Hi, I do not mean to beat a dead horse but have you tried to talk to the tech line at Edelbrock and get their recomendations as to how to set up their carburator? If anybody can help you I would think it would be them. Pete

Hi John,

I set the timing without the vacuum. So that should be OK. I'm beginning to wonder how well my carb is set up. Right out of the box and change the metering rods and set the idle, but how likely is it that I need to set the float level. I'm using one of the old fuel pumps with the glass top. Should I check/reset the float level. If so how is this done?

Thanks,

Ed

Ed:

If you set your timing at 8 degrees with the vacuum line connected, you will not have enough ignition advance for good performance and mileage.

John

John - "The Hoosier Hurricane"

Thanks guys,

 

My timing is set a little above 8* BTDC. But, I did find something that may make a difference. After I had a closer look at my set up, found that I had the distributor hooked up to the fulltime vacuum and not the ported vacuum. I also set the points to .015 gap – they were closer to .018. I got this '57 distributor new from the parts store and that’s the way it came - points and all. So assume the vacuum diaphram is set up correctly as well. I really have no idea about this stuff, but am learning as I go. I’m going to drive it for a while and see if it improves. Any other suggestions?

Hello, About your carburator. 10 MPG is way off base. At idle can you tell us how much manifold vacume you have? Not carb vacume. I don`t think that bad points are an issue but timing might be. Hook up a vacume gage and advance your distributor for the highest reading. Drive the car and if it pings then back off until you are comfortable. Why not call Edelbrock and ask their tech support to give you some direction? If it smell like it`s too rich it is. I like Holleys. Pete

Your exposed jet area in cruise calculates out to 0.00228 sq inches which is about 7% leaner than what I ran.  The 500cfm Carter on my 272 with Isky cam would get ~17mpg in city and 19 on the highway with the T-85 overdrive.  The Isky cam is ground on 108° lobe centers but was installed at a 104° intake lobe centerline.  I played around with the valve lash and the engine liked it on the loose side.  You might check that the float levels are set correctly as either too high or too low will hurt the fuel mileage.  Ignition timing is also extremely important and the Y tends to like a lot of it, especially in cruise mode.  Make sure that the vacuum advance chamber on the distributor is functioning regardless of whether it's hooked up to ported or direct vacuum.

Lorena, Texas (South of Waco)

Have a look at this page http://www.edelbrock.com/automotive/eps_1404.html

I went one stage lean - see chart on above page.

REF #    MAIN JET       METERING ROD      CHANGE FROM BASE
   6       1423 (.086)   1463 (067 x 055)     Rod

I still need to do some tuning. It's not quite right and I'm getting less than 10 mi/gal - I think it might be my timing or points or something, but it also seems to be running quite rich so even though I did follow the advice form another thread on the old forum, I can't say for sure that the above is the right choice for my application:

I've got a stock 292 with '57 distributor & intake and Edelbrock 1404 carb.

I don't know if this will help but I ran the 500 cfm Carter on my '55 for a good while before switching to the 525 cfm Road Demon Jr. and here's what I had in my notes.  I ultimately ended up using the 388/392 rod and jet combination.  If my notes are correct, the final jetting combination had an effective surface area of 0.002462 square inches.  Prior to that, I had been running 0.002490 square inches of effective primary jetting and the downsizing was worth an additional 0.3 mpg based on the average of twelve fuel checks with each jetting size change.

Lorena, Texas (South of Waco)

Ed,

What rods are you using with the carb?  I have the same carb with a little warmed over cam, and the blue thunder intake, and it feels pretty lazy/unresponsive in the midrange.  Trying to figure if thats too rich or too lean, and which way to go with the rods.  I already changed the springs, which helped a lot, but still not as good as should be.  Any thoughts?

Thanks!

Ron Grove

Wauconda, IL

Thanks again Ted.

 

I tried to buy a vacuum gauge from the local parts store here and the guy didn’t know what I was talking about. I’m going to have to keep asking around for one.

 

I know squat about tuning a carb, so will do some research before I mess with it any more.

 

Thanks again for your help.

 

P.S. This weekend I’m taking the Merc on a 1200 mile road trip. It’s the first one since I did the frame off and probably the first one that car’s had in 30 years.

 

Wish me luck! : )

 

Ed