Origin of the "Happy Time" bicycle engine

arceeguy

Active Member
Joined
May 20, 2008
Messages
1,102
Hello mb veterans! I was curious to learn the origins of the "Happy Time" engine design. Why is it called a "Happy Time?" was this coined from a poorly translated manual? Is this an "original" design by a Chinese manufacturer that a bunch of companies have started to manufacture? Or is it a design of a large company (like Honda, etc) that the Chinese manufacturers copied after the industrial patents expired. (like the Chinese ATV's, scooters and cycles powered by Honda clone engines)

How many different manufacturers make these kits? Are there any differences between the various vendors, or are they all pretty much the same?

My apologies if these questions come up too frequently!
 
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wavygravy

Guest
the happy time is a good learning tool & steeping stone to bigger & better things once one gets burned out to the ways of chinese quality control! ha!!!
 

fastboy9

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Joined
Jan 22, 2008
Messages
584
Well basically the "happy time" engine was a term coined by a guy called Augidog (one of the "fathers" of MBc) and the term just stuck. There are several factories that all manufacture the happy time engine, each factory has a slight difference to them (Dax will be able to explain more).

As for its origins: The chinese version is a enhanced copy of an older russian design from back in the 50's, these engines are called the "D" type engines. Heres a good thread about them: http://www.motoredbikes.com/showthread.php?t=3881&highlight=russian+engine&page=2.

Then the chinese got a hold of the design and created the modern day happy time, there have been a few upgrades to its design, and the engine is slowly getting better and better. I was told that the Russian engine is a copy of a British design during the war! So the happy time engine has evolved a **** of a lot since then!
 

arceeguy

Active Member
Joined
May 20, 2008
Messages
1,102
Yes -thanks for the info zev0 and fastboy!

Looks like the Russian engines suffer from their own problems! (overheating)

I noticed that some of the Chinese made Type D's have cast iron sleeves (grubee), so maybe these would be more durable?
 
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BSA

Guest
I noticed that some of the Chinese made Type D's have cast iron sleeves (grubee), so maybe these would be more durable?
Yes they certainly would be. I'd love to get my hands on one. Think of all the possible mods, big bores and they use contact point ignition unlike the chinese engines stupid CDI where the ignition cannot be easily advanced

BSA
 

arceeguy

Active Member
Joined
May 20, 2008
Messages
1,102
....and they use contact point ignition unlike the chinese engines stupid CDI where the ignition cannot be easily advanced

BSA

"Stupid CDI?"

I'll take a stupid CDI over points and condensor any day!
If you advance the timing by fiddling with the point gap, you advance the timing across the entire RPM range, and what might be better at higher RPM's may be too much advance at lower RPM. A CDI module can be programmed with a timing advance curve to allow proper low speed operation while advancing the curve at higher rpm. Some have rev limiters programmed in, and some purposely eliminate the rev limiter for racing. CDI's can be very versatile!

It sounds like the CDI used in the Happytime has "none of the above" though. Has anyone tried to use a CDI unit from a chinese pitbike or scooter? They are pretty cheap (20 bucks shipped) and have advance curves built in. The stator on the HT would need an exciter coil to power the CDI plus a trigger coil to fire the CDI. From what I can see (not owning a HT, but looking at pictures) the HT CDI uses the exciter coil to power and trigger the unit. If there is a separate trigger coil, adapting a more sophisticated CDI may be easily possible.
 
B

BSA

Guest
"Stupid CDI?"

I'll take a stupid CDI over points and condensor any day!
If you advance the timing by fiddling with the point gap, you advance the timing across the entire RPM range, and what might be better at higher RPM's may be too much advance at lower RPM. A CDI module can be programmed with a timing advance curve to allow proper low speed operation while advancing the curve at higher rpm. Some have rev limiters programmed in, and some purposely eliminate the rev limiter for racing. CDI's can be very versatile!

It sounds like the CDI used in the Happytime has "none of the above" though. Has anyone tried to use a CDI unit from a chinese pitbike or scooter? They are pretty cheap (20 bucks shipped) and have advance curves built in. The stator on the HT would need an exciter coil to power the CDI plus a trigger coil to fire the CDI. From what I can see (not owning a HT, but looking at pictures) the HT CDI uses the exciter coil to power and trigger the unit. If there is a separate trigger coil, adapting a more sophisticated CDI may be easily possible.

The CDI on the chinese engines are rubbish. I hate sealed boxes where you can't muck about with stuff.

BSA
 
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