brainsoft

I finally removed the old C3BX intake and the restored Performer 2101 is now installed along with restored rocker covers and brackets on my 1980 L-48.
Before:


After:




It is now time to start putting the qjet on and repair what ever was modified to fit the Holley.

First things I noticed: Fuel Line
The fuel line now ends very near to the fuel inlet. The fuel line looks like it was cut with a tubing cutter to remove the flare to connect the rubber hose and in-line fuel filter to the Holley. Can someone show me a picture of the proper set up here? I have a flare kit, I should be able to re-flare it and get a new compression nut and fitting for the fuel inlet if that is the proper way.




Next thing I noticed: Vacuum lines
Now that I have the holley in place I see that the brake booster line should connect directly to the base plate. It looks like they tapped the old intake to install a 90deg flare fitting because the holley does not have this connection. I should be able to re-use the steel line with some minor bending to get it to line back up. You can see the old connection in focus looking through the piping of the Tee connection I refer to below.


Also, the connection for the TH350 and headlights, etc. Can someone show me a picture of how their tranny line connects? Mine was connected in a 180deg bend into the top of a Tee fitting, with the other two legs doing the headlights and everything else. Is that the original fitting?




Last thing I noticed: When I was taking everything apart, they had used a chunk of aluminium mounted with a carb bolt as an adaptor plate for one of the throttle cable brackets. Can you think of anything else they would've had to modify to accommodate the Holley install?

cardo0

Well the stock carb line is hard line at the carb (goes into the inlet fitting) and the flex hose is down at the pump. U can set it up anyway u want but i do see that fuel line at the carb does not have a "bead" on it. Never, never install fuel line without a bead and just hose clamps. U are asking for a fuel fire and a corvette with fiberglass body will burn to the ground.

Next item, Vac line. Yes u should have a Qjet base plate that has both the booster hose fitting and a throttle cable bracket. U will want one of those and i believe u can buy these new from the vendors for your '80 (but not for my '74). Or else the booster line connection is at the carb base in which u will have to remove the plug and install the correct fitting - sorry too lazy to go out to the vette to look. But i do recall the booster connection is at the base of carb in the rear. And the throttle bracket positions the throttle cable just right so u dont have to adj it (well just a little bendology). U can buy aftermarket throttle brackets but why if using a stock carb? Just another item the stock spring (at least on my '74) was only a single spring and i had problems with the throttle (not) closing. But u can buy a double spring at nearly any parts store for cheap - i highly recommend it.

Sorry my car is an manual trans and cant help with the tranny vac line. But the headlights do need a tiny check vlv.

I think i answered your last thing with my first thing reply.

Good luck and let us know if u get it to work - feed back always helps.

Shark Racer

Not the best photo ever, but here's an old photo of my stock style fuel line (done up in stainless).

Next time around, I'd just go w/ the regular steel. It seals OK but it's a pain to line up. Once you've got it installed for a while it's OK as long as you put it back on quickly... but it will eventually return to the screwed up angle it came with.

94hokies

Sorry for the rough state of it, but the only pic I had of the line disassembled was after I had just dealt with the original frozen lines. I am set up using the '69 external filter and the one inside the qjet inlet if I remember right. Also, I second the advice not to get stainless on these. Could not get them to stop leaking until I found the aluminum flare crush seats. Even then, finally gave up and had the shop switch it back to standard steel when I just did the rebuild this summer. Second pic shows the setup when i still had the stainless in there.









I just bought the throttle cable bracket this year as well, forgot where from, I've been buying a lot of stuff in the home stretch of getting on the road this year, but it was an easy bolt on replacement for the bent piece of steel that had been stuck in there. Springs were just the Advance Auto double set from their generic off the shelf stuff.

brainsoft

Thanks for the photos guys, much appreciated! The fuel line is the original steel line I assume so hopefully I can adjust it to fit without leaking.

I have all the original throttle cable brackets, I believe they just used the aluminium as a spacer to move the bracket out to keep the cable straight after switching to the square bore mounting holes for the holley. I haven't connected any of the cables yet, was just wondering if anyone could think of any surprises I might find tonight.

Shark Racer, I see in your picture the Tee fitting that looks a lot like mine, but the top is capped off. Does anyone have a shot of this connection? The port for the Tee connection is more forward on the 2101 than the C3BX but I don't know where it would have been on the stock intake. The C3BX appears to have been on this motor for a long time!

I assume the fuel line goes to the fuel pump... where is it? If there is a flex line at the other end I had better replace it!

94hokies

On my 427 it is a mechanical fuel pump on the bottom of the passenger side of the block. Rubber line can be on the unpressurized run from the tank to the pump, hard line from the pump to the to the carb. Some applications have a return line from the pump back to the tank. I've got the '69 fuel filter in the second picture that has the return built in there.

I've removed all my vacuum run items, so can't help you there. Only problem I had on switching back to the real throttle cable bracket was the length of the cable is not forgiving at all and my PO had in a non stock gas pedal that I needed to mess around with to get more slack back to original.

I did my rebuild and installation off of Cliff Ruggles book, lots of pics and detailed descriptions. I also had him set me up with a rebuild kit to get mine back to original specs since I had no idea what else might have been done to it.

CaseyJones

I have the virtually same car as you and recently "fixed" several things that needed attention, including the fuel line and vacuum fittings. I'll try to get pictures for you later today as I tried to put it all back semi-correctly. I also have a Q-Jet on a Performer.

brainsoft

Thats's great Casey I really appreciate it

I will probably just run a hose over to the tranny line to get it up and running asap. I am not sure how much that line was bent but certainly don't want to replace it so will have to consider my options carefully.


Should the fuel line be double flared at the carb inlet?

Shark Racer

Vacuum tee goes on the rear intake manifold runner on a stock intake.

The stock fuel line uses flare fittings at the carb and at the pump.

GUSTO14

A double flare is required and most often used for high pressure situations like brake lines. It can be and is sometimes used in low pressure situations. Generally speaking the fuel system is considered a low pressure system, particularly when using a mechanical pump and a double flare is not required.

If you are using stainless fuel lines it is, in my opinion, unnecessary and very difficult to accomplish without some very professional equipment. If you're using mild steel lines, go for it, we can always use the practice.

Good luck... GUSTO

brainsoft

I had an unproductive night of problem solving and flaring practice

I got some new 3/8 tubing and replaced the brake booster line, and even though I bend pipe all the time (electrician) I put the 90 at the end pointing down like an apprentice! I cut it off and put a bead on it, it should be fine until I can get a new piece and do it right.


The fuel line did not have enough pipe to get the flaring pipe clamp on it with the nut (which I forgot any ways), so I put a bead on that too and will temporarily use a piece of fuel hose until I can replace the line down to the fuel pump. I see now that the lower half is a bendable pipe... I never noticed and could never find the other end of it!



Throttle connections... what am I missing here? I see I need a retaining ring to hold the primary throttle cable to the post. I don't know how the cruise control bar connects to that same location. The throttle post only seems long enough for a single plate and a retaining ring to hold it in place. I see the one other hole there but nothing lines up to utilize it. The qjet is from a 1978 L-82, maybe it didn't have cruise...?



The tranny kick down cable needs to be adjusted to get some slack, but it looks like there is enough to work with at the bracket. I assume it connects to that lower hole with the plastic bushing; I was just planning on using a 6-32 screw and nuts. What is the preferred connection method? I also have throttle return springs that I think are supposed to connect somewhere (I already acquired a second spring last year), but the lower arm only has one hole. Should they clip to the same thing that the kick-down cable attaches to (6-32 bolt)?


Vacuum lines! I seem to have a lot of ports on this q-jet and am hoping I can eliminate some of the clutter around the back of the carb where that Tee fitting will NOT FIT! Which ports are ported (so I can avoid them)? Is there anything that CAN be connected to the ported port? Dizzy is already setup to run on manifold vac and I have connected it to the small port right beside the brake booster line on the back of the carb.


Here are some more pictures... how is it looking? What on earth am I going to do with all these vacuum lines? Can you fill in some of the blanks?

A Ported?
B Ported?
C Fuel canister... I have PCV connected here atm. Canister lines need sorting out in all of this as well.
D PCV?
E vent? seems to just open right above the secondary air flaps, I'm not sure wtf it is for.
F Full manifold vac. I have the dizzy connected here.
G Brake booster
H Location that cannot fit the original Tee.






At H I can install a 1/2"x3/8 90deg fitting that I could hose barb or bend and flare a pipe to. I have 3 1/4" vac lines that used to connect to that Tee that I am hoping can be jammed onto some of the above mentioned fittings.

brainsoft

That is excellent news, I will stop wasting time, though it was good practice. I MAY have been able to make the fuel line work if I had put the nut on and gone straight to a single flare! IF I had put the nut on first!

cardo0

Like how u made those line beads. Thats how i did it untill i finaly bought an aircraft line beader - cost lots of $$$ but i can bead the line at any striaght length location.

As for the carb ports no one has a correct list for all the Qjet carbs. Best way ive found is to remove the carb and use some thin solid wire to probe and see what goes through into the carb throat - below the throttle plate is full vacuum, above the throttle plate is ported vacuum. For other ports that can't be probed with wire i use WD40 or carb cleaner spray looking where it leaks out.

My carb throttle lever has a hole for the spring. dont know what to tell u there. I dont have cruise control either. But hey u can always drill a hole - just make sure u drill where it belongs - look at other cars with cruise.

I see u have a throttle cable bracket. May take a little bendology but careful and make sure the throttle blades will close when released.

76CSRvette

fixed

Shark Racer

A - ported, for EGR. Usually goes to a TVS in a water port between the T-stat and forward intake bolts (right hand side)
B - not sure whether ported or manifold, but it's for AIR and EFE and goes to a TVS on the water neck.
C Fuel canister, this is the evap port for the float bowl.
D yes, PCV.
E "Fresh air" port for running air through the hot air choke setup. I'd cap it, it's not a vacuum leak but will allow unfiltered air into the carb.
F Yes, this is full manifold and in a stock config would hook up to the air cleaner thermac switch (the one that closes the valve in the snorkels), at least on my 78.
G yup.
H Worked on my Edel 3701/M4MV when I was running one.

One port you didn't list was on the left front of the carburetor, just left of C. This is the usual vacuum port for distributors. Ported some years, manifold other. Some carbs don't have them if they ran an electronic dist (but these included electronic carbs as well )

Shark Racer

Here's some photos of the 3701 (way back when):







^-- I'd have to double check, but I think the EGR port is also a signal for the charcoal canister to start pulling in fuel vapor.

brainsoft

Hmmm thats right, i dont have any egr or emissions system intact. I have a vacuum switch on the driver side beside the wiper moter... is that the evap signal?

I think I saw one before but does someone have a vacuum hose diagram?

Shark Racer

Whoops, your 80 is 2 years apart from my 78. They changed a lot of stuff between then and now.

You can search the net for one(google or yahoo image search for "1980 Corvette Vacuum Diagram"), I do when I get lazy. However, the AIM is going to be your best bet for some good manuals.

Shark Racer

Here's one I found:

lars

You are installing a Manual Transmission carb on an auto trans car. The MT carbs have the lower part of the throttle lever "chopped off" by the factory, so you have no provision for the transmission kickdown cable. The cable attaches to the missing part of your lever, so you cannot use that carb unless you "bubba" up an attachment lever onto the cut lever. The nylon grommet hole in the lower part of the lever is for your return spring. Also: Do not attach your throttle cable to the top hole in the lever - this will result in inadequate throttle travel, and you will never get the secondaries open. The cable attaches to the lower of the 2 holes on a Corvette.

You can send the carb out to me and I can convert it to an AT carb by installing the correct throttle plate with the AT levers.

Lars