Help; I switched over to a four barrel intake and carb on my 318. I bought a brand new holley 4160 600 cfm. I used it to break in the cam and every thing went well. Now it is leaking between the front metering block and when I shut it down it dumps fuel down the primaries for a few seconds. I know 4150 models well, but not these carbs. I would go after the float, but there is no float adjustment. One thing I should probebly mention is that when I was starting up I was still trying to get timing right, so I was moving the distributor and backfired up the carb twice. does this carb have a power valve and, or did I blow out the metering block gaskets? WTF with the float adj, do I have to remove the float bowl.
holley hell
- Thread starter devildart
- Start date
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Mrmopartech
Well-Known Member
I would open it up and replace the power valve and re adjust the float down to spec or move them down 3/32.If its a vacumn secondary carb,check all the bowl screws and base screws to be sure they are tight.Do check the secondarys will open when the primarys are open by hand and are not binding on the intake.Check you fuel pressure to make sure its not to high,above 8lbs.If its less your OK.If their is a filter i the bowl inlet fitting,remove it and install a 3/8 inline clear gas filter.Mrmoaprtech
Captainkirk
Old School Mopar Warrior
In answer to your questions;
1) Most certainly your float level is too high and/or your needle is leaking. Quick way to tell: pull the sight plug off the side of the float bowl. The fuel level should come up to the BOTTOM of the sight plug, just to the point where it dribbles out a little. To my knowledge, the 4160 float is adjustable unless they've changed something? If you can snap a pic of the carb and post it, I can walk you through it; I ran a 4160 on my Duster and was able to adjust it with no problem????
2) Yes, they DO have a power valve and yes, a backfire WILL blow it out and make the carb run super-rich; i.e. the engine will run like crap. Summit sells replacement "blow-proof" power valve kits; HIGHLY recommended. Any other questions and/or comments, please let me know.
1) Most certainly your float level is too high and/or your needle is leaking. Quick way to tell: pull the sight plug off the side of the float bowl. The fuel level should come up to the BOTTOM of the sight plug, just to the point where it dribbles out a little. To my knowledge, the 4160 float is adjustable unless they've changed something? If you can snap a pic of the carb and post it, I can walk you through it; I ran a 4160 on my Duster and was able to adjust it with no problem????
2) Yes, they DO have a power valve and yes, a backfire WILL blow it out and make the carb run super-rich; i.e. the engine will run like crap. Summit sells replacement "blow-proof" power valve kits; HIGHLY recommended. Any other questions and/or comments, please let me know.
torquehouse
Well-Known Member
Mrmopartech is dead on. That power valve is the primary suspect. Float level is next. On a 4160, you've gotta remove the float bowl to set the float level. A new bowl gasket is probably in order. But I'd keep the fuel pressure below 7 pounds! The stock needle and seat might have problems handling much more pressure than that at idle. And like Mrmopartech says, make sure the secondary linkage clears the intake through full travel (WOT). You should be good to go!
Yeah I figured it was a float related issue. What gets me is that there is no plug on the side of the bowl to check the level and there is no float adjustment screw on the top. It seams to be a totally sealed system. I have a few power valves laying around. I will definatly change it out. Thanks.
dusterdon
Well-Known Member
If its new, I would think that Holley would warranty it. I'd check there before I tore into it. I think that all newer Holley's have the blowout proof power valves now. Call Holley. They have a pretty decent tech line.
don
don
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