Holley 4160 - R1850-9 Rebuild Questions AND StepByStep Rebuild w/Pix

[rollo1504]

Hey Folks!

Today I started with the rebuild of my Holley 4160 Carburetor.

List Number R1850-9

4BBL-Secondary Vaccuum

Please have a look at the red marks and tell me if this is normal? From my point of view these small alleys should be completely free and NOT blocked right, or am I wrong?

As you can see that small metal parts (or rests, do not know the correct english word for it) block 90% of the with of shown alley...

I think I will have to remove them but before that I would appreciate to read your opinions...

As always - Thanks in advance

Roland

[rollo1504]

... could answer the question on my own ...

In my setup I have a 2-Corner Idle System. In that case it is NORMAL that the other alley is blocked.

Wanted to let you know this just as information as someone might come to the same question. 

Cheers

Roland

[rollo1504]

UPDATE:

I have to take back my former reply where I said that this is normal that the second "alley" is blocked by what I called "milling rests"...

I was not satisfied with my first answer I found in the web concerning this topic and continued research and it figured out that the second alley shall also be "open" or lets say "not blocked" as otherwise the alley itself would not have been milled if not needed.

Hope this might help somebody someday...

To be continued

Thanks Roland

[B5 Charger]

Hey, keep posting on this I am very interested to see your process.  I have my 4160 (4440) sitting on the bench waiting to be rebuilt.  I've never done one before and would be interested to see your process before I tackle mine.   

[rollo1504]

I have already done the rebuild, but as I have not installed the carb back onto the intake manifold I will disassemble some parts again and post some pictures.
Won't be that much work as I now already know how to do it and whats going on in there...
Further it would be a great pleasure to give something back to this forum and its members....

The very first annoying thing I learned was that in the Rebuild Kit (Holley #37-119) there IS NO Secondary Diaphragm included...

As I was very new to this topic there was a misunderstanding concerning this and now am upset due to my own fault as I have to wait 3-4 more weeks to get the diaphragm as shipping and toll stuff takes soo long time to get all parts to AUSTRIA/EUROPE....

Next thing is to consider what you will do in the future ... Will you keep your holley or will you use another brand e.g. edelbrock or something like that.... As I am planning to rebuild my engine in the future and keep going with Holley carbs for my desires I also ordered these parts for future tuning possibilities:

- Trick Kit Carb Rebuild Kit #37-933   ---> In this Kit included there are several Pump Noozles as well as PumpCams to fullfill my needs concering setting up my actual baby in a proper way
- Vacuum Secondary Diaphragm #135-4
- Secondary Diaphragm Spring Kit #20-13
- Jet Assortment Kit (Jet Size 64-99) #36-181
- 50 CC Accelerator Pump Conversion Kit #20-11
- Discharge Nozzle Screw "Hollow" #121-8
- 4160 to 4150 Conversion Kit #34-6S"
- Some different Power Valves -> But this I have bought via Ebay to find out if the power valves offered there meet up the "Holley" Power Valve Quality

Again here are my Carb Specs:

1850-9   600   (F)64,(R)plate 134-9   6.5      4160   -->            FuelJets 64; 6.5 PowerValve; PumpNozzle 31

If I rebuild by engine I am planning to go with a Holley 750 Double Pumper or something like that.

... more pix and infos to come ...

Have a nice time

Roland

[rollo1504]

... and to all other "Stealth" readers of this topic:

You are very welcome to post/reply If I am telling something wrong or misleading on this topic or just to give some hints or better recommendations.... as I don't want to provide wrong infos due to maybe not quite good enough research....

I appreciate that....

Thanks

Roland

[B5 Charger]

Well, I don't expect you to tear it back apart just for me but I will tune in if you do.  It may inspire me to get mine done!

[rollo1504]

Well, I don't expect you to tear it back apart just for me but I will tune in if you do.  It may inspire me to get mine done!

Well, the carb still is on the desk an not inside the car so I would not cost that much time for me....

I will tear it back apart and take some pictures... As I often mentioned before... I am NOT a mechanic but rebuilding this carb was a pretty easy job.... Just don't hurry and all will be fine...

I will post some pictures within the next days...

As soon as I receive the TrickKit and other stuff to be able to tune in my carb I can also post how is it going and details about initial setup and final setup if you want....

To give you an overview about the actual status: BEFORE I took the carb apart, basically the engine was running not that bad but to me it looked like it hesitated from off idle and near or almost WOT the engine stumbled... but I am pretty sure I will be able to fix it... as I have already noticed that the secondary diaphragm is broken, accelerator pump lever was wrong adjusted as well as the diaphragm was damaged and the floatbowls were not really well adjusted.

Will keep you up to date about the process if you want.

Whats my goal? Actually I want to have a stock engine running on best possible performance... I do not worry about fuel consumption as my baby is just a fun car to me and not a dialy driver.

Will also install a 3/8" fuel line and sending unit as well as a new mechanical fuel pump and a fuel pressure regulator and all the other needed stuff to ensure to have enough fuel going into the carb....

The only question I really still was not able to get answered was if the 600 CFM carb I use is enough for me or if I should go with a bigger carb... Some guys saying "the one you have is good enough" oder guys telling me I would wonder how the engine will wake up if I go with a 750 vac sec holley carb.

- Engine and distributor is ALL stock
- Intake manifold -> Weiand 8008
- 0,5" aluminium spacer

... to be continued ...

[rollo1504]

GENERAL INFORMATION:

- I took everything apart and removed all gaskets and rubber parts and SOAKED everything in laquer thinner over night. Then I cleaned all parts again with a toothbrush and brake cleaner and the result was pretty nice to me.
- Don't be afraid of doing it. Just take your time and do not hurry. You will see, removing all parts is very easy and self explaining how to put the things back together. Taking pictures might help :-)
- For the rebuild process I used the Holley "Renew Kit Carburetor Rebuild Kit" Part #37-119 --> UNFORTUNATELY a diaphragm for the sec vac is not included and has to be ordered separately.
- At first sight of the rebuild kit with all these very tiny parts and gaskets I was a little bit nervous but in the end it was very easy. During rebuilding process I just removed each old/worn out gasket one by one took pictures and searched for the adequate renewed gasket in the rebuild kit. For my 4160 1850-9 carb there were plenty of gaskets included in the rebuild kit.
- IMPORTANT: After soaking I cleaned EVERY SINGLE HOLE of ALL parts with PRESSURED AIR!
...
...
...

Ok lets start :-)

First I removed the VERY SMALL retainer from the secondary diaphragm piston/shaft

[rollo1504]

Next step was to remove the throttle body assembly which is mounted with 6 screws to main body assembly

HINT: Holley recommends NOT to use anymore the 2 centered screws (marked with red circles) as they can get loose and fall into the intake manifold so I will permanently remove them....

[rollo1504]

Then I removed primary and secondary fuel bowls. After removing the fuel bowl screws they will come off with a slap.

Do NOT use a flat screw driver for bending or you might crack or harm the fuelbowl housings or the primary or secondary metering body assembly.

To get the float bowls and all the other tiny stuff in there out you just will have to remove the small retainer (red circle).
When you put the parts together again check that the float bowl is aligned parallel to upper fuel bowl housing.

To do so just flip the fuel bowl upside down and check it (green lines). If it is NOT parallel aligned you can adjust it if you bend the float bowl "metal" (green square).

DO EXACTLY THE SAME WITH THE FLOAT BOAL IN THE OTHER FUEL BOWL

If you put everything back together later on also do not forget about renewing the Fuel Line Tube O-Ring Seal on both sides of the Fuel Line (blue squares)

[rollo1504]

Next step was having a closer look into the fuel inlet assembly and accelerator pump assembly of the primary fuel bowl....

Forgot to mention that it is also pretty nice to replace the Pump Check Valve which is the brown rubber part (blue circle)

To disassemble/reassemble the accelerator pump is does not needs word but be sure that the GREEN side from the NEW pump diaphragm points towards housing,
as I have alread seen on some pix in the internet that the new diaphragm was installed the wrong way (reverse round)

Also there are no words needed for taking apart/reassembling the fuel inlet (red square) assembly.
For that I have not pictures but will include the drawings from the Holley manual in this post....

87...Fuel Inlet Fitting
88...Fuel Inlet Fitting Gasket
89...Fuel Inlet Filter

[rollo1504]

Next step for me was to check the main body assembly

1. Remove and rebuild Secondary Vacuum Diaphragm Assembly
2. Remove and rebuild Fast Idle Cam Assembly
3. Remove and rebuild Primary Metering Body Assembly
4. Remove and rebuild Main Metering Body & Plugs Assembly

[rollo1504]

1. Remove and rebuild Secondary Vacuum Diaphragm Assembly

Take the assembly off by removing the 3 screws as well as remove the 4 screws of the secondary diaphragm cover

DO IT WITH CARE -> There is a Check Ball (red circle) inside which will fall out from the secondary diaphragm housing!

Replace the secondary diaphragm (not included in rebuild kit) and reassemble it. -> DO NOT FORGET about reinstalling the check ball!

HINT: During reassembling prepare the diaphragm to look like a mushroom. You know it is right when you see the edges of the diaphragm are FLAT on the diaphragm housing.

Ensure that the shaft of the diaphragm is hold in place until the cover is mounted to the housing. This will ensure that the diaphragm stays a mushroom during mounting process.... If you do not understand what I mean due to my bad english you will find several youtube videos about rebuilding the secondary diaphragm assembly.

IMPORTANT: Do not forget about the VACUUM PASSAGE GASKET (green circle) which seals Vacuum Passage to Vacuum Secondary Housing

Please keep in mind that the gasket shown on the picture is not the correct one, as obviously the correct cork gasket (Holley #PART# 108-67-20) is missing in my rebuild kit

[rollo1504]

2. Remove and rebuild Fast Idle Cam Assembly

Removal is pretty easy as you just have to remove the 3 screws of it.

CAUTION: Inside of the fast idle cam assembly there is also a fast idle cam plunger and a spring (red circles) which can also fall/jump out

There is nothing to do but cleaning.

When you put this thing together don't forget about the "gasket" (made of paper) from the Back-up Plate & Stud Assembly (green squares). I think this will have to be used only by MANUAL CHOKE setups...

[rollo1504]

3. Remove and rebuild Primary Metering Body Assembly

Primary Metering Body will also come off with a slap from the main body (do NOT use a flat screw driver for bending it off)

Removed Power Valve incl. gasket, removed jets cleaned everything and put all back together with new gaskets
Also check/clean the Idle Adjustment Needles and renew gaskets during rebuild (red circles)

[rollo1504]

4. Remove and rebuild Main Metering Body & Plugs Assembly

No words needed as it is self explaining... Watch the pictures...

[rollo1504]

The last to things would be the Pump Nozzle Assembly and check/adjust/remount Throttle Body Assembly

The Pump Nozzle is just mounted with one screw BUT

WATCH OUT: There is a Pump Discharge Needle Valve (red square) INSIDE and if you flip the main body upside down it will fall out!

Nothing else to do but cleaning and putting it back together

[rollo1504]

And FINALLY the close up of the Throttle Body Assembly

As we already removed the Throttle Body Assembly and cleaned it is recommended to check the CLOSED position of the secondary throttle blades.

If they are closed it is recommended to adjust the blades that inside of the intake channels the "alley" is shown as a square (green squares)-> Sorry but I am missing the adequate english words :-)

To adjust the blades you will finde a small hole beside with a screw within which is able to be turned with a flat screw driver (red circle)

[rollo1504]

DONE!

Just but the correct gasket to the Main Body Assembly, mount the Throttle Body Assembly and tighten it with 4 screws (On screw in each corner).

[rollo1504]

@B5 CHARGER

I hope this will help/encourage you enough... as well as it might help other forum members here....

IF SOME OF YOU FIND A WRONG EXPLANATION OR ANYTHING ELSE WHICH WAS NOT CORRECT SAID/EXPLAINED PLEASE MENTION IT AND I WILL CORRECT THE AFFECTED POST(S)

Thanks

Roland

[B5 Charger]

That's very informative, thanks for posting!  By the way what did you do about the blocked alleys in your first post?

[rollo1504]

For the moment I will not touch it as it was working also before....

But as soon as the new Throttle body assembly arrives I will clear the alleys to see if it makes any difference or not....

Regards

Roland