PBS SX-1 Cam Specs?

zonker

zonker

Just Another FIAT Freak
I have a PBS cam with the following markings: PBS SEX1 103 964S

Is this an SX-1 cam? I measured .382" lift on intake and .376" lift on exhaust.

Anyone have an old cam card or measured complete specs for this cam?

UPDATE: Did some more searching and found this:
110 lobe center
17-57/ 57-17 timing for 254 degrees duration (seat-to-seat),
220 degrees duration (.050-.050)
9.4mm (.380") maximum lift

The base circle is 1.112", so it's most likely not a regrind?
 
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PBS cam card

I captured this from the PBS website at some point in the past.

cam_data.jpg
 
I have one of these cams

They were made by PBS to pass smog in California and they actually did. The duration was very low and the lift was high in comparison to the duration. That meant small valve clearances or they would be very noisy since the lift accelerations were quite high and the ramp was short. I actually used clearances around .006 and .008 intake and exhaust. This was a few thousand less than PBS recommended but it made the cam much quitter and it worked just fine. Just be careful that you don't get the clearance too tight or you could burn a valve. It produced a noticeable, but small, increase in midrange torque.

Good luck
Charlie
 
Great info - thanks Charlie and Jim. Sounds like this one is a better 1500 cam than a 1300 cam, since it's more about making power within the lower rev ranges.

I'm thinking I need something with a 230 degree duration * .050" and closer to 10mm lift. Guess I should sell this one off. Going rate for a good used SX1 cam is about $250? I think Bob G. asked that price for one a few weeks ago.

Rob
 
Zonker

I actually used it in a 1300 engine. It did help since the 1300 has limited mid range torque but if your looking for real performance it probably isn't the cam for you. It would work fine on a 1500 FI engine though, but still wouldn't really be a performance cam for that engine either.

Good luck
Charlie
 
Old Fiat Driver said:
I actually used it in a 1300 engine. It did help since the 1300 has limited mid range torque but if your looking for real performance it probably isn't the cam for you. It would work fine on a 1500 FI engine though, but still wouldn't really be a performance cam for that engine either.

Good luck
Charlie
Click to expand...

Hmmm - well it's here in my hands. Perhaps I should bug JJ for the shim and tool box he has and install it in my '74 right now for the fun of it.
 
Old Fiat Driver said:
I have one of these cams

They were made by PBS to pass smog in California and they actually did. The duration was very low and the lift was high in comparison to the duration. That meant small valve clearances or they would be very noisy since the lift accelerations were quite high and the ramp was short. I actually used clearances around .006 and .008 intake and exhaust. This was a few thousand less than PBS recommended but it made the cam much quitter and it worked just fine. Just be careful that you don't get the clearance too tight or you could burn a valve. It produced a noticeable, but small, increase in midrange torque.

Good luck
Charlie
Click to expand...
I just found out that I have the SX1 cam in Gus (ex-Split Pea). Do you remember what valve clearances PBS recommended for this cam? If not, I'll set them to .006"/.008".

Yes. It is noisey now.
 
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