Edelbrock 1407

[ventura74]

Ok anyone have suggestions on where to start with rods and jets for edelbrock 1407's on a rpm air gap intake. Chevy 383 on my other post (edelbrock rpm air gap ) some people suggested these carbs so I bought a pair of used ones to go through and try.

[bigjoe1]

The stock jetting will be VERY CLOSE as it is. Do not change it unless you have it on a dyno


JOE SHERMAN RACING

[ventura74]

Ok thanks Bigjoe will do.

[quickd100]

Just dyno'd a 426 mopar wedge, 11.8-1, piss poor heads, 440 torquer , 1-3/4" headers, comp cams .525 solid cam. Best power&torque were using .107 primaries, .071x.047 rods, .101 sec.jets. 1407 eddy carb.Dave

[one finger john]

But But But ..... what were the results ? How much horse power did it make ??

John

[quickd100]

John, with a set of 516 mopar castings and stock valves and no porting it made 453.5hp@5524rpm & 502.2ftlbs@4365rpm. On my equipment best hp was made at 13.80 F/A ratio. peak torque was at 13.48.Dave

[Walter R. Malik]

Stock jetting is real close but, if you have intentions of high RPM the needles & SEATS need to be larger than the .089" which come in them. I open them up on a lathe to .107".

[DaveMcLain]

Stock jetting is real close but, if you have intentions of high RPM the needles & SEATS need to be larger than the .089" which come in them. I open them up on a lathe to .107".

I was wondering about that too Randy. A couple of years ago I had a guy with a 432 inch big Mopar for his '68 Dart. The engine made about 500 horsepower using my 950HP but I never could get it to run well with his Edelbrock carburetor when we tested it on the dyno. I could never make it get rich on the top even if I took out the jets on the secondary.

At what about what HP level do they become a problem with say 7psi fuel pressure?

[Tuner]

Stock jetting is real close but, if you have intentions of high RPM the needles & SEATS need to be larger than the .089" which come in them. I open them up on a lathe to .107".

I was wondering about that too Randy. A couple of years ago I had a guy with a 432 inch big Mopar for his '68 Dart. The engine made about 500 horsepower using my 950HP but I never could get it to run well with his Edelbrock carburetor when we tested it on the dyno. I could never make it get rich on the top even if I took out the jets on the secondary.

At what about what HP level do they become a problem with say 7psi fuel pressure?

The clone AFBs, Edelbrock and the previous Federal Mogul versions, have several problems. Many of them (nowadays most) have several reasons they won’t get rich enough on many (most) engines.

The secondary venturi cluster emulsion tube is “pinched” at the bottom with a .073” orifice the fuel must pass through to enter the tube to get up to the discharge nozzle….. and (it gets worse) …… the secondary Main Air Bleed is .073”. Imagine what a Holley would do if it had a .073” bleed in the booster leg.

The reason it doesn’t seem to matter what jet size is used is the .073” air bleed kills the venturi signal and no matter what main jet size larger than .073” is used the fuel must pass through the .073” restriction downstream of the main jet.

As if that isn’t bad enough, the primary MAB (the tube pressed in the top of the cluster) is occasionally very large, .040” or more, and occasionally different on left and right.

Occasionally the idle jet (the small tube pressed in the bottom of the cluster) is different left and right and sometimes the idle jet larger than necessary, resulting in a very rich off-idle.

The 1407 750 CFM uses the same casting for the primary cluster as the 625 CFM carbs in spite of the fact the venturi minor diameter is 5/16” or so lower in the 750 body. This places the exit of the booster venturi that much above the “vena contracta” in the air flow, the result is the “booster signal” is not obtained in the correct location and the metering is erratic, the A/F wanders rich and lean as load and RPM vary as the throttle position is changed.

[andyf]

Good info Tuner, I've never looked at the Eddy carbs that closely. I have tune a few of them on the dyno and found that it is hard to get enough fuel thru them on a big motor. The first solution is to upgrade the needle and seat. On the primary side they'll usually flow enough fuel but you have to make a custom rod. Maybe something like a 65/25 or so. The secondary side has always been really hard to increase, maybe because of what you're saying about the internal restriction.

[91stang]

So what are the advantages of doing all that work to an Eddy vs going to a 4150 Holly? Can't really be saving much money after all the mods, can you? Never used the edelbrocks on much more then stock motors anything "performance" just hot one of the numerous holly offerings.

[bigjoe1]

My experience has been very good with the Edelbrock carbs. I keep an Edelbrock 800 for starting up all the street engines I build. It has proven to be as good or better than anything I have run up against up to about 550 HP... Just last week, I ran A fresh 383 engine on the dyno, and it made 545 Hp with the 800 Edelbrock.. I put on the new 750 Hp Holley, and the best I could do after jetting was 541 HP. I have seen this relationship at least 20 or 30 times in the last ten years.. I will admit that I have done some minor rework on the Edelbrock carb--- I removed all the choke mechanism, and smoothed out all the sharp edges on the top of the carb body ( Ededbrock ) These minor tricks increased the air flow about 40 CFM over thew out of the box numbers.I sell as many Edelbrock carbs as the other types . ( i prefer Quick Fuel over Holley )



JOE SHERMAN RACING

[cgarb]

Joe,
You can't argue with dyno numbers but, out of curiosity have you ran the Edelbrock carb vs a holley at the track? I generally don't see Edelbrock carbs on bracket cars around my area. If they truly make more power I wonder why that is?

[bigjoe1]

I know exactly what you mean. Here is a cute story I have to share . About six or sever years ago, my son was using his race car to teach one of his kids how to drive at the drag strip.. The car was a 1965 Nova, with a 383 that I did for a magazine project for Super Chevy. It had GM Vortec iron heads. Custom Hyd roller , RPM Air Gap, HEI distributor, and the now famous 800 Edelbrock. It was 10 to one, built for pump gas.. At the local little 1/8 mile strip ( parking lot at Perris oval track ) it ran times like 6.60 at 105--- The fastest car there was always a Jeep with a 454 Chevy and NOS. He also ran 6.60 at 105.. One night , the announcer asked to have a match race with my sons Nova and the Jeep.. Well, after my son BEAT the Jeep in a real close race ( about 5 feet ) the owner of the jeep came over to look at the Nova. He made fun of the fact that it hade the Edelbrock carb and HEI distributor. He also said he had NEVER been beaten in two years of running there at that track... HE DID NOT KNOW WHAT HE WAS LOOKING AT. DID HE ???--- This is the same car that has run 8.75 at 153 lately


JOE SHERMAN RACING.

[cgarb]

6.60 at 105 with Vortec heads is pretty respectable. Must be something to those little carbs then. Pound for pound I still like smallblocks...mines taken a few big blocks to the woodshed. Not that mine is anything special, but there are people out there that like to say they have a big block for the sake of saying it. I enjoy hearing people say "wow, that's a small block in there?". I don't so much as care what engine anyone has, style, color, or size. I just enjoy the ones that work well. I do run methanol for brackets and I have never seen an alky Edelbrock carb. Would be different to see one made though.