Tuning X1/9 camshaft in Uno Turbo engine?

[Luckor]

Hi, I'm in the middle of installing an Uno Turbo-engine in my X1/9. The work is going fine, but som questions always pop up.

Has anybody here used a X1/9 camshaft in their Uno Turbos? If so, I'd really like to know how your engines are managing the higher lift and different duration of these cams!

I know that some people are using camshaft from Uno 75 and from what I've heard this works fine and gives slightly more power at midrange. These cams also have higher lift than the standard Uno Turbo, but the X1/9 standard cam has even higher lift.

I've seen some discussions about this on the forum, but don't think I've read about anybody really using an X1/9 camshaft. So --- if you're driving around with an Exxy-cam in your Uno Turbo, let me know how she's responding!

(Usually there is a backside to everything, I mean, Fiat themselves chose a low camlift to their turbo engine ...) /Stefan in Sweden

 

[jo0lz]

Have a read here

sportingfiatsclub on uno turbo

Best of the standard camshafts for the road is probably the Punto GT. While the standard X1/9 1498cc cam has the highest valve lift at 9.85(in) and 9.9(ex) its timing - 24/68 68/24 is different to the turbo cams and can deliver power advantages higher up the rev range. Reports from members (typically in motorsport applications) suggest the X1/9 camshaft may also be limiting valve/ engine life

 

[johorridoh]

I drive the UNO 75 SPI cam in my 1.3 UNO Turbo and it´s working fine.
There´s dozens of different X 1/9 cams.
The PUNTO GT MK3 cam is said to be the most harmonic one.
I have one and will try that on my 1.6 project.
Some people say the original one is the best one.
And I think on a turbo engine there are many other
things to be tuned before you get to the cam.

 

[alexGS]

Again I agree with johorridoh on this one - the camshaft is not as critical as for a non-turbocharged engine. FIAT made the standard Turbo cam very different to the other engines for a reason - I understand there is a risk of compressor surge if the camshaft has a 'symmetric' timing.

That is, the valve timing of non-turbo engines often has the inlet opening/closing and exhaust opening/closing crank angles the same or similar, i.e. 24/68 64/28 (I think that was the X1/9 1500 cam from the 70s).
The standard Turbo cam had an 'assymmetric' timing: 0/40 30/10.
The non-turbo Uno 1372cc is 7/35 37/5.
Again, FIAT made the difference for a reason, so I think it is a good idea to stick with it (just my opinion).

-Alex

 

[johorridoh]

And not to forget. Changing the cam always calls for changing the ignition map. If you don´t do that the engine will never ignite and perform perfect.
I look forward on changing to a megasquirt system to get perfect on that topic.

 

[Luckor]

Thanks very much for good advice! In fact, there are two reasons why I had my doubts about what cam to use in the first place:
1. I have one of each and the X1/9-cam seems to be in better shape (and have the higher lift, which sounds nice), and this of course suggests me to choose it, but ...
2. as alexGS says, Fiat made the difference between the cams for a reason. The did hardly choose assymetric timing on the turbo cam just for fun.

So, it seems that I'm leaning in a new direction ...

 

[sledgehammer]

hey,
Would you be interested in a BP285 Piper high lift cam for the uno turbo?
Guy

 

[Luckor]

Well, maybe... A little tempting after all. I understand that this Piper is a tuning cam especially designed for the turbocharged version of the Fiat SOHC, or? In other words, the timing should be "assymmetric" as discussed earlier.

Is it used or new? How much do you want for it? And ... I live in Sweden and in that case need to have it sent here.