Edelbrock 1407 on stock 402

[69SCSS]

Anyone have a baseline jetting for a stock '71 402 with an Edelbrock 1407? This is what the carb has now and it's way overrich... to the point it won't idle:

Primary jets: 415
Primary rods: 7147
Secondary jets: 407

Looks like the carb came stock with 413 / 7147 setup, but this has been upped to 415's. I can't find a calibration chart for the 1407 on the web for some reason, I find lots of 1405 / 1406's though, won't really help! I need to find the combinations for the 1407 since obviously the 415's are going to drown the motor. One thing is for sure it runs great at 3000 rpm and up right now! Fouls out pretty quick under that.

Anyone have the chart or any idea what a good starting point would be?

[engineer_gregh]

Subscribed. I'm running a 1407 on my 402 as well. As far as I know its running the jets and rods that shipped from Edelbrock. Wished I had taken pictures when I rebuilt it.

[geezer#99]

It's not the jets or the metering rods. It runs rich because you're idling on the power circuit. Get it to idle on the idle circuit and the stock jets and metering rods will work.

[slikside]

You can also call Edelbrock directly. They have a great tech support staff.

[69SCSS]

Originally Posted by geezer#99

It's not the jets or the metering rods. It runs rich because you're idling on the power circuit. Get it to idle on the idle circuit and the stock jets and metering rods will work.

Right, I can't get it to idle below 2k. I couldn't find a vacuum leak, so I'm still figuring that part out. But I know the jetting is too rich, it was when Rob had it with headers, and now that it's wearing stock exhaust manifolds it's going to be even richer. Just trying to get an idea of where to go, that is if anyone else has used a 402 with an Edelbrock 1407 and cast iron manifolds... with an Air Gap intake. Sounded killer above 3k like I said!

Originally Posted by slikside

You can also call Edelbrock directly. They have a great tech support staff.

Yea I might, I've had quite a few Edelbrocks and it's always been a process of elimination to find the cause, but you never know what you'll find. This truck has definitely stumped me a few times so far.

[trac209]

Originally Posted by 69SCSS

Right, I can't get it to idle below 2k. I couldn't find a vacuum leak, so I'm still figuring that part out. But I know the jetting is too rich, it was when Rob had it with headers, and now that it's wearing stock exhaust manifolds it's going to be even richer. Just trying to get an idea of where to go, that is if anyone else has used a 402 with an Edelbrock 1407 and cast iron manifolds... with an Air Gap intake. Sounded killer above 3k like I said!



Yea I might, I've had quite a few Edelbrocks and it's always been a process of elimination to find the cause, but you never know what you'll find. This truck has definitely stumped me a few times so far.

Is there a transfer slot adjustment? Perhaps it's closed too much making you need to turn up the idle in order to get it to idle somewhat at all.

[69SCSS]

Originally Posted by trac209

Is there a transfer slot adjustment? Perhaps it's closed too much making you need to turn up the idle in order to get it to idle somewhat at all.

Don't know if there is on an Edelbrock. Good question...

[geezer#99]

Originally Posted by 69SCSS

Right, I can't get it to idle below 2k. I couldn't find a vacuum leak, so I'm still figuring that part out. But I know the jetting is too rich, it was when Rob had it with headers, and now that it's wearing stock exhaust manifolds it's going to be even richer. Just trying to get an idea of where to go, that is if anyone else has used a 402 with an Edelbrock 1407 and cast iron manifolds... with an Air Gap intake. :

Did you know you can turn the high idle down with the high idle screw for the choke.
Once you get the idle down, put your initial timing at 12 degrees, hook your vac pot on the dizzy to a manifold port, reduce the idle down more and adjust your mixture screws. Now you should be idling on the idle circuit because you have the idle transfer slot covered correctly.

[69SCSS]

Originally Posted by geezer#99

Did you know you can turn the high idle down with the high idle screw for the choke.
Once you get the idle down, put your initial timing at 12 degrees, hook your vac pot on the dizzy to a manifold port, reduce the idle down more and adjust your mixture screws. Now you should be idling on the idle circuit because you have the idle transfer slot covered correctly.

It's a manual choke carb, and I have the screw all the way out for the choke. Normally when I slap a carb on first time after a rebuild I turn the idle screws out 1.5 turns each, bottom out the idle speed screw and turn it in 2 turns, and bottom out the choke so that nothing is in the way of the idle. I get it running and adjust timing / idle speed / mixture screws to lowest idle (usually shoot for 700-800rpm) and then set the choke (if it's electric) after it cools. Normally works well. I guess with all the trouble getting it started and replacing the coil I should just reset everything and start over. Probably just out of whack from trying to keep it running!

So anyway back to the topic, anyone have a known good tune for the 1407 on a 402?