kincaid05

Can someone please explain to me the difference in fuel requirements between these ports. I think one just has a differnt timing then the other, but I dont know what this means for me as far as designing my fuel system.

Thanks.

calvinpaul

iTrader: (2)

The primaries put in a little bit of fuel, and the secondaries put in a little more fuel. That is about the only difference. If you have a carb then you will notice that there are 4 barrels, the smaller of the 2 are the primaries, the larger the secondaries. If you pull the top thingy off of the carb you will see the fuel jets. The smaller one is for the primaries, and you'll figure out that last part. As far as the fuel requirements go just throw on a fuel pump that will put out at least 6 or 7, then throw on a fuel pressure regulator (a 1-4 psi is what I use). This is about all you will need unless you have much more than bolt on as far as mods go.

Jeff20B

iTrader: (13)

I took the top of a Nikki off for the first time yesterday evening. The bowls were filled with nasty white corrosion (Aluminum rust) and the linkage was mostly destroyed. I salvaged the secondary jets (the primaries were burried in the white stuff). Poor carb.

Anyway, the Nikki is more complicated than I thought it would be. My hat's off to the Carl Stalling project.

kincaid05

Thanks, I was talking more along the lines of fuel injection. If I had a seperate injector per port. Would I get good results running a smaller injector on the primary ports. Also do the throttle butterflys have to open at a different time? If so, exactly how different?

diabolical1

iTrader: (3)

for fuel injection, the throttles don't necessarily have to be staged. the computer will calculate fuel for the air being ingested. for the other part of your question, you can run all 4 injectors the same size for N/A engines, when turbos get involved then you may want to stagger them - running smaller ones for primaries for good throttle response, economy, etc. and then using bigger ones for top end fuel needs. the bottomline is you need to figure your fuel need FIRST ... then, figure out how to attain them.