So, as I get different projects researched as I get ready to bring my 68 back into poncho powered reality, there is one thing I am still scratching my head on. How is the choke assembled on the intake? I bought an edelbrock intake, and there is a removable plate for the choke location. All of the chokes I've seen are just the thermostatic spring, but nothing there to block off exhaust from coming out of the hole. I have searched the interwebs for a couple weeks and haven't found anything that gives me a definite answer. I understand the choke rod and the connection to the carb. I see in later years that they went to the tube type choke heater, and then to electric. Is it even worth trying to figure this out or just convert to a newer choke setup?
John
To err is human. To really foul things up takes a computer.
That plate on the E intake is more than likely for an EGR valve. I don't believe any of them were setup for a choke so you're probably looking at an elect choke retro fit.
I have an old Edelbock 1901 on top of an E-brock manifold on my 455. Edelbrock sells a heat activated, spring controlled choke setup for those manifolds. I believe it is listed as a Chevy choke system for the E-brock manifolds.
The choke housing mounts on top of the metal plate you talked about in your original message. I had to "adapt" (bend) the included choke activation level to get my 1901 choke system to function properly.
2012 Mustang Boss 302 #1918, Competition Orange. FGF replacement 2006 Mustang V6 Pony, Vista Blue. Factory ordered. 2019 BMW X3 (Titled to the wife, but I'm always driving it for her. So I'm claiming it) Old projects, gone but not forgotten: 1967 FB 400, original CA car. After 22 years of work, trashed by the guy who was supposed to paint it. I had to sell it. 1980 Turbo Trans Am 1970 Mustang fastback, 351C 4Bbl, auto 1988 Mustang GT, 5 speed 1983 F-150 4x4, built 302 1994 Chevy K2500 HD 4x4, 454 TBI
Would your recommendation be different if I had an original intake manifold?
As I read up, I see conversation about moving to electric choke allows the exhaust crossover to be blocked or plugged. Anyone with experience with this? What were your results?
John
To err is human. To really foul things up takes a computer.
If I was using my original 400 manifold (my original motor is sitting on a stand) , I would stick with the OEM heat tube choke.
2012 Mustang Boss 302 #1918, Competition Orange. FGF replacement 2006 Mustang V6 Pony, Vista Blue. Factory ordered. 2019 BMW X3 (Titled to the wife, but I'm always driving it for her. So I'm claiming it) Old projects, gone but not forgotten: 1967 FB 400, original CA car. After 22 years of work, trashed by the guy who was supposed to paint it. I had to sell it. 1980 Turbo Trans Am 1970 Mustang fastback, 351C 4Bbl, auto 1988 Mustang GT, 5 speed 1983 F-150 4x4, built 302 1994 Chevy K2500 HD 4x4, 454 TBI
Would your recommendation be different if I had an original intake manifold?
As I read up, I see conversation about moving to electric choke allows the exhaust crossover to be blocked or plugged. Anyone with experience with this? What were your results?
I'd switch to a carb mounted elec choke, regardess of the manifold. Only reason to use an original type divorced choke is if you want it to LOOK original. Most say that a GOOD electric choke is much better.
If you want the exhaust crossover to heat up the intake and carb, for cold weather operation, you must leave the exhaust crossovers open.
I live in North Louisiana, where it doesn't get real cold very often. So, a choke & exhaust crossover are not really "must have" items here. And I always blocked 'em off on all my race cars. Also removed the choke plate, for slightly more air flow.
But, if you remove the choke, you may wanna rig up an elec idle stop solenoid. These were used on AC cars, to keep the idle speed up, when the AC compressor kicks in. With a toggle switch, you could keep the engine up to idle speed, while it warms up, then flip it off, once the carb warms up enuff to idle properly without the idle stop.
Thanks everyone for the different perspectives. I'm not really happy with drilling on the 68' quadrajet to do a choke conversion. I live a just south of Corpus Christi, Texas and I believe I might just go with the blocked crossover and block open the choke. That gives me a couple options when I get it up and running.
John
To err is human. To really foul things up takes a computer.
49 years no real problem starting with my factory choke. It has always taken 3-4 accelerator pumps and a few seconds cranking when cold even after its long winter nap. Have to let it run a couple minutes to warm before I can knock down the high idle and put it in gear but I have never driven any car until it has had a couple minutes to warm up.
If I could get my hands on an 068 Intake, I'd be willing to try to try the OEM choke. Looks like it's pretty simple once it is adjusted.
They're not that rare. You have a choice of 2. Late '68 models used the same intake as '69 models. And, unless you want numbers matching, the '70 intakes are almost identical.
Hey John, I have a 68 manifold with the choke thermostat spring assembly still on it. Looks like the one in Gus's photo. Agree with him.... Stock...Stock...Stock. Those Poncho engineers knew what they were doing!!
I'm gonna have to wait until tax season before I can get back to parts buying. Holidays get the rest of my budget. If you still have it by then, I'll hit you up.
John
To err is human. To really foul things up takes a computer.
"...Those Poncho engineers knew what they were doing!! "
Yeah, like not offering a 12-bolt rear end in any 1st gen Birds or any '69 & older GTO, and using plastic teeth on the cam sprocket, to run quieter, and using cast rods in RAIV & 455HO engines, and the thin main webs of the "557" blocks, and the wimpy parts used in most of the 265/301 engines.
Yeah, those Pontiac engineers really came up with some brilliant ideas.
But, to be fair, I assume that some of those deals were the result of cost cutting decisions made by corp execs.
"But, to be fair, I assume that some of those deals were the result of cost cutting decisions made by corp execs.
If it weren't for hundreds of those cost-cutting ideas, there probably would not have been any Firebirds on the road because nobody could have afforded them. Unfortunately, some may not have worked out as well as others.
"But, to be fair, I assume that some of those deals were the result of cost cutting decisions made by corp execs.
If it weren't for hundreds of those cost-cutting ideas, there probably would not have been any Firebirds on the road because nobody could have afforded them. Unfortunately, some may not have worked out as well as others.
Yeah, that may be true for some things. But how much extra would it have cost to use a iron cam sprocket. In fact, the plastic tooth sprocket may have cost more.
And, how about the 12-bolt rear. I think every big block Chevelle thru '1970, came with a 12-bolt. And lots of those cars sold for less than $3000. So, how much extra could that option have cost ?
How about forged rods ? They could have easily made some decent forged rods, for the high performance engines. I've read that the '58-'62 forged rods would have been decent, with the proper hardening process. They proved that making forged rods was not a problem, when they came up with the SD455 rods. If they'd already been using forged rods in the high performance engines, they would not have needed to make special rods for the SD455.
And I wonder exactly how much was saved by removing the material from the "557" blocks ? They still had the molds for the good 481988 blocks. They proved that, with the XX 481988 blocks used in the '78-'79 W72 engines. How much would it have added to the cost of a Firebird, to have continued using the 481988 blocks ? Instead, they paid the engineers to design a weaker block, then had to build the molds & whatever else was necessary, to cast the 557's. And, they did the same thing to the 500810 350 blocks.
They could have built a stronger 301 block. They proved that when they came out with the 301T blocks. Also, made the 301T cranks a bit stronger. Would not have cost a whole lot more to have designed the 301 cranks even stronger than the 301T cranks, to begin with. Nothing wrong with a 301 size engine. I think the 302 SBC proved that, along with 302 Fords. There were also millions of 305 SBC engines produced. But, none of those used such weak parts as the 301 Pontiacs. If the blocks & cranks had been strong enuff, there would have been lots of performance parts made for 'em. But, since most could not keep 'em together, VERY few performance parts were made. No aftermarket intakes at all.
Plans were made to continue the 301 in the '82 Birds. But. probably because of the weak parts, there was little to no interest in continuing the 301. The 301 had lots of potential, but needed a stronger bottom end, and decent heads. It just didn't happen.
All good thoughts and comments, but the subject was the 68 intake with the quadrajet/choke.To this day, still a dependable setup
Yeah, there's no choke, a carb mounted elec choke, an intake mounted elec choke, and a stock type divorced choke. Not much left to do but choose one, & try it.
I am fascinated by these cars, and even the older ones. The simplicity of them and learning to listen to the machines to hear what they want. It reminds me of my time in the navy listening to the propulsion equipment. Modern cars take less thought to operate. Even though my car will never be numbers matching, I like tinkering with the points distributor, the carb, and other systems. Someday, I may change over to more modern components but for now I'm having fun with it.
John
To err is human. To really foul things up takes a computer.
New twist in my research, has to do with stock AC system that I just acquired. It looks like the Edelbrock intake doesn't allow the upper compressor bracket either. So now I'm leaning heavily toward the OEM intake so that I can get the choke and AC issues cleared up in the easiest way.
John
To err is human. To really foul things up takes a computer.