1968 DeVille Convertible - Restoration

[Highwayman68]

That interior looks beautiful 

[DeVille68]

That looks very nice.
I bought me triple whitewalls from Coker. They are bias ply an have awesome steering return and stability with factory settings on my 66. Had radials before, with the same settings they definately didn´t run that good. So a very good intention to change the settings.

I had 10W30 in my Caddy, was okay, but I wasn´t happy with the consumption. Changed to 20W50, too much lifter noise after a week or more. So I changed to 15W40. Awesome, doesn´t need any oil between the changes and it´s quite.

What type of washer do you mean? This wedge styled one? Be aware, this one is made from pretty high strengt steel in original. A friend has problems to find a used/new one.

Greetings from Germany,

Richard

Hi Richard,

Thanks for posting! Very interesting. Yes, I will let you guys know how the increased caster will be like.
Interesting that you experienced the same issue with the thick oil, seems that I made the right guess.

Yes, luckily I do have both special wedge style washers. However, the new moog ball joints have the hole for the cotter pin in such a low position that the cotter pin misses the castle nut!  So I have to somehow bring the castle nut higher up to the hole for the cotter pin (more to the end of the stud). Or I have to use another method of securing the nut from turning. I will leave the original wedge washer in place, because it covers the hole in the spindle.

Thanks Mark, for the compliment. I restored the Brazilian rosewood veneer myself, next up will be the recreation of some interior parts and replacing the front leather because someone used a wrong type leather on the front seat area. It is the correct color but the wrong texture.

Best regards,
Nicolas

[savemy67]

Hello Nicolas,

Wedge washer = camber eccentric?
Splint = Cotter pin?

If the camber eccentric and spindle are original, but the ball joint is new, I would suspect that the ball joint is not correct, or not correctly manufactured, if the hole in the threaded part of the ball joint does not allow the cotter pin to be inserted through the slots in the castle nut.

Or, the castle nut is not the correct height.  Is the castle nut original or did it come with the Moog ball joint?

Or, the camber eccentric is not seating fully in the spindle taper.

I would probably not alter the relationship between the camber eccentric and the spindle assuming it is correctly seated.  You might consider a thick, hardened washer of the correct inside diameter to place over the stud before fastening the castle nut.  Although a washer will probably have too large an outside diameter.  Another possibility is to use a machinery bushing.  These are thick, but with a smaller outside diameter than a washer.  Another possibility is to find a jam nut of the correct diameter and pitch.  A jam nut is a hex nut about half the height of a standard hex nut.  You could install the jam nut first, then the castle nut, and this would move the slots in the castle nut closer to the threaded end of the ball joint stud.

Generally, the taper fit of a ball joint stud in the spindle is self locking - like a Morse taper in a mill.  However, in the Cadillac with a camber eccentric, which needs to be rotated, this may not be the case.

You may want to first check if your ball joint is correct.

Respectfully submitted,

Christopher Winter

[klinebau]

I assumed he meant the large washer underneath the camber eccentric.  In combination with the nut on the ball joint, this washer is what keeps the camber eccentric anchored to the spindle.  You can see the washer in the diagram and it has flats on it.  It seems like you could easily add additional washers under the castle nut to space it out correctly, although you should not have to do that with the correct parts.

[Bentley]

Nicolas,

Glad you got your car running in time to enjoy some nice top-down driving weather.

[Lowrider2905]

Hi Nicolas,

had the same issue. There where approx. 2 mm misssing. Machined 2 shims from good steel to make sure, the pin secured the nut.
Works perfect.

Greetings, Richard

[DeVille68]

Wedge washer = camber eccentric?
Splint = Cotter pin?

Hi Christopher,
I am sorry, yes I meant cotter pin. The wedge washer (its more like a D-shape) is between the castle nut and the spindle. It basically covers the hole where the camber eccentric goes through. The camber eccentric is pushed in from the other side.

If the camber eccentric and spindle are original, but the ball joint is new, I would suspect that the ball joint is not correct, or not correctly manufactured, if the hole in the threaded part of the ball joint does not allow the cotter pin to be inserted through the slots in the castle nut.

Or, the castle nut is not the correct height.  Is the castle nut original or did it come with the Moog ball joint?

Or, the camber eccentric is not seating fully in the spindle taper.

The ball joints are replacements from Moog. The lower ones fit just fine. I am guessing that the shaft / threaded part of the stud is just too long for this application. The castle nut that came with the ball joint was even thinner. The camber eccentric fits just fine on the tapered shaft of the ball joint.
I will have to check if the eccentric is correctly seated, but I did follow the factory steps by first tightening the assembly with a normal nut. I even had the engine out and no weight on the A-arms, so it should have seated fine. I will check this next weekend.

I would probably not alter the relationship between the camber eccentric and the spindle assuming it is correctly seated.  You might consider a thick, hardened washer of the correct inside diameter to place over the stud before fastening the castle nut.  Although a washer will probably have too large an outside diameter.  Another possibility is to use a machinery bushing.  These are thick, but with a smaller outside diameter than a washer.  Another possibility is to find a jam nut of the correct diameter and pitch.  A jam nut is a hex nut about half the height of a standard hex nut.  You could install the jam nut first, then the castle nut, and this would move the slots in the castle nut closer to the threaded end of the ball joint stud.

Yes, I already made a washer and grinded the side flat, however it is just barely thick enough. I might try the idea of the jam nut. However, I don't have a jam nut and I don't know where I can get one quick. I might try a regular 1/2''-20 nut to see if this if enough or too much.

had the same issue. There where approx. 2 mm misssing. Machined 2 shims from good steel to make sure, the pin secured the nut.
Works perfect.

Hi Richard,
Ok, very good! Glad to hear. Yes, that's about the same that is missing on mine too!
I will leave the original piece in place and just put the additional washer on top of it.

Thanks, Wes. Yes, August, September and early October are my favorite months anyways!

Best regards,
Nicolas

[35-709]

The True Value Hardware store in my town carries jam nuts.  Ace Hardware may carry them too.  Wouldn't count on Lowe's or Home Depot but who knows.

[Roger Zimmermann]

The True Value Hardware store in my town carries jam nuts. 

I really doubt that Nicolas will take a plane to reach 2 jam nuts!

[Lowrider2905]

Niclas,

I think Christopher was correct with the height of the nut.

After my 2 shims I fabricated, I bought a  box with plenty of nuts during my last US holiday. What I can tell you is, that these crown nuts where higher and if I would change them one day, the cotter pin would fit perfectly. I bought a complete front end rebuilt kit 6 years ago, all the other parts where perfect in fit. But nothing wrong with shims IMHO.

Greetings, Richard

[35-709]

I really doubt that Nicolas will take a plane to reach 2 jam nuts!

  Must remember to engage brain before typing.  Forgot Nicolas was not in the U.S.  I could mail some to him though! 
 

[DeVille68]

Hi guys,

Update on the ball joint nut and cotter pin issue.
First of all, consider the first picture. The second ball joint from the right is an original upper ball joint. There is no hole for a cotter pin. Also the shop manual does not mention a cotter pin but a lock nut. These are to "old" style lock nut, without the nylon. The other ball joints to either side are reproductions of unknown original or age.

I did check that the eccentric is sitting right, there is no space between the top of the hole for the eccentric, so it must sit good, also the ball joint stud fits tight. Both sides look the same.

I bough some 4mm thick washers and cut those to mimic the shape of the original one. Together with the original ones they are now about 8mm thick. Now I could torque the nuts and insert the cotter pin.

I then moved the Caddy on to the lift to reattach the exhaust, because I had an exhaust leak. I also but in all cotter pins, had to adjust the wheel bearings, install the flex plate cover and do some other smaller stuff.

Then I was on my way to a longer test drive, about 60 miles on highway and up a smaller mountain road.
Car performed nice, the suspension is super nice. The pure hydraulic shocks are worth it.
Attached a few picture of my "control panel" inside the car.
The second to last shows highway driving, 120 km/h (75mph), rpm is about 2600, vacuum about 16-17'', oil pressure around 40 psi, air fuel ratio is between 14.5 - 14.7.
So right about perfect.

The last pictures shows idle, with about 600 rpm, vacuum is too low at 15'', oil pressure at about 18psi, and air fuel ratio is horrible at around 13. So much too rich.

I did not know what would cause this richness in the idle. I was also not able to adjust idle nicely.
Today after work I realized that this must be caused by a too wide open throttle plate exposing the idle transition slots, because the idle mixture screws are almost complete turned in.

So now I screwed the idle speed screw out "completely" and will set the idle mixture to about 4 turns out. Let's see what happens. I noticed too that the throttle plate does not close completely, it is strangely held open by the accelerator pump lever! Strange. I have to investigate this issue further.

Next post will be about the new distributor and the test stand that I build myself to test it.

Best regards,
Nicolas

[Lowrider2905]

Nice to see that you solve the cotter pin issue.

What type of carb do you have?

Will check my vac, so normally you should have highest vac at idle. Is the panel temporary for adjustments? I installed a fixed panel in my 66 made from aluminum with oiltemp and pressure. And real water temp.

Oil pressure is pretty good while driving. The 429 has a pretty low pressure compared to this.

Where do you have installed the fuel/air mixture sensor?

Greetings, Richard

[klinebau]

You probably aren't going to get the same vacuum as stock with an non-stock cam.  You may find that the engine wants more idle fuel.  You can pull the idle tubes and enlarge slightly if needed.  The restriction is at the very bottom of the idle tube.  I don't think that the 68 Quadrajet has idle bypass air, so you will need to be careful that the primaries are not open too much and causing nozzle drip.  You should be able to close the primary throttle completely so you need to look at why that is hanging up.  You might need to re-bush the primary shaft and re-index the throttle plates so that they close properly.

There are a lot of resources available for Quadrajet tuning/adjustment, but I personally like Cliff Ruggles' book the best.  I wouldn't be too worried about the A/F ratio at idle.  You just need to focus on getting the lowest smoothest idle possible.

[DeVille68]

What type of carb do you have?

Oil pressure is pretty good while driving. The 429 has a pretty low pressure compared to this.

Where do you have installed the fuel/air mixture sensor?

Greetings, Richard

Hi Richard,

Unfortunately, I don't have an original one but close. 7029232 - it is for a 69 Eldorado (if my infos are correct).
The panel is just for the initial break-in and tuning period. So I guess until the engine drives nicely.

I have welded an adapter to the exhaust pipe about 10 inches after the pipes connect. I have added a few pictures. I thick I have jet to take a picture with the exhaust installed. It clears the floor pan and the shift linkage.

You probably aren't going to get the same vacuum as stock with an non-stock cam.  You may find that the engine wants more idle fuel.  You can pull the idle tubes and enlarge slightly if needed.  The restriction is at the very bottom of the idle tube.  I don't think that the 68 Quadrajet has idle bypass air, so you will need to be careful that the primaries are not open too much and causing nozzle drip.  You should be able to close the primary throttle completely so you need to look at why that is hanging up.  You might need to re-bush the primary shaft and re-index the throttle plates so that they close properly.

There are a lot of resources available for Quadrajet tuning/adjustment, but I personally like Cliff Ruggles' book the best.  I wouldn't be too worried about the A/F ratio at idle.  You just need to focus on getting the lowest smoothest idle possible.

Hi Kurt

I have not jet noticed a nozzle drip, but that could also be a problem. I think the idle tube supplies enough fuel but there is not enough air. The mixture is always pretty rich. You are probably right, I need to drill or open up the air feed. Unfortunately I only have the book Rochester Carburetors from Doug Roe, it does not explain how to modify those.

Would you mind to scan me the relevant pages about idle mixture and tuning tips?

I was able to adjust the linkage to give me a bit lower throttle blade. I let the engine warm up with the choke and shut it off, throttle only open one turn. Would not start. Only started and idles with about 2,5 turns. Once I got about 18 inches, so that tells me that I am working at the right issue. In gear at 450rpm  I have it idle better at 15 inches and 12.8 air fuel ratio. 
(if I increase the idle speed in gear the speed in park increases to about 900-1000)

Thank you very much
Best regards,
Nicolas

[Roger Zimmermann]

I have it idle better at 15 inches and 12.8 air fuel ratio. 

It would be interesting to know his value 12.8 air/fuel ratio is translated in CO at the exhaust. In those years, 2 to 3 % CO was acceptable. One is sure: you never will get 14.7 at idle with a carburator.

[Highwayman68]

Unfortunately, I don't have an original one but close. 7029232 - it is for a 69 Eldorado (if my infos are correct).

Awh Nicolas I could have included a proper carburetor if I knew you needed one with the shipment of parts last summer.

[DeVille68]

Hi Roger

I can measure this tomorrow or the day after!

Hi Mark,
Nice! You have one with the correct number? Anyways, I probably have to modify the idle air system. There is a restriction that I need to open up. Strangely the current baseplate has no provision for an idle air bypass!
I do not know if this is correct or not.

I might have a car (not mine) that will be sent over. So might sneak this part into the trunk...

Best regards,
Nicolas

[DeVille68]

Hi

Can anyone tell me if the base plate of my Quadrajet is correct? (first picture).
There is absolutely no air bypass passage.

Usually the picture of a Quadrajet looks something like this:

(picture from here: http://www.crankshaftcoalition.com/wiki/How_to_rebuild_a_Rochester_Quadrajet_4MV_carburetor#Air_fuel_ratio)

In general:
What Quadrajet mods are needed for a 472 with MTS #5? Does anyone of you has an experience with this combo?

Thanks!
Best regards,
Nicolas

[klinebau]

I don't believe the '69 quadrajet had idle bypass air, so I think your carburetor base plate is correct.

Although you can modify the carburetor to add idle bypass air, I think you probably can get it working as is.  I am not sure of the MTS #5 cam specs, but I don't think it has much overlap.  What source are you using for the vacuum advance?  Ported or manifold?  You will see a lot of disagreement on the internet, but you will get a more stable idle in and out of gear using ported vacuum.

With any non-stock cam, you are going to get less vacuum and therefore a weaker signal for the idle system.  This is typically why you need to add more idle fuel in these situations.  To increase idle fuel you can either enlarge the idle tube restriction or increase the idle down channel.  The idle bypass air helps to get the throttle angle in the right position relative to the transfer slot.  If the throttle blade is too high, you can increase the size of the bypass holes (or add bypass air in your case).

To start with, I would make sure the float is set correctly.  A higher float setting will get you more fuel everywhere (including idle).  I would also make sure that you are using ported vacuum.  More initial timing will also help a little.  Next, you need to figure out if the idle wants more air or fuel.  You can put your hand over the choke opening to check for a too lean idle (I like to use a heavy glove).  If the idle quality improves, you need to add idle fuel.  To check for a too rich idle, you can pull off a small vacuum hose.  If the idle improves, you need to add more idle air  (this assumes that the throttle blade is in the right spot already).  Let us know how that goes.