Dual quads versus big hammer!!!...

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Just ay observation but we all know that the best throttle response usually comes from a smaller carburetor. The best throttle response I ever had was with the thermal quad and an M1 single plane. Very small primaries . your primary consists of opening a whole 4 Barrel at once a snap off low RPMs May Never Be achievable.
 
lean or rich.... ok, that wouldn't be my concern. IF those flaps don't come open, your in trouble. And, as you have discovered, TQ's and the such with a back flap cannot be set in the garage idling in neutral. Trust me, for years TQ's were the carb of my choice and all I ran. Tuning them to 340's, 360s, and even 318's in heavy trucks with tight converters, and no bog. Going lean on the primaries could be "offsetting" for the back flaps not opening. It runs better, but not the solution to your problem. I cannot believe a 625 Demon out of the box that was designed for a stock 350 Camaro is too fat for that 410 C.I. with headers and ported heads. I'm not there, but I think it's deeper than leaning out your primaries.
If you look at the carbs reviews and even the tuning kit reviews everybody and I mean everybody is saying they are way too rich out of the box.. nowhere have I found or somebody said they had to put richer or larger jet's in them.. times that by 2 and I may have a extremely rich situation...
 
Just keep leaning the primary jets down until the numbers are more normal, or it starts to lean surge.

If it lean surges before the numbers look right...... might need to question the gauge.

If it’s lean surging and the numbers still look too rich, jet up in small increments just until it runs right.

Running right always counts more than what the gauge reads.
In other words..... I don’t care if the gauge is reading perfection..... if it runs crappy....... I’m not leaving it like that.

You bought the doors...... try some holes. That why you got em.
 
Just keep leaning the primary jets down until the numbers are more normal, or it starts to lean surge.

If it lean surges before the numbers look right...... might need to question the gauge.

If it’s lean surging and the numbers still look too rich, jet up in small increments just until it runs right.

Running right always counts more than what the gauge reads.
In other words..... I don’t care if the gauge is reading perfection..... if it runs crappy....... I’m not leaving it like that.
I totally agree! I just put a brand new Bosch O2 sensor and and everything seems to be working normal with it once again. I have new metering rods coming tomorrow which again I'm not sure exactly when I'll get a chance. Also the weather is going to turn Friday and Saturday for the worse but next week looks great. anyways I'll try the fatter metering rods and trying to get it clean and get the idle mixture screws to a normal setting. From what I gather if you're in more than 1 1/2 turns in you need leaner Jets, if you're out past two and a half turns you need fatter jets. and right now I brought them into about one turn and it's starting to run better. Also the O2 sensor or gauge is showing more normal readings.
 
I know someone who put 2 Ede 650 AVS’s on a 471 Hemi with ported heads and a roller cam.
They had to jet way way down.

With the ootb jetting, the A/F ratio was in the 10’s.

On the other hand, I had a 557 with 2 Carter 750’s on the dyno once....... couldn’t get it rich enough.
I ended up with .119 jets in all 8 holes.
 
I know someone who put 2 Ede 650 AVS’s on a 471 Hemi with ported heads and a roller cam.
They had to jet way way down.

With the ootb jetting, the A/F ratio was in the 10’s.

On the other hand, I had a 557 with 2 Carter 750’s on the dyno once....... couldn’t get it rich enough.
I ended up with .119 jets in all 8 holes.
Tons is what I've been getting and 11th and finally yesterday when I screwed them damn idle mixture screws weigh-in I finally started seeing numbers I recognized.. I just got my tracking order for the Jets and of course they're coming from Texas dammit! LOL via USPS... AKA slow pack mule LOL...
 
I know someone who put 2 Ede 650 AVS’s on a 471 Hemi with ported heads and a roller cam.
They had to jet way way down.

With the ootb jetting, the A/F ratio was in the 10’s.

On the other hand, I had a 557 with 2 Carter 750’s on the dyno once....... couldn’t get it rich enough.
I ended up with .119 jets in all 8 holes.
yep, you have to give the engine what it wants. The ring on J pars plugs looks rich, that's obviously the primaries.
 
yep, you have to give the engine what it wants. The ring on J pars plugs looks rich, that's obviously the primaries.
hey that reminds me I should go pull plug or to see what they look like after it was running on a little bit better..
 
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If I can get it to run an even better by rejetting or the metering rods I'll probably buy another set of plugs and run it for a little bit.. actually probably will buy a set of plugs either way.. just so I can get a fresh read..
 
If I can get it to run an even better by rejetting or the metering rods I'll probably buy another set of plugs and run it for a little bit.. actually probably will buy a set of plugs either way.. just so I can get a fresh read..
one step hotter plug would help clean that up.... (I've said this before I think... LOL)
 
one step hotter plug would help clean that up.... (I've said this before I think... LOL)
I thought it was funny how the two plugs look a bit different especially on the porcelain. I'm getting about two or three rings of heat. I know the angle on that one doesn't look so but I've already went a little bit hotter than I used to be before..
of course when I put those aluminum heads on they want you to run a colder plug and also let's not forget about the other thing that I'm going to try that wants two heat ranges colder...
 
Choke does exactly that - it chokes the air, doesn't stop fuel flow. You and I both know this. Per say, if you remove the back flap, it will not only be lean at the initial stomp, it will never recover because the flap (at least on the TQ) is part of the syphoning process. Fuel syphoning is what I'm talking about.


Right...I'm saying it's not a LEAN bog.
 
Well surprise surprise USPS says tomorrow for the Jets. I should get everything else today. Of course Friday and Saturday they're predicting rain and possible snow. But after that nothing but sunny skies for the next week. I'm trying to schedule Monday off and possibly a half a day Wednesday off. The days are starting to get longer as well so I will be able to do some tuning after work I believe if the weather holds... Stay tuned... (Pun intended....)
Again from everything I've been reading in researching everybody is saying these carbs are rich, and I mean everybody. No one should I read where somebody said it was lean and they needed to put bigger Jets. So I have to Rich carbs. What I ordered are the leanest Jets and the fattest rods. Again my idle mixture screws are too far in. They should be out at least a turn and a half and they're out one turn and it's just starting to run good... The metering Rod should be here when I get off work and possibly I could give those a try....
 
Have you read where everyone has to lean these carbs out because OOTB they are rich? Have you read that? If not, go read what the reviews are....
 
Hey Jpar! I was just reading the reviews on line, seems everyone is saying these come rich out of the box. Have you read that???
 
As I sit here and reflect on the two conversations I had with lwa performance that did this dual quad setup I think about the first conversation I had with the engine builder. Him saying that he's no engine tuner but can tell me what he sees them doing on the dyno... He said that they really keep pointing things out till there's a problem and then back it up a little bit. What seems to be the direction that I'm trying to head in. Second conversation wasn't as productive as it was the son of the owner more telling me that he was the one that did the tuning for the article and it was all done using a dyno. I didn't offer early any thing that he tried or that he had to make the carbs leaner or richer or really anything. Honestly and reflection a little smug.. where has the engine builder guy was very kind and tried to offer anything he could to help the situation..
One other seat of the pants thing and this is taking into consideration all the stopping and starting warming up driving and tuning... I do seem to be using more fuel than usual....
 
Hey Jpar! I was just reading the reviews on line, seems everyone is saying these come rich out of the box. Have you read that???
Are you really reading up on the stuff or just mocking me?I don't know if you have any experience with the forum but when a thread gets kind of long people don't generally read back everything that said so sometimes you have to reiterate...
 
Are you really reading up on the stuff or just mocking me?I don't know if you have any experience with the forum but when a thread gets kind of long people don't generally read back everything that said so sometimes you have to reiterate...
LOL... just mocking you.... you've stated that about 4 times per page. And you posted it again today.... :D :D
 
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Hmm, carbs are rich? Not enough port velocity in the heads? Too large of a plenum? Carb spacers too large? Not enough load or RPM’s to open doors? Replace the plenum with this, add a blower and over come any issues listed above.... lol
Blow the doors off your competition. Pun intended. ;)
 
View attachment 1715485826 View attachment 1715485827 View attachment 1715485828 Hmm, carbs are rich? Not enough port velocity in the heads? Too large of a plenum? Carb spacers too large? Not enough load or RPM’s to open doors? Replace the plenum with this, add a blower and over come any issues listed above.... lol
Blow the doors off your competition. Pun intended. ;)
It may not be his car.... the reviews online say these are rich OOTB. J par, did you read the reviews on these carbs???
 
If you are getting new air doors on Thursday you can put some small holes in yours and if it helps you can increase the hole size until you need to tighten up the spring. If you go too big, you'll have new doors on Thursday.

I'll wait to get the extras before the drilling starts... Oops we sent the wrong ones.. got lost in the mail...
Did you forget how my luck works..?.

Yeah, I did forget about your luck. With that in mind, I'd hold off too!!
@yellow rose remember this suggestion and conversation? They sent me the wrong stuff! LOL just when I was giving one of those kids on the tech line some credit.. they sent me four of these old divider plates that go down in the secondaries... Absolutely no use.. I'll call again tomorrow morning and see if I can get them to send the right thing...
 
@yellow rose remember this suggestion and conversation? They sent me the wrong stuff! LOL just when I was giving one of those kids on the tech line some credit.. they sent me four of these old divider plates that go down in the secondaries... Absolutely no use.. I'll call again tomorrow morning and see if I can get them to send the right thing...
bummer, man.
 
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