EFI or Carb

[618 Syndicate]

And they were 1 BBL TbIs too.

Made like 200 hp...

 

[PlayingWithTBI]

Made like 200 hp...

Yeah they did with the long runners. It was a pretty good design IMO

 

[Supercharged111]

No such animal...

They have one in the Corvette Museum.

1983 Corvette Specs – National Corvette Museum

www.corvettemuseum.org

Yes I trolled, it too had the Crossfire 350.

 

[618 Syndicate]

Yeah they did with the long runners. It was a pretty good design IMO

From what I read it was a modern take on a crossram intake.

 

[618 Syndicate]

They have one in the Corvette Museum.

1983 Corvette Specs – National Corvette Museum

www.corvettemuseum.org

Yes I trolled, it too had the Crossfire 350.

Not just one, they have the only one in the Vette museum!
No such animal....in the wild!

 

[454cid]

Yes sir. 82 and 84 Vettes, and 82, 83, and 84 Camaros and Firebirds.

82? I didn't realize the C3 got it.

 

[618 Syndicate]

82? I didn't realize the C3 got it.

Yep. It evidently bridged the gap.

 

[Schurkey]

www.chevelles.com/threads/adjusting-automatic-chokes-a-semi-universal-approach.1131913/

Adjusting Automatic Chokes: A Semi-Universal Approach

www.chevelles.com

1. PROPERLY TUNED a carbed engine will start and run as FLAWLESSLY as an injected engine. It won't get as good fuel economy, and it won't meet emissions regulations during warm-up, but it will start and run perfectly.

2. This assumes you're using fuel blended for winter use. "Winter blend" fuel vaporizes easier than warm-weather fuel, would cause vapor-lock in summer if you didn't have a pressurized fuel system.

3. Also assumes that the engine is in good mechanical shape, hasn't been abused/neglected, all the tune-up parts are in good condition, curb idle and fast-idle speeds are adjusted properly, ignition timing is reasonable, and there's a heated exhaust crossover that actually works in the intake manifold. Ideally, there'd be a heated air-intake system feeding exhaust-heated air into the carb. And clearly, a bigass battery helps a lot.

4. Camshaft duration doesn't mean as much as some folks think. You only need enough manifold vacuum to operate the choke pulloff, and that doesn't take much.

What do you mean as in set up? its an edelbrock 650 and an hei dist. has an elec choke and will be a turd until the choke actually clicks in and decides to work? this is the second one ive had cause i thought it was a problem with the choke but this one does it too. Have to pump it 3-4 times and hold it wide open till it fires up.

Many people have spent many cold winters driving carbed vehicles.

An engine that won't start at -20 F has something wrong with it. Is it that cold where you are?

An engine that won't start at -40 F may just be normal--unless there's a block heater that is plugged-in and working.

Between -20 and -40, tuning, battery capacity, engine condition, etc. become VERY critical.

I think that you need to focus more on tuning that carb.

ABSOLUTELY.

That carb needs to have the choke tuned, and the operator needs lessons on starting a carbed vehicle.

You are squirting gas in with pumping it, then clearing that gas out by holding it wide open. Makes no sense.

THANK YOU, thank you, thank you.

THERE'S the real problem. First, the engine is flooded from too damn much pumping, they he has to clear the flood by popping the pedal to the floor so that the choke unloads.

Is the fuel pump working? Is the top butterfly closing when the motor is cold? Is there consistent power to the choke (if electric)?

A consistent problem with starting any vehicle with a carb, is that the gasoline will evaporate out of the float bowl when the vehicle is parked. This is especially bad in hot weather, but it happens in cold weather, too. What fuel may remain in the float bowl has had the easily-vaporized components of the fuel removed, so that what's left is the hard-to-vaporize stuff. If the fuel won't vaporize, the engine won't start.

Very helpful for an electric primer pump--or just an electric main pump--to fill the float bowl when the key is turned. Otherwise, you've got to crank the engine long enough for the engine-driven fuel pump to prime and pump fuel up to the carb.

The choke blade needs to be SHUT. TOTALLY SHUT. And that will not happen unless you tap the gas pedal to lift the fast-idle screw off of the fast idle cam. How much you pump is a function of the accelerator pump capacity, the engine tune, and outside temperature. The colder it is, the more you pump. At 50 degrees, you might need to tickle the gas pedal. At 32 degrees, maybe you need a third or a half-pump. At 0 F, perhaps a half pump to one full pump. At -20, maybe two full pumps. Again, you have to experiment and learn your vehicle. A Holley double-pumper with a 50cc rear pump is going to squirt a whole lot more fuel down the carb than a Q-Jet or other "stock" carb. But if there's no fuel in the float bowl, pumping the pedal is doing little more than masterbatiing the carb--you're setting the choke, but no additional fuel is given a chance to vaporize in the intake manifold.

You need a functioning choke break, adjusted properly, that pops the choke blade open as soon as the engine starts. It'll open the choke blade maybe a quarter of an inch, but fractions of a fraction of an inch are crucial--it's gotta be adjusted RIGHT. This is the number-one problem I see with chokes that piss people off--the choke pulloff/choke break aren't adjusted correctly, or don't work at all.

When tuning the choke coil, you set it up so that it OPENS at the right speed. It's a total waste of time to adjust the choke coil so that it CLOSES when you think it should. The second most-common error I see with carbed engines is folks dicking with the choke coil, trying to make it do the job of the choke pulloff. (i.e., the choke coil is nowhere near tight enough, 'cause they think the choke needs to open faster than it really should--because the choke pulloff is screwed-up.)




^^^Having said all of that, I think it's bat-shiiit crazy to put a carb on a vehicle intended and set-up for fuel injection.

From what I read it was a modern take on a crossram intake.

It was a piece of crap using tiny runners producing no real power. The hot set-up was to put a Smoke-Ram, or Offenhauser Cross-Ram base on the engine, fabricate a flat sheet-metal cover, and mount the two pathetic one-barrel TBI units on that. Then spend time "tuning" the EGR out.

There's a guy that has cast aftermarket "crossfire" manifolds specifically for the '82--'84 Crossfires. They're called "Renegade" manifolds. I've heard of them, never seen one. They may still be available via Summit. ( I can't find it on the Summit site)

crossfire renegade intake manifold? - Third Generation F-Body Message Boards

TBI - crossfire renegade intake manifold? - Anybody order one of these new crossfire intake manifolds from Dynamic crossfire solutions ? They say the intake alone will give you 33hp and 16 lb/ft of torque at the rear wheels with the timing set at 9 degrees. What other crossfire mods to do I have...

www.thirdgen.org

You must be registered for see images attach

 

[618 Syndicate]

It was a piece of crap using tiny runners producing no real power. The hot set-up was to put a Smoke-Ram, or Offenhauser Cross-Ram base on the engine, fabricate a flat sheet-metal cover, and mount the two pathetic one-barrel TBI units on that. Then spend time "tuning" the EGR out.

There's a guy that has cast aftermarket "crossfire" manifolds specifically for the '82--'84 Crossfires. They're called "Renegade" manifolds. I've heard of them, never seen one. They may still be available via Summit. ( I can't find it on the Summit site)

I didn't say it was a good take on the idea....

 

[DamHoodlum]

That's a loaded question, ha ha. A bored 46mm throttle body flows ~650 CFM which is enough for 6000 RPM on a 5.7L engine. The 7.4L 50mm can feed more. You want torque, go with ~ 170 cc intake runner aluminum heads. You want top end go bigger. Vortec heads (1.90/1.60) flatten out with over .500" lift where my Summit Racing heads (170 cc intake, 62cc chamber, with 2.02/1.60" valves) flow better up to .600". It's a myth that you can't go with a bigger cam on TBI, you just tune for the lower vacuum, AE and PE. You may need a VRFPR to get it to idle better.


There is the EBL Flash-II which tunes its VE tables automatically. A more aggressive SA table helps too. Unfortunately it doesn't support an electronically controlled trans but, with your NV3500, it should work. I guess the question is, how much do you want to spend?

EBL_Flash

Stock TBI unit about 330-350. 454 TBI unit about 500. Dual TBIs a hell of alot.

I wasn't sure if TBI could support Nitrous was the main reason I went carbureted

Im old school, grew up in the carb era, I would consider EFI system in my project tho....