Edelbrock 1406 conversion

[VickyBlue]

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This write up applies to 1956 stock intake and motor. After my last incident with vapor lock and a leaking Rochester stock carb, I had two options: rebuilt it and hope for the best or replace it. My car is not 100% stock. For the most part it is but it not a 100 points car. My main concern is drivability and peace of mind, so this might not apply to you. Don't condemn me or criticize this conversion as it is used as information only.
Parts used:
New Edelbrock 1406 600cfm electrick choke carburetor from Jegs
TD trans dapt 2064 from Jegs (kit comes with studs)
Stock fuel line and vacuum lines were removed. Unhooked the throttle arm and return spring, then it was a matter of removing the 4 nuts from the carb studs. Carb came out easy. The TD adapter is the closest match I could find. Spent hours on the phone with parts people and this was going to work but it needed a slight mod. Once the adapter stud holes were drilled (they come pre marked but not pre drilled) it sat on the stock intake but the stock intake studs were protruding and the new carb would not "sit" flush with the adapter. The adapter was counter-sunk and one inch long 5/8 counter-sunk screws were used after the 56 year old stock studs were heated and removed.
The hot air pre-heat holes (air from the right manifold is used as carb heat during cold starts, but it also heats up the stock carburetor after it is warm and as a result it contributes to vapor lock.) I drilled and tapped the pre heat holes for 5/16 brass plugs. I came to that decision after I saw that the adapter was leaving a gap between the intake and the adapter itself. Even with the gasket air would leak. So opted to plug them. Then the intake was washed in the parts washer, set the adapter on the intake, screw in the 4 counter sink screws using red loctite. The adapter is tappered and the narrow holes go down towards the intake, the larger holes up towards the carburetor base.
Insert the carb hold down bolts from underneath the adapter before you screw the adapter on the intake. Once the adapter is on the intake simply put on the carburetor supplied gasket and bolt the carb on the adapter. I used new manifold gaskets and this is where I am as I had to go to work. But the Edelbrock is on and from what I was told by Jegs it can handle up to 6 to 8 psi at the inlet, which is what my electric pump maxes out. I will get it running over the weekend and will post an update then.

[wildcat465]

Cool. Great info. Now to get your original air cleaner housing to fit the new carb.

[NTX5467]

Thanks for the pictures. Good that you plugged the "heat track" holes in the intake! That item was there to help decrease carb icing in colder weather . . . which affected some cars more than others, with the brand and mix of gasoline used being something of a contributing factor.

Although the particular E-AFB is calibrated for an engine of approximately your CID, for the best results, it might take some "playing" with the metering rods and jets to get it better fine-tuned to your engine. If there's a speed shop with a chassis dyno in your area, they might rent you some time to do some air/fuel ratio checks at "road load" to see where things end up. With that knowledge, then you can determine your next plan of action.

The "ideal" air/fuel ratio for non-ethanol-extended fuels (the "as designed" fuel for when the car was new) is 14.8 to 1. With E10, this drops to 14.2 for best results. Once the rpm increases to where the "main system" is operating, the air/fuel ratio needle should approach these figures . . . even with the trans in Park and "no load". Idle a/f ratio should be something like 13.5 or leaner. I like the "lean-best-idle" method where you maximize the idle mixture for the correct hot base idle speed, then lean the mixture to achieve a 20rpm drop (each idle mixture screw), then adjust the idle mixture screws to just get back the 20rpm loss . . . or you can leave it at the lower speed and tweak the idle speed screw a little bit.

"Back when the car was new . . . " the "best idle" method would have involved using a vacuum gauge to seek the highest intake manifold vacuum level and not have the engine speed high enough to get a "jerk" when the trans was put into gear. The idle-speed-drop method is a different way of doing it, plus probably a little more precise in nature.

Keep us posted on how things work out, please! PLUS how you adapt the starter switch and such to the carb!

Enjoy!
NTX5467

[NTX5467]

Cool. Great info. Now to get your original air cleaner housing to fit the new carb.

That's another adapter?

OR is it "chrome open element" or "salvage yard OEM" time? Dual snorkles with dryer tubing going forward for "cooler air" . . . hehe, that "1956 NASCAR trick". (Gotta have some sort of interesting name for it when the cruise spectators ask)


NTX5467

[buick5563]

VB,
Are you gonna use an electric wiper?

[buick5563]

That's another adapter?

OR is it "chrome open element" or "salvage yard OEM" time? Dual snorkles with dryer tubing going forward for "cooler air" . . . hehe, that "1956 NASCAR trick". (Gotta have some sort of interesting name for it when the cruise spectators ask)


NTX5467

Or use the finned valve covers and the O'Brien Truckers air cleaner (the best finned one available, hands down)
Air Cleaner 14" Round Finned Air Cleaners - O'Brien Truckers

[VickyBlue]

VB,
Are you gonna use an electric wiper?

I am planning on moving to Houston at some point in time. Commuting to IAH from Fresno is no fun. To get the TX DOT sticker I need wipers and the vacuum motor leaks... So yes, it's on the list but not a priority right now.

Af far as the air cleaner goes, I know I will have clearance issues I really want to use the stock cleaner but it will have to wait untill I get home. The gas pedal start feature was not present in the car probably removed and a push start button was installed under the dash.

[VickyBlue]

With the new electric pump on the old Rochester was leaking gas from every corner, every gasket was soaked and fuel dripping down the manifold... I knew if I was to start the motor it would have to be on the new Edelbrock. New gaskets came in from Rockauto and last Saturday the intake went back on to the engine. Hooked up the electric choke, adjusted the linkage and that was pretty much it as far as installation. I still had to do the tune up, had all my parts, so I started by replacing the wires one by one, measure, cut, crimp and install. When all the wires were on, plugs were already installed, I put it the igniter kit using the stock coil. She would turn over but no start. But no fuel leaks either... Put the new coil in still no start. Then I took the igniter kit out and put a new set of points with a new condenser, gapped them and tried again. Still no start. By that time it was almost 5pm and I had been in the garage since 9 am with a couple of trips to the store for some vacuum line fittings. I took some pictures of what I had done so far, some video of the fuel flow I was getting (I thought it was too much, pump is rated 30 GPH at 5-9PSI) and emailed it to Willie. He replied almost right away and asked me to call him. I did and told me to look for spark amongst other things. Sunday morning I got up at 330 am as this was bugging me... I had to find out what was going on. I made some strong coffee and read about the ignition system in the shop manual. Took a lot of notes and it basically came down to this: primary and secondary, components, values and limits. I was getting 12.5V on the battery, both resistor terminals, both coil terminals. Coil was wired backwards, but it was working. I read a coil can fire both ways, but it is recommended to be wired POS to POS and NEG to NEG. I did that, then saw the resistor was hot all the time, so hot I couldn't touch it. Coil checked out and it was with in specs on both the primary and secondary windings. Then I looked for spark at the cap, I hooked up a spark plug, but I was getting none. I removed the wires one by one and looked for resistance values by the ft length, they were with in specs. I used my test light on the NEG of the cool and POS on the battery light was on with key on and off... I cranked the starter the light did not flicker... Remember, this is all new to me. I figured the points were the issue as they were not opening. I had my 7 year old hit the starter ( I was too tired to drop everything, go to the store and get a remote start button) and saw the points open and close... I took everything out again as Willie had said to make sure they were clean. I was going to spray some brake cleaner spray, when I saw this: the wire that goes from the NEG stud inside the distributor to the points and from there to the condenser, the wire I had made the day before using a U shaped terminal instead of a round one, as I was tightening the little stud nut, it "slipped" and grounded itself to the bottom of the distributor... Points grounded... I made a new one using a round terminal, till I get some copper ones with flex wire. Did the same test again with my test light and light was flickering... Put everything back together and tried one more time. She fired right up! High idle for 2 min then dropped. I checked for leaks and they were none. Idle mixture screws were set properly from the factory as even I adjusted them they ended up where they were originally. Warmed up the engine, dropped the idle to 300-350 RPM and checked the timing. The mark was 4inches south of the 5 degree mark... The hardest was to loosen the distributor clamp bolt to spin it, as the motor was hot... I am sure there is a special tool for that too... I spun the distributor clockwise and saw the pulley mark moving up, till it hit the 5 degree mark. Tighten the bolt and that was it. Kragen sells a generic carb adapter/spacer kit it sell for $9.99 here, I am not home and don't have the part number but it is plastic, two adapters two spacers. I used the one inch spacer and trimmed 1/4 or so. Used the carb provided gasket, spacer then rolled the stock bottom filter basket lip inwards so it wouldn't hit the carb inlet. Used the stock center stud as the new one was short. Put the lid back on and measured. It showed 2/16 taller, which in my book is almost the same height. I spun the nut on and put a piece of paper with grease on it. Closed the hood then opened it paper was still on the air filter...'Put some gas and took her for a spin... Right out of the box the 1406 is a plug and play. Acceleration was so smooth, no hick ups, no low points, smoothest idle as it can be, my vacuum advance is not working as when I sucked into the line there was no vacuum, but even with this she still runs unbelievably well... Starts right up, half a turn and she is awake, by the seat of my pants she picked up some ponies, there is no bogging down when I get on the gas, now braking is the issue as I have all new brake shoes and 50-60 mph come so quick...
I am happy.... I had to go back to work but this was such a cool experience for me, I learned a lot along the way, I made a cool new buddy and she runs so well, better than I ever thought she would. Sure there was some Nigerian engineering in the past but that's all taken care off now. Still have a small radiator leak, put in an expansion tank and some bar's leak. I do plan on taking care of it the right way but for now I just want to drive her...
Thanks Willie...

[WWS]

I did the same conversion on my 56. For the aircleaner, I bought one of the new reproduction "batwing" style aircleaners. Fit the new E-brock perfectly and looked period correct. It also cleared the aluminum valve covers nicely.

[old-tank]

Looks like for less than $400 you can have a dependable ride. Next you need to report on the mpg after all is sorted. There may be one of these in my future, since it seems you and others report better tolerance to ethanol.
Willie

[NTX5467]

GREAT "BLOW-BY-BLOW" COMMENTARIES! GREAT information and pictures, too! Thanks for providing all of this information, too!

Now that we know the E-brock AFB (or even AVS) will "bolt on" a Nailhead, that increases the possibilities for carb upgrades. Including the new "Street Demon" carb.

Please keep us posted!

NTX5467

[VickyBlue]

30 mile ride today. I got her up to 80 mph... she was asking for more...

[NTX5467]

Nice BUICK!


NTX5467

[VickyBlue]

An update and a question. Willie was right: my vacuum advance was shot. Bob's sent me a new one (exhange program) I think after everything total cost was $65
Just hit 300 miles on the odometer: 21 gallons total, city driving. Knock on wood, not even a single hick up... Got some cool 56 yellow/black plates on EBay for a steal, now waiting for the new registration.
Here is my question: what is the difference between these two brake boosters? Why such a huge price difference and which way should I go? Brakes work fine but at some point I would like to pull the booster and rebuilt it.

Power Brake Exchange 5455060 Power Brake Booster | eBay

1956 BUICK DELCO REBUILT BRAKE BOOSTER TREADLEVAC TREADLE VAC RARE | eBay

[MrEarl]

The Power Brake Exchange unit is the actural cost with you providing the core up front. The Arizona dealer returns a $250 core fee after you pay the full price of 600 bucks then send your core in exchange. Not only is Power Brake Exchange $100 cheaper, they are in my opinion the best and most dependable rebuilders out there. I have had 2 units rebuilt by them and the do a quick turn around and the units are still functioning fine after several years. Many brake booster restoration shops actually send their customers units to them. I know for a fact Whitepost Restorations use to.

Thanks for posting all the great carb info, made for a good read.

[VickyBlue]

http://

We both thank you Mr Earl... Sounds like I found a winter project

[old-tank]

Over 14 mpg in city driving is much better than most. Mpg on a road trip would be interesting (after CA gas prices go down).
Willie

[VickyBlue]

$4.99 for supreme... This guy has got to go...