Motocycle engine design

[Chiptosser]

If you look for aircraft suppliers, FBO's, race shops. I know there are rally racers, in your area.
You really don't need cromemoly for your frames,but if it is easier to find.
DOM, (drawn over mandrel) will have plenty of strength for your use.

 

[napoleonb]

Perhaps you've already visited this website, if not you're in for a treat!
http://flashbackfab.com/excelsior-project-paul-brodie/

 

[Chiptosser]

Are you sure that you want to make the crankcase, with 4130??

 

[Goldflash]

You just have to watch this
Home Built Engine in a Harley Hummer . Looks like a full size Hoglet Engine ( almost )
[ame]https://www.youtube.com/watch?v=-708khmH3vY[/ame]

 

[Mitchg07261995]

I designed the crank disks the other night, the book mentions that they should weigh close to 24lbs for the pair, but with the given dimensions my cad software is telling me they will weigh 12-13lbs for the pair?
I wonder if he just scaled the drawings for a hoglet to a larger size?
Is there another material other than 4130 that you guys would suggest?

 

[1dbweldor]

The best places to buy tubing is Ryerson and Marmon Keystone. I've spent a small fortune at both through the years. Myself for a motorcycle frame I would use Chromoly 4130. Reason being stronger than DOM and not much more in price. I was always looking for performance and speed as well as handling, with that being said, the lighter weight would be your friend. The stronger material is easier to keep a clean look as well as a compact structure. On your frame design keep your tubing in compression as much as possible.
The preferred material for the cases is aluminum. 6061 T651 would be a good start, and easily found. Another would be 2024 T6, this A/C grade and a little pricey but you could heat treat if needed.
I hope this helps and good luck on your build.