Great tuning tips for Edlebrock 1406 carb!

[MikeB]

In my 30 years of working with Edelbrock carbs, this is the best tuning information I've seen. https://www.vintage-mustang.com/thre...k-carb.812713/ Go down the page and start reading the post by 1969sag.

I never really thought of 1406 jetting this way, but have almost always ended up with richer primary main jet/metering rod combo. Checking my notes I see that I've used #18 and #23 on the 1406 calibration chart, both of which are richer in cruise and power modes. Looks like a good place to start would have been the "stock" 1405 calibration, like the article suggests.

So, make your 1406 a real performer like the 1405. And probably get rid of any bogs and hesitation you're experiencing.

This info is intended to help those who are already using a 1406, so please don't turn this thread into an Edelbrock vs. Holley vs. Q-jet debate. Thanks.

Edit: I see where the newer AVS2 650cfm manual choke and electric choke carbs (1905/1906) both use the same calibrations. But I'm not sure if that's for economy or performance. I need to dig into that. Could be the 1405 was never CARB certified by California, but the 1406 was. I'd appreciate any comments about that.

[Dead Parrot]

IIRC - The 1405 was always listed as "Off Road Only". Since I live in OK that doesn't have emissions checks, didn't really care when I bought one. Truck was already setup for manual choke.

After reading some advice on this forum, ended up with going a couple steps lean from the base 1405 set. Mostly stock 350 with performer manifold. Which according to the above advice, is still two steps richer then the base 1406. But I was trying for a bit better economy. 2nd the idea of buying the calibration kit.

Altitude tip: If you are normally a low level driver but are planning to make a trip to higher altitudes, check the tune chart and find a tune about 2 steps leaner that only needs a rod change. Take those rods with you(pill bottle makes a good container). Part way up the mountain, swap the rods. Rod swap can be done(at least on the 140X series) via the small access ports. Simple 10 minute job. Enjoy better performance and not leaving a cloud of black smoke behind you. Reverse on the way back down.

[MikeB]

Originally Posted by Dead Parrot

Altitude tip: If you are normally a low level driver but are planning to make a trip to higher altitudes, check the tune chart and find a tune about 2 steps leaner that only needs a rod change.

Did something like that when I lived at 9,600ft and occasionally drove down to the the lowlands at 5,000ft! Also used a cam that closed the intake valve very early to get back some of that lost cylinder pressure. Ended up with a 350 that made good torque at 2500-3500 RPM on twisty windy mountain roads, even though it signed off below 4500.

[AcampoDave]

And now that O2 sensors work via Bluetooth to your phone as a guage, it's really easy and fairly economical to really see the results of any changes you make in real time.

[MikeB]

Originally Posted by AcampoDave

And now that O2 sensors work via Bluetooth to your phone as a guage, it's really easy and fairly economical to really see the results of any changes you make in real time.

I'd like to hear more about those type of sensors that you and other guys here have used. Maybe links them.

[AcampoDave]

Sure, I made this thread when I paired one with an Eddy carb. https://67-72chevytrucks.com/vboard/....php?p=9129708

[Willshook]

Originally Posted by AcampoDave

Sure, I made this thread when I paired one with an Eddy carb. https://67-72chevytrucks.com/vboard/....php?p=9129708

That's a great write-up.

It's so easy to get an F/A meter any more I pretty much always install an O2 bung and sensor. Pain is that they need to be powered even when not in use.

I still use this beast for most stuff that I do - far from perfect, but easy and relatively cheap. I like the Innovate stuff a bunch, but it's great to see all the new options out there.

https://www.innovatemotorsports.com/...ust-clamp.html

[AcampoDave]

[QUOTE=Willshook;9359245]That's a great write-up.

It's so easy to get an F/A meter any more I pretty much always install an O2 bung and sensor. Pain is that they need to be powered even when not in use.



Thanks, but at least it's a "set and forget" kind of thing, then you just put the threaded plug in and keep the sensor fresh for the next time.

[AcampoDave]

One more link I have is just to a thread I made about a book on Eddy carbs. I read it before I started messin' around with mine since I was still a little bit of a "greenhorn". https://67-72chevytrucks.com/vboard/...8982538&nojs=1

[cadillac_al]

I run a Eddy marine carb, I think it is 1408 but not positive. It is jetted richer and it runs excellent on every vehicle I put it on. I had an Eddy carb on an Impala 10 years ago and it was a dog. I'm sure it just needed to be richened up. I always assumed that the Eddy 1406 and Holly 600's were jetted for 305's anyway.

[MikeB]

Originally Posted by cadillac_al

I always assumed that the Eddy 1406 and Holly 600's were jetted for 305's anyway.

Sure, a 305 doesn't require as much air and fuel as a 350, but the carb doesn't know the engine size. It's about matching air flow and fuel flow with the the engine to get the correct A/F ratio.

Edelbrock didn't jet the 1406 for smaller engines, but for fuel efficiency.

That's why Edelbrock's literature mentions nothing about choosing jets & rods based on engine size. But somewhere they probably recommend the 1403/1404 500cfm carbs for a 305. And because of reduced airflow, those carbs use smaller jetting.