourque loss at lower rpms? Higher fuel consumption? I assume Mark would be the best person to comment on this.

For your info, I have a K&N panel filter, stock FI and intake, planning to install a ported and gas flowed 2 liter head with 42/36 mm valves, new cams as above (possibly with adjustable cam gears), stock 4-2-1 exhaust manifold, 2" free flow exhaust w/o cat.