lets talk efi in putting 318 mag malti port efi in to my 1964 valaint tell what you know please
Which Carb Gives a Balance of Power & MPG?
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Actually, the '71 is the least desirable. This is straight from Demon sizzler's Thermoquad site:
"The next generation of T.Q.'s was the one year only oem 1971 Mopar 340 carb. It shared features with the C.S. series carbs in the metering rods and piston, floats, choke pull-off, the top bowl gasket and the screw-in jets. This carb is # 4972 for the 4 speed and # 4973 for the automatic cars. These carbs had the idle mix screws similar to the C.S. carbs. It was often replaced by 1972 carbs by Mopar dealerships since the 72' up carbs were improved over the 71' carbs and are relatively scarce carbs today. These are also air metered carbs."
The air metered carbs are not that great. The solid fuel metered carbs of '72 to about '74 are the ones you want.
EL5DEMON340
Well-Known Member
The 71 carbs or C.S. carbs are the most forgiving if jetting is not spot on they will make good power on a stock 340 and also a 420+ stroker in stock form. 72 and later carbs have conventional jets ect.. and are better to tune due to the same jets used from 72 to the end of production. but if your going to use it on anything other than a mild motor your going to need a lathe to drill out jets and also the seats are small at .093 any kind of motor making over about 425hp should have the seats drilled out to about .100 to .105. no one makes aftermarket pri/sec jets and hi flow needle and seats.
needsaresto
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Heres my .02$;
Edelbrock; Dont bother unless you want your car to reek like raw fuel all the time.
Thermoquad.Dont bother unless you have spare parts and know what you are doing. I have 6 tq's but only run 1.
Holley. Expect to tune it unless you get lucky.Prolly should buy a holley book and a tune kit.
Edelbrock; Dont bother unless you want your car to reek like raw fuel all the time.
Thermoquad.Dont bother unless you have spare parts and know what you are doing. I have 6 tq's but only run 1.
Holley. Expect to tune it unless you get lucky.Prolly should buy a holley book and a tune kit.
1974DartSwinger
Well-Known Member
I've had a similar talk with the owner of an old time carb shop here in detroit. I was debating about sticking with the carter AFB on my 360 or going with a new eddy or holley. He said that a properly tuned original carter AFB is about the best carb you could ask for. He also said that the old AFBs are better than the new eddys. Another bonus is you can get a used AFB or AVS and rebuild it (jetted for YOUR engine) for less than an eddy or holley or whatever.
I do trust this guy, he really knows carbs
I do trust this guy, he really knows carbs
dustoff440
Well-Known Member
Best all around carb for me has been a thermoquad. Parts to tune it are hard to come by but if you can find one that was for a 400 or 440 the jetting would be just about right for a well oiled 360. I once had one off a E58 cop 360 that I put on a mild 350 Chevy that ran like a scalded dog and got good mileage. For overall tunability and ease of finding tuning parts go holley
My take is a little different.
Edelbrock; Takes time to tune them up really well. You'll need there kit of jets, rods and springs. Perhaps even (Though not likely) a squirter pack.
These carbs are very good in the street and fairly decent performers at the track. I like the AVS models myself.
ThermoQuads. I'll have to agree here. But I do like them. For a mild street strip engine or just plane old hopped up, these carbs are good. But learn them before tossing it. It may very well give you fits. There a bit particular on how there set up.
Holley; This carb will run the best MPH and has super tunabilty that will take on a lot of kits for a lot of tricks. In it's basic OOTB for, a jet kit is all you should need to tune it. Maybe springs for the secondaries.
Carter made Strip Kits for Thermoquads. They are very expensive when you find one today. The only reason the Thermoquad got a bad rap was because it was used primarily on emmision controled cars and trucks where the under hood temps were so high that it would warp the center plastic body resulting in a leaking and generally bad running carburetor. In a performance application where under hood temps are kept in check, they work very well. People have run them in several drag racing classes with great success for a long, long time. Present company included. There are a lot of them still out there. All I can say is, if you don't like Thermoquads, either you never used one or you never learned to tune it correctly. They are light years ahead of any carburetor made by Carter at the time, including both the AVS and AFB. You should go here and read about them. http://thermoquads.com/
This carb discussion was so Ripe...I felt the urge to jump in here.
I personally have bought about (10) or so carbs in my Mopar Experience.
Holley 650 VS - Good Carb...easy to setup...ran good out of the box -318
Holley 650 DP Mech. Choke, Mech Secondaries...little more complicated than the 650 VS, but easy enough to understand.
Holley 750 VS 3310- I personally HATED this carb...it is "supposed" to be easy to tune, versatile, good gas mileage....ehhh I never got a good clean run with this carb on my setup.
Edelbrock 750 Mech. Choke...easy to mess with....too BIG for a 318 IMHO.
And so here I am today with a Edelbrock 600 Electric Choke.
Through it all I learned some valuable lessons about the Holleys'........MOST of the gaskets RUIN when you crack them open....which equals $$ for the REusable ones.
The Better Holleys' require a special fuel inlet line...which costs from $3x-$1xx extra after the carb purchase.
I like the edelbrocks because they are Easy to disassemble. Easy to change parts out....(parts that O'Reilly's most likely stock for a fair price)
and there is a guide to changing out the Metering Rods and Jets for the Perfect Combination of Cruise Effeciency, and WOT Power....depending on your setup and fuel needs.
Later when I upgrade my 360 with some Boost, I will be using a Modified 750 Double Pumper.....but for everyday NA driveability and such....I believe the AVS style carb is hard to beat.
I personally have bought about (10) or so carbs in my Mopar Experience.
Holley 650 VS - Good Carb...easy to setup...ran good out of the box -318
Holley 650 DP Mech. Choke, Mech Secondaries...little more complicated than the 650 VS, but easy enough to understand.
Holley 750 VS 3310- I personally HATED this carb...it is "supposed" to be easy to tune, versatile, good gas mileage....ehhh I never got a good clean run with this carb on my setup.
Edelbrock 750 Mech. Choke...easy to mess with....too BIG for a 318 IMHO.
And so here I am today with a Edelbrock 600 Electric Choke.
Through it all I learned some valuable lessons about the Holleys'........MOST of the gaskets RUIN when you crack them open....which equals $$ for the REusable ones.
The Better Holleys' require a special fuel inlet line...which costs from $3x-$1xx extra after the carb purchase.
I like the edelbrocks because they are Easy to disassemble. Easy to change parts out....(parts that O'Reilly's most likely stock for a fair price)
and there is a guide to changing out the Metering Rods and Jets for the Perfect Combination of Cruise Effeciency, and WOT Power....depending on your setup and fuel needs.
Later when I upgrade my 360 with some Boost, I will be using a Modified 750 Double Pumper.....but for everyday NA driveability and such....I believe the AVS style carb is hard to beat.
I need to straighten out my 360's oil leak. Then I'll be checking out a T-Q on top of it. Just to be different and piss off a few of my freinds. LOL!
The engine is a bit more cammed up then previous engines, so, this should be interesting.
The engine is a bit more cammed up then previous engines, so, this should be interesting.
I have a REAL nice thermoquad. It's a 1980s Competition thermoquad called a Superquad. They didn't make many and they're gettin hard to find. It's real clean and the gas was drained out of it before it was stored. It'll probably bolt on and go....but I'd slam a kit in it just to be sure. If you're interested, give me a PM.
i am in search of some mpg when i do the 400 swap in my duster. i had planned on using the 383 4 brl intake and my 3310, then i thought of going with a thunder series but decided i want a spreadbore carb. i picked up a brand new 440 truck TQ. its no too loaded up with smog junk and was cheap, never run. im just trying to find a cheap performer intake. i have only owned holleys and have no complaints. i only had issues tuning one 800 dp. otherwis it took time but they worked great when tuned, i never really cared about mpg though. always left them running a little fat. this should be interesting.
Well, you picked the right carburetor for both mileage and haulin butt. Kinda conflictin statement, but it's true. Offenhauser makes a great spread bore intake for it.
Ah! Man, I just seen this, sorry, I so missed it. I'll have to pass for now, but I'll PM you anyway. I do have several T-Q's ready to go. Big and small.
Most overlooked, understood & underated carb of all time.
Hey James, when it comes to the T-Q, make sure you have the O rings seated well and the rest of the carb in spec. Measure the distances for the openings and slots etc.....
What model number is it?
On a spreadbore intake, I'm not to certain what intakes are out there for the T-Q. Strokerscmp sez the offy intake is out there. Also, theres the M1 single plane and of course the Edelbrock Performer. I don't know if the M1 will clear. Best do a search on this topic or post a question for pictures.
If you go for the Offenhauser, you need to be careful. There'sone Summit has marked "spread bore" that's a square bore intake. Here is the Spread bore. http://www.autopartsdealer.com/offe...highrise_intake_manifolds_5765-p224971-p.html
That's about as cheap as I've been able to find it. i also am not crazy about the fact that there doesnt seem to be any pics of it available. kinda spooky.
oops...I found it cheaper. http://www.aaamarine.com/servlet/the-795/5765-Offenhauser-tall-single/Detail
Or how bout this.... http://www.summitracing.com/parts/OFY-5750/ A DUAL SPREAD BORE for the low deck motor. LAWD HAVE MERCY could you imagine hearin TWO thermoquads openin up? Good grief!
That's about as cheap as I've been able to find it. i also am not crazy about the fact that there doesnt seem to be any pics of it available. kinda spooky.
oops...I found it cheaper. http://www.aaamarine.com/servlet/the-795/5765-Offenhauser-tall-single/Detail
Or how bout this.... http://www.summitracing.com/parts/OFY-5750/ A DUAL SPREAD BORE for the low deck motor. LAWD HAVE MERCY could you imagine hearin TWO thermoquads openin up? Good grief!
Entirely true, but the only performance advantage whatsoever is weight savings. The Performer for the Chrysler is an exact dupe of the stone stock intake....and it does NOT come in a non EGR model. Not that there's anythingwrong with the stock intake design. They worked well....but if I upgrade to an alluminum intake, I'm going to upgrade to something that will actually add performance instead of just cut pounds. Know what I mean, Vern?
MopaR&D
Nerd Member
I definitely noticed better throttle response and torque when I swapped from an iron 4-bbl. intake to a Performer on my 318. And the one I have is non-EGR...
do you have any dyno results or photos with demensions to prove that? the offy doesnt intrest me and i seriously doubt it will outperform the performer intake, let alone the bang for the buck you can get for the price of it. i did have a 400 tq intake and if i still had it id use it, but im not going to pay for one. i have a 30 383 4 brl intake but its a square bore. for what its worth i do remember reading the 400 spreadbore egr intake was the best power maker for a factory b engine intake. i did buy an offy 2x2 intake for a project but it was a period looking build and it fit the bill. they all have thier place.
There's a lot of stock eliminator cars running really fast with Thermoquads. Doesn't address the mpg aspect, just my .02
well i picked up a performer rpm since i couldnt find a performer for what i wanted to pay. i guess im going to weld it up, offset the bolt pattern to center it over the square bore opening and hog it out to fit. the secondaries hang over the flange about 1/4" on each side. ill probably weld up a choke pocket over the heat crossover too. well see.
bamacuda
Well-Known Member
whew! That roller coaster was bumpy!
1wild&crazyguy
Banned
pick a carb on the small side, and then tune the sht out of it for gas milage/ slightly lean with a high/highest vac advance you can get away with, along with the hottest plug and comp ratio you can get away with, use a small runner intake and a multi spark ignition.
the rest of the motor is the other/performance side of it.
your done, you've basically taken a performance motor and neutered it's induction and rpm hp
the rest of the motor is the other/performance side of it.
your done, you've basically taken a performance motor and neutered it's induction and rpm hp
You'll not have the meat in the intake to hog it out for a T-Q.
Ethier a Edelbrock Performer, Weiand Action plus or the MoPar M-1 single plane will have the spreadbore intake abilty for the T-Q. Theres also a Offenhauser to look for. Becareful if ordering new since they have many versions of there small block intake manifolds.
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