JohnnieUtah

After a 4 month wait I finally received my new custom built Q-jet from Clifford Ruggles. I was under the impression that I would have all the necessary vacuum ports but alas I am short a few. It's not a huge concern at this point but in the future I will not be able to make my engine completely OEM stock because required ports are missing on the baseplate. While trying to figure out the port situation I noticed one screw that has me baffled. In the picture you will see an adjustable screw with a spring behind it that is positioned between the idle mixture screws. What the heck is this! I'm supposed to have a port for the fuel vent canister here but its not there. Someone tell me what this screw is why is it adjustable?


Next question, in my situation what should I connect my canister hose to now? The only other port available to me is the long slender one by the choke pull off diaphragm and I don't even know if this ported or manifold vacuum. What a mess. I should have just went with Lars in the first place.


Oh and another problem, the throttle cable connection point is too high shortening the required throw. I have to connect to the lower hole but the ball stud that is in place right now is sweged in place. Not sure how to get that off so I can get full throttle cable motion in the other hole when I put another ball stud in.


PS. My carb body ID number is 7044213 (1974, 4-barrel, Chevy, manual trans)

LS4 PILOT

Have you called Cliff and asked him . He should be able to answer these fairly easy i would think.

carb does look nice !

Maybe , your old base was unusable and another substitued . I would start by calling him though.

JohnnieUtah

Oh believe you me...I'm calling him. After what I paid him and how long I waited and to get this surprise...it really disappoints me. BTW, I had no carb to give him. This is his carb.

LS4 PILOT

ok....i sent you an email. That explains the base issue . He did both of my 74 cars carbs . My vette carb got the same recolor complete deal , but my carb was my cars original carb i sent him.

that base does not seem right , both of my 74 manual carbs , camaro and corvette use the base with the big front port.

Also......the throttle linkage off the shaft is different from various cars and trucks of the same year . My shaft throttle linkage is different on my Z28 and corvette . If i was home i could go look and tell you more . i would want specific corvette carb parts . the shape looks correct , but i can't remember off hand with out looking about where the stud was located .

CanadaGrant

That center screw in the base plate is the APT adjustment. It is set from the factory and covered with a press in round anti tamper cap. Yours has been modified to a longer open screw for easy adjustment. The APT screw was placed in the base plate from around 1965 to about 1975. The linkage looks to be from something with an automatic. No idea.
I believe the open port in your second pic and the capped port through the choke linkage in your third pic are manifold vacuum and the upper one with the black vacuum hose on it is ported. On my 69 that lower front port (open in your pic) is used for manifold vacuum advance and the side port (capped in your pic) is used for the smog pump diverter valve which is also manifold vacuum.

JohnnieUtah

• Well I talked to Cliff this morning. First off, he confirmed that my carb has the APT in the base plate and it was set by him for proper metering height and air fuel mixture ratio. He also mentioned that it was set at his altitude so at mine which is 4600' above sea level I may need to lean the carb just a tad. The unfortunate thing is that I will never be able to put this Vette in pure form because its missing the EGR port and fuel vent canister port. So much for winning a trophy. Anyone who does carbs as long as he has should have known this!

• Regarding the ball stud location, he said he has never seen anyone hook up there throttle cable on the lower hole. He said the lower hole is reserved for cruise control. So I will check out my throttle cable if it is the correct length today. According to Lars in his papers, the top is reserved for trucks and station wagons and I should be using the lower hole. So who's right?

• The long slender tube by the choke pull-off is manifold vacuum and is reserved for use with a thermac on the air cleaner housing. This will be plugged on mine.

• He also recommended that I use ported vacuum for the distributor he rebuilt for me. This connection is on the right side of carb looking from the front. The only thing he could not help me with is the fuel vent canister hose connection. He looked at 50 carbs in house and could not find one Chevy base plate that had this needed connection for that hose. He found one for a Cadillac and said it was very weak ported vacuum and would only start sucking fumes under a strong load like a hill. At idle and cruising it would not see any vacuum. So at this point I have no idea what to do with this vent hose other than tee off the PCV hose for now. I'd love to hear from you guys on what to do with it.

• My experience with Cliff's Performance has been less than pleasurable. I paid for plating service I did not ask for and I got a carburetor that was not the right configuration and paid through the nose for it too. It kills me to pay top dollar for something that is not 100% correct. Had I known this was going to happen I would have just went with an Edelbrock intake and carburetor. It would have been a cheaper alternative for being not original.

lars

The 1974 baseplate should have the canister port in it and an EGR port. Here are some photos of a 1974 Corvette Q-Jet:

Top view of a 1974 baseplate by itself - the canister port is just to the right of centerline, and EGR is at a 45-degree angle coming out of the forward corner to the left:


Front view showing correct ports in the 1974 baseplate:


Corvette carbs do not use the top position for the throttle cable attachment. There is not enough throttle travel on a Vette to be able to use the top hole. You must use the lower hole. Here is a Corvette carb throttle lever with the ball stud installed in the correct location:


Photos of the assembled 1974 Vette carb showing the canister fitting and the correct throttle cable attach point on the carb:




The baseplate on your carb is not a '74 Corvette carb baseplate, but you can easily modify it. You can drill the hole in the baseplate for the canister nipple, and you can remove the swaged-on ball stud by using a high speed sanding disc to removed the swage and knock it out. Install the ball stud in the lower hole.

I probably have some correct '74 baseplates that I could use to make the carb correct. E-mail me if you would like to consider that.

Lars

7T1vette

Wow! I can understand your disappointment. I'm disappointed [for you] and I have no 'skin' in it at all. Makes me think twice about recommending Cliff's shop for that work. Sorry, man. But, sounds like you can follow Lars' advice and get back to what you need. Or you might contact Lars to see if he can rework your baseplate or swap it for a correct one.

LeMans Pete

Is the '74 base plate the same as a '75 baseplate?

lars

No. Significantly different.

Big2Bird

That's what I would do.

JohnnieUtah

I sent you two emails. Did you not get them?

Big2Bird

Did you use V8Fastcars@msn.com?

marshal135

Hey we all go through it.
I purchased one of those high speed low drag pretty carbs of Ebay.
Feedback was good and many many listed.
Figured the sellers legit.... right?
It arrived and looked awful pretty. I figured I'd done good.
Come to find out....
It was a hack job rebuild Hodge Podge of parts piled on top of each other. A real bargain at $300.00 + shipping.
I could not get it to tune or idle or warm up properly for the life of me.

Then thee sky's opened up and the trumpets sounded and I heard
the voice, "Should have read my papers"
Yes, it was the Carb Guru Lars.
Well, I read and I read and I read some more.
That carb came off in a New York City minute.
I now have a NOS Edelbrock 1901 and never looked back.
If I had not read, I'd still be dicking with that abortion.
Thanks Lars.
Some times these hobbies have an expensive learning curve.
Hope you get it straightened out. I've shared your frustration before.
Marshal

Jeff_Keryk

Hey - I paid over $400 maybe 15 years ago (when $400 was real $$) from a name shop...
I won't say "Carb Shop". It was whack!
Lars fixed it for me and did a write up...

Calo69

Ask to buy the carb in Lars pics, it's a beauty

lars

I have no unanswered e-mails in my in-box... I did send you an e-mail on the 11th with response to your questions.

Lars

JohnnieUtah

Thanks Lars. Yes I got your email. Thanks so much for responding. I spent the weekend hooking up my OEM intake and carb to see how it runs and then decide which direction to go.

Redvette_22

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