X 1/9 camshaft

You won’t be able to tell from those images. If he can send accurate measurements (better than the calipers he is using) then you may be able to work it out from these specifications courtesy of Steve @fiatfactory. The reading he show should be 37.75mm

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xcamdimensions FIA4331512 — Postimages

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Camshaft Identification 4331512

Just got a new cam, a 4331512, I think. There doesn't seem to be any identifying marks - is there some way of identifying the cam without setting it up for detailed measurement? I know the base circle is hard to measure, but perhaps the dimension from the base to the tip of the lobe would be...
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One problem is Fiat did not put the part numbers (or any identifier for that matter) on their cams. So you can't tell what it is without careful measurement.

Also, it is my understanding (but I could be wrong) that the "128 Rally cam" is not the preferred one. It is better than the stock US spec cam (almost any cam is), but not quite as good as the Euro spec 1500 cam. Again that is only my understanding. Review the cam section in the Steve C write up. Portions of it are difficult to follow clearly but I believe it discusses both of those Euro cams (128 and 1500).

Furthermore I'd be a little suspect of buying any used cam. Especially not without being able to inspect it and measure it in person. It is one of those components that can easily have wear or damage that isn't obvious - particularly in photos - or even be misrepresented as to what it really is. The one in your linked listing is around $118 USD, plus shipping. Shipping from Italy is VERY expensive, if they will ship to the US at all - many Italian sellers will not (the listing says to contact the seller to find out).

The "good" Euro 1500 cams have become a bit difficult to get compared to a few years ago. Up until recently there were still brand new ones available for around $100 or so. But I haven't seen any new ones offered for some time now. And prices for used ones have escalated, to much more than I think a used cam should be worth. I think the next best alternative might(?) be to get one of the 'clone' cams that a couple of makers offer. However be careful, I've seen some described as a "Euro cam clone" but the actual specs are nowhere close to the real thing (including one listed by a well known Fiat specialty vendor - I won't mention names on the forum but you can message me for more info).

It's a shame the real Euro 1500 cams aren't still more readily available, as it is a ideal cam for a mildly built street engine.
 
Dr.Jeff said:
One problem is Fiat did not put the part numbers (or any identifier for that matter) on their cams. So you can't tell what it is without careful measurement.

Also, it is my understanding (but I could be wrong) that the "128 Rally cam" is not the preferred
Click to expand...

The 128 coupe and rally are both 24/68 64/28 cams PN 4331512. The late 1500 X1/9 cam is also a 24/68 64/28 camshaft PN 4333059.
The 1512 and the 3059s are the only "Euro cams" that offer any performance increase to our cars.
Any and all other oem stock cams (European or not) are either the same, very close, or slightly better then the standard US spec cams, and are not worth the effort or cost to swap. That also includes the '74 US cam.


128 Coupe 1290cc Type 128AC.000
24/68 64/28 (checked at 0.50mm)
9.75mm gross lift
Running clearance 0.40mm inlet 0.45mm exhaust
Nett Lift 9.35mm inlet 9.30mm exhaust
"Specifications and Features" Nov 1971

128 Rally 1290cc Type 128AR.000
24/68 64/28 (checked at 0.50mm)
9.75mm gross lift
Running clearance 0.40mm inlet 0.45mm exhaust
Nett Lift 9.35mm inlet 9.30mm exhaust
"Specifications and Features" Jan 1972

128 coupe / X1/9 1300 (75hp) 24/68 64/28 lift at the valve (no play) 9.75mm for intake / exhaust (Fiat part number 4331512)

X1/9 1500 carburettor (85cv) 24/68 64 28 lift at the valve (no play) 9.85 inlet 9.90 exhaust (Fiat part number 4333059)
 
Thanks. As per your post:

"128 coupe / X1/9 1300 (75hp) 24/68 64/28 lift at the valve (no play) 9.75mm for intake / exhaust (Fiat part number 4331512)
X1/9 1500 carburettor (85cv) 24/68 64 28 lift at the valve (no play) 9.85 inlet 9.90 exhaust (Fiat part number 4333059)"

So you are saying they are NOT identical. 9.75 does not equal 9.85 nor 9.90.

And that is what I meant about the 128 cam not being the preferred cam - as in not the ultimate factory one. Otherwise I agree there is little difference between them. And either will be a definite improvement over the stock US spec cam.
 
Dr.Jeff said:
Furthermore I'd be a little suspect of buying any used cam. Especially not without being able to inspect it and measure it in person. It is one of those components that can easily have wear or damage that isn't obvious - particularly in photos - or even be misrepresented as to what it really is. The one in your linked listing is around $118 USD, plus shipping. Shipping from Italy is VERY expensive, if they will ship to the US at all - many Italian sellers will not (the listing says to contact the seller to find out).
Click to expand...
The original poster does show as being from Italy, so they could possibly see the part in person, and save a lot on shipping.
 
Dr.Jeff said:
Thanks. As per your post:

"128 coupe / X1/9 1300 (75hp) 24/68 64/28 lift at the valve (no play) 9.75mm for intake / exhaust (Fiat part number 4331512)
X1/9 1500 carburettor (85cv) 24/68 64 28 lift at the valve (no play) 9.85 inlet 9.90 exhaust (Fiat part number 4333059)"

So you are saying they are NOT identical. 9.75 does not equal 9.85 nor 9.90.

And that is what I meant about the 128 cam not being the preferred cam - as in not the ultimate factory one. Otherwise I agree there is little difference between them. And either will be a definite improvement over the stock US spec cam.
Click to expand...
Correct, I think.
They're not identical even though they are both 24/68 64/28 cams.
The numbers posted are straight from USOHC.
The total lift between the two are different.
The coupe/rally cam is 9.75 intake & exhaust.
The late 1500 X is 9.85 intake 9.90 exhaust.

ALL OTHERS (including the common 4358713 "Euro cam") are either 12/52 52/12 or 10/54 54/10 with varying lift numbers.
 
Eastep said:
Correct, I think.
They're not identical even though they are both 24/68 64/28 cams.
The numbers posted are straight from USOHC.
The total lift between the two are different.
The coupe/rally cam is 9.75 intake & exhaust.
The late 1500 X is 9.85 intake 9.90 exhaust.

ALL OTHERS (including the common 4358713 "Euro cam") are either 12/52 52/12 or 10/54 54/10 with varying lift numbers.
Click to expand...
That is the same source I was remembering. To be completely honest I've found a few errors in that document, and some of the writing is difficult to follow. So I could be wrong on the facts I mentioned.
 
Corra said:
hello, do you think this camshaft is really a 4331512?
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Albero a Camme Fiat 128 Rally 1300 - X1/9 | eBay

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Click to expand...
no it's not.

As mentioned in my tome on the sohc, and quoted several times in this thread it should measure 37.75mm (base to nose) and 28.35mm across the flanks, just as per the FIA recognition documentation.
x19 1300 type 1 cam specs.jpg


SteveC
 
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