small block buick - carburetors, radiators, suggestions?

[AuroraGirl]

I made a mistake here. Your carb has a hot air choke so it’s an M4MC. I saw the black choke heater and looked no further at the steel tube going into it. It’s more like your thermostatic mechanism for an electric choke being integral to the carb rather than being divorced and sitting on the intake. I would actually prefer this over electric and divorced myself, but you can convert to electric if you so desire. They sell the kit but you’d be wise to wire it through an oil pressure safety switch so the choke doesn’t run away if you leave the key on for a little before starting and screw you up on a cold day. I’d also do it on a fused circuit, but if you do it to just a keyed hot, put an inline fuse in the circuit for extra safety.

Bruce gave a lot of good info. The main thing I’ll add is you car should have the emissions sticker which tells you what all accessories are supposed to be coming off the carb. Then you can discriminate between what you want to keep and what you want to delete. If it’s gone, Autozone has the diagrams. Yours should just be federal emissions for a ‘77 Buick 350.

I’d expect a turnaround of 5-10 business days. I think I waited a week for mine to get done so it was pretty quick. These boutique carb builders should stock a few BOP Q-Jets, but you already have the core so I wouldn’t pay more than you have to.

For the rad, I like the idea of the Champion all aluminum or saving the OEM one if it’s the brass/steel unit. If you have access to a good radiator shop, you can have it cored out and any leaks soldered. That service around my area is 50-100. Plastic tanked aftermarket rads are throwaway and replace after they bust IMO, but I don’t care for plastic very much. If you can see the leak, and it’s just one or two tubes where they meet the tanks, it’s no big deal to fix it and keep rolling.

The radiator had washer fluid in top of the rad. I cant see the leak but it comes out the top, because it leaks down about an inch on its own.

Why would you prefer the hot-air choke to a electric? Im curious. what does it do for you

 

[1985c20]

The radiator had washer fluid in top of the rad. I cant see the leak but it comes out the top, because it leaks down about an inch on its own.

Why would you prefer the hot-air choke to a electric? Im curious. what does it do for you

Does the radiator have an overflow bottle hooked to it? If not when the car warms up the coolant will expand and push past the cap then when it cools the radiator won’t be completely full anymore.

 

[Vbb199]

That's quite a collection of cars.

I need to take a trip and get those pesky poncho motors off your hands.

 

[1987 GMC Jimmy]

The radiator had washer fluid in top of the rad. I cant see the leak but it comes out the top, because it leaks down about an inch on its own.

Why would you prefer the hot-air choke to a electric? Im curious. what does it do for you

It’s a purely mechanical circuit rather than an electro-mechanical one so it’s rodent proof. I’ve had to replace the choke heater pigtail because of them, and I’d rather mitigate stuff like that in the future. Plus, you don’t have to worry with the aforementioned safety/usability add ons because there’s no hot air with the engine running. There is power, though.

Don’t get me wrong, I like my electric choke, it’s served me well, but I hate rats and mice with a passion and anything that I don’t have to fix because of them is a winner in my book. I had a couple years where they were constantly tearing up my vehicles. I fight them pretty hard now so they all end up dead till new ones come along.

 

[AuroraGirl]

Does the radiator have an overflow bottle hooked to it? If not when the car warms up the coolant will expand and push past the cap then when it cools the radiator won’t be completely full anymore.

yes it is hooked up. it pulls from it, too,and expands. but as soon as car has no flow of coolant, it starts hissing and spraying out 15 or whatever psi from the hole.

It’s a purely mechanical circuit rather than an electro-mechanical one so it’s rodent proof. I’ve had to replace the choke heater pigtail because of them, and I’d rather mitigate stuff like that in the future. Plus, you don’t have to worry with the aforementioned safety/usability add ons because there’s no hot air with the engine running. There is power, though.

Don’t get me wrong, I like my electric choke, it’s served me well, but I hate rats and mice with a passion and anything that I don’t have to fix because of them is a winner in my book. I had a couple years where they were constantly tearing up my vehicles. I fight them pretty hard now so they all end up dead till new ones come along.

you say choke doesnt have hot air when running.. what is making hot air im confused. And choke heater? What does my carb have you think and how does it function? And I hate mice. I have a graveyard of them from when I dumped a bucket of poison blocks through my shed, and there are only 2 left after 3 weeks. Ive seen a lot of half alive and necrotic tissued mice dying all over. Seen one keel in front of me. Its kind of beautiful, in a sick kind of way.

That's quite a collection of cars.

I need to take a trip and get those pesky poncho motors off your hands.

poncho motors?

 

[Vbb199]

yes it is hooked up. it pulls from it, too,and expands. but as soon as car has no flow of coolant, it starts hissing and spraying out 15 or whatever psi from the hole.



you say choke doesnt have hot air when running.. what is making hot air im confused. And choke heater? What does my carb have you think and how does it function? And I hate mice. I have a graveyard of them from when I dumped a bucket of poison blocks through my shed, and there are only 2 left after 3 weeks. Ive seen a lot of half alive and necrotic tissued mice dying all over. Seen one keel in front of me. Its kind of beautiful, in a sick kind of way.


poncho motors?

Pontiac Motors

 

[CorvairGeek]

The 'hot air' comes from the exhaust crossover port inside the intake manifold. The heat from the exhaust warms the choke mechanism / tube, just like the electric heater does on the electric version. Oldsmobile used it clear to the end of production on their V8 Quadrajets in the 1990 model year.

 

[1987 GMC Jimmy]

^^^ What he said. I was saying that there’s no hot air with the engine off. Without the safety mechanisms of the oil pressure switch and a fused circuit, there’s power to the electric choke with the key on. If power is interrupted, you have no choke. If power isn’t regulated, your choke can open prematurely, and that’s useless to you when it’s 10* out. The safety mechanism of the hot air choke is the engine cannot make hot air if it’s not running. The choke heater is the bimetallic thermostat under the black plastic piece. In your case, you pipe in the hot air, it moves, and pulls the choke open. It’s dead simple, no frills. The electric choke is fine 99.9% of the time, but if you can simply one thing here and there, it mitigates the possibility of encountering problems down the road, and those individual things add up. The TLDR is I would keep the BOP Q-Jet with the hot air choke, but like you said at the beginning, the Quadrajet lovers would say their piece, and I’m unabashedly biased.

And yeah, I’ve been doing a combo of mothballs in the engine compartment, Irish Spring soap in the cab, and Ramik mini bars for them to dine on. Mice and rats tear those things up, and like you said, they stumble around like zombies and keel over. The soap is the only thing I’ve found that can kill the smell of necrotized rodent. I’ve learned this after forgetting about glue traps and coming back to putrified mouse.

I’m looking at your car list here, and I’ll bet that Grand Am is a babe. You sure have a lot of them.

 

[AuroraGirl]

Pontiac Motors

Its a 400 from a long gone era of barely any smog but also no power and ran-when-parked

^^^ What he said. I was saying that there’s no hot air with the engine off. Without the safety mechanisms of the oil pressure switch and a fused circuit, there’s power to the electric choke with the key on. If power is interrupted, you have no choke. If power isn’t regulated, your choke can open prematurely, and that’s useless to you when it’s 10* out. The safety mechanism of the hot air choke is the engine cannot make hot air if it’s not running. The choke heater is the bimetallic thermostat under the black plastic piece. In your case, you pipe in the hot air, it moves, and pulls the choke open. It’s dead simple, no frills. The electric choke is fine 99.9% of the time, but if you can simply one thing here and there, it mitigates the possibility of encountering problems down the road, and those individual things add up. The TLDR is I would keep the BOP Q-Jet with the hot air choke, but like you said at the beginning, the Quadrajet lovers would say their piece, and I’m unabashedly biased.

And yeah, I’ve been doing a combo of mothballs in the engine compartment, Irish Spring soap in the cab, and Ramik mini bars for them to dine on. Mice and rats tear those things up, and like you said, they stumble around like zombies and keel over. The soap is the only thing I’ve found that can kill the smell of necrotized rodent. I’ve learned this after forgetting about glue traps and coming back to putrified mouse.

I’m looking at your car list here, and I’ll bet that Grand Am is a babe. You sure have a lot of them.

i understand ya now. i accept your logic on the choke, the system has less-to-fail because it relies on simple thermodynamics rather than a system that uses things in the likes of Ohms law

 

[1987 GMC Jimmy]

Whoomp, there it is, as the kids say.

 

[Ricko1966]

Oh im not gonna rebuild it myself. Id do an edelbrock maybe but not that. Ive comfortably done 2 small engine ones, and that was dicey. The info was helpful tho, thanks. And this is on a 1977 buick sedan. small block buick not chevy

What have you got to lose it already doesn't work right.If that carb is original for your car a rebuild and a few adjustments and all good, no getting, no swapping power valves just bolt it on and go.Qjets aren't that hard to rebuild.You can do it.I bought giggles book I wasn't impressed, but that may be because already had 30+ years of expierience.Its' probably great for most people.Look for a qjet teardown video on you tube.Im sure somebody's made one.Qjets are counter intuitive as to they come apart.But great carbs. Carbjunkies is where I get my kits