: 83 Sedan de Ville engine swap. DONE!

09-01-11, 12:25 PM
I have an 83 Sedan de Ville with 86,000 miles on it. It's in pretty good shape other than some rust on the bottom of the doors and the typical gm headliner drop. It came with the dreaded 4100. I picked it up a couple of years ago from a buddy's girlfriend for dirt cheap. It had been sitting in her parents pole barn for about 14 years before I got it, it had been her grandparents car before they passed away. I put a new fuel pump and all new brake lines on it once I got it home and started driving it. I put about 2,000 miles on it and a whole lot of engine related parts on it before the rod started knocking. :( I parked it for awhile and hunted down an olds 350 on craigslist for cheap. I decided to finally do the swap and took the caddy for one more spin before pulling the motor, this is when it threw the rod. Drove it to my mom and dads to begin the swap. Other than motor mounts it was pretty simple. Well I took pics while doing this in hopes of helping someone that wants to try this swap also. I followed greencadillacmatt's engine swap post and was hoping to see him complete his first but that didn't happen so I dove in and here is my swap. I'll start posting pics. The first two are of the car that I did the swap in. Well....... I can't get my pics to upload here, so I'm going to create a photobucket account to post them on.

Here is the link to my photobucket album of this engine swap. http://s1094.photobucket.com/albums/i448/firemantim/

09-01-11, 02:20 PM
I have a few things left to do, but have been driving it and really like the power that the new engine has. I need to figure out where I lost power for the heater blower and also the cruise control. I also need to pick up the kit to get the lock up torque converter to work correctly. I have it wired to a toggle switch for right now.

09-01-11, 02:54 PM
Wow! That looks like a ton of fun! Seems you also pulled off the swap in just a few days. I'm sure it's loads better than the 4100.

Kudos to you camarotim, for jumping right in as a new member. The pics are very informative.


09-01-11, 03:08 PM
Thanks for the compliments Greg! You're right, it only took me a few days. And yes it is tons better than the 4100!!!! Much better acceleration and driveability!!!

09-01-11, 03:22 PM
nice. I've wanted to drop a 350 in my 87 every since I've had it. the 307 is just a dog.

These pictures have inspired me :)

09-01-11, 03:28 PM
Lol, well I'm glad to hear that outsider. I have to believe that your swap would be a lot easier than mine was being that your caddy already is olds powered.

09-01-11, 04:05 PM
yeah, the 350 is supposed to be able to drop right in and bolt up. I've seen some olds engines for sale but haven't been able to bring myself to pull the trigger. Maybe next year around tax season :)

09-01-11, 04:17 PM
There you go. I lucked out actually. I bought the 350 for the same price I picked this car up for.... 200 bucks. The people that I bought the engine from race circle track and had bought an 80 or so olds wagon and pulled this motor out to put in their 350 chevy that they use for racing. It came complete with everything but the carb. The flyweel, starter, power steering pump, and alternator all came with it.

09-01-11, 04:35 PM
great deal! You didn't have it rebuilt or anything huh? I'd be afraid of engine problems putting in an old engine without rebuild. did you do any investigating or replace any seals etc?

09-01-11, 04:39 PM
GREAT JOB! That is Sooooo cool that you brought that cool old Cad back to life and gave it a new heart! You made my day saving that neat car! Have fun with it! Dave :)

09-01-11, 06:00 PM
Thanks. No, I didn't rebuild it, the kid that I bought it from claimed that the guy they bought the car from said that it had been rebuilt at some point. I'm not sure how true that is as I found some slop in the timing chain and did replace the timing chain and gears and front main seal. I was a little worried until I got it running the first time since I hadn't got to hear it run before I bought it. But when it started up it ran great, sounded good and didn't smoke. I figure if something does happen with it then I will tear it down and bebuild it, but for now it's good.

09-01-11, 06:03 PM
Thanks Dave. Yeah, this is my first caddy. I've always liked this body style and when I got the chance to buy this one I did.

Robin Banx
09-02-11, 07:59 PM
Tim, your 83 is almost a twin to mine. I looked at your photobucket pix and noticed one item on your 4100 engine that is broken on mine. That is the A/C compressor adjuster block and bolt. Could I buy it from you before you toss the engine. I have transferred a few of your pix in photobucket to my album. you could look in my album to check out my 83. Anyhow pls let me know on the compressor adjuster.

09-02-11, 10:58 PM
Well that's cool Robin, I'm glad to hear there's another one like mine, lol. I know I still have the adjuster block, I think I tossed it in the bucket with all of my spare bolts, I'll have to go out to the garage tomorrow and find it for you. I'll send you a message to get your address so that I can check shipping for you.


09-02-11, 11:47 PM
Hey, I just added some more pics to the photobucket album of the 4100 out of the car. You should see the holes blown in the side of the block!!!! And as I put in one of the pic captions that the amazing thing is that it still ran and even idled like that!!! It actually threw the rod a little over two miles from my parents house and I drove it there under it's own power!!! It was vibrating and smoking like mad but still running and I couldn't believe it when I finally got it in the driveway and let my foot off the gas that it didn't quit but just sat there and kept running!!! I left it sit for a couple of months until I was ready to do the swap and when I was ready I hooked the battery up and fired it up and drove it up to where I did the engine swap, I was so happy to not have to push this beast at all!!!! :)

cadillac kevin
09-03-11, 12:29 AM
Tim, congrats on breathing new life into that old beast. 99% of people would have sent it to the scrappers and picked up another car when the 4100 blew out.
I can't believe that engine ran like that. I imagine it didnt run fast or well, but the fact that an engine can run (and move a heavy car) with holes blown out of it and no lubrication is amazing.
btw I bet its nice to have a car that can move with some authority, as opposed to one that cant get out of its own way.

09-03-11, 12:55 AM
Yeah, I really had thought about calling it quits when the motor started rattling, but I've always liked this body style of caddy and I had got the car for a steal so I decided to save it. The car is really solid other than the bottom of the drivers door being rusted through.

Lol, yeah I was really amazed once I got it out of the car and saw how bad it really was that it still ran too. I knew exactly what had happened when the rod went while I was driving it and hoped that it would at least get me close to home. I didn't baby it either, I ran it in hopes that the faster I got it home the better my chances were of making it. It would do about 40 mph and that was it. I two footed it all the way home in fear of it stalling and not starting back up, but once I got it in the driveway I let my foot off the gas expecting it to die and was amazed when it actually sat there and idled!

Yes, it's definetly much more fun to drive now since it does have a ton better acceleration than what it had with the 4100. I am trying (notice I said trying) to baby it so that the trans and rear end hold up, but I've gotten in it pretty hard a couple of times and it really does get up and go with the 350 in it. It's broken the tires lose a couple of times going around corners too, which it wouldn't even do on wet pavement before, trust me I tried really hard with the 4100 several times, lol! I haven't driven it on any long trips yet, but around town it seems to be getting about the same mileage as the 4100 so far too.

Robin Banx
09-03-11, 01:28 AM
Tim.....This is the most difficult forum I have ever seen. Yes......$5 for the adjuster + postage is perfect. Now I don't know if this will get to you so let's try email. My address is richard-whelan@shaw.ca. Try to connect there. I will give you my address and I'd guess that USPS charges will be another $10 or so. Time is not a factor as my 83 car is about to go up on blocks again for more winter undercarriage detailing. If you give me your address via email, I will send a bank draft and you can then package up the adjuster and post it to me. Is that a deal?

09-03-11, 01:36 AM
Wow, you did a number on that 4100. I've heard of people putting holes in blocks but that was the first I've seen. Love how you can see through the block, I meant the "crank ventilation system" you installed. What were you doing to throw the rod like that?

09-03-11, 02:31 AM
I'll email you Robin, sounds good to me.

cs, I've seen quite a few blown up engines in my day too and nothing like this either. I had driven the car for about a year after buying it and getting it running again. It always had a faint rattle or knock to it from the day I got it running and I didn't like that, but it never used oil and the noise never got any worse in that years time. But I knew something was wrong with the engine for a little while because it developed a louder rattle on my way home from work one day about a half an hour from home. I stopped and checked the oil and it was full so I drove it home and it didn't really get any worse, it definetly didn't get any better either. So I parked it and contemplated what to do with it. During this time I would still get it out and drive it around town once in awhile though, just not super far from home. I knew I didn't want to rebuild the 4100, I knew it was a bad motor before I even got on this forum. I did consider junking it since I really didn't need another project but I did like the car a lot and bought it cheap enough so that's when I decided on the swap. I looked off and on for a motor but not real hard because it wasn't a priority, but after about a year I found the 350 on craigslist near me and bought it. After I bought it, it still took me a few months to get around to putting it in. When I finally got the ambition to finally do the swap I decided to drive it for a little while longer because I had missed driving the car. My brother had just dropped of his 72 Caddy hearse at the body shop about 20 miles from us and wanted to know if I could meet him up there to pick up some trim. So I decided to drive my caddy to get the trim since I knew I had the new motor sitting there for it if the 4100 did decided to finally give out. Well it made it up to the body shop fine, just the same rattling it had when I parked it. On the way back I ran it a little harder than on the way there to keep up with my brother and that's when the rattling started to get progressively worse. By the time we got back to his house to unload the trim from his car it was knocking pretty good. I left his house and made it about a mile down the road when the rod let lose. I was a little over two miles from my parents house where I planned on doing the engine swap, so I drove it there (hoping the whole way there that it was going to make it). It was vibrating and smoking like crazy but still ran pretty good considering what it looked like when I pulled it out, lol. I wasn't beating on it by any means when it blew, but I will say when I pulled it up onto the cement where I did the swap I did hold it to the floor for about a minute before I shut it down, so that probably help beat things up a little more too, lol.

09-03-11, 09:25 AM
Nice job! Congrats! That's a tough job changing those frame mounts. Do you suppose a 350 Chevy would have bolted in without changing frame mounts? That Olds engine sure cleaned up nice. I have seen very few of those corporate blue ones. I have 5 Cutlass's and they are all 76 and older with darker blue or gold engines. Yours must be a 77 or 78. That will make a nice cruiser and those Olds engines are smooth power. Enjoy.

09-03-11, 10:46 AM
Thanks! Yes, changing the frame mounts was a pain in the rear!!!! And then having the one being a little off and having to move it was a real pain!!!! I'm not sure if a chevy would have dropped onto the existing frame mounts without moving them too. I haven't checked yet if they fit into a chevy plate or not but the old mounts do closely resemble chevy mounts. Thanks for the compliment, but I didn't do anything to clean the olds motor, that's exaclty how I bought it, I was really pleased with the condition of the engine. I thought about cleaning it up and shooting another coat of paint on it but decided to just get it in and running. Yeah I like the color of it too, unique. I'm not 100% sure of the year of this engine, a guy at my local parts store checked out the engine before I put it in and he's into oldsmobiles and thought it to be an early motor because it has "all" of the valve cover bolts rather than the later ones where they eliminated some of them. I do know that it came out of a cutlas wagon, and when I went to get an oil filter for it they told me they started using my filter in 80 on the wagons. I tried finding an engine stamping number on it to date it, but I couldn't find one on it. I agree with you, so far it's been a great smooth running engine and I'm quite pleased with it.

09-09-11, 08:51 AM
Still running strong. :) I've put about 1500 miles on it since the swap and so far so good. I haven't dug into the electrical to figure out the heater blower or cruise yet, but otherwise it's doing great. I haven't officially sat down and checked the mileage on paper yet, but it seems to be using the same amount of gas as the 4100 on the same trips. I passed a truck yesterday with it and was really pleased when I hit the gas that it just picked right up and went. Much much better than the 4100!

09-10-11, 10:43 AM
Tim, That is soooo cool! Glad the car is giving you so much pleasure! It's also nice to hear of a Cad from that vintage that can actually move quickly - most early 80's Cads can't move at all! :) Dave

09-10-11, 02:31 PM
Lol, very true! I drove it for about a year before the 4100 gave out and it was a gutless wonder! When you kicked it down to pass I swear I heard laughter coming out from under the hood when the 4100 was still in there.

09-10-11, 08:47 PM
About your heater and blower.... The ECM would give the heater control a ground when it got up to temp to turn it on.. All you have to do is find that wire and ground it and everything will work.. thats what I had to do on my 81 when i did a swap..

09-12-11, 09:05 AM
Ah, thankyou very much, I will check that out. I figured it had something to do with the ecm since the heater had worked fine until the swap.