Carb trouble...Should I Switch to an Edelbrock?

[IDC10]

I'm running the original 307 on my '68 C10. The motor was running nice and strong, until one day it stalled out and would barely start and run. When I opened the hood, I found gas all over the intake manifold.

I have a Holley 4160 carb. I removed the front bowl on my carb and cleaned out the needle valve, then reset the float level. Then I started having issues with severe hesitation and stalling. Checked the accelerator pump, and eventually replaced the power valve.

When I replaced the power valve, the motor idled great, and initially seemed to drive great.... after a mile or two, the hesitation and stalling started again, barely holding an idle, and I could barely make it home.

I have a Summit clone of a GM HEI distributor. Replaced the ignition control module....exact same behavior.

Fuel pump doesn't even have 100 miles on it and the motor is getting plenty of fuel...and I can see the gas in the clear fuel filter next to the carb.

So I'm thinking I have to completely tear down and rebuild a carb that is only a few years old and hasn't seen a lot of use. I want to throw it across the shop and just get a new carb.

Are the Edelbrock carbs less temperamental? From what I'm reading about, they seem to be simpler. I'm looking at a 500 CFM model 1403. I need something that is going to be solid and reliable.

[franken]

Chances are it has problems because the ethanol in the gas is toxic and attracts water. You may have bad gas as well.

[IDC10]

Originally Posted by franken

Chances are it has problems because the ethanol in the gas is toxic and attracts water. You may have bad gas as well.

I'm using non ethanol gasoline....from a fairly new gas station.

[Rickysnickers]

If the carb has been sitting a while, potentially it's gummed up to some degree, even with using non-ethanol gas. Try rebuilding and cleaning it well. I'm betting that will cure your problem.

[Ziegelsteinfaust]

While the Edelbrock is a better driving carb then any Holley I have used.

It is a good bit of money to spend on a carb that just needs a spray can rebuild. Like the others have said. Today's gas is likely the cause, and has its own issues. The ethanol attracts water, and causes all sort of problems. Along with like mentioned the probability of bad gas.

Before I soent money on parts with any carb. I get the engine warm, and rev it to 3000 rpm roughly, and put my hand over it to suck debris or gunk out of the small passages. If it gets better. Then drive it around, and floor it to get the juices flowing through the carb.

[IDC10]

I'll try tearing it down and rebuilding it.

If I keep having problems with it, then I'll go with an Edelbrock and pawn off the Holley. I need something that is going to be as close to dead reliable as I can get....and I'm not taking this thing to the track.

I'm using non ethanol 87 clear gas from a new Maverick station. All of the testing I've been doing is with the motor fully warmed up to operating temperature.

[RustyPile]

Well, here we have that old argument Holley V Edelbrock argument.. I'll jump in from a different angle.. 4160 doesn't fully describe your carburetor, The 4160 is available in several CFM ratings, 390 to 750 are the most common.. Which one do you have?? The "list number" stamped on the front of the air horn will tell you which one you have.. You said you replaced the power valve?? Again, there are several, which one did you install??

Any carburetor, no matter the brand, needs to be squeaky clean.. Spraying some aerosol cleaner and throwing a few parts at it does not constitute a rebuild.. There is a ton of information on the Holley site.. Down load and study everything.. Learn how the carburetor works, what makes it "tick" and then get busy..

[IDC10]

Originally Posted by RustyPile

Well, here we have that old argument Holley V Edelbrock argument.. I'll jump in from a different angle.. 4160 doesn't fully describe your carburetor, The 4160 is available in several CFM ratings, 390 to 750 are the most common.. Which one do you have?? The "list number" stamped on the front of the air horn will tell you which one you have.. You said you replaced the power valve?? Again, there are several, which one did you install??

Any carburetor, no matter the brand, needs to be squeaky clean.. Spraying some aerosol cleaner and throwing a few parts at it does not constitute a rebuild.. There is a ton of information on the Holley site.. Down load and study everything.. Learn how the carburetor works, what makes it "tick" and then get busy..

LIST-1850-3 0510

I believe it's 600 CFM.
I'm thinking a 307 should have something in the range of 500-600 CFM.
I have a perfomer RPM intake.

I replaced the power valve with one from the Holley renew kit. It was marked 6.5. Couldn't make out the markings on the one that came out.

[Willshook]

The carb is fine; it just needs an overhaul. I suspect your needle is still sticking a bit.

The size is fine; as a square-bore, vacuum secondary carb it's perfectly workable for your application. Tuning the secondary opening spring will probably improve your low- and mid-range throttle response since you probably need only 300 CFM or so. For a daily driver, a spread-bore carb is generally the best choice, but a square bore works fine.

The RPM is kind of the wrong choice for an intake, but the impact is minimal.

Edelbrocks are fine; they do tend to be more tolerant like a Q-jet, but like a Q-jet they are significantly more difficult to fine tune for a performance engine. There's a reason you see Holleys on 99.999% of performance engines...but if you don't need it, they do require more tuning to get it just right for your particular use. ANY carb will do the basic job - swapping out a carb that was working and suddenly isn't makes no sense to me - you know it works, it just needs to be fixed.

Holleys aren't temperamental, but it is surprising if it's a new carb is having issues. This is often reflective of particulate in the fuel, so it's worth taking a look at your filter.

[RustyPile]

Originally Posted by IDC10

LIST-1850-3 0510

I believe it's 600 CFM.
I'm thinking a 307 should have something in the range of 500-600 CFM.
I have a perfomer RPM intake.

I replaced the power valve with one from the Holley renew kit. It was marked 6.5. Couldn't make out the markings on the one that came out.

For a "stone stock" engine, nothing beats the OEM intake manifold, but that Performer should work for you.. The 1850 is a 600 CFM carburetor, very suitable for a small displacement, stock engine. But as with any replacement carburetor, you'll need to tune it to the engine.

There is a formula/process for power valve selection.. As I said, the information on the Holley site will be invaluable for you.. Download the Installation, Tuning, and Adjustment Manual. It will aid you tremendously.. Also, check your PMs, I sent you a message.

[AcampoDave]

The 1403 is a good carb, but it is jetted quite rich as it is designed for...and I quote Edelbrock.... "dual quad and performance applications in 305 and smaller."

I have one on a 283 and I love it now that I leaned it out.

[vintovka]

Previous 350 sb had a holley - nothing but trouble. Went with a new 350 crate and a 1406 edelbrock on edelbrock performer. First one would not idle right out of the box. Finally sent it back and got another 1406 directly from them. Had to add a 1" spacer as it was not machined right but better than first . With spacer it Runs great, plenty of power BUT seems to draw 20+ inches when ice cold starting and drops to 15-16 when warm. Also seems to have an occasional miss on acceleration when warm. I think some of these were never machined right

[RustyPile]

Originally Posted by vintovka

it Runs great, plenty of power BUT seems to draw 20+ inches when ice cold starting and drops to 15-16 when warm. Also seems to have an occasional miss on acceleration when warm. I think some of these were never machined right

When the choke is closed or near closed, the intake air is restricted.. This higher intake vacuum is a normal event.....

[vintovka]

Yes you are right I forgot. but the intermittent missing on acceleration after being run then parked has me baffled. All the issues with edelbrock lead to many concerns. We measured the first one on a precision granite measuring block with calibrated tools nd there was visible distortion in the carb bottom both cold and hot. Second one was less but use of 2 gaskets and a phenolic 1" riser kinda works.

[RustyPile]

Originally Posted by vintovka

Yes you are right I forgot. but the intermittent missing on acceleration after being run then parked has me baffled. All the issues with edelbrock lead to many concerns. We measured the first one on a precision granite measuring block with calibrated tools nd there was visible distortion in the carb bottom both cold and hot. Second one was less but use of 2 gaskets and a phenolic 1" riser kinda works.

In the interest of not hijacking IDC10's thread, let's not discuss your problem here..

If you'd like to discuss it further, send me a Pm please..

[AcampoDave]

I forgot to mention, I too use a 1" phenolic spacer. The 4 hole Summit branded pastic one. It does help with the Edelbrock for heat soak and tip in throttle response.

[karlbenz]

I'll take an edelbrock for reliability