76 eldorado convertible rebuild

[Leary75]

Did a bit of work on the rear suspension as well.   The ALS is completely shot, with a few pinholes in the pump / pressure tank, so I pulled the pimp, and replaced the shocks with KYB gas filled.   
The whole area was a mess, so we wire brushed, and painted with a rust encapsulating rubberized undercoating.  Got my son to sand the springs. Add in the new brakes and the underside is starting to look good.
-Brian

[Leary75]

So I got everything back together and installed, and tried starting the car.   Nothing....   I mentioned that this was an original EFI.   The computer was a replacement at some point, and not installed properly in the dash. 

Went through everything, I had compression, spark, but no fuel.   After a while of testing, found that I was not getting any signal to the injectors.  I tested the injectors themselves and they opened fine.   

I was hoping this was not the case, as parts for these are rare.   The wiring was a little screwed up too.   I ended up deciding to replace the EFI system with a sniper unit, so Thai wouldn’t be fighting with this for ever.   

Last pic of the old efi attached from May
-Brian

[Leary75]

I decided to use the EFI intake, but opened up the throat to allow more air and fuel mix to pull into the engine,  the throttle body opening was restrictive.   I had to modify a spacer and make a gasket to mount the sniper to the throttle body mounts. 

I plugged the injector holes with threaded plugs to ensure no leaks.  The overall height was about the same as the original so the air cleaner was usable as is. 

Used the cruise control bracket as a mount for the fuel filter, and replumbed the feed and return fuel lines.   

Once installed, the engine started up pretty easily,  timing was real bad, and I realized quickly that both the battery and the alternator were shot.   Once I got the tuning correct, the car started running well !

-Brian

[Leary75]

After all this work, the car deserved a nice shower 😊

I love how the car looks all clean.  Drives like a dream.  The kind of dream where you are floating...

- Brian

[The Tassie Devil(le)]

G'day Brian,

Boy, she is looking really nice, and thanks for showing the picture of the EFI Intake Manifold.

Great job on the trunk drip rail.   The before pictures are great, and show what a lot of people would have discarded this vehicle as being a parts car.   You are resurrecting it.

Bruce.

[MaR]

You car is looking great! I used a lot of the interior restoration products that you have used with great results also.

[Leary75]

Thanks guys, unfortunately, the joy of driving her was short lived.   She ran for about 200 miles.  I had the oil changed and the coolant flushed and then all hell broke loose ( and probably a bunch of engine sludge.... ).  I took the car for a drive, and had a massive backfire on the highway ( bad AIR diverter ) which was shortly followed by the car overheating, and the engine dying on me.   After a bit of diagnosis by both my local mechanic (who did the oil and coolant) and then getting the car home, it was clear that the engine blew.  Compression was down below 100 on all cylinders and the car smelled like burnt gear oil.   It also would not turn over with the spark plugs in it, and would barely crank by hand.   

The backfire took out the muffler too,  blew it up like a balloon 🎈

In the end, I decided to pull the engine, dig in and see what was what. 

-Brian

[Leary75]

Pulled the heads, and the top of the engine looked ok.   Valves are all operational, rods and lifters look good.  Even the cylinder walls on the top side looked decent. 

So the problem was not here, and it appeared that the backfire didn’t damage the valve train which is a plus

-Brian

[Leary75]

So on to the bottom of the engine.   Pulled the oil pan, and it was immediately obvious that the crank bearings were the problem.   The rod bearings were completely gone on 7&8, and spun on 6.   All of the pins were tight on the pistons, and the rods were stiff.   There was also some scoring at the bottom of the bores, likely from the tight pins.   

The bearings were the main culprit through.  I found it interesting that the problem got worse towards the back of the engine although the cooling passages in the back of the engine were full of crud when I pulled the freeze plugs.  Could have been uneven cooling, oil pump failure, all of the above or the bearings were iffy, and just went when I took it on the highway for a couple of exits.   

Either way, the block and crank are at the machine shop.  And I guess we are doing an engine rebuild. 

So the saga of the car continues.  And you are basically caught up.  I have been working on the heads, which I will post about separately.  The upside is my 11 year old got to hammer pistons out of a 500 ci engine, and that doesn’t happen every day

Thanks, Brian

[The Tassie Devil(le)]

Oh dear.   No mention of any knocking noises before you stopped it?

Looks like the damage to the Crank Shaft will require a replacement, as with that damage, it probably won't have sufficient metal to take a full grind.   Plus, probably new Connecting Rods as well.

Looks like the engine has been run without sufficient lubrication.

The "massive" backfire is from the over-rich mixture filling the Muffler, which in turn received a spark from hot exhaust gases, and the tail pipe simply couldn't exit the explosive pressure fast enough.

Seen this sort of damage when people drive a car, turn off the ignition momentarily, then turn it back on, and there is an explosion in the exhaust system.    Been done a lot of times with Rental cars especially going through tunnels, just to make noises.   Probably not done as much these days with cars that have steering locks, but back in the day, the "lads" had fun.   

Bruce.

[Leary75]

The lube could definitely be an issue.  Did I mention that the dipstick was snapped off prior to my owning it.   When I had the oil changed, I had them put in the full 6 qt capacity, but this could have been an issue for longer than I had the car. 

I a hoping the crank can be salvaged, should find out next week.  I am expecting it will be a full .030 under if they can get it to grind. 

I am expecting to need a few connecting rods, especially on 6, 7, and 8 where the bearings were spun or completely destroyed.   They did mic the block, and it needs to be line honed. 

And a full new set of pistons

At least money grows on trees here hahaha

- Brian

[Leary75]

I am considering switching to a carb manifold instead of using the modified efi unit.   Someone mentioned that the channels would have been designed for fuel air mixture better than the efi manifold, and that could lead to an uneven mixture to the different cylinders.   Thoughts? 

-Brian

[The Tassie Devil(le)]

From my memory banks, every time an engine spins bearings as bad as yours has, the crankshaft will end up being bent.

I hope the shop checks that before proceeding on any grinding.

These bearings came out of a full race engine that spun 3 bearings, and the damage shown was from just 1/2 a lap before the engine was turned off.

Luckily, the Billet Crankshaft was salvageable, but not so for 3 of the Rods.

Bruce.

[The Tassie Devil(le)]

I am considering switching to a carb manifold instead of using the modified efi unit.   Someone mentioned that the channels would have been designed for fuel air mixture better than the efi manifold, and that could lead to an uneven mixture to the different cylinders.   Thoughts? 
-Brian 

Possible, but converting the Carb Manifold to the EFI Manifold looks like it is just a Flange change.   The Factory wouldn't have used a bolt-on adaptor as it would be too "messy".

Bruce.

[hornetball]

The look on your 11 year old's face as he is checking out the 500 is great.  He is thinking "my Dad is cooler than your Dad."  Haha.

I would definitely seek out a carb manifold to host the Sniper.

[MaR]

I had the ol' "exploding muffler" routine happen on a '74 CDV that I had long ago. In my case, it was a bad pickup coil on the HEI distributor that was cutting the ignition out randomly. It shut off on the expressway and then came back on a few seconds later with a sizable BOOM. Good luck with your rebuild. My vote would be to swap out EFI manifold for a carb manifold and then use the Sniper Quadrajet system also.

[Leary75]

There are a few differences in the EFI manifold that I can see. 
1. The mounting flange and bolt pattern are different.  The efi throttle body had only the two holes, so less open area.  There are off the shelf adaptors to convert Quadra jet to spread bore mounting
2. The EGR routes very differently.   The efi comes in from the side and into the top of the air passage.  On the carb, the channel routes to the back and the gas enters from underneath the secondaries. 
3.  The EFI manifold is smooth beneath the throttle body.  The carb manifold has raised ridges (assuming these are to help with vaporization.). 

I was able to get a cheap used carb manifold off of eBay, and I am thinking I will switch to that just to be safe.   I just have to get a new AC rear bracket...   

And for the record, my 11 year old’s dad is pretty cool 😎 😆

Thanks -Brian

[Leary75]

Cleaning motor parts is gross, but rewarding.   Cleaned up the oil pan, and pickup tube, and the whole valve train.  Also ground some of the flash out of the oil return Passages in the heads.   

Also, new flowkooler water pump, and Cloyes roller timing set arrived.   My old timing set is in surprisingly good shape, with all the nylon on teeth still fully intact.

-Brian

[The Tassie Devil(le)]

You are lucky with those teeth, as they are very worn, and wouldn't have been long before they started to fail.

Bruce.

[Leary75]

I was really surprised to see the teeth intact.  The chain was sloppy.  Maybe I can send it to a museum... or hang it on the wall in my garage.   

I found and bought a carb intake.  Looks like all my pretty painting on the other intake was for nothing 😆.   

Been doing some head work while I wait for the block.  Had my valves ground, and have been lapping them in by hand,  The seats were in good shape.  I used a dremel with a brass brush to clean them up. 

Also just received my new camshaft , springs and lifters form CAD company.  It’s a mild cam, their 120 cam,  designed for smooth idle, with a little better lift and duration than stock.  Really looking forward to feeling the difference.   The car never really idled solidly which probably had something to do with that sloppy chain.... 

Aiming to re-assemble the heads this weekend and then get them pressure tested next week.  Getting a house project done in the mean time. 

Best.  -Brian