I just put on my BC1 a pair of Abarth Profilo 068 50-68/64-43 cams. Regrinds from original lobe profile. They replaced my 42-82/82-42 Alquatis that fought for 3.5 years.
Anyone tried those? They feel very torquey (with 99 and 100.5 degrees lobe centers and 4.70 mm TDC lift they got to be). I can't get them to work right even though the potential is obvious. They are timed as they sould be and no carb leeks, but I can't find the proper jetting.
I run 40IDFs with 34mm venturis and 34 mm matched manifold to head inlet. I've tied all air correctors from 175 to 210 and all mains from 135 to 145 with F11 tube. Any ideas???
Performance Camshafts
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bandit
Hello Vassilis
What is the car doing Running good at lower RPM then dropping off ?
or running lean at lower RPM then better at higher range ?
Jetting is a pain to get it right takes hours of tuning the Last 124
i did with 44 IDF's took hours to get it close and was driving me
crazy with the top end, it never had the power it should of, turned
out the hood was a couple inches from the Air horns just a bit on the
close side limiting air intake errrrrrrrrrrrr wish i had checked that in
the first place !
I know 195 - 210 air correctors sound about right for those cams on
a 2L or 1800 ? 175 would be to small your jetting ranges sound about
right , any thing else change with the cams ?
Only thing that sounds off to me is the Venturies might be a step to
small try 36s .
What Cam Deg are you running ?
Dan
What is the car doing Running good at lower RPM then dropping off ?
or running lean at lower RPM then better at higher range ?
Jetting is a pain to get it right takes hours of tuning the Last 124
i did with 44 IDF's took hours to get it close and was driving me
crazy with the top end, it never had the power it should of, turned
out the hood was a couple inches from the Air horns just a bit on the
close side limiting air intake errrrrrrrrrrrr wish i had checked that in
the first place !
I know 195 - 210 air correctors sound about right for those cams on
a 2L or 1800 ? 175 would be to small your jetting ranges sound about
right , any thing else change with the cams ?
Only thing that sounds off to me is the Venturies might be a step to
small try 36s .
What Cam Deg are you running ?
Dan
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vcg
Car pulls well from 2000rpm. Struggle at 3800, and generally slow raise from 3500 to 5000, then ok.
I feel the car needs to be better fed. I've never tried 35 or 36 venturi to 40IDF, it sounds like no venturi...:) I tried my 44IDF from the 131 Racing with 36 venturi, but the car doesn't work until 4000rpm.
I have compromised for the time being with 210air 140main with 34 venturi. I will try opening them to 35, and see how it works.
Due to the characteristics of this cam profile, it's obvious that it needs lot's of feeding in the mid range.
I feel the car needs to be better fed. I've never tried 35 or 36 venturi to 40IDF, it sounds like no venturi...:) I tried my 44IDF from the 131 Racing with 36 venturi, but the car doesn't work until 4000rpm.
I have compromised for the time being with 210air 140main with 34 venturi. I will try opening them to 35, and see how it works.
Due to the characteristics of this cam profile, it's obvious that it needs lot's of feeding in the mid range.
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bandit
Hey Vassilis
Is this a 2L or 1608 1800 ?
Can you see smoke when you rev the engine while parked ?
When you say " Ok " after 5000 is the car pulling hard till 7000 ?
Your new cam's are much bigger so you need to feed them more
i believe the 35 or 36 venturies will help but this sounds like your
settings are off .
Dan
Is this a 2L or 1608 1800 ?
Can you see smoke when you rev the engine while parked ?
When you say " Ok " after 5000 is the car pulling hard till 7000 ?
Your new cam's are much bigger so you need to feed them more
i believe the 35 or 36 venturies will help but this sounds like your
settings are off .
Dan
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vcg
It's BC1 so it's 1608cc. It pulls up to 8200rpm with the rev limiter off (usually set at 7600). It's a racecar with 11:5 CR, and the settings are to the point. Power and torque went significantly up moving to Abarth profilos coming from Alquatis, but I have trouble in the midrange while the low end is very good actually. I will try 35 venturi tomorrow, if that doesn't help then I need to work with the tube, try F16 or F7maybe if I can find those...
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mdrburchette
- Posts: 5754
- Joined: Wed Jan 25, 2006 5:49 am
- Your car is a: 1972 Fiat 124 Sport
- Location: Winston-Salem, NC
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vcg
Problem solved! Used F34 tube from Alfa and 35 venturi, and car works everywhere. This the final setup:
11,5:1CR with custom made Gozzoli pistons and shaved head
40IDFs with i55/F34/m145, matched 34mm manifold to head inlet
42mm/66cm 4-1 manifold to 58mmpipe
Stock 1608 block and head with 3 angle seats
Profilo068 Abarth cams with necessary verniers
Flywheel lightened to from 6.7Kg to 5.4Kg
I don't believe the switch to 35 from 34 venturi and F34 from F11 changed anything from 5000rpm and up, that was already working well. But it changed everything from 3000 to 4500rpm for the better...
11,5:1CR with custom made Gozzoli pistons and shaved head
40IDFs with i55/F34/m145, matched 34mm manifold to head inlet
42mm/66cm 4-1 manifold to 58mmpipe
Stock 1608 block and head with 3 angle seats
Profilo068 Abarth cams with necessary verniers
Flywheel lightened to from 6.7Kg to 5.4Kg
I don't believe the switch to 35 from 34 venturi and F34 from F11 changed anything from 5000rpm and up, that was already working well. But it changed everything from 3000 to 4500rpm for the better...
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mdrburchette
- Posts: 5754
- Joined: Wed Jan 25, 2006 5:49 am
- Your car is a: 1972 Fiat 124 Sport
- Location: Winston-Salem, NC