John Britten: the ultimate "modder"?

[blueflame]

Oddly we have a few good bike designers and riders from NZ, like Burt Munro and his Indian. Motocross riders from NZ are very strong. Kiwis may have flown before The Wright Brothers, jet boats are a kiwi idea too. Mostly innovative Scots from the South Island.

The latest innovation from Godszone is a radical new diesel engine

Shepherd Engine > News

[Christ]

Burt Monro is not a biker... he's a legend, as far as I'm concerned. We're talking about a man that built a bike while basically living in a shed, poor and content with his life, and made it against odds to Bonneville to set a freakin record.

There's a person I consider a hero. SuperMan can kiss my backside.

[Bicycle Bob]

"The latest innovation from Godszone is a radical new diesel engine
Shepherd Engine > News"

How wonderful to find 50% more efficiency from solving a basic problem with levers that does not even show up in the textbooks. I'm looking forward to the new diesels with efficiences between 80 and 110%.
I wish I could find a population that would all just laugh at such promotions.

[NeilBlanchard]

Yes, it is a cam driven engine, like the Revetec (that I mentioned earlier). The problem with a crankshaft engine is the maximum pressure occurs when the connecting rod in nearly straight up, and there is very little leverage that can turn the crankshaft. (A lot of force is trying to bend the crankshaft...)

With a cam driven engine, you can design the amount of leverage you have; rather than being locked in to a sinusoidal piston motion.

On the Shepard engine, is the combustion sleeve inside (and concentric with) the rotating cam sleeve? I wonder why the levers are required at all, then?

[Christ]

Originally Posted by NeilBlanchard

Yes, it is a cam driven engine, like the Revetec (that I mentioned earlier). The problem with a crankshaft engine is the maximum pressure occurs when the connecting rod in nearly straight up, and there is very little leverage that can turn the crankshaft. (A lot of force is trying to bend the crankshaft...)

With a cam driven engine, you can design the amount of leverage you have; rather than being locked in to a sinusoidal piston motion.

On the Shepard engine, is the combustion sleeve inside (and concentric with) the rotating cam sleeve? I wonder why the levers are required at all, then?

Check out Honda's R-series engines. The crank is slightly offset, so TDC is actually slightly aft of traditional crank angle, and the combustion pressure builds when the piston/rod assembly would be creating a leveraged force on the crank shaft.

[Bicycle Bob]

"The problem with a crankshaft engine is the maximum pressure occurs when the connecting rod in nearly straight up, and there is very little leverage that can turn the crankshaft."
The only with problem with that is a bit of blow-by and cooling as the piston slowly accelerates. The potential energy of the main charge is not affected, just stored. It might be better to design an engine that holds the combustion chamber volume constant throughout the burn time, but it would be slow and heavy. A regular crank system gives the lowest average acceleration forces on a piston and rod, yet an engine is still more likely to be destroyed by internal inertia forces than combustion pressure.

[Silveredwings]

Originally Posted by NeilBlanchard

Hi,

I'm thinking that beyond the bike, which is awesome -- the fact that such an amazing machine was conceived of, designed, built from scratch in 11 months, and have it perform at such a high level is quite inspiring!

What sort of things are possible if one wants to build an uber-efficient EV in a backyard workshop?

I can't wait to find out. ONLY IN MAYNARD

[bgd73]

Originally Posted by Christ

As awesome as it would be to own one, I think I'd end up killing myself on it. I don't think I could resist lifting the front end up a little bit every time I hit the throttle, and that's what got me in trouble the last time I had a bike years ago... that and just speed in general.

That's why I bought a 180cc...

I was a nut first trip out too. Never got a bike. I turned into a torquer.

This britten guy a had a few benefits. the stoich was maxxed enough to crack cylinders. manufactures pansy all thier products to respect warranty and maintain reputation. Who was going to stop him? nothing to lose but the drivers...

and the choice for v-twin..the strangest ever. outright flunking bizarre.

love the bimmer photos. If me to get a bike, it is that or the flat four goldwing.

I do like the opening under the seat, in brittens design, for the engine he was working with...and he still cracked a cylinder. The vtwin is a nut.

[Christ]

Originally Posted by bgd73

I was a nut first trip out too. Never got a bike. I turned into a torquer.

This britten guy a had a few benefits. the stoich was maxxed enough to crack cylinders. manufactures pansy all thier products to respect warranty and maintain reputation. Who was going to stop him? nothing to lose but the drivers...

and the choice for v-twin..the strangest ever. outright flunking bizarre.

love the bimmer photos. If me to get a bike, it is that or the flat four goldwing.

I do like the opening under the seat, in brittens design, for the engine he was working with...and he still cracked a cylinder. The vtwin is a nut.

I've got a GL1000.. I think it's a '78, and it's got a BoS from Georgia, so you can get a title. You want it?

[dann6968]

One of my favourite V-twins. Worth big money today.