Forgive the Noob Question

jolfstn

jolfstn

Member
I'm sure there is a reason, but why, on the China Girl engine, is the intake in the back and the exhaust on the front? Would it not be more efficient the other way around? or would the air rushing in the carb be too much? Just curious
 
Nothin' to forgive ;)

As most, if not all motorcycles, mopeds, scooters & bikes have that setup - I would say it's most likely to help protect against carb ingesting water and debris, "ram air" being exceptionally rare on any stock vehicle... but that's jus' my guess ofc

If you're curious, there has been some experimentation in reversing the jug to do exactly what yer askin' about: http://motorbicycling.com/f38/backwards-engine-experiment-1939-colson-13458.html
 
jolfstn said:
I'm sure there is a reason, but why, on the China Girl engine, is the intake in the back and the exhaust on the front? Would it not be more efficient the other way around? or would the air rushing in the carb be too much? Just curious
Click to expand...

It might be because this Chinese engine was not made specifically for installations on bicycles.

Methinks it was some sort of tiller/edger/weedwhacker engine.
 
Lots of reasons. Heat, debris, ease of packaging and by that I mean routing the exhaust away from all heat-sensitive bits(including the rider) and having room for the carburetor. There is no benefit from running the carb in front. In order to get any type of ram-air effect, the bike would have to be moving well faster than anyone has ever had one of these before.

The copy-cat "china girl" engine and the original, the Russian D, actually was designed specifically for mounting on bicycles.
 
BarelyAWake said:
Nothin' to forgive ;)

As most, if not all motorcycles, mopeds, scooters & bikes have that setup - I would say it's most likely to help protect against carb ingesting water and debris, "ram air" being exceptionally rare on any stock vehicle... but that's jus' my guess ofc

If you're curious, there has been some experimentation in reversing the jug to do exactly what yer askin' about: http://motorbicycling.com/f38/backwards-engine-experiment-1939-colson-13458.html
Click to expand...

Yup, I think Baird's played around with that set-up more than any of us. He'd be the one to get in touch with. That '39 Colson of his is one cool bike.
 
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