27.2cc Zenoah Engine 4.25+

Just a quick question, was your stolen bke that one with the sprocket mounted on the disc brake and with a custom made expansion exhaust chamber and a Delorto knock-off? If so, Hope you get the ******* who stole it and get it back.

Mine was a zenoah based GEBE on a raleigh Apex MTB frame... new one will be another GEBE 2S using a 32cc engine on Schwinn deluxe 7 cruiser

Jemma xx
 
BS

I'd like to know how they measure HP. I had a 138cc Whizzer motor that was only 2 HP before I did a major hop up. Even at 2 HP it was a LOT stronger than my GS 460 from DDM. I have their best TS head on that 47cc X-Can too. They say it is 4.2 plus HP. BULL!! They LIE!! I'm one dissapointed customer.....
 
Could be torque vs HP....As an example my Cummins Diesel is rated at only 160 HP but 400 LB ft at only 1600 RPM....My gas Dodge has a higher HP level but the HP and torque arrive a lot later in the RPM band so depending on load.....the gasser may never get up to it's power band where as the diesel already there putting the power to the road.....My diesel truck pulls Soooo much better than the gasser plust it gets better MPG's..all with less HP but probably more usable HP to the road because I am not running the gasser to 5 or 6K RPM's all the time...FWIW some small RC nitro engines like the .21 CU IN 1/8 scale engines put out more HP than the happy times and in race tune probably around 3-4 HP but they do so at insame rpm's....sometimes 30,000 +.......but they wouldn't be real practical to run on a motorized bike....good power but at too high an RPM.
Andrew
PS - I have never actually used a pocket bike motor but I understand they are little screamers too.....have to rev pretty high to achieve max power where as the whizzer is probably is more "diesel like" comparatively.... i.e. low speed grunt
 
I'd like to know how they measure HP. I had a 138cc Whizzer motor that was only 2 HP before I did a major hop up. Even at 2 HP it was a LOT stronger than my GS 460 from DDM. I have their best TS head on that 47cc X-Can too. They say it is 4.2 plus HP. BULL!! They LIE!! I'm one dissapointed customer.....

The problem isnt one of BHP its more one of wringing power out of an engine.

There are two methods - one basically involves more power per revolution - aka different tune, breathing, timing, and in the case of multicylinder engines one carb per cylinder... turbocharging would come under this banner as well..

The other method is that used on smaller engines which is design the engine with similar setup regards fuel etc. The trick here is raise the revolutions limit...

A 98cc villiers engine produces 2hp at 3750rpm ... a 32cc Tanaka produces 1.6hp at 7/8000 rpm. Technologically they are fairly similar engines.

Take a 25.4cc zenoah and build it to run at 11,000rpm - you'll get around 3-4 hp depending on carb and tune etc... on the bench.

Trouble is you will hit a problem on the road because in order to get 3-4 hp out of the engine you have to get the engine up to 11k rpm under roadgoing conditions...

If we assume the max revs available on a single speed drive is 7500rpm without LPA then with a normal spec zenoah you'd be looking at about 1 - 1.2hp. If you put the rooted one on the same bike at the same ratio you'd get the same rpms - but given the different powerband you would likely get less actual power to the wheel and also the torque curve would be difficult.

in order to be able to use the extra power, you'd have to change the ratios in order for the engine to spin up to the relevant RPM's. Its the same thing as would happen if you put a new engine in a car but used the same original gearbox and final drive ... if the engine has been set up as a high revving engine and the transmission ratios dont allow it... then the extra power will not be available...

Jemma xx
 
An less-expensive alternate gear-reduction box!

:cool:Well put, Jemma.

As I stated before, the STATON rear chain box can harness ANY high-rpm engine, even without the NuVinci hub. A 10t/16t drive/driven ratio yields 1.6:1. Multiply that by 18.75 begets 30:1 final drive.

With these gears on a 26" bike, an 11,000rpm engine can be harnessed to 4,000rpm/8,000rpm/11,000rpm speeds of 10.6mph/21.2mph/29.2mph.

Higher or lower speeds can be adjusted by a simple $15 drive sprocket.

That's after you buy the $240 STATON gearbox.

Like the old saying goes, "Speed costs money. How fast do ya wanna go?"

Myron
 
Back
Top