Need engine information

stevehuckss396 · **Posted:** Sun Feb 19, 2006 4:08 am

I need all the information i can find on the Bugatti t50 engine. If you have photos, shop drawings, parts manuals, links to websites that someone documented a rebuild, a rusty old head behind your barn, anything!

If i can find enough information I plan to build a 1/4 scale engine that will start and run. I have started to make a set of drawings for the crankshaft, rods and pistons, cylinders, ECT. Makes you realize how much you dont know. Here is what i do know.

No of cylinders: 8
Bore x stroke: 86 x 107mm 3.3858 x 4.2125in
Capacity: 4972cc or 303 ci
BHP (approx): T50: 225; T50T: 200
RPM Limit (prudent): 4000
Camshafts: dohc
Valves (per cylinder): 2
Camshaft drive: Front, spur train
Crankshaft bearings: 9 plain, plain rods
Supercharger: Roots, bevel driven
Carburettor: 2 Zenith 36 or Schebler
Ignition: Coil
Plugs per cylinder: 1
Firing Order: 1, 6, 2, 5, 8, 3, 7, 4

Herman · **Posted:** Sun Feb 19, 2006 9:59 am

I thing the book "Bugatti type 46 and type 50" by Barry Price will be a good place to start. I will also check other books.

I also think J.J.Horst (Jaap) and Rivaaquarama (Martijn) will jump into this.

Pico · **Posted:** Sun Feb 19, 2006 2:03 pm

The Bugatti Trust has original factory drawings and will make copies for you. Check them out. Pico

stevehuckss396 · **Posted:** Sun Feb 19, 2006 2:19 pm

Both great suggestions guys

Keep em coming.

Herman · **Posted:** Sun Feb 19, 2006 7:18 pm

On small thing that is not yet clear to me:

Do you want to construct an engine with working internals, or do you want to construct an engine which runs on some sort of fuel?

The last version will be more tricky...

stevehuckss396 · **Posted:** Mon Feb 20, 2006 3:18 am

Hello Herman.

This will be an engine that runs on fuel. 100% working and as visually exact as i can get without actualy making molds and casting parts.

It will have...

.850 bore
1.05 stroke
8 Cylinder
4.77 Ci or .08 liter.
Needle bearing on nine mains and 8 rods. 4340 steel crank shaft
Mostly made from 6061-T6 aluminum with cast iron sleeve.
I will make the camshafts to exact spec only 1/4 lift with full duration.
Valves will be exact unless valve stem gets to small.

Im talking about a 1/4 scale RUNNING Bugatti. If it goes well and runs well then i will try to reproduce (reasonably) the supercharger. Carbs will never look like original. They will need to function well so I dont see exact replica in that department!

Anybody else need any info ask. This is not a top secret project. Just dont any of you go and beat me to it!

Ps: I emailed the trust for some help so i'll let you know what they say.

stevehuckss396 · **Posted:** Wed Feb 22, 2006 4:15 am

Well i have not heard from the Bugatti trust. Do you think there are a few people standing around the computer, reading my e-mail, and laughing there a$$ off. I guess my request for information may have been denyed. Have any of you good people ever requested information from the trust? If so how long did it take to get a responce?

I have started to create my first jig to turn the crank journals. I am making the crankshaft modular to insert bearings on the main and rod journals. I have been told that the real crank was all roller bearing.

J.J.Horst · **Posted:** Thu Feb 23, 2006 11:03 am

My experience with the Trust is that they are somewhat eratic in replying, especially I wouldn't count on a rapid reply on a request by e-mail.

Herman · **Posted:** Thu Feb 23, 2006 12:28 pm

One more question:

Are you familiar with surface-hardening of the materials you use?

There is a dutch guy who makes a V8 engine, and on another forum they had a great discussion on surface hardening, but in Dutch, of course...

stevehuckss396 · **Posted:** Thu Feb 23, 2006 9:57 pm

Quote:

Are you familiar with surface-hardening of the materials you use?

Yep.
Of course the rings will need to be hardened as well as the cam. The folks i have polled told me that the crank wont need to be hardened IF THE MOTOR IS FOR DISPLAY ONLY. If there will be any load on the crank it to will need to be hardened. I will harden the crank anyway then grind the last .010 off I will need to also build a fixture to keed the warpage to a minimum. I have read a few articles about it but have never tried it so some experimentation will need to happen.
[/quote]

Herman · **Posted:** Fri Feb 24, 2006 11:21 am

Something that I do remember, is that you MUST lower the crank into the liquid vertically. Doing it horizontally is a garantee for failure. (warpage)

stevehuckss396 · **Posted:** Fri Feb 24, 2006 6:51 pm

Thanks for the info. I have never heard that.

I'm not shure that i can carry on with the project. I can't find anything as far as tech papers on that engine anywhere.

rivaaquarama · **Posted:** Fri Feb 24, 2006 7:15 pm

Hello stevehuckss396. Welcome to the Forum,

I am not sure the T50 engine has a roller bearing crankshaft. If so…. It is damn difficult to build one. I spoke to A Dutch Bugatti collector here in the Netherlands who has a passion for roller bearing Crankshaft and specially ones made by Bugatti. He is overhauling these crankshafts for people all around the world.

Most of the people restoring a Bugatti engine do not dare to touch the roller bearing crankshafts…. He made special tools for doing this in real size… It seems to me almost impossible to align them in a small scale. We are talking about 8 cylinders… As a designer working at the Mitsubishi engine division I am a bit skeptic about these types of scale projects… I have the feeling that a lot of drawing work needs to be done before the actual building can start. If you want to have a real running engine a lot of redesign needs to be done… It is not only an issue of scaling the engine drawings down… Lots of other things should be changed to make the engine run…. The good news is that the bigger the scale.. the smaller the modifications are… I will ask around at the office… One of my colleagues has shown me a web page about a scaled version of the Rolls Royce Merlin aircraft engine… Fully running….

Why a type 50 engine....... and not start with a much easier 4 cylinder type 40 engine. For the 4 cylinder engine it is much easier to get information. Lots of drawings are presented in books and so on, and there are more real engines to have a look at. If I understand correctly the engines of the T37 and T40 are almost identical… and made in great numbers….. You will probably find one in the place or neighborhood you live in….

Herman · **Posted:** Fri Feb 24, 2006 7:32 pm

I also recall a Lotus Elan 1:4 with a real running engine. However, that was even before the Internet became popular...

I will try and relocate the thread in Dutch about building the V8, and translate some (interesting) parts.

Herman · **Posted:** Fri Feb 24, 2006 7:34 pm

http://forum.modelbrouwers.nl/phpBB2/viewtopic.php?t=184

This is the thread anyway.

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