Motorcycle engine ideas

[Siddly]

I'd like to make a model single cylinder motorcycle engine and I'm going to need help ;D

Here is my wishlist :-

1) The engine must look 'classic' - 60's or earlier
2) It must be a 4 stroke, air cooled. Side or OHV
3) It doesn't have to be a replica of any particular engine, just give the feel of the period
4) The smallest fastener I'd prefer to use is M2 and I'd like the fasteners not to look too far from scale

My machinery is size limited - Emco Compact 5, X2 mill, medium sized drill press.
Having been a motorcycle mechanic and a gunsmith I've got machining skills and I also know how engines work, which is something which should help a bit. Maybe
I'm also able to use Solidworks ( although a bit rusty )

Can anyone suggest a free plan I could modify to get the look I want ?

 

[Jasonb]

Bill Connor has done a lot of motorcylcle engines, mostly 1/4 scale such as Velocette, Matchless, vincent, etc but they are all scaled from full size engines or drawings see here.

The most obvious engine that plans are available for is the Hoglet which looks a bit like a harley V twin. Plans are available from Model Engine Builder Magazine, do a search here for Hoglet and you will fins several builds. Thsi is my one still to be finished.

J

 

[Siddly]

The only drawings I have been able to find of any classic bike engines are the cutaways published by The Motorycle.
Fantastic pieces of artwork, but not enough there to make engineering drawings from. Not enough for me anyway

The Hoglet is perfect except for being a V-Twin - I've been eyeballing the build threads already...

I should say the V-Twin is actually my favourite engine configuration but I really want to start with a single for reasons of simplicity.

I also didn't want to commit to buying plans at this stage but I should probably check how much the Hoglet plans are though...

Thanks Jason

Edit - I can't seem to find a plans section on the Model Engine Builder website, is it a case of buying back issues ?

 

[slick95]

Here is the link to MEB issue ten:

http://www.modelenginebuilder.com/issueten.htm

Issue 10 and 11 have the plans. Very nice plans too.

Jeff

 

[IanR]

Edgar Westbury's Kittiwake looks similar to a British single, as current motorcycle practice inspired the design in 1930something. It has occurred to me to build it with redesigned crankcases as a 1930 ish Panther.

 

[Jasonb]

It would be quite easy to build the Hoglet as a single, the basic design has been used for an inline 2,4 & 6 and possibly a single as well.

Yes you have to buy the back issues 10 & 11, go to the subscription link to order back issues.

Kittywake is a bit more complex

http://www.myhobbystore.co.uk/product/17501/kittiwake-pe5

J

 

[Siddly]

Edgar Westbury's Kittiwake looks similar to a British single, as current motorcycle practice inspired the design in 1930something. It has occurred to me to build it with redesigned crankcases as a 1930 ish Panther.

That looks VERY promising.

I probably once actually had those plans in an issue of ME - a retiring model engineer friend gave me about 3 decades worth of copies. I'm afraid to say I binned them in the end though, as the mostly steam loco content wasn't my thing at all and the missis was moaning about how much space they took up. C'est la vie

 

[Siddly]

Jeff, Justin, thanks.

$16 plus shipping seems very good for the plans, especially considering the extra content in the magazine.

Kittiwake doesn't look too bad to me apart from the crankcase. Maybe I should think about learning to make castings.
I'm going to build a furnace to smelt my own steel for knifemaking soon so melting the aluminium wouldn't be a problem at least.

 

[BobBJ]

Hi chaps
I'm a new reader as of today as I'm interested in engines and motorcycles! I'm building a Westbury Atom Minor 2-stroke on my South Bend lathe but would like to go bigger so that the engine could power a bike of some sort. I'd be interested in the views of HMEM readers as my ideas for a motorcycle engine are a bit of a "cheat". The cheat I'm considering is to use the internals from a common power unit like a Honda 90 (crank, conrod and piston assy) and then make my own patterns and castings in order to house these modern internals in a old retro style crankcase, cylinder and head. I did bit of time in a pattern shop but can see that the head would be a complex piece of work. Most Honda 90's nowadays are overhead cam so that would make the head even more difficult. I'm sure that I had a 90 as a kid that was a push-rod single but it would be crucial to get the valve sorted out properly... Any thoughts would be great..
Cheers

 

[Jasonb]

Maybe this will give you some ideas, its a whole bike but there is a lot about making the engine

http://flashbackfab.com/pages/excel00.html

J

 

[dsquire]

Maybe this will give you some ideas, its a whole bike but there is a lot about making the engine

http://flashbackfab.com/pages/excel00.html

J

Jason

Thanks for that link to Flashback. I read all about "The Excelsior Project" and found it fascinating. I'm going back to read some more on that site. :bow:

Cheers

Don

 

[steamer]

Oh that is COOL!

Dave

 

[Dave G]

Building an engine of your own design is a very rewarding adventure. I highly recommend it. If you are capable of drawing and understand the basics of engine design, give it a try. I have been looking at what is available for pistons on e-bay. You can buy pistons with rings and wrist pins for as little as $20 US at about 38 - 40 mm bore size. A little large but these fit 50cc commercial engines. Some are designed for 4 stroke engines and have flat tops and valve reliefs. Having a commercial piston would help in longevity and make the odds of success greater in my opinion.

There are many here on the forum that build their own designs, any questions one would have would probably be answered by many of these individuals as we all like to see new engines being designed and built. Good luck, Dave

 

[BobBJ]

The "Excelsior Project" looks brilliant - I can only dream of that standard of work. I believe in getting my feet wet with a simple project getting progressively more and more complicated as time goes by. It would be great to have a motorcycle built by my own good (ish) self. The key of course is the engine in the centre of things. The Excelsior guy made up a dummy cylinder head which was a great idea. I must go through his "story" in detail - it's very generous and open of the builder to make so much information available. Boy I'm glad that I joined this site. many thanks Bob

 

[Mosey]

Steve should be building an engine like this for his minibike about now. I would expect nothing less than a single with OHC, maybe something with a tower shaft to the cam. What do you say Steve?

 

[stevehuckss396]

Steve should be building an engine like this for his minibike about now. I would expect nothing less than a single with OHC, maybe something with a tower shaft to the cam. What do you say Steve?

Sorry to disappoint but I need to make a flathead valve in block type engine. Wouldn't look right with anything else.

"Anything else would be uncivilized" - Hulk Hogan

 

[Mosey]

OK, get on with it. It will be as gorgeous as expected, I'm sure.