1956 Buick Century Project

jacob

Member
I have a 1956 Century convertible that is my daily driver. I'm starting this project thread to hopefully help people restoring similar cars. I have found that there is only a little information and parts availability for this year in particular. I have experimented with different engines, open drive swaps, steering and suspension.
So to begin with, I purchased a 1956 Century convertible from the Los Angeles area. It had been in storage since the 80's and had not been on the road since at least the 70's. it was rough- rust, missing parts and in a thousand pieces when I bought it. I had it shipped up to Vancouver, WA where I did the work on it. I originally started with a LT1 / 4l60e out of a 1994 corvette. it ran fine, got decent mileage. I switched to open drive using chevy truck trailing arms and a 1961 lesabre differential. I left that in for about 1 year / 20,000 miles and have since switched to full jaguar suspension and a 2002 LS1. Here are some pictures to get started, I'll update this as I can.
















 

jacob

Member
Here are some pictures of my first open drive conversion.
1961 Lesabre differential
Stock 56 axle housing
Stock 56 axle shafts
1970 something chevy truck trailing arms, u bolts
Custom bracket at the front of the arms using just plate metal, and 3/8 bolts







 

jacob

Member
Here are some assembly and body work pictures. All of this stuff can be done at home for very little money. I used quality base / clear and the whole paint job, from body work to finished cost around 1000. The seats are one of the only things I wasn't able to do myself. I used advanced adapter motor mounts and made my own transmission mount, all very straightforward in the large buick frame.
For wiring, after looking at all of these expensive aftermarket kits and looking over my old harness, I decided to make my own from scratch. It much much easier than it sounds. I just got several 100' rolls of different color 16 gauge for most of the body stuff, used spade connectors and hooked up the wires directly to the factory fuse panel using the original as a model. I used Modern halogen headlights and housings, and used the factory chevy engine wiring harness. All done and said, it cost maybe $300 and took two days.























 
If you have a...........

If you have a 4 bbl. Rochester carburetor --- I have one ++ BRAND NEW ++
Centerpiece of my counter last year at Hershey -- and had a 2 bbl. guy at my counter, a 4 bbl. Carter guy,
and a 4 bbl.Rochester "friend of a friend"in Sweden -- and he didn't contact him.....

1 LUCKY WINNER !!!!!!!!!!!!!!!!!!!!!!
 

jacob

Member
After having the LT1 for about a year, I got the modification bug again and put the engine on craigslist. Funny enough, someone with a 1956 Roadmaster called me and ended up hiring me to install it in his car. I ended up putting the engine, transmission, differential and chevy trailing arms in it. The whole process took about 3 days start to finish, not counting removing the parts from my century. This is such a straightforward conversion- the LT1 requires no special tuning and the advanced adapter kit makes it a breeze. I learned that the distance from the center of the X in the frame to the rear axle is the same in the smaller Century and larger Roadmaster frames. So the trailing arms and my old bracket bolted right in (after I drilled holes of course). Degreed the axle in (which required cutting and rewarding of the spring perches). I used an external fuel pump (MSD 2225) but I would highly recommend putting one in the tank, as that is what I did after this project on my car.

On my car, I relocated the batter to the trunk and modified my inner fender. On the Roadmaster, I was able to fit a smaller batter in the tray, and notched the tray to allow for clearance of the serpentine belt. I think this is a problem only for the corvette accessories. the camaro had a different set up and would probably be a lot easier. On the other hand, the corvette set up sure leaves a lot of room for a turbo on the passenger side....








 

jacob

Member
1956 Buick Century Project- jag suspension and LS1

After I sold the LT1, I bought a 2002 corvette LS1, a 4l60e, and a 1983 jaguar XJS. The Jaguar had 60k miles on it and was in beautiful shape. It had a blown head gasket, and I got it for only $1200. I almost felt bad to part it out but I made up my mind.

The rear jaguar suspension fits under these cars BEAUTIFULLY. no cutting of the frame is needed, the track width is perfect, and cragar makes 15" wheels that accept factory hub caps and have the 5x4.75 jag lug pattern.

The front is a pain but doable. about an 18" section of the front frame rate has to be replaced with 2x4 steel, and bend upward and inward. Easy work with a good chop saw, a grinder, and a welder. It can be done at home in your garage! I have more pictures I'll post later but I just used the jag suspension as a guide.

Why the jag suspension? it's a bolt on, self contained subframe. You basically just drop the buick frame over the jag stuff and you're done. I never even got mine aligned and 20k miles later my tires are great. The XJS weighed around 3900 lbs I think, and the buick is the same with an aluminum engine and transmission.

Rack and pinion steering, 4 wheel disc brakes, independent rear suspension, the factory jag thick sway bar, a dana 44 posi (jaguars used american dana differentials), spring rates meant for a car of the same weight, and a 100% factory look on the outside. It went from handling like a boat to a modern sports car. Lane changes at 80 mph on the freeway are no longer scary haha.

The LS1 engines are a fantastic option. Sorry originalists. I got 22 mpg on my most recent trip from LA to las vegas at 75 mph. I haven't taken it to a race track but I would expect a low 14 second quarter mile / high 13 (it has a few upgrades, I'll talk about it later). It can be a calm grocery getter or it can light up the tires and shift at 7,000. But the biggest thing is reliability. I drive between Vancouver and Las Vegas a couple times a year so reliability is a must.










 

jacob

Member
1956 Buick Century Project- jag front suspension

Here are some more pictures of jaguar front suspension. I had to cut out about a 18" section of the buick frame and make my own out of 2x4 steel. If I remember right, I cut 16" back from the front of the frame where the bumper mounts, and then 18" back from that. So this removes the front cradle and all of the suspension mounts, but still keeps all of the bolt holes to mount the inner fenders. I did a Z shape cut and the most forward part of the Z of the rear cut started directly above the forward of the two inner fender bolt holes that are behind the tire.
The jag unit is very self explanatory as to how it mounts- two big bolts that mount as pins in the front, and two rubber mounts in the back. so I just positioned the front suspension where I wanted it, and welded the steel frame around it.
I thought I had better pictures, but this should shed some light.

Also, the jaguar sway bar mounts in the factory buick sway bar mount bolt holes, so that helps roughly line things up.

I cut out the frame one side at a time, and before I cut it, I welded in a support bar (the rusty metal in the pictures) so that the alignment of the front portion of the frame would be unaffected.

Of course I welded in supports and gussets on the inside, as well as a piece of tube steel to tie the two sides together. It took about 2 weeks along with the engine and rear end swap.



A nailhead to act as ballast for testing the ride height..






 

jacob

Member
1956 Buick Century Project- front jag suspension

Here are a few more pics with the inner fenders on and all together. The car turns and stops worlds better, it feels so much lighter and is much more comfortable to drive in traffic. Cragar makes a week that gives you the factory track width, bolts to the jag / chevy bolt pattern, and accepts a factory hub cap. The car still looks 100% factory on the outside. part number CRR-69565035.






 

jacob

Member
1956 Buick Century Project- Brakes! New Master cylinder and booster

One of the bigger obstacles to this project was the brakes. I had a factory power booster, and just finding someone to rebuild it was a hassle, it took forever, and it was expensive. And it leaves you with 1950's brakes. They work fine but not like a new car.
I set out to design a completely bolt in kit for 1956 buicks (and possibly other years) that replaces the factory air box / water drain. It's taken a lot of measuring, designing and testing but I now have a working model. It's CAD designed and is cut on a plasma table. I plan on making these for sale later in the future, after it has been thoroughly tested. Here is what I have so far. It uses a modern booster, a modern dual outlet master cylinder, and a new brake pedal. It requires removing your firewall vent (aren't these cars drafty enough anyways?), removing your factory brakes and the sheet metal support (the factory bracket would interfere with the new pedal), and absolutely no cutting or anything else irreversible.

It has provisions for water drains and I am making a bracket that bolts to the steering column to hold it in place as the factory air box did.

The final product will be welded much better, and likely powder coated black.

And also patent pending :bgrin:











Heres a look at the beginning of the CAD design

 

jacob

Member
1956 Buick Century Project- Brakes! New Master cylinder and booster

Also, I if anyone has a 54-56 Buick and is interested in helping me test this out please contact me. From pictures, 1956 larger cars and 1954-55 Buicks have the same bolt pattern on the firewall. I just have a 56 century and special so I can't test fit it to find out.

I plan on instilling this on the yellow car and test driving it within the week.
 

jacob

Member
1956 Buick Century Project- Brakes! New Master cylinder and booster

I painted and mounted the new set up on my running car today. Everything went pretty smoothly. I didn't get a picture of the inside but the brake pedal is hung, and sits in about the same position as factory. Tomorrow I will plumb it in and give it a test. It's fairly tight between the master and the inner fender, but certainly enough to bend the 3/16 line safely.









 

jacob

Member
1956 Buick Century Project- Brakes! New Master cylinder and booster

Test drove the new brakes today and I am pleased to report that it was a success! I went clear across Las Vegas, from stoplights to freeway. There is at least double the power compared to the factory buick power brake booster. With the 4 wheel disc brakes and the factory booster, you would really have to step on it in an emergency situation. It feels like modern power brakes now. The pedal is actually a little softer but it bites the brakes much more strongly.

I plan on testing this on a couple other cars but hope to have it for sale in about a month.

Here are some pictures of the new plate that sits beneath the steering column. Unfortunately the factory plate has to be removed entirely because the tabs for the pedal get in the way of the new pedal.


Factory plate (and new brake pedal)



New plate:
 

jacob

Member
I just finished a 3,000 mile trip in my 56- las vegas to Washington and back, including hot august nights in Reno and several detours. Here are a few pictures from the trip, and the next ideas for the project.














As usual for me, I haven't been content with my drivetrain. Ive been doing some research and a gen 5 chevy V8 makes 355 horsepower factory and gets 23 mpg in their big 4wd trucks. And of course there's always room for improvement with a cam and a tune. I picked up a 2015 engine out of a silverado with hardly any miles for surprisingly cheap. I will be putting a 6 speed auto behind this. I am hoping to get around 23-25 on the freeway while still running about a 14 second quarter mile with complete reliability. More details to come, but I am excited to get going on this. Here is a picture of the engine (L83)




Also, I recently completed a 401 / 3 speed auto / jaguar rear suspension conversion in my friend's 56 Buick.

 

jacob

Member
These pictures are from last year, but shortly after I put my LS1 in, it seized up on me. All of that work for a more modern, reliable engine, and it gave up on me. Turns out the oil pickup tube came loose from the oil pump. I ended up doing a full rebuild in Las vegas, a 1000 miles from my shop in Washington.
While I had it apart, it was too tempting not to get the heads ported with bigger valves, dual valve springs, a 224 / 224 .600" lift cam, and a higher stall converter. Wow did it come alive after this! And best of all, it still gets over 20 mpg on the highway.









 

jacob

Member
1956 Buick Century- Cold Air Intake

I have had issues with power loss that seems to come on after the car is fully warmed up, and especially on hot days or after a lot of stop and go. I bought a remote thermometer and placed it inside my intake tube, behind the air filter and turns out my intake air temperatures would creep up to 130 degrees or more! So I set out to make a cold air intake, the first to my knowledge on a 56 Buick! I used an inline air filter and some 4" intake piping. I drilled a 4" hole by the driver side horn, which was by an oval hole that the factory made (I'm not sure if this had a purpose originally?). so far intake temperatures are down dramatically!




 
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