More Carb Thoughts

[ACJC]

I'd like to expand futher on carburetion thoughts and this is the panel of experts with which to do it. It involves tuning on Edelbrock performer carbs. I have a 600 CFM Performer (1407) on a Performer Intake manifold.

FIrst I haven't contacted Edlebrock with my issues because I feel I can get a starighter answer here.

1) How many of you are using some type of spacer, phenolic/plastic, wood-fiber, or aluminum between you carb and intake? Currently, I have a .320" insulated base gasket installed.

2) If not; are you having any problems with flooding or hard starting after short runs, and even worse hydro-locking? I experience the hard starting on a warm engine routinely nad have experienced hydro-lock once. I corrected the latter by leaving the gas cap loose.

3) If you are using a carb spacer, what size are you using/recommend; 1/2", 3/4", 1", or 2"? I'm leaning towards a 1/2" to 3/4" spacer.

I know I need to varify correct float level and check for trash in the bowl, point dwell, and ignition timing. May have to decrease jet size too.

Some have told me with Edlebrock cars, you either get a winner out of the box or a dud. So far I've got a dud. Any thoughts/comments/advice?

Jim

 

[Rick]

I have the same carb no spacer and it runs great all day long and with alot of start and stops.(My wife and son drive my car now as i messed up my back at work and this little will beat my back to death)I did drive it once this year before i hurt mt back.

 

[GT63]

How much vacuum do you have at idle? All you may need to do is change the needles and springs.

Usually a hard start on a warm engine is a timing issue.

 

[donsrods]

I've been using Edelbrocks since they came out, and all I do is bolt them on and run.............no problems whatsoever. I had two on my '27 for about 7 years of almost daily driving and the only thing I had to do was occasionally take the tops off to clean the rust that accumulated from driving in lots of rainstorms with no hood. That wasn't the fault of the carbs though, and I was always surprised that the car kept running when I would drive in one of So. Florida's torrential storms.

I also had one on my Jeep/5.0 that I also drove daily for about 5 years. Never touched it in all that time. So, obviously, I am a big fan of Edelbrocks. I used to use Holleys, but got tired of fidgeting with them, and they HATE dirt, even a little spec will shut them down.

Don

 

[Coupefreak]

I've been using Edelbrocks since they came out, and all I do is bolt them on and run.............no problems whatsoever. I had two on my '27 for about 7 years of almost daily driving and the only thing I had to do was occasionally take the tops off to clean the rust that accumulated from driving in lots of rainstorms with no hood. That wasn't the fault of the carbs though, and I was always surprised that the car kept running when I would drive in one of So. Florida's torrential storms.

I also had one on my Jeep/5.0 that I also drove daily for about 5 years. Never touched it in all that time. So, obviously, I am a big fan of Edelbrocks. I used to use Holleys, but got tired of fidgeting with them, and they HATE dirt, even a little spec will shut them down.

Don

Its funny how things work out........I have had 3 Edelbrock carbs......all fresh outta the box.....had to re-spring and re-jet every one of them!
wound up swapping all 3 for Holleys......that ran GREAT right outta the box!! replaced the Holley 600 vacuum secondaries that was on the Coupe, for a BG Road Demon......took me 3 weeks of tinkering and "tweaking" to get it right. so I don't know if its just "luck of the draw" or if I really am a "Fecal Magnet".....as some of my co-workers so lovingly refer to me as.........

 

[putz]

A good way to check for vacuum leaks hold hand over carb intake and see if idle goes up if yes you have an vacuum leak. Could be at carb base or intake.

 

[tfeverfred]

I have a 600 and use their plate to mount it to my stock 305 chevy intake. I'm not using a choke and have had no problems at all.

 

[ACJC]

Thanks to all!

I will check for vaccuum leaks and of course timing. That could be out of whack. Unfortunately not knowing the cam spec.'s will make it difficult. I believe the stock timing ('72 350 2 bolt) is 4 deg. BTC.

It may also require some jet work. A budy of mine also suggested we look at the intake manifold gaskets to see if they have a restriction or not in the exhaust cross over. It may be getting to hot underneath.

Thanks again as the more information I can get the better I can diagnose. Best to use no cost, or low cost fixes before tearing the engine down and replacing a cam shaft, bearings, and lifters (last resort).

Jim

P.S. To Rick, I hope you get healed soon to enjoy your rod.

 

[TheAntiBoyd]

first things first, Hot start is probably a timing issue so check your timing (this may require a new balancer or at least a timing tape. Id also replace your points and condenser and make sure your distributor is locked down snug, and check your plugs.

If all that checks out, get a can of Ether, or WD40 and spray along every mating surface. If you have a vacuum leak, this will raise your revs when you find the leak. Thats done, and no leaks (which I doubt), I would then replace each and every vac line ONE AT A TIME and see what happens by testing the car in between each replacement. Lastly, Id also replace your vac advance can. This is cheap and most are worn out.
Id also check the torque on your intake manifold bolts. My dads 327 has a Performer RPM Airgap which btw is one bad ass street manifold, and he had trouble getting it to seal to his legit fuelie heads. Solution? MLS gaskets and ARP aluminum manifold bolts and a TQ wrench...along with a lil permatex.

There you have it, in my estimation, one of these should cure your problem. Expensive? naw...Time consuming? yeah, but you'll most definitely notice a difference.

Lastly, you can go to edelbrocks page (Edelbrock.com - Tech Center - Carburetor Frequently Asked Questions)
and download the 1407 owners manual which has some basic tuning tips.

On my dads car ( with identical carb) After we hooked up the electric choke, we used his 30yr old Sears Engine Analyzer which measures timing and a few other things, and even with his Pertronix Ignitor II (which I like a lot) it helped dial in the vac advance and ignition as well as the idle speed. The car is much nicer to drive and doesnt buck and hump across the parking lot.
Oh...check your distributor cap too for arcing, carbon tracking or cracks. You can get a nice black one with BRASS contacts from Classic Chevy for 14 bucks I believe.


Sorry for the long winded post, but I know it can be annoying and with a lil fine tuning, you'll get there

 

[ACJC]

Well, the problem is fixed. My side kick Ray, found the problem with a hand vacuum guage; the vacuum advance control was FUBAR and the centrifugal weights were corroded closed.

So, we field stripped the distributor and cleaned every thing, replaced the vacuum advance pot, new plugs and wires and a clear Mr. Gasket cap, and set the dwell and timing, and adjust the carb. Good to go right?
Wrong.

We shut thecar off and the gas is just pouring into the carb. Ray says, "pull that carb and let's look inside." I went a picked up a rebuild kit and when I get back Ray has the carb field stripped. He says, "check this out."

The bowl looked like it had GA red clay in it, evidence of varnish, and the floats were way outta wack, one up and one down. :cussing:

Geeze alou, we had to ask what D.A. was in this thing, no wonder it wouldn't run right.

So, now the :rock: pegs when the loud peddle goes down and the gas guage and speedo aren't chasing each other.

ACJC

 

[Turbo-T]

I see you got the problem fixed and that's good. Another possible problem that I was going to suggest checking bears mention anyway.
On a lot of these cars the fuel tank sits above the carburetor. The gravity feed from this can cause fuel to leak by the needle and seat. It's possible to put a tank of fuel into the crankcase.

 

[ACJC]

That is absolutely correct Turbo-T and I have probably the cleanest engine in the southeast. Now that the carbruetor is clean and properly adjusted, I don't have to worry as much about washed out rings and bearings.

JC

 

[JeffBorn]

Great Thread learned a bit by reading your ideas.
Now for my Flooding proble. I am buidling a 27 with a newly rebuilt 305 and edelbrock 4bbl most likely cfm500 manual choke. Replaced plugs with Autolite 25 gapped at .035, fired right up. Set Timing at too low rpm (600 I am told should set it at 2000) and set dwell at 25. After 10 Minutes of idling pain was cooking of passenger side header and started running rough. Messed with air mixture and no change. Revved it up to see if there was hesitation, none backed off throttle and it died not to restart.
I pulled new plug and was dripping with blackened fuel. Now on this fine morning I have pulled the top of the carb off and floats look intact the passenger side bowl had more fuel than the driver side. Small piece of gasket in bottom of bowl and some minor crud. Cleaned things up and now what to do with the floats.
I am obviously at the beginning of my journey to becoming an "expert". so any specific changes or adjustments would be greatly appreciated. I have NGK plugs to put in after I fix my flooding problem. I'll be checking out Edelbrocks site for the manual while awaiting a response. All ideas are appreciated.

 

[mikesplumbing]

I just called a buddy that has this carb and he said the carb can flood if the fuel pressure is too high.He had flooding problems because the stock fuel pump was replaced with a high performance fuel pump, sometimes that can cause the problem. A fuel pressure regulator can help you sometimes also.

Just a thought.

Mike