327_TPI_77_Maro

iTrader: (8)

Hi guys, I have been screwing around rebuilding several different CCC Qjets for my frieking stock 305, in search of one that runs anywhere near good. One thing that seems to be common to all 3 carbs is that I find the float levels before disassembly and rebuild are all waaaaaay lower than the recommended setting of 11/32" (and by "lower" I mean they actually measure more than 11/32", making the fuel level at float shutoff lower in the bowl). When I bring the float level to 11/32" during rebuild the carbs seem to become very sensitive to hard turns, hard braking, etc. One carb would trickle fuel out of the boosters unless I had the float level way lower than the spec. I am measuring correctly using a float level gauge from the casting surface to the line marked near the float toe. Has anyone else found a float level significantly different than 11/32" worked better for you and why?

five7kid

iTrader: (14)

I set my new float to 11/32" per the spec sheet during my rebuild last summer and have not had any problems.

99Hawk120

I always set mine to a little lower than that. I've always found the factory setting to be too high. Maybe everything I have just puts out too much fuel pressure. I end up setting mine at about 14/32". I have a tech article around somewhere from a corvette guy specifying .420" for 1975+ carbs.

327_TPI_77_Maro

iTrader: (8)

Too much fuel pressure eh? I am running whatever 3/8 in/out pump came off my 327 camaro before I converted that to multiport EFI. I have no idea what the pump is off of.

99Hawk120

Most vacuum gauges double as a fuel pressure gauge, at least for low pressure systems. My 83 Regal w/ a Buick 455 is currently putting out over 10psi and blowing the needle off the seat, so it can be a real problem. QJets don't likeanything over 6psi, although I've gotten them to run okay at 7psi by setting the float level even lower. The fuel pressure has a tendency to make the float bowl level higher for a given "dry" float setting.

Damon

Funny, I run mine a little more than 1/4" and don't have any problems with turns/braking. That's almost where the top of the float is parallel with the top of the bowl, but lower across the whole length by a little more than 1/4". Are you putting the plastic stuffer back into the float bowl when you reassemble? It definitely gets funny if you don't use that little piece.

Agreed, if your fuel pressure is too high you'll be constantly setting the float lower and lower to try to get it to run right.

99Hawk120

Yeah, I am putting the stuffer back in. I've just never had any luck with the factory float setting. I've never figured out why. I did get the fuel pressure fixed (installed a regulator) and the idle air bypass on the Buick drilled out bigger, so it starts and idles fine now. If I take the thing apart again to rejet, I might try the higher float setting.