Edelbrock 1905 rebuild

[RockwoodMike]

Hello Everybody!!

My D22 1973 440 motorhome came to me with an Edelbrock 1905..With all the research I have done, this carb was made to replace the Thermoquad..

It was granted a smog replacement number VC27156 to replace the Thermoquad..

As the original instructions for install states...

Edelbrock Performer Q-Jet Carburetor for Thermo-Quad Applications is legal for street use on pollution controlled motor vehicles in all 50 states. To assist you with emissions equipment certification, we have included a fan shroud decal to help testing personnel verify that the carburetor is a legal replacement part for 1985 & earlier Chrysler
360, 400 and 440-equipped vehicles.

 The adhesive-backed decal should be affixed to your fan shroud next to the existing
emission and engine specification decal. Do not cover your original equipment specification decal with the Edelbrock

I am going to rebuild mine and use it..Here goes..

These 3  pictures show the thing at it's worst..

[RockwoodMike]

This thing has been abused pretty badly..But I think we have a good core to work with..

Here is an example..The idle screws..1 has been totally turn in to shut it off..The other was backed out some..

Look at the primary plates..They are partially open to where the transfer slots are..So the adjusting idle screws were not actually working at this position..

It really had a fuel delivery problem with this mess

[RockwoodMike]

My tear down tray..All parts neatly arranged and organized..  

[RockwoodMike]

Some soda blasting preliminary cleaning..Soda blasting will not wear away the metal..

[RockwoodMike]

Some more pics of the cleaned up parts..will soak them in simple green..check all the passages for gunk

[RockwoodMike]

https://cliffshighperformance.com/

https://quadrajetpower.com/

https://www.carburetion.com/Rochester.asp

https://quadrajetpower.com/primary-shaft-bushing-kit-drill-bit-bronze-bushings-screws/

I want to start with the primary butterfly shaft..Install new bushings that will make it perform like new

I have been taking pictures of the teardown..Unless someone wants to see them, I won't post them..

I will take pictures of it all going back together..

[Eyez Open]

Considering your talents and tool depth a APT mod really assists in fuel metering.A Very simple operation to to utilize it,it's called a "tip in procedure" made simple variable jet midrange tuning..almost the same as idle mixture tuning..


https://youtu.be/rl7s9S394xU?feature=shared

[RockwoodMike]

Yes..For the last three days, I have totally submersed myself in everything "Quadrajet"..

30 years ago I helped a coworker rebuild his on his 78 Monte Carlo..Everything came out fine, but it was the blind leading the blind, trying to read the "instructions" included in the kit..

I have been "Holley" and "Motorcraft" user..And have only the previous experience with the Monte Carlo on Rochester..

The APT (adjustment Part Throttle) is totally new to me..Adjustment is critical to prevent a off idle bog (lean)..

This mod to cut the top open and thread the plug allows you to adjust the metering rod in very small increments..

Initial start points can be anywhere from 2-3.5 turns out on the APT screw..

All it is doing is creating the resting point of the metering rod at idle..

The idle screws will affect idle..Even if you did not have a metering rod in place, your idle screws will adjust the quality of your idle..

It is when you partially open the throttle above idle is when the metering rod and the adjustment comes into play..

Well..I skee-ruude up..I just unscrewed without checking it adjustment..So I have no idea of where it was..I just wanted it out of there to clean everything..

This carb has a Main Jet: .073; Metering Rods: Primary-50M, Secondary-DR...

SOOOO..Big learning curve right now..

Here is a couple of pics of the metering rod assemble and the APT screw..squared off in red..   

[RockwoodMike]

https://www.ebay.com/itm/266627128673

You might think I am nuts on all this, but modifying a Edelbrock carb is an internet No-No..

To remove that plug above the APT screw and tap a removable plug devalues a unaltered Edelbrock..

So here is something I was thinking of doing..A mid to late 80s Rochester is pretty much a carbon copy of the Edelbrock..

Use this Rochester for the 440 and modify it to what it needs..

The Edelbrock's calibration is what I stated earlier..
Main Jet: .073; Metering Rods: Primary-50M, Secondary-DR...

So why not run a Rochester Q-jet on the 440 and put this Edelbrock in a display case in my garage to look and admire it  

 

[RockwoodMike]

[Eyez Open]

They say perception is eveything...the eldelbrock is a direct copy of the Quadra Jet. What ever you choose to do I'm quite sure it will work. The eldelbrock would be my first choice, that old Rochester has landmine potential...


That carb in the eBay link is one of two models made for RV'S HD trucks.
https://cliffshighperformance.com/simplemachinesforum/index.php?topic=4486.0

1. 212
2. 213

I'm quite sure that 1905 you have is a direct copy of the two above carb numbers.

As to modifying the eldelbrock,actually your only enabling access to APT systems. The same type of modifying has to be done to gain access to the idle mixture screws. I am with you on a Rochester that has modified internally. Rochester carbs were tuned as emission carbs with emissions type of ignition  timing. Fuel has changed dramatically since that time frame, just a few metering and timing changes can bring very good results, Combustion efficiency can be greatly improved upon.

Below is thread related to your carb, and as you can see he's quite open and friedly..Very down to earth.By the way...he will get you dead nuts on your required metering for that engine carb combo...yes he is that experienced and good.


https://cliffshighperformance.com/simplemachinesforum/index.php?topic=4295.0

If you want to get it up to par call me at the shop and I will put together a custom rebuild kit with tuning parts so it's basically "plug and play"....tks.....Cliff

[RockwoodMike]

I had a 45 minute talk with Cliff Ruggles on Friday..He knows his stuff is a very under statement..WOW!!

He is sending me a kit with different rods and jets..new float and idle screws for the Edelbrock..

I bought his book..That will be an interesting read for sure..

Got the rebush kit for the primary shaft and I will get the APT access hole set up..

[Eyez Open]

Good for you, your fuel metering will now be correct for your engine needs. Quadra jets are precise metering carbs,not a one size fits all. Often they are called emission carbs, meaning highly calibrated to a specific engine size and rated horsepower to provide a very specific fueling results..emission results. Not efficienct power and economy. Much has changed since the 70's/ 80s...Fuel is vastly different.

Was he aware of your new intake? He's not a fan of certain dual plane design's.

[RockwoodMike]

I never mentioned anything about the intake manifold..Need to do more research on that Edelbrock intake..Worth the money or not..

The kit is very complete..A lot more in it than your typical kit off Ebay..
With a car rebuild, you need to be in the right frame of mind when reassemble time is here..

I am not in that right mind ..My mind is on the engine with all of it involves..