Q-jet for offroad use

[PUO]

I have a 17051723 on the 468 in my truggy. the engine is a basic stock peanut port big block with edelbrock intake and 1-3/4 headers.  at extreme angles there is fuel leaking out of the bowl vent and when encountered with serious bumps/jumps it seems to flood out and you have to feather the throttle to get it to clear out. 

[Cliff Ruggles]

For off road use we block all external vents except for the front vent, then install a taller one.

Did you install a new float?

What height is the float set at?

What type of pump and what is the fuel pressure?....Cliff

[PUO]

Sorry for the late response .

I just threw a federated rebuild kit in it and didn't replace the float. In fact i really didn't pay much attention to the float level or any of the adjustments because the carb ran fine when I pulled the engine so I just freshened it up and epoxied the casting plugs.  I'm running a jegs street pump and just recently installed a regulator but I havent put it on a guage yet.  I added a piece of fuel line to the front vent and that seemed to solve the stumble over rough terrain.

I'm going to order your book and a new float/gaskets then go from there.  Thanks for your help

[Cliff Ruggles]

Sounds great, just give us a call in the shop when you get time.  I don't recognize the carburetor number, but we'll figure it out......Cliff

[PUO]

Ok I finally pulled the carb off. the # was actually 17054930.  bought a new nitrophyl float and bowl cover gasket.  you said you plug all the vents and before I do this I thought i would ask which vents.

you have the fuel well with these holes in it that look to feed the adjacent areas whre the . fuel can seep into these at extreme side angles then eventually out the vent in the top. should I plug these? (I used a parts carb for the first pic)



are these tubes some sort of secondary air bleed or fuel enrichment. if I plug the holes in the fuel well will it affect their function? 



or do I plug these holes?




I am going to plug this vent for sure. and leaf the front vent open with a length of fuel line attached


any help would be appreciated.  Thanks.

[Cliff Ruggles]

Do NOT plug the well supply holes.  Plug the center hole, and the vent holes above the wells.  Internally vent the wells back to the main fuel bowl with a very slight notch in the partition in the main casting leading back to the main fuel bowl.

Install a taller front vent, and put a peice of electrical taper over the holes in the gasket where the secondary metering rods go down thru it.  Push the rods thru the tape after the top is back in place, and lube them with some light oil or grease.

I would also replace the secondary plastic cam and spring, upgrade to one of our Viton high flow needle/seat assemblies, and complete Viton accl pump assembly.  We have the plugs for the airhorn in stock as well.

It looks like you are working with a large main airbleed Chevy carb, it will benefit greatly from a recalibration, we have press-in and screw in airbleeds and all the tuning items for this as well.....Cliff