Miniature v8 or v6 on a bike?

Will'smotobikes19

Well-Known Member
Joined
Apr 9, 2018
Messages
1,658
Time for another think tank on these ideas I have lol jk. But I saw a homemade 394cc v8 bike on youtube made by a guy named Dennis Franz. He made the aircooled beast by hand without any plans of course his didn't have pedals and I don't really think there would be any room for pedals either. HE used a BMW motorcycle shaft drive transmission. You could use Honda GX25 pistons or GX35 pistons or maybe even the pistons for the GXH50. If the GX25 pistons were used it would be 200cc, if the GX35 pistons were used it would be a 280cc and if the GXH50 pistons were used it would be a 400cc!. I know people make them as model engines and RC engines but wouldn't one on a bike be cool?
 


Frankenstein

In memory of Frankenstein 1991 - 2018
Joined
Jun 24, 2016
Messages
5,077
Yes it would be cool! It's just an extremely difficult task without ALL the exact right tools and skill. Just linking up two China girls is a huge undertaking.. The hardest part for someone like me to build a v6 or 8 would be to make or get cams or lifting mech, I have the foggiest clue where to start with just that type of component.

It would be nice but too big for a bicycle imo.
 

Will'smotobikes19

Well-Known Member
Joined
Apr 9, 2018
Messages
1,658
Yeah you would have to use a motorcycle frame. I think regular bike frames could only handle a 2 or 3 cylinder engine at most. I wish I could turn a room in my basement into a little machine shop. Even a small v6 300cc with 50cc pistons would be amazing everyone would be jealous because not many of the craft built v6 or v8 bikes exist, many of them are just modified existing engines. Maybe a scaled down automatic transmission could be used idk or a shaft drive manual. And for the camshaft there is already existing small v8s made by conley maybe you could base it off that. I don't know how many blueprints there are for these scaled down engines but I think it would be more fun figuring it out yourself.
 

Will'smotobikes19

Well-Known Member
Joined
Apr 9, 2018
Messages
1,658
So I think I want to build a 300cc v6 engine maybe based on a nissan VQ35de. How do you make a model for the castings? should it be out of wood or lost wax? does anyone know anything about this? how do you know what size for the pattern to be? would it be hard to scale down the dimensions of original parts? I'm thinking of buying a lathe, mill and starting a little machine shop. As well as getting taps and dies.
 

Frankenstein

In memory of Frankenstein 1991 - 2018
Joined
Jun 24, 2016
Messages
5,077
So I think I want to build a 300cc v6 engine maybe based on a nissan VQ35de. How do you make a model for the castings? should it be out of wood or lost wax? does anyone know anything about this? how do you know what size for the pattern to be? would it be hard to scale down the dimensions of original parts? I'm thinking of buying a lathe, mill and starting a little machine shop. As well as getting taps and dies.
Lost wax is probably your best bet for simplicity and allowing you to reform mistakes before a hot pour. When you scale down you need to scale up a tiny bit so the part will shrink to the proper dimensions after it cools.

Engines are a bit intricate, the ports and paths that will ultimately be filled with plaster during molding will need to be designed as such that you can clean them externally. If it is especially difficult because your plaster won't dissolve in water (which is what you need because 'normal' plaster isn't capable of being kilned without falling apart, which is needed since otherwise the molten aluminum WILL shatter cold plaster molds) you can use a weak acid solution to strip it out.

I have never lost wax molded anything larger than a 4 inch figurine, a v6 could probably be packed into something a bit larger than a cinder block, but that's a lot more than 18oz of bronze so it will probably be much more difficult (other than aluminum being easier to cast than copper and gold alloys.)

Buy hard wax, soft wax will deform too easily as you handle and bring measuring tools up against it.
 

darwin

Well-Known Member
Joined
May 26, 2008
Messages
3,939
Look up a Honda Valkyrie or a Triumph Rocket. Both come w/factory V6s and look amazing.
 

Will'smotobikes19

Well-Known Member
Joined
Apr 9, 2018
Messages
1,658
I thought the triumph rocket was a inline 3? Anyways it was just an idea most people would be incapable of building a miniaturized engine except for senior hobbyists and people that have been machining their whole life. I might try casting a stock motorized bike case or cylinder first for practice. I'm working on a 74cc high performance 2 stroke right now.
 
Top