Holley VS. Edelbrock debacle
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I doubt the Edelbrock was leaking fuel into the motor while sitting unless it was because of excess fuel pressure forcing fuel past the floats because of a plugged vent line. Do you have a return line to the fuel tank and a vent line? Make sure the rest of your fuel system is good. I had a buddy recently chasing his tail with multiple carbs and it ended up being bad old gas in the tank plugging up every carb he put on.Without a doubt this will go off the rails fast, just like the Holley 🤪
Although the Edelbrock worked, it didn’t work well. Even after running the bowls empty (seemingly) I was still ending up with gas in the oil over time. Wether this was from the carb still leaking, or rings not being seated is out of my realm of knowledge. I got paranoid over the gas thinning out my oil and allowing my engine to begin to eat itself, which when I found the Holley, it seemed like a good deal.
The Holley wouldn’t of worked in the condition I got it in, it was fairly beat up.
View attachment 157899
It’s hard to see, but that choke linkage was bent inwards by an 1/8th of an inch.
I replaced every component save for the big items, it got every gasket and seal, needles and seats, throttle shafts, throttle plates, and every spring. I put the correct squirters in it according to the list number.
The other reason I bought it was because I plan to race the car when I’m done and got sucked into the idea that “every racer has a Holley”, and I underestimated what it would take to revive this thing.
Another thing I ran into with Edelbrock carbs is their 1406 is calibrated for "fuel economy", the 1405 is the same cfm but calibrated for "performance". I noticed a difference and run the 1405 now. You could just go back to your 1406 that worked and change rods and jets to match what the 1405 has.
Don't overlook timing! Have you checked what your timing is at idle, under load, and max mechanical timing? Timing makes all the difference and I've chased stumbles, idling issues, and off idle problems thinking it had to be the carb just to find out it was a timing issue.
I'm assuming your Holley problem is a plugged idle circuit. Because it seems like you can get it to idle when you get past the transfer slots and pull fuel through the primaries. Plugged idle circuits can be a bear to clean because they are so small.
Let us know what you find out.
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No transfer slots on the secondaries, as far as i know. Double pumpers may be different?
That's another thing: have you adjusted the accelerator pump?
Hard to believe it's dropping vacuum that low. If the brake booster is bad, that's a huge vacuum leak, though. You're chasing your tail until that goes away.
That's another thing: have you adjusted the accelerator pump?
Hard to believe it's dropping vacuum that low. If the brake booster is bad, that's a huge vacuum leak, though. You're chasing your tail until that goes away.
I had first fed the Edelbrock with one of those cheapo Chinese shaker fuel pumps, that thing could barely make 2.5 PSI. The Edelbrock would leak fuel when the fuel pump was off, to the point where if it sat overnight, the only fuel in it would be in the accelerator pump.
Af far as timing goes, it’s currently at 16 degrees initial, calculated to be 32 total, I can’t read my balancer anymore due to rust. Using the mechanical advance on my distributor with the heaviest springs it was supplied with, I probably need to go to a lighter spring to bring more timing in faster. According to Top Street Performance’s charts (I got this dizzy on a heck of a deal), timing with their black springs doesn’t start until 2500. Or I just need to add more initial.
From what I’ve been understanding, both primaries and secondaries need to be adjusted equally, that includes transfer slots exposure. The primary accelerator pump sprays as soon as the throttle is even touched, it doesn’t lag behind.
The engine would stall wether it was in gear with the wheels blocked, or with the brakes applied. The booster just took longer to stall it out, perhaps because the vacuum draw is made up as the engine runs, but the power valve opened, starting to flood the engine. Either way, I bought a 4.5 this morning because that’s all the speed shop sold separately.
I’ve got the secondaries and primaries adjusted pretty equally, and the 4.5 is in. I’ll be firing it up shortly.
I’ve got a paint mark on it already, but the broad range timing marker I've got on it obscures almost all of the rusted timing marks. Works well enough though.
SUCCESS! Don’t know which was the right call, but the car will idle in gear with the wheels blocked or holding it with the brake and it won’t die even after sitting for a solid minute in that state.
The 4.5 power valve might be still to high, as it died with the brake on while stopped on a hill. Either way, progress is progress.
Now I have to figure wether or not I should be or should not be able to stall the engine by bottoming out the idle circuit screws, because it still doesn’t. Might need readjusted again, I did play with both stop screws.
The 4.5 power valve might be still to high, as it died with the brake on while stopped on a hill. Either way, progress is progress.
Now I have to figure wether or not I should be or should not be able to stall the engine by bottoming out the idle circuit screws, because it still doesn’t. Might need readjusted again, I did play with both stop screws.
.....it helps it you don’t put the throttle blades in upside down. I’ve been wondering why I’m getting very little airflow through the primaries with the transfer slot showing a square, turns out the angle on the primary throttle blades is reversed. DOH!
Try cracking the secondaries open a little. That should allow you to close up the primaries enough to cover the transfer slots.
I also want to add not to worry about the power valve just yet. Get you base timing and mixture figured out. I typically do this with a vacuum gauge making adjustments so that I can get the highest vacuum reading I can. I will even vary the idle speed. I will select a power valve after I figure out where it makes the highest vacuum and seems to idle the best.
Make sure you have the correct power valve installed, there is an adjustment screw behind the choke housing to adjust the high idle while choke is closed
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