Phenolic Carb Spacere
June 10th, 2022, 06:12 PM
#1
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Thread Starter
Join Date: Aug 2018
Posts: 41
Phenolic Carb Spacere
After getting my Cutlass back together last summer, I drove it from July - October occasionally without any major issues. It has a slight hesitation off idle (typically part throttle from stops) and horrible gas mileage.. so this spring, I planned a couple upgrades to help diagnose the issues and start working on the carb to get it tuned. While waiting on the AFR guage, tachometer, and vacuum guages to ship, I drove it a couple times and it was the same as last year. Fast forward to late May, I got the vacuum and afr guage shipped so I had my buddy weld in the O2 bung and install everything. Right after installing, I filled the tank for about 120 mile round-trip. After 8-9 miles, the car lost all horsepower and started missing out very badly. After it died, it wouldn't restart so I start digging into it to try and figure out what happened. Fuel was visible in my clear filter and spark was good. After about a 20 minute cooldown, car started right up and drove back home. I've driven it a few more times since then and around town, it does fine. But as soon as I start on a decent drive, same thing. I'm thinking it's a problem with the fuel. Higher prices = more ethanol in it = easily burns off in the bowls of the carb once everything gets nice and warm. I'm hoping a simple spacer will cure this issue. Any of you guys had success with a particular company? And how big should I shoot for? 1/2" 1" 2"?? I just don't know. I'd like it to be as small as possible but also I don't want to end up buying 2 or 3 1/2" ones when I could have just gotten the right one to start with. Thanks guys!
70 SBO 355 with big valve iron heads, mid range Elgin cam, long tube headers, and a 750 Edlebrock
70 SBO 355 with big valve iron heads, mid range Elgin cam, long tube headers, and a 750 Edlebrock
June 10th, 2022, 07:38 PM
#3
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Join Date: Feb 2013
Location: Phoenix, AZ
Posts: 14,146
Yeah, I agree that you need to actually diagnose what the problem is before attempting to fix it.
FYI, here in Phoenix we’ve had 10% ethanol fuel forever and my car runs OK on it even during 110+ summer temperatures, so Your theory of fuel boiling is not my first suspect.
With that said, a spacer isn’t gonna make things worse so no real detriment in trying one.
FYI, here in Phoenix we’ve had 10% ethanol fuel forever and my car runs OK on it even during 110+ summer temperatures, so Your theory of fuel boiling is not my first suspect.
With that said, a spacer isn’t gonna make things worse so no real detriment in trying one.
June 10th, 2022, 07:58 PM
#4
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Join Date: Mar 2013
Location: St. Clair, MI
Posts: 1,667
Even If the ethanol were to boil off, youd be left with pure gas, and that wouldnt be a problem. 1/2" spacer is more than enough. Check under the car to make sure your fuel line isnt close to the exhaust from back to front. Check to see if you have a sealed gas cap, It may be causing a lack of fuel flow. Drive the car till it stalls, then remove the cap and listen for a sucking sound from a vacuum iin the tank.
June 10th, 2022, 11:02 PM
#7
CH3NO2 LEARN IT BURN IT
Join Date: Jul 2010
Location: Land of Taxes
Posts: 4,932
Hi Brad,
2" spacer is more than enough. I'm still running an old Mr Gasket laminated heat spacer. Metal/gasket stack. The Phenolic is fine too.
What is your general elevation above sea level?
Iron or aluminum intake? Single or dual plane?
Stick or auto?
Compression ratio?
What series is the Edelbrock carb? AVS1400 or 1900 or?
Is it new?
Electric choke?
Do you have the Edelbrock rod/jet/spring kit? If not purchase the larger kit. Follow the tuning guide. If it's a lean tip-in prob the carb needs to be dialed in using the springs rods & jets.
Do you see a good steady shot of gas down the carb while actuating the throttle full travel to WOT?
Do you know how to tune timing & A/F using only a vacuum gauge?
Any idea what the fuel pressure is?
Does it exhibit this tip-in hesitation when cold?
You may need to verify the float level and drop settings.
In my opinion, do not run ethanol in anything with a carburetor on it. Use ethanol-free and drop in some 104/108 octane boost.
If tuning the engine (ignition & carb) and installing the spacer does not improve this then I'd say it's heat-related.
This is a summer cruiser, right? Pull the intake and weld the plugs into the exhaust crossover in the intake(not in the heads). This will eliminate all of the exhaust heat under the carb.
The plastic spacer under the carb helps as well. Electric choke will solve the now cold-bloodedness it will exhibit with these 2 mods.
Steve
2" spacer is more than enough. I'm still running an old Mr Gasket laminated heat spacer. Metal/gasket stack. The Phenolic is fine too.
What is your general elevation above sea level?
Iron or aluminum intake? Single or dual plane?
Stick or auto?
Compression ratio?
What series is the Edelbrock carb? AVS1400 or 1900 or?
Is it new?
Electric choke?
Do you have the Edelbrock rod/jet/spring kit? If not purchase the larger kit. Follow the tuning guide. If it's a lean tip-in prob the carb needs to be dialed in using the springs rods & jets.
Do you see a good steady shot of gas down the carb while actuating the throttle full travel to WOT?
Do you know how to tune timing & A/F using only a vacuum gauge?
Any idea what the fuel pressure is?
Does it exhibit this tip-in hesitation when cold?
You may need to verify the float level and drop settings.
In my opinion, do not run ethanol in anything with a carburetor on it. Use ethanol-free and drop in some 104/108 octane boost.
If tuning the engine (ignition & carb) and installing the spacer does not improve this then I'd say it's heat-related.
This is a summer cruiser, right? Pull the intake and weld the plugs into the exhaust crossover in the intake(not in the heads). This will eliminate all of the exhaust heat under the carb.
The plastic spacer under the carb helps as well. Electric choke will solve the now cold-bloodedness it will exhibit with these 2 mods.
Steve
June 11th, 2022, 05:04 PM
#8
Registered User
Join Date: Jul 2014
Location: Anne Arundel county, MD
Posts: 25
I've experienced that with other cars. The problem was usually that the old fuel filter in the QJ body needed replacement.
Repost: Sorry, i just noticed that you're using an Edelbrock carb.
Have you checked fuel pressure at the pump?
Repost: Sorry, i just noticed that you're using an Edelbrock carb.
Have you checked fuel pressure at the pump?
Last edited by Tadpole11; June 11th, 2022 at 05:08 PM.
June 11th, 2022, 05:18 PM
#9
Registered User
Thread Starter
Join Date: Aug 2018
Posts: 41
Thanks for all the replies!
If it was the coil or ignition, wouldn't it do it randomly (intermittently) or just all the time? This is pretty consistent and only under very specific circumstances. I've drove it 4 times since this started and it only happens at highway speeds. I can drive around town all day and not have any issue. My assumption was since there's more load at low speeds, the gas isn't sitting in the carb as long and therefore see less heat.
Hi Brad,
2" spacer is more than enough. I'm still running an old Mr Gasket laminated heat spacer. Metal/gasket stack. The Phenolic is fine too.
My main concern is how much room is there under the hood? My car is stock hood, qjet to edelbrock adapter (metal), 1411 carb, and stock air box
What is your general elevation above sea level?
Google states 810' for Kokomo, Indiana
Iron or aluminum intake? Single or dual plane?
Factory Iron 4 barrel Intake
Stick or auto?
Auto Turbo350
Compression ratio?
10.25 I believe. I didn't see the pistons before the long block was put together but when I setup everything with my machinist that's what I asked for.
What series is the Edelbrock carb? AVS1400 or 1900 or?
It's a 1411. At Advanced Auto I was told it would be a 600 cfm (1406) but when delivered the box showed 1411. By that time, I was just glad it wasn't smaller than expected and there.
Is it new?
Yes when ordered but now its almost a year old at this point. It didn't sit over winter with fuel in it. I pulled the fuel line and ran it dry during winterizing.
Electric choke?
Yes but not hooked up to anything. Since I don't drive the car when it's cold out, I never bothered finishing it.
Do you have the Edelbrock rod/jet/spring kit? .
I do. I had planned to take it on a visit to see my Dad and on the way back, make a change to see how much it improved. Never got far enough in said trip.
If not purchase the larger kit. Follow the tuning guide. If it's a lean tip-in prob the carb needs to be dialed in using the springs rods & jets.
Do you see a good steady shot of gas down the carb while actuating the throttle full travel to WOT?
Yes. Even when it started missing out I could blip the throttle linkage and get it to squirt out. I feel like it's a little less than normal but that's just by eye sight over a hot engine. Who knows if I'm right or jus my mind at this point.
Do you know how to tune timing & A/F using only a vacuum gauge?
I'm not an expert at it but I'm pretty sure I got the basics. I've read and reread the Edelbrock tuning guide 5 or 6 times now. Timing was set at the machine shop on the dyno but with a different carb so I wasn't planning on messing with that. So far I've only set the idle and mixture screws off vacuum. Still waiting on Jegs to ship a tach that I ordered in April so I haven't made any heavy changes. My first concern was being able to cruise on the highway again.
Any idea what the fuel pressure is?
This should be my main concern when ordering parts, I know. Right now its just a factory pump going through a filter up to the carb. New tank and sending unit. I keep hesitating ordering everything for the carb setup because I truely want fuel injection. I'm way more knowledgeable with F.I. and I'd like to be able to control a modern transmission with it one day (6l90, 8l90, or even 10l90)..
Does it exhibit this tip-in hesitation when cold?
Not sure. I usually warm the car up pretty well before leaving. A gallon of gas is cheaper than a new engine. I'll try to report back.
You may need to verify the float level and drop settings.
Already have when installed. I had heard that Edelbrocks from time to time can be off from the factory so I pulled the top last summer. I don't remember the exact measurements at this point but it was within about a 1/32" from the specs in the manual. Maybe 7/16" at rest and 15/16" drop. Those might be wrong though.
In my opinion, do not run ethanol in anything with a carburetor on it. Use ethanol-free and drop in some 104/108 octane boost.
I've been looking around where the car is stored at. No such luck. Closest place I know of is a 20 min drive each way.
If tuning the engine (ignition & carb) and installing the spacer does not improve this then I'd say it's heat-related.
This is a summer cruiser, right? Pull the intake and weld the plugs into the exhaust crossover in the intake(not in the heads). This will eliminate all of the exhaust heat under the carb.
It is. Ill keep that in mind if the spacer doesn't help. Thanks.
The plastic spacer under the carb helps as well. Electric choke will solve the now cold-bloodedness it will exhibit with these 2 mods.
Steve
2" spacer is more than enough. I'm still running an old Mr Gasket laminated heat spacer. Metal/gasket stack. The Phenolic is fine too.
My main concern is how much room is there under the hood? My car is stock hood, qjet to edelbrock adapter (metal), 1411 carb, and stock air box
What is your general elevation above sea level?
Google states 810' for Kokomo, Indiana
Iron or aluminum intake? Single or dual plane?
Factory Iron 4 barrel Intake
Stick or auto?
Auto Turbo350
Compression ratio?
10.25 I believe. I didn't see the pistons before the long block was put together but when I setup everything with my machinist that's what I asked for.
What series is the Edelbrock carb? AVS1400 or 1900 or?
It's a 1411. At Advanced Auto I was told it would be a 600 cfm (1406) but when delivered the box showed 1411. By that time, I was just glad it wasn't smaller than expected and there.
Is it new?
Yes when ordered but now its almost a year old at this point. It didn't sit over winter with fuel in it. I pulled the fuel line and ran it dry during winterizing.
Electric choke?
Yes but not hooked up to anything. Since I don't drive the car when it's cold out, I never bothered finishing it.
Do you have the Edelbrock rod/jet/spring kit? .
I do. I had planned to take it on a visit to see my Dad and on the way back, make a change to see how much it improved. Never got far enough in said trip.
If not purchase the larger kit. Follow the tuning guide. If it's a lean tip-in prob the carb needs to be dialed in using the springs rods & jets.
Do you see a good steady shot of gas down the carb while actuating the throttle full travel to WOT?
Yes. Even when it started missing out I could blip the throttle linkage and get it to squirt out. I feel like it's a little less than normal but that's just by eye sight over a hot engine. Who knows if I'm right or jus my mind at this point.
Do you know how to tune timing & A/F using only a vacuum gauge?
I'm not an expert at it but I'm pretty sure I got the basics. I've read and reread the Edelbrock tuning guide 5 or 6 times now. Timing was set at the machine shop on the dyno but with a different carb so I wasn't planning on messing with that. So far I've only set the idle and mixture screws off vacuum. Still waiting on Jegs to ship a tach that I ordered in April so I haven't made any heavy changes. My first concern was being able to cruise on the highway again.
Any idea what the fuel pressure is?
This should be my main concern when ordering parts, I know. Right now its just a factory pump going through a filter up to the carb. New tank and sending unit. I keep hesitating ordering everything for the carb setup because I truely want fuel injection. I'm way more knowledgeable with F.I. and I'd like to be able to control a modern transmission with it one day (6l90, 8l90, or even 10l90)..
Does it exhibit this tip-in hesitation when cold?
Not sure. I usually warm the car up pretty well before leaving. A gallon of gas is cheaper than a new engine. I'll try to report back.
You may need to verify the float level and drop settings.
Already have when installed. I had heard that Edelbrocks from time to time can be off from the factory so I pulled the top last summer. I don't remember the exact measurements at this point but it was within about a 1/32" from the specs in the manual. Maybe 7/16" at rest and 15/16" drop. Those might be wrong though.
In my opinion, do not run ethanol in anything with a carburetor on it. Use ethanol-free and drop in some 104/108 octane boost.
I've been looking around where the car is stored at. No such luck. Closest place I know of is a 20 min drive each way.
If tuning the engine (ignition & carb) and installing the spacer does not improve this then I'd say it's heat-related.
This is a summer cruiser, right? Pull the intake and weld the plugs into the exhaust crossover in the intake(not in the heads). This will eliminate all of the exhaust heat under the carb.
It is. Ill keep that in mind if the spacer doesn't help. Thanks.
The plastic spacer under the carb helps as well. Electric choke will solve the now cold-bloodedness it will exhibit with these 2 mods.
Steve
June 11th, 2022, 06:29 PM
#10
Registered User
Join Date: Jan 2010
Location: central Indiana
Posts: 5,341
Bradley, pretty sure we have met before. I also live in Kokomo. I can guarantee you heat is not the problem. I have several carbureted vehicles in my fleet, none have drivability problems.
You didn’t say what ignition system you have. If it’s HEI, I’d suspect random ignition module shutdown.
Get a spark tester from harbor freight. It looks like a spark plug, but with a alligator clip. They are calibrated to require a minimum of 25000 volts to fire. Next time he car gives you problems, immediately put that on a plug wire. If you see no spark, it’s time to dig a little deeper.
Put a test light on the TACH terminal of the HEI. turn on the ignition. The test light should be on. If not, either the coil is open (unlikely since the engine usually runs) or your randomly loosing power to the ignition. If the light is on, next crank the engine. The light should flicker s the module pulses the coil. If not, either the module is shutting down or the pickup coil is defective (again, unlikely since the engine usually runs)
You didn’t say what ignition system you have. If it’s HEI, I’d suspect random ignition module shutdown.
Get a spark tester from harbor freight. It looks like a spark plug, but with a alligator clip. They are calibrated to require a minimum of 25000 volts to fire. Next time he car gives you problems, immediately put that on a plug wire. If you see no spark, it’s time to dig a little deeper.
Put a test light on the TACH terminal of the HEI. turn on the ignition. The test light should be on. If not, either the coil is open (unlikely since the engine usually runs) or your randomly loosing power to the ignition. If the light is on, next crank the engine. The light should flicker s the module pulses the coil. If not, either the module is shutting down or the pickup coil is defective (again, unlikely since the engine usually runs)
June 11th, 2022, 06:43 PM
#11
Registered User
Join Date: Sep 2013
Posts: 2,011
A fuel pressure gauge should be #1 on your list. Even if you are going to fuel injection later a cheap gauge and hose extension so it can be temporarily mounted outside the hood is a must to see what the fp is.
I’ll guarantee you with that stock pump and a mild 350 it will be low after a short full throttle run.
Ebrocks need a minimum 5psi in my opinion. Without a gauge it’s only guess work. I don’t know how many cars of tuned where guys have just refused to check pressure or install a gauge…only to find out later fp was never what it should be.
i even had one guy so adamant that he didn’t need to know his fuel pressure he mounted his cell phone under the hood to video his fuel bowl sight glass on his Holley.
the phone fell off mid run and got destroyed..$600 down the drain.
I’ll guarantee you with that stock pump and a mild 350 it will be low after a short full throttle run.
Ebrocks need a minimum 5psi in my opinion. Without a gauge it’s only guess work. I don’t know how many cars of tuned where guys have just refused to check pressure or install a gauge…only to find out later fp was never what it should be.
i even had one guy so adamant that he didn’t need to know his fuel pressure he mounted his cell phone under the hood to video his fuel bowl sight glass on his Holley.
the phone fell off mid run and got destroyed..$600 down the drain.
June 13th, 2022, 07:30 PM
#13
CH3NO2 LEARN IT BURN IT
Join Date: Jul 2010
Location: Land of Taxes
Posts: 4,932
Read the plugs Get 12VDC keyed voltage to that choke.
Don't toss parts at it. Is the vacuum gauge capable of reading fuel sys PSI? If not get a decent one...ahem...Ummm not hjunk
Do not purchase any parts until you know what the fuel & ignition systems are up to. Always test each system to verify they are within operating specs. Then buy parts.
Don't toss parts at it. Is the vacuum gauge capable of reading fuel sys PSI? If not get a decent one...ahem...Ummm not hjunk
Do not purchase any parts until you know what the fuel & ignition systems are up to. Always test each system to verify they are within operating specs. Then buy parts.
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