biggest engine?

[rickie h]

the biggest engine kit ive seen is an 80 cc with 69.7 cc displacement...anyone seen bigger?

[TheOtherStyle]

i've seen much bigger....but 800CI doesnt fit in a bike

[rickie h]

well id like something bicycle worthy :P

[42blue15]

Originally Posted by rickie h

well id like something bicycle worthy :P

No reason to commercially manufacture anything much bigger, unless you want to manufacture rear wheels as well.

When you start putting much-larger engines on bicycles (4-5+ HP) you run into the issue of the rear wheel bearings and spokes dying very early deaths. You can get thicker spokes with the Worksmans and Huskys, but the bearings are still the same.

The couple bikes I've seen (online) with Lifan motorcycle engine/trans setups--one had a moped rear hub laced into a bicycle rim, and the other used a whole motorcycle rear wheel.

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If you want something that will really scream, look at some of the snowmobile engines.... They're still mostly 2-strokes, so they're pretty compact and powerful--the SMALL ones are 30-40+ HP, and they have a CVT already built-in.
Ted Wilkins - Snowmobile engines | FF Web
~

[azbill]

whizzers are 138cc, and I have seen HF 79cc four strokes as well

[Dan]

This is the biggest I have seen.
http://motorbicycling.com/f37/harbor...ine-11757.html

Great thread too. Some amazing folks around.

I forgot who made this pic! Sorry. (Was this one of Tom's?)

[TheOtherStyle]

ROFL @ Dan's pic

[KilroyCD]

Dan, I think this one might have yours beat. (LOL)

[Dan]

Originally Posted by KilroyCD

Dan, I think this one might have yours beat. (LOL)

LOL KillRoy! Man, would need some really wide peddles for that thing!

[Finfan]

You know Dan you MAY have to modify the frame a little to fit that engine. Tune it well, any blow back through the intake could be painful!