Carburetor conversion and cams

[ozmington]

It has been suggested to me that because my 81 has been converted from FI to dual 40IDF's, I should need to change out the cams as well. This was by my little brothers who I've always let get in my hair but the way the sort of explained it is that it would be to compensate for the lack of fuel delivary force in the FI fuel system. That simply relying on what fuel the intake can "suck in" would not be enough and a change in the lobe measurement on a different cam size would help.
Thoughts???? I'd really love to have a solid explaination on this. Sibling rivalry thing, male female thing.....whatever.

[narfire]

Not sure what you are asking. Are you looking at new cams for the 2L with the dual 40's? If so, perhaps contact the moderator ( Mark) or Vandor and explain what kind of driving you are doing. They would suggest a cam that would work for you.
What is better FI or the dual 40's....? I dunno, all about personal choice really, both have pro's and cons. What can produce more power with modifications.....perhaps the Dual 40's but one can upgrade from the stock injector system and that evidently produces better power over stock as well.

[azruss]

are you asking whether the FI cam is a different cut than the stock carb cam. Answer is no. The FI is just a fuel injection system and has nothing to do with the way air is drawn in or exhaust is pushed out. Cams just determine the way the valves are opened. Most from what I have read is the FI systems will give you more power in a stock configuration and that modifications have to be substantial to bring a carb motor up to the stock FI performance.

[131]

I'd be telling my brothers to go to school.

[ozmington]

Thank you so much. I felt like they were taking me down a nonsense road and I needed some confirmation.
The reason for original conversation is that I'm having some "popping" on the intake side of things. Primarily in lower gears at around 2500 rpm on acceleration. Once I'm into the upperside of third gear or into fourth (both around 3200 rpm) it's smooth sailing. I'm going to keep working on getting those carbs properly tuned. I've checked timing and it's per Mark's specs for the computronix unit.

I think they just can't resist being little brothers and I WILL send them back to school.

[So Cal Mark]

cams are the same, BUT, the dual carbs will allow you to use a performance cam with more overlap. The stock FI isn't ideal with performance cams at lower rpms. But there isn't a need to change cams after the conversion

[ozmington]

Thanks as always Mark.