holley 4160 bogs at cruise

-
dartswing72

dartswing72

Active Member
Joined
Apr 22, 2013
Messages
41
Reaction score
9
Location
socal
alright so i recently bought a dart with a 318 and it came with a 4160 600cfm holley and at any speed, any gear, at 1/4 throttle i always get bogging so taking off is a hassle, but once i put the pedal down more it goes away, and runs the way it should. idle is nice and smooth, also if im stomping on it hard it runs good, it was flooding so i adjusted the float level to where it barely comes out of the sight hole. im running at 12btdc, it had a 31 nozzle and then put 35 nozzle and same problem, im running a 6.5 power valve. idle mixture screws are out 1 1/2 out, i also retarded and advanced it and same problem so i put it back to 12btdc. maybe it could be the main jets or power valve? im running at 10hg on idle in drive and 13 hg in neutral. any idea what else it could be?
 
I have a similar set up with a similar hesitation. Went to the 35 shooter & reset idle under load & it seemed to help but didn't cure. I run 16* initial & 34* total by 2500 RPM. I'm thinking pump cam, may be not enough fuel early in the pump shot for the the cam (xe268 ). will be trying the red or orange cam I'll post if does indeed help.
 
I'm reading that you're experiencing a "lean" bog. The #35 is a lot of nozzle for most street type setup's. Sounds like you have some cam by the vacuum numbers you posted. I'm curious how much plenum your dealing with, meaning what intake (dual/single plane) and are you using a spacer? I agree with Saetun, that you could use a little more initial, but the fact that your timing experiments have showed no change, i'm leaning toward a in jump primary jet as you suspected. Your mixture screws are just about dead on at 1 1/2 for a Holley, so what jet is in it now? Another random thought is, what is your ported vacuum port hooked too? Vacuum advance? Not likely the problem, but if there's a leak in that line, it can show up at 1/8-1/4 throttle.
 
I'm guessing a pretty lumpy cam and single plane? Those numbers are pretty close to what my old 340 used to do. I put in a Mr. Gasket quick advance spring kit and disconnected the vacuum advance, set advance to 32 degrees total (full advance @ 1500)
 
I also had the same problim as you,what i found was the pump arm needed a slite bend. See if there is any up and down against the pump cam.If so bend it down.
 
it has a dual plane intake manifold by edelbrock, and i dont know if it has a cam or not the guy i bought it from didnt know what was done to it either, im running manifolds to dual exhaust. and i will check what size main jets im running later on this week, im sure they are stock, do you think my power valve is too high im running a 6.5 when i should actually be running a 4.5 since im at 10hg idle right? and im also running the orange pump cam maybe i should change that for a more early shot? and the ported vaccum is hooked up to the vacuum advance
 
The power valve should be as close to half your vacuum at idle i believe. On my 340 I resprung the adv in the distributor. Plugged the vacuum adv and played with tube type squirters. Also had to mess with the pump cam. The squirter I used was smaller so the squirt lasted lonher. All this combined with my initial timing got mine running with no bog. Mind you im running a 850 holley on a single plane.
 
The power valve should be as close to half your vacuum at idle i believe. On my 340 I resprung the adv in the distributor. Plugged the vacuum adv and played with tube type squirters. Also had to mess with the pump cam. The squirter I used was smaller so the squirt lasted longer. All this combined with my initial timing got mine running with no bog. Mind you im running a 850 holley on a single plane.
 
On my 318 we run 28 nozzel 68 on the front and 72 on the back. Ran as good as a 318 will.Look down the carb and make sure your squirt is instant that you dont have to pull your throttle to get juice I had to bend the arm on mine, Im gonna bet your squirter isnt adjusted right. And a 35 squirter isnt doing you any good on a 600 start with a 25 and work upafter everything is adjusted right. Try 18 -20 initial timing with a total of 34-36 should put you back in the game.
 
My trucks 318 with the same carb was doing that I have a cam idk about you.

Mine wanted WAY more initial as soon as I gave it more timing that dead spot went away.
 
alright so you guys think the 35 nozzle is to big? and i did advance my timing and it still did it, so i doubt its the timing. i will change my main jets and hopefully thats the problem, and my accelerator pump is adjusted right on so when i barely move the throttle by hand it squirts
 
Can you not tell by how it sounds if the cam is non stock? It doesn't take a trained ear to tell. Throw us some bones here. We're not miracle workers.

That said, check the vacuum advance can. See if it works.
 
to my ear it doesnt sound cam, but i also dont know what is the engines history, and i dont know whats done to it internally. but ill check the vacuum advance
 
This is were I am talking about with the throttle closed is there any play there?................
 

Attachments

  • 012.jpg
    46.7 KB · Views: 239
there isnt any play on that, and i also bumped the timing to 20btdc and same bog and then back to 10btdc and same thing, so i just left it at 15btdc, im gonna get a different power valve and bigger main jets and hopefully it makes it run a bit better.
 
Don't go lower on the power valve! I believe you're experiencing a lean condition and dropping the opening # will just contribute to that. From experience, i disagree with Holley's recommendation as far as using "half" the vacuum on many applications. Anything at least 2 to 3" under your lowest idle numbers are fine. Try the jets first and you actually should be able to drop that pump nozzle back down to the #31. I'd also recommend leaving the pump cam alone if it's the one that came with the carb. I think that your combo is mild enough that you would just add more issues to the mix that are not necessary.
 
alright so i opened up the carb today and cleaned it out again and rebuilt the carb and on the main jets it said 641, also im still experiencing the same problem, i will order bigger jets this week and hopefully that will make it better
 
When you rebuilt the carb, did you set the clearance on the front pump shooter to spec with a feeler gauge?
No guessing here you have to set it with a feeler gauge.
 
You must log in or register to reply here.
-

Back
Top