JohnZ

The '66 and '67 L-79 used a steel hard line from the pump to the 3367 and 3810 carb inlet fitting; the '65 L-79 used a rubber hose and spring clamps from the fuel filter outlet to the 2818 carb inlet as shown in the photo below (poor design practice, but that's the way it was released).

PAmotorman

there is only 5/6 psi in the line and with the with a ridge on the end of the tubing very little chance of the tubing coming off. if using a home made line just put a brake line double flare on the end of the tubing and it will not come off

Factoid

DansYellow66

Ford used pieces of rubber lines on at least some of their hi-po engines also. Steel lines up to the fuel log and then rubber to the carb.

Mr Fufu

Hi John - that's one fine looking engine compartment you have there! Clean as a whistle! And an example for the rest of us to live up to!

So, I'm learning that mating the steel fuel line to a rubber hose to connect to the carb isn't so bad, as long as the fitting is tight and secure, as on your engine.

I need to find out if the Holley 1850 has an internal fuel filter at the carb inlet, or not. Otherwise I need to install an inline filter, as is done on your engine.

Anyone know if the 1850 has an internal filter?

John BX NY

Last summer my 67 L79 started running rough and I wanted to put a generic 600 CFM electric choke model on and adapt the fuel line to keep driving and rebuild (again) the dated carb.. Ultimately I purchased a brand new Holley 3810. It was pricey but it bolted right up and the car ran great right out of the box. The few hundred dollar difference in price was worth it to me. It was the single biggest improvement in driveability in almost 30 years of ownership.

jet-tech

You could use a flexible fuel life that is lined with PTFE. I replaced my fuel line from pump to carb after five years of use. Cut the old line down the middle that was made with PTFE, looked brand new on the inside.

PAmotorman

interesting carb picture as I have never seen a corvette holley carb with out angle cut bowl vent because of how close the top of the air cleaner is to the bowl vents

Mr Fufu

Hi John,

Where did you buy your new Holley 3810? Was this an NOS carb? Does Holley still sell new ones? How much did it cost you for the new carb?

My car runs fairly well with the Holley 1850 it has on it now. I has an electric choke. I had someone rebuild this carb about 18 months ago. The only drivability concern I have now is that on occasion the car will die if I come to a stop very suddenly. The carb also has a propensity to leak bits of fuel from places like the float adjustment screws and at the accelerator pump area. The carb also leaks a bit as I notice evidence of raw gas on the manifold from time to time. All this tells me that this carb isn't fuel tight.

I'd like to go back to the 3818 my car is supposed to have. Did you restore the divorced choke OEM setup? Or did you install an electric choke?

Lastly, what problems were you having with the original carb on your L79?

Thanks for your feedback.

phil jr

I don't know if your question was answered I can't read all this off point response, You can get a new front bowl for your carb you can get the one that uses the original fuel line, they are interchangeable. If you have a electric choke the second best place to hook it up to, is the wiper motor, the two wire connector on it has power when key is on. The best place is assy post on the starter. Phil my 2 cents

lars

All the 1850 carbs with the banjo fitting that I have worked on have had the inlet screen in the bowl at the banjo fitting. This is not a real "filter," though - it's just a screen to keep the big chunks out of the needle & seat.

You can convert the banjo fitting carbs to an OEM-style screw-in hard line configuration by using the bowl for the "marine" carbs. Marine carbs do not use rubber line on the pressure side of the fuel system. It's Holley part number 34R10918AQ

https://www.holley.com/products/fuel...rts/34R10918AQ


These marine bowls are not drilled and tapped for the idle vent system using the wire lever, but it wouldn't be tough to do the machine work to replicate the OEM bowl, if you had the lever, spring, and hardware components.

Lars

Desert Nomad

I have a '67' 427/390 with the vented marine bowl as described by Lar's above. Last year, I noticed the front bowl was warped although not leaking. I tried to find one of those top vented Holley bowls but could not find one. The only one they were still making was the non-vented bowl. I contacted Holley and spoke to their rep. on this. He said the non-vented would work just fine. He gave me the name of a couple of classic carb restorers that may still have those vented bowls on the shelf. I never pursued it any further. I tried purchasing a non vented bowl from Holley, but they were out of stock and didn't know when and if they would be receiving any more. Went to Summit and got one. They had plenty on hand. In the end, I'm glad I went with the non-vented bowl as the gas fumes in the garage were greatly reduced and the car runs just as good if not better. Just my experience.

lars

Good comments and correct observations. The bowl vent is not needed for correct operation of the carb - the bowl is vented through the vent tube. GM/Rochester used a similar design bowl vent on the 1967 - early 1970 QuadraJet carbs as well. Realizing that the additional vent was not needed, the bowl vent was eliminated early in the '70 model year, and the carbs vent normally through the vertical vent tube, just like the Holley. For the OEM C2 Holley carbs, the vent system becomes more of a cosmetic item to make the carb appear to be "correct."

Summit keeps them in stock - I have been receiving them in 2 days from order:
https://www.summitracing.com/search?...ord=34R10918AQ


Lars

tbarb

Lars is right about the vent on the production Holley carburetors, you don't need it and with the low evaporation temps of ethonal fuel you are better off without it.

That being said, the purpose of the little device was to vent hot fuel vapors to atmosphere instead of into the carburetor air horn causing a over rich condition and stalling when temps got high. Seems funny to think that way now with the newer cars equipped with OBD2 and natural vacuum leak detectors to ensure all fuel vapor gets stored and burned in the engine.

The vent stacks in the Holley air horn are by design connected to the float bowls and vent vapors to the engine plus they ensure the fuel inside the bowl stays at the same pressure as the air flow inside the carburetor throat (air horn). This helps push fuel into the main well at higher than atmospheric pressure at higher rpm's.

SI67

Mr. Fufu,

If you want to buy a new 3810, try

Specialty Parts Direct

Atlanta, GA.USPhone: 404.416.8757They're listing the 3810 for about $711. Eckler's wants $820 for it. Or, if want to still have externally adjustable floats, you could spend $36 more for the 1966 version the 3367. If there's some good reason to prefer the 3810 on a '67, other than judging points, I'm sure someone more knowledgeable than I am will pipe up. I figured from your A/C compressor that you weren't 100% devoted to originality.

SI67

Mr. Fufu,

If you want to buy a new 3810, try

Specialty Parts Direct

Atlanta, GA.USPhone: 404.416.8757. They're listing the 3810 for about $711. Eckler's wants $820 for it. Or, if you want to still have externally adjustable floats, you could spend $36 more for the 1966 version, the 3367. If there's some good reason to prefer the 3810 on a '67, other than judging points, I'm sure someone more knowledgeable than I am will pipe up. I figured from your A/C compressor that you weren't 100% devoted to originality.

DansYellow66

To address your comments - it's possible the stalling from a hard stop is due to a high float setting in the rear fuel bowl and fuel sloshing over and through the bowl vent at the top and flooding the carb. I would check the float level and consider lowering it a little and see if that helps. They also make a vent extension you can get from Holley that is a piece of plastic that snaps in the vent and extends to the rear to help prevent fuel sloshing through there. The length may have to be trimmed to clear the float.

Holleys do have a lot of potential fuel leak spots but for the most part they are easy to fix. Often the float adjustment screw and the side of bowl sight glass just need to be tightened and even if he little washer seals have seen better days and need to be replaced - they are cheap. Fuel bowl screws need to be snug enough to prevent leaks on to the manifold but if you are having to tighten them excessively to stop a fuel drip from one of the bottom ones, draining the bowl and replacing the plastic screw seals is also again cheap. If the bowl gasket is leaking even with the screws pretty snug then I would be concerned that a bowl or metering plate is too warped to seal. That may require either straightening or replacing.

lars

If the float level is correct, install a "whistle" vent baffle in the carb. These prevent fuel slosh up and out the vent tube, which will cause engine stalling on hard braking:


Holley part number 26-89.

Lars

Edit:
Oh... wait... that may be difficult to do on the secondary side of a 4160 carb with a secondary metering plate and no metering block...

Mr Fufu

Hi Lars,

Thanks for your tip about using a marine bowl to allow the OEM hard fuel line to be connected directly to my Holley 1850.

Seeing as my carb is working fine, this would be a great solution to eliminate the rubber hose now used to on my fuel line to carb connection.

I'm going to order one of these marine bowls from Summit today.

A couple of questions for you:

1. Once I receive the new bowl, what will be involved with installing it on my carb? Can the marine bowl be installed without removing the carb from the car? I see there are four bolts that hold the float bowl to the carb, but I wonder if there's anything else I need to remove?
2. Do I need to order a new float bowl gasket to install the marine bowl? Or, can I re-use the old one? I had my carb rebuilt about 18 months ago, so the gaskets on it now aren't that old, but of course I'm not going to cheap out if I should replace the gasket!
3. Anything else I should consider when swapping in the marine bowl?

PS - my Holley 1850 doesn't use the idle vent system setup with the wire lever, so that's not an issue here.

Thanks for sharing your knowledge - guys like you are what make this a great forum!

-Alex

DansYellow66

Opps - sorry to create confusion. I have 1850s on a 427 Ford FE dual quad intake that mounts them backwards so the whistles worked for them since they are the back (primary) fuel bowls.