Opinions on spreadbore carburetors

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MOPAROFFICIAL said:
If spread bore carbs were something so fan'fukintastical... they'd be on gawd damn top fuel funny cars so help me Jesus hallelujah amen
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T.Q 's do work with SERIOUS research... As,for me,Holley on "race it "... Used the remodeled A.F.B./ Edelbrick (on purpose) on milder cars. It's the time ,to tune this stuff,..mand with the internet availability... people get in a damn hurry. Stick to a combination PROPERLY set up,tune it...Otherwise ,you're not gonna go fast....
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AJ/FormS said:
Oh, poking fun, I missed it. But I knew it wasn't the Official you talking
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Yeah, I played the wine bar last last night, 60's country and blues band... had few n a half and was ham' n up some wording I had read here before from an overly passionate poster.
Everything has it's place and usage. A Thermoquad has taken a 71 demon down the track et 10.80-11. in the 1/4 in g stock.. so we know it can be done, but it's just like a hammer vs a crescent wrench...you can beat a nail into a 2x4 with a crescent wrench...but the hammer does it faster.

And honestly even the example I give of stock class racing, it's not an attribute to great mixing or metering by said carb...its the fact that those engines operate at rpms so high a coffee can full if gas with screwdriver holes punched into could deliver the fuel about as good. Low rpms operation, mileage and emissions, the spread bore was invented for such and still make a decent wot power ... but it will always be give or take and most people can't tuna fish.

I don't really fret over what someone prefers, I can work with either.
 
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Static compression and cam timing go hand-in-hand, one is not a "crutch" for the other... the compounded effect of having both higher compression AND a longer-duration cam is greater than the sum of the two changes separately. Increase the compression without changing the cam, yeah you'll get a fractional increase in torque over the entire rev range. Change to a bigger cam without increasing the compression, you'll basically just trade off low-end torque for upper-end power. But do both together, and the gains are staggering. The increased combustion speed and improved expansion ratio of a high-compression engine actually helps the cylinders scavenge exhaust and pull in fresh intake charge which becomes critical as cam duration/overlap increases.

An engine will only make as much torque at a certain speed as it can, meaning it doesn't matter how big or small the carb throttle bores are, the engine will only pull in as much air/fuel as it can use. Smaller carb primaries help with transient conditions i.e. opening the throttle from closed; once the throttle is opened and the engine is pushing the car under load all that affects performance from that point on is the engine itself (compression, cam, cubes etc.) Spread bore carbs like the ThemoQuad are more "crisp" and responsive when opening the throttle compared to square-bore but they won't actually increase the steady-state torque output at lower engine speeds unless the square-bore carb it's being compared to is too big to allow sufficient airspeed through the boosters.
 
Mope I like your thinkin

And that's why for a streeter, like me
it's good to have several different carbs, for several different circumstances.
And also why for a streeter, a spreadbore can be those several different carbs!
I like the TQ because;
You gotcher small primaries for low rpm everyday useage including cruising the hiway. And
you gotcher mondo secondaries for flat-out honking on it. And
you gotcher adjustable air-valve to match it to the engine. And
you gotcher metering rods to dick the response around this way and that to match the engine to the driver's expectations,lol.
And don't forget the TQ is so handsome, runs cool, and is the author of the awesome TQ moan.
But yes,there are times I'd rather have a Holley, or two,lol.
 
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AJ/FormS said:
Mope I like your thinkin

And that's why for a streeter, like me
it's good to have several different carbs, for several different circumstances.
And also why for a streeter, a spreadbore can be those several different carbs!
I like the TQ because;
You gotcher small primaries for low rpm everyday useage including cruising the hiway. And
you gotcher mondo secondaries for flat-out honking on it. And
you gotcher adjustable air-valve to match it to the engine. And
you gotcher metering rods to dick the response around this way and that to match the engine to the driver's expectations,lol.
And don't forget the TQ is so handsome, runs cool, and is the author of the awesome TQ moan.
But yes,there are times I'd rather have a Holley, or two,lol.
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Maybe you and the TQ should get a room. Damn this forum may need an *** rating.
 
yellow rose said:
Maybe you and the TQ should get a room. Damn this forum may need an *** rating.
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Well there is the phrase "Spread bore carburetors" in the thread title... lol

There's also the reality that ThermoQuads don't work well on low-vacuum big-cammed engines like the OP is talking about anyway, without lots of mods at least. I love my TQ on the stock 318 in my 1988 Fifth Avenue. Would I use it on a built engine? I might try it just for fun... as long as it didn't require an adapter on the manifold. But I probably wouldn't considering I have a nice barely-used 750 cfm Street Demon ready to use lol.
 
MOPAROFFICIAL said:
I was poking fun. lol

But look around at who is running what, says a lot.
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It does say a lot, and you're right. Without a doubt, the Holley style carburetor is most prolific in racing and even perhaps street cars too.

The spread bores can be made to work well on milder street cars, though and you know yourself that many stock eliminator records have been made and broken with spread bore carburetors. So they CAN work.

Main reason I like the TQ is cause of the noise they make. LOL
 
Yeah it's addictive. Ya just want to hit it over and over and over.
I put 2.76s in my FormulaS one winter with the 318 and a double od. I used to up-shift her as fast as she'd take it and let her moan for like 2 minutes on the way to cruising speed.......or maybe a bit more now and then. She cruised at 65=1300ish
I tell you tho, she didn't moan on the 367;at least I never heard it.
 
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AJ/FormS said:
Yeah it's addictive. Ya just want to hit it over and over and over.
I put 2.76s in my FormulaS one winter with the 318 and a double od. I used to up-shift her as fast as she'd take it and let her moan for like 2 minutes on the way to cruising speed.......or maybe a bit more now and then. She cruised at 65=1300ish
I tell you tho, she didn't moan on the 367;at least I never heard it.
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AJ/FormS said:
Yeah it's addictive. Ya just want to hit it over and over and over.
I put 2.76s in my FormulaS one winter with the 318 and a double od. I used to up-shift her as fast as she'd take it and let her moan for like 2 minutes on the way to cruising speed.......or maybe a bit more now and then. She cruised at 65=1300ish
I tell you tho, she didn't moan on the 367;at least I never heard it.
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Going *** again.....im not a prude but some of you are just potty heads lately!!!!!!!!
 
Abodybomber said:
T.Q 's do work with SERIOUS research.
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Serious research? Not IMO. Add Holley air bleeds to the top of the boosters. That should help a ton.
Just look at the carb. Understand the Holley and then look at the Carters. They lack air bleeds for adjustability.
Air entry into the throttle bores are not what I call ideal.

Used the remodeled A.F.B./ Edelbrick (on purpose) on milder cars.
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Agreed. There very good IMO for daily drivers and mild hot rods. Some guys have gone very fast with them because there limited to there useage.


Here is a quiz, of all Holley that were OEM, what’s the best one to use for high performance/racing?
 
I know that there is some people that hate them, but my guess is the 3310.
I made this guess because I read that is what Mopar recommended for their 360 crate engines.
 
I have had tha carb. I also converted it to a 4150 as so to remove the secondary tuning plate for a more percise jet. Overall, it was just a fine carb for what I was using it for. I also did the same to the 600 cfm model. It also worked great, for what it was doing. On the engine/car combo in question, (mild build) there was zero performance difference.

What other OEM 4bbl. Holley carbs are out there?
 
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