1940 Oldsmobile Barn-Find Restoration by Erndog

By diyauto
( 4 )

1940 Oldsmobile Barn-Find Restoration 

Compliments of Erndog @ aaca.org


Well, my son wanted his first car to be something he could work on and actually see around the engine. At first it was to be a 60's or late 50's car, 70's if absolutely necessary, but then I came across this one. He liked it immediately. 

It is a 1940 Series 70 Four Door Sedan.

It sat on blocks in a barn in WV for at least 35 years as part of a 30+ car collection a car loving farmer had. Whether or not he was ever going to restore it, or just own it, who knows? Upon getting it home in VA, I managed to get the stuck hood latch open. It was the first time the hood had been open since it was driven into the barn. I checked the dipstick and found no water or evidence of moisture. I then grabbed the fan and pulled. It turned easily with a pleasant fwoosh! from the cylinders. God is good. The interior has a set of early seat covers installed and from the peeks I have managed, they were put there to protect the upholstry, not hide it. I can see a beautiful fresh grey material everywhere I look under it. The headliner is perfect, except for a small hole over the driver. The instruments look as fresh as the day it was built. Every piece of glass is perfect. Three original hubcaps are on the wheels and the fouth is in the trunk. The key was in the ignition. I tried it on the trunk (only made for ignition and door) and it locked it. However, it won't unlock it. The original horn button is in the glovebox, along with a pass to Skyline Caverns that expires in 1952 and two free tickets for five gallons of gas each at the local station. 

Now we need to freshen it up. It has one ding on a front fender and a handful of minor bumps, but all are easily fixable. The one piece of missing trim was hiding in the glovebox. Of course, the bumpers will have to be redone.

First pictures.


Thank you. Yes, he wants to keep it as original as possible, other than going through everything to bring it up to snuff. I am also going to regretably put some seatbelts in it. Safety first. That will be the only modernization and they can be tucked away when not in use, anyway.


Well, we got the trunk open. Had to take the back seat out and remove the latch bar brackets. Unfortunately, I had to cause some damage to the still perfectly intact divider boards between the seat and the trunk. #&(*^$#! Found the two center bumperettes for the bumpers and a new taillight lens. Also found the missing brake shoes and hardware from one wheel. We knew the fourth hubcap and spare wheel were in the, but we did not know that there is still a little red paint in the emblem on the hubcap and the wheel is in new condition, except for dirt. The three vermillion stripes are perfect! Got the trunk latch off and removed the handle. FYI, the key/cylinder code is stamped on the base of the handle. True for the locking door's handle, too. Now I just need to find somebody that knows what to do with it. Also noted that the undersides of the seats look really good.


Well, we are woefully behind on keeping this thread up. I will try to do some recapping.

Removed crossbars under hood, fan, and radiator. Removed hood latch assembly. Wired wheeled and painted crossbars and fan. Tested radiator and found no obvious leaks, but will probably have it looked at. Reassembled painted crossbars. Put second coat of paint on fan. 

We got keys made for the trunk and glove compartment. Unfortunately, after we got them home we noticed that the two new keys were different from each other. one does nothing. The other will work for the glove compartment and the trunk. However, when you open the trunk the key won't come out. And when you close it, you have to lock it to get the key to come out. Is that the way it is supposed to operate?? 

  • Removed left front fender. Required removal of left kickpanel to access three of the bolts. One problem bolt at very front of running board. It had a special thin flat head that came off. Needs replacing.
  • Removed all brakes and slave cylinders. Started honing and rebuilding same with nice kits from Fusick. They were rocked up pretty hard. We'll see if they are leak-tight after they get back together.
  • Removed left engine compartment sidewall. Started cleaning and painting same.
  • Removed LF shock and wheel assembly.
  • Took brake shoes and original set of linings to Automotive Manufacturers in Richmond, VA to get them put on. Fantastic job! All four wheels for $50. That included drilling holes in the linings for the rivets.
  • Investigated the LF shock. Bone dry. Cleaned it as best I could. Verified the valves work.
  • Completely tore down the LF suspension, cleaned and painted same. Reinstalled.
  • Removed front bumper, RF fender (found a 1909 penny, 1951-D penny, and a beautiful 1937 Buffalo Nickel under the floor covering), grill, and hood.
  • Took 1930 Buick out of garage and rolled the Olds in.
  • Pulled out the engine and transmission. No problems.
  • Set engine on engine stand. Powerwashed the engine so we could see what we are working with.
  • Removed head, carburetor, manifolds, water pump, valve covers, and oil pan.

Glad we decided to tear the engine down. It is pretty well gooked up.

Left fender removed.

Brakes as found.

Slave cylinder originally.

Slave cylinder rebuilt.

Time to go, old engine buddy!

I'm pulled at last, I'm pulled at last.

Jonathan gets down and dirty.


Added some photos. 

Took off the timing chain and gears. Took a peek at one main bearing. It looks good. After a lot of very dirty effort, got the oil pan relatively clean for evaluation. Found a few pinhole leaks that will need fixing. Waiting on a valve spring compresser and ridge reamer. Then we will remove the pistons, crank, and cam. Then it is off to the hot tank with the block. Of course, we will need to remove the cam bearings, freeze plugs water distribution tube, etc first.


Still no luck getting the water tube out. I will keep trying. Just got back from Hershey. Found many things we need, tune-up kit, carburetor rebuild kit, fuel pump kit, gas cap, tail lights, fenderwelt, hood lacing, and definately not least, four whitewall tires$$. It was amazing to us just how few old Olds parts were available at the Hershey. Also, we were unsuccessful at meeting up with any national club members. I tried to buy a ridge reamer there, but there were few and no bargains to be had. Met a great couple who were showing a 1940 four door sedan just like this one.

Since last post we removed the valves, lost three keepers in the gook, did a little painting on the firewall and cowl area, and replaced our parts washer. Fried the old one. Just for the heck of it, I asked the Autozone people if they had a ridge reamer (didn't even know what it was last time), and they said no. But, they had two they would loan for free! Used it tonight and removed all six pistons. Bearings look nice. We'll probably reuse them. Removed the crankshaft. The mains are not making me happy. I see cracking on one (from age?) and a little too much wear elsewhere. I guess we need new ones. Went through the oil pump and it looks ok. Removed the distributor. Started removing oil galley plugs and other items to improve hot-tanking results. 

Gave up on eco-friendly parts washer and went back to washing parts in gasoline. So much better! 

Does anybody have an oil pickup screen? Ours really needs replacing.


Thanks! Good to know.

By the way, couldn't remove any of the tappets. Felt like metal to metal, as though the adjusting nuts were hitting the sides of the holes. Used some brake cleaner spray and they came right out! It was just 40 years of goop stopping them. God, I love that brake cleaner!!!


Thanks. I will be replacing the mains for sure now. I just pulled out the upper shells and found that the rear bearing has a weird defect in it, almost like it was wire-drawn at one corner. Not sure if it is due to heat or something in the oil, but it's gotta go. Pity, other than the two problems I found they look really good.

 I finally got the old water tube out after two weeks of trying!!!!!!

What a b****! It came out in many pieces and every one of the was thouroghly stuck. I had to make a special removal tool and also use a screwdriver down through the center head bolt holes. It was so rusted, it looked like it had been shot with a shotgun. As near as I can tell there are no little pieces left. :cool:

Got all the studs out, 

Soon to go to the hot tank.


Well, the engine block and crankshaft went to the hot-tank yesterday. The man said it may take several dips and a couple weeks to get it really clean. He uses the real deal, boiling caustic. He says the jugs have a lot of taper to them, but I explained I can't afford to rebore it right now, but would sure like to. That can come down the road. This is going to be a daily driver, so the engine will probably be coming back out again someday. He looked at the main jounals and was impressed with their condition. I liked that. However, the shells show signs of age (cracking, etc), so the bearings will be replaced.

I asked him about some scary looking cracks down the left side of the block, but he agrees that they don't look like actual cracks. He says they look more like a crappy casting job. We will see when it comes back.

He also clued me in as to why the old greasy oil from the engine is so incredibly messy; tracks everywhere and hard to remove. A lot of the oil back then (this car hasn't been driven since the early 60's and probably had even older oil in it) was parrafin base. So I have been experiencing a dirty, waxy oil. I will be glad when that's all gone.

I will put up pictures when I get it back. :cool:


The block is in its third week in the hot tank. Should be done this week. Said the shop,"that thing was really nasty!" I actually cleaned it a lot before I took it in.


Well, we finally got the engine parts back from the machine shop. We had the block, head, crankshaft, camshaft, and oil pan hot-tanked. 

The openings for the cam bearings were so tight that he had to line bore the bearings after he installed them to get the camshaft in. The "cracks" in the block were verified to be a bad casting after all. The crankshaft mic'd out beautifully and the rod journals are all within a 1/10,000th of each other and still in the factory specs! We ended up buying new mains and rod bearings. That is really the ONLY way to do it right, although the mains were in good enough shape that the shop said to keep them for spares. Good idea, since I got the last set of std's from Egge and they said they probably will never make any more.

Somewhere, I have misplaced the three camshaft gear bolts. Along with that, I can't locate the spring or thrust plunger that go in the end of the shaft. I sure hope they are together somewhere!!

We decided the valves looked good, so we just lapped them real good. We then installed them, the springs, lifters, camshaft, and crankshaft. We had to trim the vertical cork inserts on the rear main a little to get the cap installed. Sure hope it doesn't leak, but it was impossible to install otherwise. We left a little extra in length so maybe the oil pan will squish it into a better sealing situation.

Now we will rebuild the fuel pump and carburetor. We will wait on the pistons, as the weather is bad and they need cleaning. I do most of that outside. 

Here are a few pictures to show how it is going.


That's an awesome story! Thanks for the tip and the offer. I will take a look at it. It is definately out in the open at the moment and easy to get to. One thing I need right now is the plunger w/spring that goes in the end of the camshaft. I haven't been able to locate the set that came out of my son's. It was there, but I guess my brain wasn't. 

I would sure like to see some pictures sometime of your project if you took any.



I still haven’t found the cam plunger and spring, but I still have half of my garage to go over with a fine tooth comb.

We were putting in the pistons yesterday with new rings and bearings and #5 somehow broke the second land from the top and part of the XS500 compression ring (neat set of “period” rings with special names for their rings). It was my son’s first time installing pistons and I think he may have been a little heavy handed in conjunction with my letting the compressor slip a ring out.

I ordered a new piston from Kanter and I have most of the old rings, so I will substitute one of the old fire rings for the broken one. Since it uses two compression rings and two oil rings I think we will be ok.

Now for my technical question…

While we were installing those pistons, my son noticed that the crank seemed to be sitting a bit to the aft. This morning I applied some pressure and discovered that the endplay on the crank is about 1/8”. The specs call for .004”. The thrust washers are in the right places at #1 bearing; one in and one out and lined up with their pins. The only thing I can think of is that we have yet to install the small timing gear and pulley and cinch them down. I think that will pull the crank in, as the gear rides on the outer thrust washer that sits against the brass thrust washer. Am I right or am I looking at a major problem?


Nope, it was just as I thought. Tightening up the front pulley pushes it against the timing gear, which in turn presses against a steel thrust washer, which rides on the brass thrust washer, which is pinned in place against the number one main bearing. There is no thrust bearing, per se, as we know them. Different, but it works. After tightening, the endplay is within the .004 specs.

Had a minor setback today. The new piston came and I had changed out the rings, so it was ready to go. I figured I would pull all of the pistons back out to double check them for damage, since the #5 had broken. Also, I was not satisfied with the smoothness of rotation. Turns out that number #4 and #6 both had a broken lower oil ring. The cylinders and pistons were ok, though I had to work the lands where the breaks had occured. Not sure if it was something we did or old metal in the NOS rings. Probably the fact that we were installing the pistons with the block horizontal. Stupid idea on my part. Never did it that way before and never had any issues before, either. I found two of the old oil rings that looked good and got the pistons ready to install. Decided that this was a good time to do things right and drive out all the wrist pins and apply assembly lube, as they had gotten pretty dry over the last 40 years.

We then reinstalled the pistons, checking rotation after each installation, and found no issues. Then, just to be safe, we double checked the torque on the mains.

Installed a new timing chain and verified rotation again.

Tomorrow we will install the head.


Head is installed; three passes on the bolts. Did a cold adjustment on the valves. So far, so good.

Finished searching the garage. It's official now, the cam plunger and spring are seriously missing! Bad, bad, bad. I am really hoping one of you has a replacement or specs to get it custom made.


Thank you, Bob Petters, for supplying us with the cam plunger and spring! What a show-stopper that would have been. We rebuilt the carburetor using a kit we bought at the Hershey. Worked fine, except the needle valve was wrong. The old one looked fine, so we are reusing it for the time being. Installed a new timing chain and heat riser spring. Rebuilt the fuel/vacuum pump. What an experience that was! Never done that before. Not for the faint of heart. Rebuilt the distributor and nstalled it along with the oil pump. I hope we got them pretty well geared in right. Thought the water pump was going to need replacing, but it seems to be water tight. Took it apart and cleaned it up. The engine is just about ready to return to its home now. Just need to get the bell housing clutch, starter and generator ready. We have a new front end wiring harness on the way from Rhode Island Wiring. Bought some NOS motor mounts, so that won't be an issue. Mom repaired the oil pick-up screen with a little metal sewing magic. Another headache solved! Photos to follow when I can get them posted.


 Well, the stars lined up and we finally got the engine put back in the car. It was a learning experience to be sure. I discovered that we forgot to mark the flywheel when we removed it, so setting it up so that the timing mark was right was a real challange. We finally figured it out and got the flywheel installed. The bolts went in a whole lot easier then, too, since the spacing is microscopically different. Of course, when we went to install the bell housing we discovered that it had to go on before the flywheel, which we had already torqued. It is not as easy to install a flywheel when the bell housing is on already. Then we proceeded to install the clutch. I used the same place to reline the clutch as the one that helped with the brakes. They had the right facing in stock, removed the old, sandblasted the metal and clear-coated it, installed new facing all for $50 with tax. God, I love them! We shortly discovered that the clutch cannot be installed with the bell housing cinched up. Eventually we got past that hurdle. Then we had to get the transmission installed. It took a little inginuity to disengage the clutch to free things up enough to get into the pilot bearing. Finally, we were ready to install the motor. We carefully babied her into place and after some re-education with motor mounts and the oddities of Olds motor mounts, we got her in.

Next we need to start hooking things up and get the new wiring harness in. Also need to go through the fuel system, tank to front. Making progress little by little.


Made new brake lines all around. Found a major kink in the fuel line, so started repairs on that. May go ahead and make a whole new one. Installed a new wiring harness for dash and engine compartment. The old one was in shreds. The only thing that I think I goofed up on was that the clock light is always on. Easy fix. Found the original trunk key in the seat. If I had found it earlier, I would not have had to ruin the perfect original cardboard dividers that go behind the back seat.

Tried to get the engine to fire with just some gas in the carb. It did, but I will need a real fuel supply to get it going right. Pulled the left rear fender and removed the gas tank. It is full of rust, has some bad old repairs and is starting to get pinholes in it. Repairs have been estimated to be an easy $400. Therefore, if anyone has a spare gas tank in good shape for this car, I am interested.


Well, way overdue for an update! 

Tried to locate a tank for over six months. Evidently, they don't exist or nobody is letting them go. Cleaned up our tank and took it to be reworked in January or so. Still waiting on it. Should be ready next week, as the previous several weeks. 

On a better note, we had the radiator rodded out and returned to as-new overall, and then installed it. 

Worked over the passenger side front suspension and shock absorber; hadn't been done yet. 

Cleaned, regreased, and reinstalled the front wheel bearings. Installed the brakes all around. Front slave cylinders were fine after rebuilding, but the rears needed to be replaced. Brakes work great!

Took a lot of doing, but finally got the emergency brake cables freed up and usable. 

Reinstalled front fenders.

Reinstalled the hood and the shined up grill with new red accent stripes. 

Painted and installed one parking light grill. Other still needs stripes painted. -painful.

The starter was kicking out early, so we installed a new drive gear assembly, and reinstalled the starter. Haven't tried it, yet.

Removed all four doors and installed new weatherstripping. all door trim panels are off for redoing when ready. Installed proper weatherstrip for trunk. 

Reinstalled the headlights.

Located and bought a replacement piece for the big trim at the rear license plate.

Rebuilt both rear shock absorbers. What an education! Both were frozen. Discovered that we broke the screws that hold the two pistons together in one. Didn't realize they existed until the pistons would not relocate after stroking. Replaced screws. All better now! Rear of car bounces approximately 1 and 1/2 times or less, as per design.

Been cleaning and painting underside in preps for receipt of gas tank.

Sandblasted all four rims (spare is still in original condition in the trunk) for free at work (-$) and painted them. Had new tires installed on the rims and put the front wheels on the car. Backs are waiting for gas tank. 

Looks nice with those big 4" whitewalls!

Still looking for new muffler, horn ring, and a few small items.

Getting closer!!

Pictures forthcoming.


My guy has had the gas tank for several months now. I always get the "It'll be ready first thing next week" or "I'll call you day after tomorrow", which he never does, etc. Very frustrating. Yesterday morning he said it should be ready to pick up in the evening. Called at about 3 pm and he had already gone home for the day and nobody else knew much about the tank. He did a great job on my radiator, but he has lost me as a customer for anything in the future. I would like to get it back and installed before my son loses all interest in old cars.


Well, finally got the gas tank back last night. Looks pretty fair, but pretty rough coating on the outside. Feels good and smooth on the inside. Functional, not asthetic. However, it is not like these grow on trees. Had to take the spare tire indentation and filler neck from the original tank and scab them onto a very similar new tank. Too busy to work on it right now, but hope to jump on it in a couple weeks.


Time for a few photos. Thought I had a lot of shock absorber before and afters, but they have gone missing.


Installed new gas tank sending unit into the tank, since it won't be accessible after the tank goes in.

After much blood, sweat, and tears, got the tank filler tube through the opening between the frame and the body. The tank won't fit up into the saddle and is generally way off in several dimensions. Will take it back to the shop next week for adjustments.


Thought I made a follow-up on the tank, but I guess not.

We cut the filler tube off at about four inches from the tank. Fits into the saddle just fine now. Got a piece of marine grade rubber tube and a few of the heaviest hose clamps I have ever seen! Mated up with the truncated cap end of the tube. The rubber is kinda stiff for getting the exact right angle coming through the fender, but will have to do for now. Still need to do gas line fit-up, but work has not allowed any time for this in the last several months. Doing what we can when we can.


Well, lapping the valves was not a good choice for a 70 year old engine. Should have had them ground while the engine was out like I usually do. After engine would not run we did a compression check and found horrendous results. To make matters worse, my tester was too deep and bent the exhaust valve in #1 jug. We removed the valves and took them to the shop to be ground. I was able to talk the machinist into making a housecall to grind the seats and lap the valves in. Had to replace four exhaust valves, one wouldn't dress and three were bent. Reinstalled them yesterday and adjusted them. Getting those keepers installed on one of these engines with it still in the car is probably the most tediously difficult thing I have ever done. Thank God I got it done. Next time I will pull the engine, or at least remove the right fender and engine compartment wall. Now to put stuff back on and see if it will run...


Yes, but college and the failure of the engine to run has taken its toll on the enthusiasm. Been fighting to get the engine running for almost a year. Following a lengthy conversation with Bob Petters at Hershey and a pep talk, I got it running last night!! More to come.


Not really. The last things I did were disconnect all the wiring and just used jumpers for the minimum required circuit across the coil, etc., and rebuilt a correct carburetor for it. It started acting more promising and then with more timing adjustment it got going. I then systematically reconnected wires to determine the culprit, but it never stopped working. All wiring is back in play and it still starts. The weird thing now is that it seems to only be firing on #1 and #4, and maybe an occassional other cylinder. I am getting very good spark to all of the spark plugs, and I have compression on all cylinders. I have all of the valve lashes set at ~.013 for the time being, and the valves were all just reground. About the only thing left is the timing, but can it be that far off and still have two jugs working?? I installed a Pertronix ignition system into the distributor and now I am wondering if the magnet section on the rotor shaft is for an 8 cylinder engine by mistake. Not sure how I can check that one out, though.


Yes, time flies so fast. Faster than this Olds, at any rate. My boy is in college and my daughter has gotten married and started grad school since this thread started. ...depressing.

Anyway, I agree the Pertronix is suspect. Today after work I will pull the distributor and change things back. Yesterday, using a timing light on the wires, I determined that the spark plugs (except for #1 and sometimes #4) do spark for the first 5 seconds or so after the engine starts. Then...nothing, zippo! So I am thinking that the distributor, being a little bit worn out, probably has some slop in it on a small scale. As the speed increases, the rotor shaft may be moving axially just a bit. The Pertronix units are very sensitive in that direction. This unit actually has an extra 1/16th plate that I originally did not install because I didn't think the mounting screw was long enough. I could not get any spark whatsoever and contacted Pertronix. They said the extra plate had to be there to line up the magnets properly. I added the plate and all was good. So, if it is that sensitive there is a good chance it is messing up for whatever reason. I will report back with what I find out.

Well, I changed the distributor back to original equipment, but left the 40,000 volt coil in service. Holy cow!! She runs like a top, and on all six cylinders! Once she got running, I discovered she was about 20° advanced. Fixed that and moving on. 



Excellent article on wires. Thanks!

Engine running:

The car is mobile!!:


Update: a couple days after getting the engine running, my boy came home from college for the weekend. Of course first on the agenda was having him "try" to start the engine. Boy, was he excited and happy! After basking in the purr and glory of success, the inevitable was next. He got in the passenger side, I behind the wheel (he doesn't have 3-on-the-tree experience) and we proceeded to see if she rolls. The previous videos tell the story. The enthusiasm has definately returned! Of course, now he is no longer willing to sell me his headache project. Now he is constantly asking, "what's the next thing we need to do?". Yes!!

Shortly before getting the engine running I decided it was time to find out why the engine seemed to get so tight occasionally that I frequently had to put oil into the cylinders to free it up. Before any real rpm caused damage. Turned out that the oil pump had never picked up a prime and wasn't oiling anything. I have never experienced that before, but filled it with oil and tried again (after trying the vaseline trick, which didn't work). Worked great after priming. Thank God for assembly lube. I bought a complete exhaust setup for Jonathan off of eBay. Very nice stuff, except the engine-end flange had to be trimmed down to fit into the manifold. After we did the initial drive I dropped the old system and replaced it with the new one. Turns out that the old muffler had about a 6" diameter hole on the topside. That explains the throaty volume. The new one sounds much better. I think we will tackle putting in the new windshield gasket and wiper gaskets next. That should stop the little water intrusions during rain storms. After we know it will stay dry in there we will redo the door panels. We have done one and it came out nice, but did not install it because of moisture.

I did get him behind the wheel and he did very well. He was grinning from ear to ear and obviously very proud!


Love this build. Got an classic Olds running and a new generation into wrenching. Interested to see where its at now!

Posted by stevegolf on 12/3/18 @ 12:09:43 AM

Great build and story! Thanks for sharing !

Posted by Diggymart on 11/30/18 @ 12:51:58 PM