Why all the hype about horse power and torque?

[396C-10]

So I find myself looking for the correct carburetor combination for my 67 C-10 with a bone stock built 396/402 engine. When I web search for the correct carburetor to run, all I get is horse power, 1/4 mile E/T times, pro street mods and what is hot on the market.
What about dependable, smooth, quiet and economical daily drivers? I don't care about horse power, I want it to start when I turn the key, I want it to run like a sewing machine, and I want it nice and quiet.
It is irritating to think we are all on the drag strip every weekend having pissing matches about who can tear up their trucks in the least amount of time.
Ending on this note, has anyone found a good carburetor combination for their big block sewing machine?

[truckster]

You're going to have a hard time finding anything better than a Quadrajet. There's a reason they went on millions of cars and trucks built by GM. They offer a great combination of available power with reasonable fuel economy and reliability.

If you're getting a remanufactured Quadrajet, I would recommend getting one with an electric choke.

[davepl]

Why are you even searching for performance parts on the Internet? Get what your truck was designed for.... A Quadrajet, like something with casting number 7040206. That's a Q-Jet for a 1970 402, 50-state emissions, automatic transmission.

Then have that carb gone through by someone GOOD like Cliff Ruggles.

Then bolt it on and tell your friends you have EFI if you like. My truck starts and runs like a new vehicle.

But that is all dependent on everything being there and operating properly, from the heat riser to the heat stove to the unblocked crossover and choke and pulloff and everything the factory did to make them operate smoothly.

Far too often people rip off all those parts, stuff a Holley HP double pumper on their vehicle, and then complain carbs suck.

Just assemble your truck like GM designed it an all will be well.

[fatbass]

Originally Posted by davepl

Why are you even searching for performance parts on the Internet? Get what your truck was designed for.... A Quadrajet, like something with casting number 7040206. That's a Q-Jet for a 1970 402, 50-state emissions, automatic transmission.

Then have that carb gone through by someone GOOD like Cliff Ruggles.

Then bolt it on and tell your friends you have EFI if you like. My truck starts and runs like a new vehicle.

But that is all dependent on everything being there and operating properly, from the heat riser to the heat stove to the unblocked crossover and choke and pulloff and everything the factory did to make them operate smoothly.

Far too often people rip off all those parts, stuff a Holley HP double pumper on their vehicle, and then complain carbs suck.

Just assemble your truck like GM designed it an all will be well.

This resonates. Q-jet done right all day.

[Lattimer]

All depends on what you want to do. Lots of very good options out there.

As mentioned, a properly rebuilt Qjet is a very good option, but you would want to have ALL of the factory components in place to make it work perfect.

Otherwise, there are several aftermarket carbs out there that work very nice. I'm running the StreetDemon 625 on my SBC, and I believe they recommend the Street Demon 750 for BBC applications: https://www.holley.com/products/fuel...mon/parts/1903

I've been impressed with the easy setup, smoothness, and easy starting I get with mine. It was inexpensive compared to some others, looks pretty good, but most importantly works well.

[truckster]

Originally Posted by Lattimer

As mentioned, a properly rebuilt Qjet is a very good option, but you would want to have ALL of the factory components in place to make it work perfect.

I'm not sure what you mean by all the factory components, but the Quadrajet works fine with aftermarket intakes, headers, removing smog equipment, HEI, etc.

[cla511]

I've gone to Q-jets on most all of my engines. I have them on stock 350s and 454s all the way to hot 400s and 427. They work very well. The electric chokes work great also. It's hard to find anything over 750cfm but most motors are over carbed anyway. Summit has a big list of them.

[davepl]

Originally Posted by truckster

I'm not sure what you mean by all the factory components, but the Quadrajet works fine with aftermarket intakes, headers, removing smog equipment, HEI, etc.

Depends on what you mean. One man's "works fine" is another mans "what a POS to drive, I have to use two feet and it stalls when cold and bogs in the winter" and so on.

GM didn't put all the other stuff on because someone dared them to lose money!

When I say "it drives fine", I really mean "Your mom, who drives a Camry, cold-started my truck in the winter and drove it and thought it ran really well".

Switching to an aftermarket intake usually means losing the heat crossover (though not always) which makes them ugly in the cold. Same with an open filter element and no heat stove, it's bog city.

Removing smog equipment usually just screws up the carb calibration without improving performance, so I never do that. I mean if my truck originally had an A.I.R. pump I wouldn't seek one out just to have it, but I sure wouldn't take one off to save 3 horsepower unless I was in Pro Stock. And the PCV is an important anti-wear device, so I wouldn't remove that. And that's about the entire extent of smog equipment on these.

[James the III]

Originally Posted by davepl

Depends on what you mean. One man's "works fine" is another mans "what a POS to drive, I have to use two feet and it stalls when cold and bogs in the winter" and so on.

GM didn't put all the other stuff on because someone dared them to lose money!

When I say "it drives fine", I really mean "Your mom, who drives a Camry, cold-started my truck in the winter and drove it and thought it ran really well".

Switching to an aftermarket intake usually means losing the heat crossover (though not always) which makes them ugly in the cold. Same with an open filter element and no heat stove, it's bog city.

Removing smog equipment usually just screws up the carb calibration without improving performance, so I never do that. I mean if my truck originally had an A.I.R. pump I wouldn't seek one out just to have it, but I sure wouldn't take one off to save 3 horsepower unless I was in Pro Stock. And the PCV is an important anti-wear device, so I wouldn't remove that. And that's about the entire extent of smog equipment on these.

I agree 100% BUT [and there is always a but)
Your mom and my mom who drives a camry most likely forgot what it was like with older vehicles, that you back then, started and waited a few minutes before popping it into gear.. Today they get in and go..

The removing the other factory equipment will cause cold start/run issues.. but that only matters if the vehicle gets started and run in the cold..
Most don't anymore.. so .. G.m. put the parts there for all year round use.. and it is great for that.. BUT.. you can use newer parts either g.m. or aftermarket and have the best of both worlds..
Sure if you use an air gap intake and try to jump in and drive it when it's 60* or lower out it's gonna not like it..
I've found that a block heater is better than a heat stove and a heat crossover in the intake.. but that isn't for everybody.. and no way the oem's would ask owners to plug in vehicle to warm it up to start it.. lol

Like everything it depends on how you plan on using the vehicle..

I was forced to drive my vehicle that was a far weather car one winter for a month.. with a carb with no choke.. no fun.. but I did take and put a 12v small rv heater in front of the dual snorkel air cleaner and blocked one side.
and would run the heater for the first 5 minutes of running and it did just fine cold.
Today.. I think I'd try to find the heaters that went under the carb's and tbi's in the 80's and install it into a 1/2 carb spacer.. if there was any chance of driving it when cold out.. as it makes the carb'd vehicle get in and drive.. better than a heat stove and crossover.. that and a j-qet with correctly set electric choke would be my choice..

[truckster]

Originally Posted by davepl

Depends on what you mean. One man's "works fine" is another mans "what a POS to drive, I have to use two feet and it stalls when cold and bogs in the winter" and so on.

When I say "works fine" I mean a Quadrajet properly tuned starts easily, runs trouble-free, and gives good economy and power. In other words, exactly as I would expect it to.

Originally Posted by davepl

GM didn't put all the other stuff on because someone dared them to lose money!

The cast iron manifolds are cheaper than aluminum, and that's why they were used when weight wasn't a primary consideration. Same with cast iron exhaust manifolds. AIR pumps were an early attempt to improve emissions. I don't think any of it was a dare to lose money.

Originally Posted by davepl

When I say "it drives fine", I really mean "Your mom, who drives a Camry, cold-started my truck in the winter and drove it and thought it ran really well".

Switching to an aftermarket intake usually means losing the heat crossover (though not always) which makes them ugly in the cold. Same with an open filter element and no heat stove, it's bog city.

A Quadrajet is no worse and may be better than other carburetors under these conditions if it's properly calibrated.

Originally Posted by davepl

Removing smog equipment usually just screws up the carb calibration without improving performance, so I never do that. I mean if my truck originally had an A.I.R. pump I wouldn't seek one out just to have it, but I sure wouldn't take one off to save 3 horsepower unless I was in Pro Stock. And the PCV is an important anti-wear device, so I wouldn't remove that. And that's about the entire extent of smog equipment on these.

A.I.R. pumps have absolutely nothing to do with carb calibration. That would only happen in a feedback loop situation, such as with the electronically-controlled Quadrajets introduced in 1982. A.I.R simply pumps fresh air into the exhaust manifold to help burn unburned hydrocarbons.

On the other hand, the PCV system is important on all engines, and there would be no reason to remove it when replacing a Quadrajet with another Quadrajet. All factory Quadrajet installations had PCV valves. But all you need to run a PCV system (aside from the PCV valve) is engine vacuum, which you can do with any carb.

So I'm still not seeing how a Quadrajet is in any way inferior to an aftermarket carburetor whether in a stock installation or in a modified engine. The original poster was asking about a replacement for his stock carburetor, and the Quadrajet is the best choice in my opinion.

And I agree with James III on the block heater. I'm putting two in the engine that's going in my Blazer (one will be a spare) because winters here are pretty cold and I like getting warm as fast as I can.

[Lattimer]

Originally Posted by truckster

I'm not sure what you mean by all the factory components, but the Quadrajet works fine with aftermarket intakes, headers, removing smog equipment, HEI, etc.

The ones I have dealt with in the past had cold weather issues if you didn't keep the heat stove functional, so swapping air cleaner or headers was a bit of an issue.

[James the III]

Originally Posted by Lattimer

The ones I have dealt with in the past had cold weather issues if you didn't keep the heat stove functional, so swapping air cleaner or headers was a bit of an issue.

I never understood the open air cleaner .
Sure if you have a cowl induction or a ram air set up..
but other wise you are just adding more hot air to the intake charge..

I've always added a 2nd snorkel and run hose/duct to in front of the heat exchanger..

No point of giving up some efficiency and power to look cool..

[special-K]

If you just want one of these trucks to run right, like the day it was new, put what came on it the day it was new...and decades later. I just fired up my '72 that has been sitting all winter, hadn't run in a few weeks. It has a properly rebuilt and operating Q-Jet with no choke rod. It started right up with depressing the pedal to set the choke. Ran pretty rough at first, like a plug was fouled or carbon tracks, having me think I'd have to do a little work before driving. But, as it warmed up it smoothed out nicely. I let it run a while, hopped in, revved it to cruising RPM and it sounded great, smooth as glass. Back on idle I tromp the pedal and it revs right up, no flat spot/hesitation/nada, just a snappy "REPPumm!", just like new, just like fuel injection. I was thinking how good life is when a carb works right. That has been my experience with carbs. My original 350 has bigger valve higher compression heads now and the carb that was set-up stock runs it like a Swiss clock

Originally Posted by James the III

I never understood the open air cleaner .
Sure if you have a cowl induction or a ram air set up..
but other wise you are just adding more hot air to the intake charge..

I've always added a 2nd snorkel and run hose/duct to in front of the heat exchanger..

No point of giving up some efficiency and power to look cool..

Until EFI, pretty much all vehicles ran on under hood temp air. We know cooler air is more dense and engines make more power with more air. That is the same reason an open element air filter truly makes more horsepower than a factory housing...single or dual. It's more than looks. There have been tests where they used the factory dual snorkel compared to the open element and the open element gave about a 15hp boost on an all stock engine with no other changes. The greater amount of warm air from an open element puts more air into the carb than less air that is more dense from a snorkle housing.

[franken]

Since the OP, while yelling a lot, never grasped what HP and torque are.
Torque is measured. HP is calculated. Who tells the truth?

Doubt?
Torque has units, HP has none.

[1972RedNeck]

Originally Posted by franken

Torque has units, HP has none.

This is almost as good what brand of oil is best.

When it comes to horsepower and torque measurements, one is no good without the other.

[i82much]

Originally Posted by 1972RedNeck

This is almost as good what brand of oil is best.

When it comes to horsepower and torque measurements, one is no good without the other.

Technically, power tells us the rate at which work is done. As a consequence, we can calculate the acceleration of a given load knowing only the horsepower without knowing the torque. It does not matter whether we have 200 ft lbs of torque at 1000 RPM or 100 ft lbs of torque at 200 RPM, we simply change the gear ratio and the load accelerates at the same rate.

Practically speaking, knowing both the peak power and the peak torque and the respective RPMs at which they occur gives us a good bit of insight into how much average power the engine makes across a range of engine speeds. This sometimes results in some real confusion over what the word "torque" really means.

If we could have an infinitely variable CVT, we could always accelerate a load fastest by using the engine with the highest peak horsepower we could find and running that engine at that RPM. Engine torque would quite literally be irrelevant. Since we can't do that in practice, we manipulate gearing the best we can to suit the output characteristics of the engine we have, and it is very helpful to have an engine that produces a broad power curve which, when we rate the engine for peak power and torque, will show good low RPM torque numbers and good high RPM power numbers.

[my56chevytruck]

Originally Posted by 396C-10

So I find myself looking for the correct carburetor combination for my 67 C-10 with a bone stock built 396/402 engine. When I web search for the correct carburetor to run, all I get is horse power, 1/4 mile E/T times, pro street mods and what is hot on the market.
What about dependable, smooth, quiet and economical daily drivers? I don't care about horse power, I want it to start when I turn the key, I want it to run like a sewing machine, and I want it nice and quiet.
It is irritating to think we are all on the drag strip every weekend having pissing matches about who can tear up their trucks in the least amount of time.
Ending on this note, has anyone found a good carburetor combination for their big block sewing machine?

I have run Edelbrocks and Holleys, no experience with Qjets, so I can only say I'm running an Edelbrock 600 on my BBC454 in my 56 truck. Since mine didn't have a manual fuel pump, I'm using a small electric pump and she starts right up, everytime. my .02 worth.

[El Dorado Jim]

Originally Posted by my56chevytruck

I have run Edelbrocks and Holleys, no experience with Qjets, so I can only say I'm running an Edelbrock 600 on my BBC454 in my 56 truck. Since mine didn't have a manual fuel pump, I'm using a small electric pump and she starts right up, everytime. my .02 worth.

I have the edelbrock 600, model 1406 with electric choke on several of my vehicles, runs great on my wife's 454 in her suburban...edelbrocks are so easy to rebuild also,unlike quadrajets...i don't like holley carbs...had no luck with them...you can order one thru summit for about $325.00

[dennislbrooks]

My reasoning --- If it has a spread bore manifold, put a correct quadrajet on it. The timing, choke, and idle can usually be adjusted for a reasonable street setup. I run a quadrajet on my 70 442 -electric choke- and my 67 K10 bbc -divorced choke. No they are not daily drivers but I want them to act right when I start, drive, and stop. I do not find quadrajets hard to rebuild.

[geezer#99]

What!!
No luv for the rochestor 2 bbl on your 396!
Clean, simple, runs like a top all the time!

[truckster]

Originally Posted by geezer#99

What!!
No luv for the rochestor 2 bbl on your 396!
Clean, simple, runs like a top all the time!

I wasn't aware what carb was original equipment, but if the OP is happy with it, I'd have it refurbished and run with it. Why make life more complicated?

[71CHEVYSHORTBED402]

I recently had an Edlebrock installed on the 72 402. It runs great, about a $400 carb. Word I got was for your basic carbs I suppose, Edlebrock for fuel efficiency, Holley gets you more speed. Another guy says BS, they should be about the same.

[James the III]

Originally Posted by 71CHEVYSHORTBED402

I recently had an Edlebrock installed on the 72 402. It runs great, about a $400 carb. Word I got was for your basic carbs I suppose, Edlebrock for fuel efficiency, Holley gets you more speed. Another guy says BS, they should be about the same.

The difference is the edel is a vacuum 2nd carb and only mildly tune able.

The holley either in vacuum 2nd (street) or double pumper (street/strip)
is you can tune everything on it..

The q-jet is in the same boat as the edel.. as far as user tuning but has tiny primary bores for crisp throttle response and flipp'n huge 2nd's..
and when tuned correctly will run as good as the holley . most times better..

Holley claim to fame is K.I.S.S. and user changeable parts to tune it to your app.

Think of it this way, your shower head the q jet is the fine mist, the holley is the thick streams..
holley dumps the fuel, the edel and q-jet meter it..

[71CHEVYSHORTBED402]

Originally Posted by James the III

The difference is the edel is a vacuum 2nd carb and only mildly tune able.

The holley either in vacuum 2nd (street) or double pumper (street/strip)
is you can tune everything on it..

The q-jet is in the same boat as the edel.. as far as user tuning but has tiny primary bores for crisp throttle response and flipp'n huge 2nd's..
and when tuned correctly will run as good as the holley . most times better..

Holley claim to fame is K.I.S.S. and user changeable parts to tune it to your app.

Think of it this way, your shower head the q jet is the fine mist, the holley is the thick streams..
holley dumps the fuel, the edel and q-jet meter it..

I feel I definitely lost power with the Edelbrock. It had a perfectly good Rochester. I still have it. I had never serviced a carb. before and needed a choke very soon. The mechanic talked me into the Edelbrock. He said he's not a fan of Rochester, but more than that I bet he just didn't want to deal with it. Since then I've discovered you can add an electric choke onto a Rochester. I don't know if that would require the heat stove & pipe, but I'm guessing not.

[truckster]

Originally Posted by 71CHEVYSHORTBED402

I feel I definitely lost power with the Edelbrock. It had a perfectly good Rochester. I still have it. I had never serviced a carb. before and needed a choke very soon. The mechanic talked me into the Edelbrock. He said he's not a fan of Rochester, but more than that I bet he just didn't want to deal with it. Since then I've discovered you can add an electric choke onto a Rochester. I don't know if that would require the heat stove & pipe, but I'm guessing not.

You're correct. All the electric choke requires is 12 volts.