1968 DeVille Convertible - Restoration

[DeVille68]

It seems to me that the plugs in front of each head are not expanded enough. I see just a slight indentation, (see the arrows on the picture); is that deep enough?

Hm, I don't know! These plugs are used to plug the casting holes. They are usually not included in the freeze plug kit. My engine rebuilder removed the "original" ones and put those in. I have not checked if they are correct. However, they are a different style than those that were in there. "Original" where some that looked like freeze plugs. These new ones are basically flat with just a little bow, but on the outside. They seemed pretty tight? I don't know where those plugs go to but probably water or oil.

Best regards,
Nicolas

[DeVille68]

This is just a suggestion.  If you apply masking tape to the entire machined surface and extend the tape over the edge of the machined surface, you can use a soft-faced hammer (bronze, lead, plastic) to tap the edge of the machined surface all the way around the part.  The edge of the casting is sharp enough to cut the tape, which you can then peel off, leaving the machined surface perfectly masked.

Yes, thanks. For the most part I used your suggested method but I used a razor knife instead.
One some surfaces I did put the tape on it and then put the gasket on top and traced it with the razor knife.

Best regards,
Nicolas

[DeVille68]

Today, all day was spent with the oil pan, pickup and dip stick.
First, I did cut the bracket of the pickup in half because the ARP studs have a thicker washer and nut so the pickup screen would not sit right. I then measured the proper clearance to the bottom of the oil pan and used some small wood "blocks" with paint on it and then installed the oil pan. Without the gasket those blocks would mark the pan slightly, so I know now that I have about 6mm (1/4'') clearance from the screen to the bottom of the pan. First five pictures show this.

Then I turned my attention to making a oil pan baffle, I used a cardboard and made a template. Then I cut it to fit, and made another one from this, again fitting it to the pan. Then I used this final template and transferred the shape to a 1.5mm thick steel plate that I had laying around. I think it was an old pc housing.

I used a plasma cutter to cut out the "funny" shape. Then I used a grinder to smooth the edges and work the metal some more. All in all it took me about 4 hours to finalize the baffle. I bent four taps on each side such that I can weld those to the pan.
The purpose of the baffle is to prevent to oil from sloshing around while braking, accelerating and turning sharp corners. There are now trap doors, this is just a simple baffle. I just want it to keep the oil a bit longer around the pickup when I drive up and down the mountains.

I will do the welding next week.  Until then, let me know if you have any further suggestions to the baffle.

Best regards
Nicolas

[DeVille68]

I also installed the lifters and pushrods, cleaned them inside and out. Soaked the lifters in engine oil and then did put some assembly lube around the contact surfaces. The pushrods still looked good, no real wear on the tips.

Then I cleaned to rocker arms and also put assembly lube on the contact surfaces. Installed those in the order they where removed, also the pushrods ended up in the exact same spot.

I then torqued the bolts down and made a mark on the pushrod, then I released the tension of the bolt and made another mark. The distance between the marks is the lifter preload - I measured about 0.040'' - which is right in the middle of the specs.

Then I did not use the rubber gasket for the china wall but used permatex all around. Then layed the valley pan on top of it and coated the upper side with a some permatex. Then I lifted the intake onto it not bolting it down but just resting there. I waited about an hour and half before I torqued the intake down. This allows the permatex to cure a little, such that when you torque it down it can compress. Otherwise, it you immediately torque it down it will just squeeze the material but it will not compress properly.

Still made a huge mess, cleaned up a bit, but still have traces of permatex all around! :-D

[Bentley]

Nicolas, Thanks for posting the updates. I'm learning a lot about my own engine from your blog. Is your valley pan corrosion resistant? I read on CadillacMike68's post about how the bottom of his pan rusted and caused engine damage.

[Roger Zimmermann]

My engine rebuilder removed the "original" ones and put those in. I have not checked if they are correct. However, they are a different style than those that were in there. "Original" where some that looked like freeze plugs. These new ones are basically flat with just a little bow, but on the outside. They seemed pretty tight? I don't know where those plugs go to but probably water or oil.

Those plugs are closing the water chamber from the heads. If they are not tight, they may pop out. Ask your rebuilder about that.

[DeVille68]

Nicolas, Thanks for posting the updates. I'm learning a lot about my own engine from your blog. Is your valley pan corrosion resistant? I read on CadillacMike68's post about how the bottom of his pan rusted and caused engine damage.

Well depends, it is just a stamped steel pan, seems to have some sort of coating. The reason why it rusted out in CadillacMike's case was probably high humidity and a bad seal between the pan and the manifold. I noticed this too on mine and had to pull the manifold off again and increased the permatex bead on top of the valley pan. Otherwise humidity will get between the pan and the manifold, where it is basically trapped. No vacuum issues arise but you may have corrosion issues.

Best regards,
Nicolas

[DeVille68]

Those plugs are closing the water chamber from the heads. If they are not tight, they may pop out. Ask your rebuilder about that.

I hope to see my engine rebuilder this Friday - I will ask him about those plugs.

[DeVille68]

Hello everybody,

Pan baffle is welded in. Added to welds to the rear of the baffle to give a tighter fit of the baffle, this will keep more oil in the sump. Was quite difficult to weld this with my mic/tic machine, main problem was getting the gun and filler rod into the pan and then sticking my head with helmet into the pan as well. But got it done, took quite a while but looks good now. Had to repaint the pan of course, all the paint would melt away from the welded areas....

Opened up the oil pump and cleaned to pressure limit valve. My spring is a bit too short about 2mm too short, that means that the valve will open a bit earlier to release the pressure. I don't think this will be a problem, if it is a problem I can open up the plug which is accessible from the outside and insert a shim to increase the force of the spring.

Cleaned and painted the fuel pump. Make sure that you prime the pump with gasoline before trying to pump it. The membrane in mine got very stiff from sitting on the shelf for more than a year, so I drizzled a bit of gasoline into the pump and after just a few minutes the plunger would move with much less force.

Test fitted the oil pump, fuel pump and distributor with the front cover off.
Had to install the pulley again because I made a mistake last time, the zero mark is of course the first notch with the zero behind it. 5 BTC has only a notch and 10BTC has a 10 labeled!
I am using a 70 crank pulley to remove the smog pump, had to add another notch about 2 degrees offset. My original 68 pulley was right on. Not sure if this is just manufacturing tolerances of if the 70 really has a 2 degree of difference.

Checked the crank hub, it had a small groove at the seal surface. So I measured the distance of the new seal on the front cover and then determined that when I move the new seal 0.5 to 0.7mm further out the lip would ride on flat surface. So I made a small shim which goes under the new seal on the front cover.
Normally, one would turn the hub down and shrink a new sleeve on - but I am out of time now and want to put things together, no one will notice and I just want a good seal. Hope it works.

Tomorrow, I hope to put everything together.

Best regards,
Nicolas

[DeVille68]

Continuation of the assembly, had the impression to recheck the rod side clearance, well turned out that the clearance was a bit on the low side. Journal 1 and 4 had about 0.006''. Journal 2 and 3 about 0.008''.
The cap Nr 8 even had scraping traces from the crank journal. The guy that did the balancing probably left a burr on the last journal while removing weight.
I used a piece of glass to give a flat surface and 1000er sandpaper and sanded a few connecting rod bearing caps on the inner side, that is the side without the bevel. After a few forth and back I ended up with 0.009'', 0.009'',0.011'', 0.011'' from front to rear. I am much more comfortable with those numbers, was too tight to me. Original spec is 0.008'' to 0.016''.

Pressed the front cover seal in and installed the front cover. Used the water pump just to hold the cover in place. Still need to check and paint the water pump. I put a liberal amount of assembly lube on to the timing chain, fuel pump arm and distributor drive gear.
Then I installed the seals for the oil pan. Now the engine is basically completely sealed - ready for some oil!

[DeVille68]

Latest update:
Various parts installed, rebuild and updated original distributor  with HEI. Wired external coil, added engine hooks. Installed carburetor. Re-bent the fuel line, too way too much time, its nicer now, but I guess I have to do it properly with all the accessories installed. Want to have the line ever neater. Installed the exhaust manifolds.

Left to do: water pump, spark plug wires, checking belts, install flex plate and starter. Do some wiring and then mount it on the engine stand to break in the cam.

Best regards,
Nicolas

[DeVille68]

Another weekend working on the engine.
Painted and lubed the water pump. With lubed I mean that I used a very thin oil that is used for sewing machines. I put a few drops into the "leak" hole and some on each end of the shaft. Because the pump was sitting now over 1.5 years I wanted to prevent the sealed bearings to run on a dry shaft. You could really feel how the pump was easier to spin after lubricating it.
Then installed. Used sealer on the three lower small screws.

Installed the pulley and checked belt alignment again. Generator, Water Pump is perfect. Power steering is a bit off, angle is about 0.4 degree. Allowed is 0.5 degree. So all good. Painted the power steering bracket. Have not yet rebuild the pump, because its the wrong one.

Disassembled the fan, found an original part number. Turns out that this type of fan with its 6 blades was used for a 67 Eldorado with AC. Part Number is: 1482915.

For a 68 with AC there should be a 7 blade fan, part number 401371.
So I am in need of a correct type of fan! 

Painted the fan and brackets anyways because currently I have no choice, will replace the fan with the 7 blade version when I put in the A/C compressor

[DeVille68]

I borrowed a crimp tool to clean up the spark plug wire mess. Those are 8mm AC Delco wires, but some of them are way too long. I did cut length out from 7cm to 41 cm out of the wires!
Also made a custom coil wire, because my coil is now external just like original, but it is a HEI system, so I am using the HEI wires.

The first pictures show the mess, then I show the original crimps. I carefully bended the taps up again, and slid the wire in and crimped again. The new crimp looks as good as the old one, and is also tight.

The next "blog" entry should hopefully talk about my o2 sensor and some wiring for the engine test stand.


Best regards,
Nicolas

[hornetball]

Nice work.  What do you mean by "lube" the water pump?  Mine seems to have sealed bearings (1974).

[DeVille68]

Nice work.  What do you mean by "lube" the water pump?  Mine seems to have sealed bearings (1974).

You are right. I rephrased my post above:

Painted and lubed the water pump. With lubed I mean that I used a very thin oil that is used for sewing machines. I put a few drops into the "leak" hole and some on each end of the shaft. Because the pump was sitting now over 1.5 years I wanted to prevent the sealed bearings to run on a dry shaft. You could really feel how the pump was easier to spin after lubricating it.

The shop manual does not have any description on how to restore one of these pumps, they simply say: replace when leaking!
I hope mine survived the long time of sitting dry on the shelf.

Best regards,
Nicolas

[DeVille68]

So, it has been again a while! Now I have a week vacation and plan on starting the engine on the engine test stand. Unfortunately, my engine builder had and has again no time to get his engine test stand ready for my test phase. So now I have to build my own test stand. He will hopefully show up when I let the engine run for the first time.

But first I had to install the flex plate. Checked again the bolt length. They are close to the block but have about 3mm room. So that should be plenty.

[DeVille68]

Now let me show you what I have come up with for my engine test stand. I hope to inspire some of you that plan on doing the same thing!

First, I wanted to use the engine stand and just extend it to an engine test stand. I already installed the motor mounts, so I decided to just add two reinforcements to the front legs of the engine stand. (Picture 1 and 6).
The two "vertical" bars sit on the legs with a u-shaped profile. I did not have one in the correct size, so I just welded two angle pieces together. There is a M10 bolt that goes through them to bolt the bars to the legs.

Then I decided to use my radiator and have two support bars coming of those vertical bars to support the radiator. The radiator sits in a u-shape profile. Picture 5, 8 and 12.

The radiator is held in place partially by the hoses but I also added a "finger" to the top vertical bar. The top bar is where the gauge cluster will be mounted. Picture 13

Next post explains the gauge cluster. Last picture here just shows everything installed. Picture 19.

[DeVille68]

Now to the gauge cluster. I wanted to have all the important gauges to monitor the engine. So I need: tacho, oil pressure, water temp, vacuum, oil temp and o2 (lambda) sensor.

I also want switches for power, ignition and stater.

I bought a temperature sender from jegs but no gauge, because I thought that I just use my ohmmeter to get a reading. But now on the engine stand I don't want to calculate or read a table to find out what temp the oil has. So I measured the characteristic curve of the sensor by measuring the resistance (ohm) while heating it in a water pot and measuring the water temp with an accurate sensor.
Picture 14 shows this, I measured the "original" water temp sensor and the new oil pan oil temperature sensor.

With those measurements I got a NTC curve but this curve is not linear. You either need a display that corrects this nonlinear behavior or create a linearization using resistors in series and parallel. Picture 2. The set of equations is pretty simple it is just a quadratic equation that you can solve by hand. I used an excel to plot the results. The results are how many ohm for the parallel resistance and how much ohm for the series resistance. So I searched and combined the resistors I had to get the final values. I then added those resistors to the wiring and re-tested the sensors with the gauge again using the hot water.

The gauge I am using is a milliampere meter from my grandfather. I had this laying around. So when I put 12V volt on the gauge it will give a current flow that changes with the change in resistance due to temperature increase or decrease. More or less current will flow, this is displayed on the ampere gauge. I choose the scaling and linearization of the resistors to give equal numbers, so for example 60mA equals 60°C. 100mA equals 100°C. The gauge will be "accurate" between 60°C and 100°C.

Last two picture show the final gauge cluster for the engine test stand.

[DeVille68]

Since I want to hear if something is making a strange sound I want to add an exhaust. I had to remove my current exhaust from the car. I anyway had to fix some issues and add an O2 sensor. So first I had to fix the flange that mounts against the heat riser valve. Because the metal was corroded, I had to weld in a new piece. Then I also drilled a hole and welded in the o2 sensor mounting plug.
Now, I can use my air fuel meter gauge also while driving and really see what the carburetor is doing.

[Bentley]

Nicolas, that is a lot of nice engineering work. I've never rebuilt an engine or had one rebuilt by a shop. I always thought they just put the finished engine back in the car, hook up everything, and start it to test it. Would a shop test a rebuilt engine using your same method?