V Twin Crankcase. Any Released Yet?????

If this twin cylinder (v-twin or upright inline twin) were made in china, I would pay 200-300 for it, price depending on reliability and adaptability to my favorite Felt cruiser. I'm assuming that this will be a relatively high volume, cast alloy engine

If this thing were made in the US, I would pay up to 600ish for some thing that was a dependable design, easy to to adapt, looked trick (even a high quality casting can be nice) and took off like big smoking freight train....

You generally get what you pay for... the bulk of people that buy the china doll kits are happy them as single cylinders.

I personally like the look of upright twins myself

...and I just have a hard time leaving well enough alone....

Harold_B said:

Derbi, Merini, Bizeta all command high prices in the market (and it's highly likely that I mis-spelled them!). I think that a v-twin or u-twin either two or four stroke would appeal to a different market segment than the kit engines just like those three engines so a low volume and high price tag would not be a bad thing. Not everyone would have one because of cost but also because the cost of maintaining the thing would be higher. Sort of like buying an old Saab. I can't afford the car because I can't afford the repairs.

The Lifan 250cc v-twin goes for about a grand with shipping and that is China built in volume and includes a five speed tranny. Perhaps somewhere around the $600+ mark in volume for a 100cc if the market would support it? Who makes the Varadaro 125cc v-twin? Is that the same engine as the Rebel 125cc v-twin? Those are both UK engines that were not marketed in the US. Find the China manufacturer and perhaps a bulk purchase could be negotiated?

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$600 i could see, though I think its still a lot more than i could afford, i could say its reasonable. a grand i just think is pushing it a little. but two points here. one, the cost to mass produce these engines would be probably be more than the market would bear. two, we dont have any control over the price of such an engine, so this discussion is a little bit moot. not being disrespectful, just saying.

I (for one) appreciate your being clear about your intent since tone is always tough to get right on a forum. That having been said, I was asking originally from the perspective of a build your own vs buy it complete and how much much would you be willing to pay. By "you" I'm thinking the typical or at least frequent participant on the forum. The first thing I had thought when this thread started was perhaps there would be an interest for a machined casting or a CNC from billet case and the other small parts required. There are several machinists on the forum already that produce add-on parts so it doesn't seem like a big stretch. A couple hundred for two engines and then the cost of the additional case etc. Although recouping the engineering would be a challenge if a person really expected to do that. Just my opinion but conjecture is free! Gives me something to think about other than work and stuff.

yeah, i hear ya. if it could be done inexpensively, it would be great. as far as the average frequent participant on this forum, everybody got different situations financially. we got people ranging from being on the verge of homelessness all the way up the gamut to moderately well off. its really tough to say who could afford an engine and who couldnt. i dont think any machinist worth half his salt is gonna charge what the less fortunate of us are gonna want to pay, and thats just being honest. its not hard to say where the interest lies. i myself would like a twin engine if i could afford it or i had the skills and tools to build something myself. and i am sure that most of the ht kit builders here feel the same way. some of them can afford to purchase one, or have the skills and tools to build their own. it would probably be cheaper to produce them by individual order than to mass produce them. unfortunately, i dont think any machinist is going to see enough profit in that to make it worth their while either. i know of a particular machinist whose name i wont mention, who is trying to break into the ht parts market right now with some very innovative new products, and he is charging top dollar because he feels that its justified based on what he puts into making the custom parts. his prices may be reasonable, but i dont think the market is going to bear what he is expecting it to, and he is not producing anything close to the scale of a v-twin engine. that right there tells me the market wont bear a mass produced v-twin version of an ht engine either. i could be wrong, but this is just my opiinion. if we are lucky, someone will come along and produce some (real) performance parts at a price that (most of us) can afford, and I think that is all we can hope for.

A real v twin will be very difficult to design because both cylinders need to fire at the same time, otherwise the one that lags behind will have less crankcase pressure when the transfer ports open. A u twin is better.

young grease monkey said:

A real v twin will be very difficult to design because both cylinders need to fire at the same time, otherwise the one that lags behind will have less crankcase pressure when the transfer ports open. A u twin is better.

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I agree a U-twin is much better! (does the "U" stand for upright?)

I think an upright twin would fit in more bikes, brodening the appeal.

Does any multi-cylinder two stroke need to use a common crankcase? or just v twins?

I was hoping each cylinder would have its own crank case to pressurize, then the pistons could be run 180 degrees apart.

It would be extra cool if there was a neat way to use two HT cranks, somehow connected.

The more HT parts that can be used, the better to keep prices low (two HT electrical systems, etc). I think the crank would be a rather tricky part to make cheaply...

The case is going to cost enough as it is, and the first run may need to be CNC'd, maybe even continue on as the "Bently standard".

Then that company could take their idea/design to china, and have much cheaper cast version made for the masses, while retaining the production of the "Bently standard" for those who appreciate and have means for such finery...

If some enterprising American does make this (and they totally could) I would save and scrimp to come up with the scratch to buy one... if I'm still saving by the time they come out with the cheaper Chinese version, I would settle for that!

Here's how Cherokee Motor Bikes built his V-Twin:

http://www.cherokeemotorbikes.com/how_they_re_built

Chris
AKA: BigBlue

As I understand it, that is a U configuration and not a typical single crankshaft V. Always fine with being wrong but that's the way I understand it. A v-twin can be a single or off-set journal but both cylinders share the same crank. Perhaps it's just semantics but it's always best to be specific and clear I think.

i believe as long as it has a single output shaft, its a vtwin. that engine has one output.

BigBlue said:

Here's how Cherokee Motor Bikes built his V-Twin:

http://www.cherokeemotorbikes.com/how_they_re_built

Chris
AKA: BigBlue

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They make it look so easy... and SO COOL!

And I know that isn't easy (for me anyway)...

This was done on CNC, so that means he probably has a program for each step in the production process, as well as a blue print. He could totally produce many more of these. the hard work looks like it has been done!

They could totally run a cheaper line of engines with a cast case using similar dimensions. It uses the guts from two HT engines, perfect!!!

Electric start would be cool too. Could sit between the cylinders, maybe spin the flywheel? So many possibilities!

Thank you Big Blue for posting that link. Totally made my day!

I think it's pretty cool too and I wonder what it would take to convert to a casting. Still think it's a U engine though.

http://en.wikipedia.org/wiki/U_engine

MotorBicycleRacing said:

They took the 50 cc 2 stroke motors off and replaced with a 4 stroke
so Double Trouble is no more.....

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Double Trouble is still alive!!!

We just could not do it!
This bike is SO MUCH FUN!
And the sound this bike makes is unbeatable!
Even Timm's 49cc TROMBONER can not compete!
We will keep Double Trouble as it is and may bring it to the
Grange Race in October as a pitbike!

yikes! a ragjoint with 2 engines!

young grease monkey said:

yikes! a ragjoint with 2 engines!

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Just because you see 9 bolts and make an assumption?

Big BOy don't use no rag joints!

They make their own heavy duty hubs that their sprockets bolt too.

wow, id love to get one of those hubs! i have to spend $80 just for an adapter and sprocket! i really want a lathe...

young grease monkey said:

wow, id love to get one of those hubs! i have to spend $80 just for an adapter and sprocket! i really want a lathe...

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THIS is what we use!

It's Bomba proof!

I have a 3D automated CNC machine, if someone were to come up with a complete set of plans for either a Inline twin or a V-twin, I would probably at least make one for them as well and seriously consider selling them for a reasonably low price. Depending on what the materials cost, Considering a block of aluminium big enough for one half would be around $60 - $90, and I need two, probably around $200 - $300 depending on the price. Any thoughts?

I have a $65K CAD station on my desk and I am a partner in my own business. In other words, I could squeeze this in. What I don't have is spare parts for dimensions. What do people want to base the engine on (48, 66, ?cc and whose) and is there anyone that would care to supply me with parts to measure (junk or otherwise). I can return them if the shipping is reasonable. I would be happy to be part of a team on this.

How about air cooled vw parts? cut a crank in half, 2ea of the cyl, pistons, rods, cut a head in half cam in half. etc. You would just need a "V" crankcase machined to fit the cut parts. Plus there is a wide selection of HP parts that can be used.

Bigboy said:

Double Trouble is still alive!!!

We just could not do it!
This bike is SO MUCH FUN!
And the sound this bike makes is unbeatable!
Even Timm's 49cc TROMBONER can not compete!
We will keep Double Trouble as it is and may bring it to the
Grange Race in October as a pitbike!

Click to expand...

I wanna see and hear it again so please bring it to the next
SoCal Motor Bicycle Racing event this October 20th.