1967 - 7027240 - Fuel Inlet Upgrade - Needle and Seat Kit

[65WildCat]

Early Q-Jet Needle and Seat Upgrade Kit - 7027240

Question - I have installed the long brass tube with o-ring from the upgrade kit put the two screws in and dropped the needle in where the old plunger valve was.
The kit comes with a third small brass piece with o ring. as in the pictured in the book.
Is this another type of early upgrade seat for another carb?

I have installed this piece upside down - O-ring facing down in the plastic baffle hole to block off the fuel inlet when installed. So all fuel should enter thru the new needle and seat.
Is this correct or am I just trying to use all the parts with the kit?
Thanks for the confidence. First time Q-Jet User and Rebuilder.

[Cliff Ruggles]

Not sure about the third part.  Our kits for the early units include the updated fuel inlet seat assembly and the "O" ring plug for the fuel supply hole.

We don't build many of those carburetors or sell too many kits for them, other than once in a while doing a complete stock restoration. 

They are fine once upgraded, but most lack the secondary POE system, and the small fuel inlet seat assembly and poorly located float fulcrum is not the best set-up for high performance work.

I hope that you leak checked and sealed the bottom plugs?  Never had one in here  to date that didn't leak.  It probably needs shaft bushings as well, most units we've worked on here were pretty loose at the primary throttle shaft.

The early units are still good enough for at least 400hp with the upgraded parts, maybe even a tad more with a good fuel delivery system.....Cliff

[65WildCat]

Just a stock rebuild carb for a 66 Buick 425. Factory 340 HP with the single small Carter Carb. Should do a bit better with the Q-Jet. Figured early stock q-jet should get better fuel economy and off course already has the correct linkage hook-ups for my app.

I have Re-Bushed the Shaft and Plugged the wells. A few of them were already popped out when i opened it up. So I just made screw plugs and JB weld for all of them... Just following along with your book.

Not to sure what I'm Doing - But that's how you Learn

Comes off idle fairly nice - No tire smoke show
But when I mash it - not all that spectacular - still playing with the set screws - idle - and timing....

As far as the small extra brass piece it's seems to fit in that hole in the baffle just perfect. Effectively blocking off the original fuel inlet. so all fuel now flows thru the new needle and seat
Just worried about fuel starvation if the new needle seat can't handle highway speeds....
Guess the only way to know is Take out for a long ride and work the kinks out.......

[Cliff Ruggles]

JB Weld is not effective at holding back fuel, at least if it's dabbed on.  It may work better trapped by the threads of the screw in plugs.  Marine Tex or Devcon are the only two epoxies that we could find that did not "soften" in the presence of gasoline.  I thought I mentioned this in the book?  Anyhow, good luck with the new carburetor.....Cliff

[65WildCat]

Don't Recall reading anything about what epoxy to use or not in your book. I do admit it's a lot of information for the first time user to take in. Maybe I'll be redoing the epoxy after a 1400 mile run up the east coast --- If I make it. After a week in light test service. It does seem to run dry all ready. I thought it was just flowing back out the fuel inlet to the tank. External Filter, none in the housing, no check valve. And that would also mean a leaking needle and seat. Live and Learn...

After Dialing In - kick down linkages, Timing and idle to stock and for best vacuum. I get the slightest of hesitations light throttling from a stop light. And after sitting at idle in traffic or stop light slight hesitation and it bucks like its running out of fuel for a moment once in a while. Slow mechanical fuel pump action at low r.p.m.s.  I guess. Or maybe all my fuel just dumped down the plugs while sitting at hot idle. Can that happen?

Other than that --- Runs like a champ

Will the JB Weld screw up the internal passages as it softens and possibly clog something up?
I'm sure I was on the heavy side coating the threads and underneath the plugs.

Anyways, Not Bad for a Campground Table Rebuild with basic hand tools. Other than the Epoxy part....
Thanks Again -- And so Far I'm pretty happy with my new found performance..... I'll know about the economy part while cruising 1400 miles -all highway- watching my vacuum gauge all the way. And hoping something else don't break along the way...........
Jim

[Cliff Ruggles]

We do NOT allow any epoxy to get under the screw in plugs, as it can get loose and plug up passages in the carburetor.

Page 71-72 of our book describes the process, and we recomend using "fuel resistant epoxy", which JB weld is not.  It will soften up and fall off over time.

Marine Tex is excellent, and Devcon makes a similiar product that will hold back fuel....Cliff

[65WildCat]

Thanks Cliff, Found some Marine Tex for the next time. Until then I'm enjoying my new carb. Just drove from Orlando, FL to Massachusetts with no Problems. Except for a bout of 1 hour Vapor Lock right on the Jacksonville FL I-10 / 95 Split Bridge over the bay. Great View Of the City while getten Tan / and of course - Smiling at all the pretty gals as they poke on by..... while letting the engine cool, taking it all in stride....

Happened with the Original Carter Carb in High Heat - Slow Rush hour traffic as well.... I would guess all the PRE - electric fuel pump car would do the same. Don't see so many cars on the side of the road with there hoods up anymore like you used to.

Anyway - I'm very pleased with the overall result.
Pulling a Tow Dolly loaded with a 1993 pontiac sunbird.
My 65 Buick WildCat  GreatDale HouseCar.
 Averaged 10 Miles per gallon over 1200 miles @ 60 - 65 mph Cruise Control
Power was up and more responsive than before.

One 250 mile section of road was 13.5 mpg @ 15 to 16 steady on the vacuum gauge -- Then into the east coast hills.

Thanks Again -- You Took the Mystery out of Doing the Quadrajet Conversion from my old Carter.
Jim  --- Kudos

[Cliff Ruggles]

Good news, glad it's working out for you. 

The biggest problems we see these days is from the ethanol enhances fuels.  It is hard on anything rubber in the carburetor.  If you used Viton parts, fuel inlet seat and accellerator pump, it will be fine for many miles.....Cliff

[65WildCat]

One problem I'm noticing about this set-up..... Is when I goose it for a while.... Goes real good for a little bit, then, fuel runs short I guess, and it starts to buck a bit... I let off the pedal and let the fuel refill the bowl.... Runs fine again... Is this because of the older large float design, small fuel bowl??? The conversion needle and seat kit not flowing enough fuel to keep up....maybe???   I did not use the spring on the needle to the float as stated in your book... other then that, Perfect Daily Driver..... Feathering it..... Maybe I should start looking for a newer 800 cfm core for my next expirement......

Jim

[Cliff Ruggles]

Those upgraded fuel inlets seats usually have a really small hole in them, so that's the place to start if you are having fuel starvation issues at WOT.....Cliff

[65WildCat]

I have a new problem.. After sitting for a few months or so, I went to start up the car...

The fuel bowl had dried out by this time i guess .. Mechanical fuel pump... Got it going after a bit of cranking,

Then ran great for 40 seconds or so --- Then, fuel kept overflowing the top of the carb.. A lot of it...

Pouring out everywhere it could... Obviously running real rich....   After a few more tries with the same results over a few hour

period, she finally settled down and ran correctly after that initial fuel break in period...  Then I parked it for another two or three weeks

thinking that would be the end of it...   Cranked her over today -- Ran smooth as ice for half a minute --

then the wonderful smell of raw fuel overflowing the carb once again....  And a lot of it...

This is kind of dangerous, and I'm not prepared for an engine fire while cruising down the road.... 

Or for just jumping in and starting the engine and not having to constantly check under the hood.

And for --- Piece of Mind.....

Foam Float stuck in the down position, Not rising Needle stuck open after sitting and refilling the bowl   Accell Pump    
Too Much Air in the Bowl    

Stumped after such a perfect rebuild and run earlier this season...   And Thanks for all Your Help Thus Far..

[Cliff Ruggles]

Did you replace the float during the rebuild?  The ethanol in the fuel may have ruined it, and it may have also ruined the tip on the fuel inlet needle valve?.....Cliff

[65WildCat]

Darned Plug Popped out of the fuel supply hole... Stuffed it in there real good this time... Maybe I should have epoxied that in as well....  anyways, now it's a shelf spare... Got a decent 7027248 Late 67 Core.. with the screw in windowed seat... Just swaped my rebuilt base plate and should be good to go.... Will find out come spring time....  Until then.... Thanks for all your help............................. Still thinking 'bout switching the primary shaft to the 7044240 or 7044270. Just concerned about the manifold exhaust cross over not being completely sealed with the newer base plate being of a slightly different pattern, as well as the fast idle adjustment resting on the manifold mounting surface, requiring a 1/2 inch spacer..  I have searched and from what I'm finding, the spacers available don't completely cover the same manifold area as the older base plate... I suppose I could just tap and plug the exhaust cross over holes with some screw in plugs that should cure any probable exhaust leakage problems. I'm convinced I need the bigger primaries for this application. Just got to make it fit on my end.... 

[Cliff Ruggles]

Those very early carbs can be troublesome.  You are finding out why they upgraded the design in 1967.

There are no negatives from plugging off the exhaust holes in the intake.  We've been plugging them off for years on Chevy and Pontiac applications.....Cliff

[65WildCat]

Figured I would work my way up thru the years.... This is definitely an on going education - starting from scratch....  I'm getting a lot more confident playing with em and am really starting to like these carbs... Not to bad for a Street Book Apprentice... still not ready for any recipes yet.. but do enjoy the basics... also have noticed enough performance increases to warrant further into the subject...

In Your Book -- On Page 39 --- Picture on bottom right hand page states -- "Here is a quadrajet with the choke flap removed. In addition to not having any choke operation for cold starting, removing the components offers some additional airflow often needed for high-performance applications." 

Question --- How much airflow improvement or More CFM will a 750 or 800 get by removing the choke flap? It is a rather large restriction on the primary side if not used or needed.

Merry X-Mas and Happy Holiday's ----  Jim