Speed difference between 49cc 2 stroke and 88/66cc

[rayz4321]

I was wondering the speed difference between a stock, broken in 49cc motor and the stage 3 80/66cc bike berry kit. Thanks!

 

[Sidewinder Jerry]

I was wondering the speed difference between a stock, broken in 49cc motor and the stage 3 80/66cc bike berry kit. Thanks!

Well parameters have to be set. Are we talking stock vs stock or modified vs modified? As a general rule a larger displacement means a higher amount of horsepower for the same rpm. More horsepower means it'll be able to move the same amount of weight at a higher rpm than the lower horsepower engine. Thus a speed difference.

What does all of this mean? Well for example: take a eBay performance enhanced 49cc engine put it on a bicycle with sealed bearing wheel hubs using road slick tires while riding on level asphalt with a 140 lbs rider up against a eBay stock 80/66cc engine on a bicycle with cone bearing hubs using knobby tires while riding on level asphalt with a 200 lbs rider; the 49cc performance enhanced engine is going to be faster.

However, if all aspects are equal then the 80/66cc will be faster.

 

[ImpulseRocket]

There are a lot of factors at work, as Mr. Sidewinder Jerry pointed out. Also, why not a 49cc 2 stroke?

If all things in consideration are equal - both engine kits are of good quality and setup/tuned optimally, but otherwise stock, the 66cc 2 stroke will be a bit faster. Nice round approximate figures for good out of the box engines for absolute maximum top speeds, a typical 49cc 4 stroke kit can achieve about 35mph whilst a 66cc 2 stroke would be about 40mph. Note, these are just approximations and either can be within a couple MPH either direction, and to reiterate his is with the best quality kit in the best state of tune in the best conditions with both setup for "top speed" as the main goal.

Now, which one has a higher potential top speed? The 2 stroke, hands down. These cheap little 2 stroke engines are nowhere near optimal in their ports, exhausts, etc. The 4 stroke engines will be more consistent, more reliable, and more practical for a bike that may need to be used for commuting for the vast majority of people. That doesn't mean they aren't without their own problems that require a bit of tinkering either, but as a whole are a bit less involved on the user end, which many problems coming more from the driveline side (gearboxes).

The 4 strokes also have forced air cooling, which really does make a difference for practical use as the 2 strokes are static/motion cooled an can be much more prone to overheating in hot weather. There are forced air 2 stroke engines that could also be used in a similar function, but don't come in a kit form, don't really make a whole lot more horsepower (1.8-2.5), and would require fabricating a mount system. On the plus side, they do use the same clutch system the 4 stroke engines use, so the same transmission options can be applied.

I am looking to do my own 4 stroke build after a decade of playing around with 2 smoke bikes. I've done 50mph on a bicycle because of it and enjoyed the tinkering endlessly, and I even used a 2 stroke as my main form of transportation for a couple of years while I was going back to school and on a tight budget (why I joined this forum back in 2014). I have learned that 30-35mph is plenty on a bicycle

 

[robe]

There are a lot of factors at work, as Mr. Sidewinder Jerry pointed out. Also, why not a 49cc 2 stroke?

If all things in consideration are equal - both engine kits are of good quality and setup/tuned optimally, but otherwise stock, the 66cc 2 stroke will be a bit faster. Nice round approximate figures for good out of the box engines for absolute maximum top speeds, a typical 49cc 4 stroke kit can achieve about 35mph whilst a 66cc 2 stroke would be about 40mph. Note, these are just approximations and either can be within a couple MPH either direction, and to reiterate his is with the best quality kit in the best state of tune in the best conditions with both setup for "top speed" as the main goal.

Now, which one has a higher potential top speed? The 2 stroke, hands down. These cheap little 2 stroke engines are nowhere near optimal in their ports, exhausts, etc. The 4 stroke engines will be more consistent, more reliable, and more practical for a bike that may need to be used for commuting for the vast majority of people. That doesn't mean they aren't without their own problems that require a bit of tinkering either, but as a whole are a bit less involved on the user end, which many problems coming more from the driveline side (gearboxes).

The 4 strokes also have forced air cooling, which really does make a difference for practical use as the 2 strokes are static/motion cooled an can be much more prone to overheating in hot weather. There are forced air 2 stroke engines that could also be used in a similar function, but don't come in a kit form, don't really make a whole lot more horsepower (1.8-2.5), and would require fabricating a mount system. On the plus side, they do use the same clutch system the 4 stroke engines use, so the same transmission options can be applied.

I am looking to do my own 4 stroke build after a decade of playing around with 2 smoke bikes. I've done 50mph on a bicycle because of it and enjoyed the tinkering endlessly, and I even used a 2 stroke as my main form of transportation for a couple of years while I was going back to school and on a tight budget (why I joined this forum back in 2014). I have learned that 30-35mph is plenty on a bicycle

Well done!

 

[Sidewinder Jerry]

There are a lot of factors at work, as Mr. Sidewinder Jerry pointed out. Also, why not a 49cc 2 stroke?

If all things in consideration are equal - both engine kits are of good quality and setup/tuned optimally, but otherwise stock, the 66cc 2 stroke will be a bit faster. Nice round approximate figures for good out of the box engines for absolute maximum top speeds, a typical 49cc 4 stroke kit can achieve about 35mph whilst a 66cc 2 stroke would be about 40mph. Note, these are just approximations and either can be within a couple MPH either direction, and to reiterate his is with the best quality kit in the best state of tune in the best conditions with both setup for "top speed" as the main goal.

Now, which one has a higher potential top speed? The 2 stroke, hands down. These cheap little 2 stroke engines are nowhere near optimal in their ports, exhausts, etc. The 4 stroke engines will be more consistent, more reliable, and more practical for a bike that may need to be used for commuting for the vast majority of people. That doesn't mean they aren't without their own problems that require a bit of tinkering either, but as a whole are a bit less involved on the user end, which many problems coming more from the driveline side (gearboxes).

The 4 strokes also have forced air cooling, which really does make a difference for practical use as the 2 strokes are static/motion cooled an can be much more prone to overheating in hot weather. There are forced air 2 stroke engines that could also be used in a similar function, but don't come in a kit form, don't really make a whole lot more horsepower (1.8-2.5), and would require fabricating a mount system. On the plus side, they do use the same clutch system the 4 stroke engines use, so the same transmission options can be applied.

I am looking to do my own 4 stroke build after a decade of playing around with 2 smoke bikes. I've done 50mph on a bicycle because of it and enjoyed the tinkering endlessly, and I even used a 2 stroke as my main form of transportation for a couple of years while I was going back to school and on a tight budget (why I joined this forum back in 2014). I have learned that 30-35mph is plenty on a bicycle

Also many of the 4 strokes use the oil in it to serve as a coolant as well as a lubricant.

 

[rayz4321]

There are a lot of factors at work, as Mr. Sidewinder Jerry pointed out. Also, why not a 49cc 2 stroke?

If all things in consideration are equal - both engine kits are of good quality and setup/tuned optimally, but otherwise stock, the 66cc 2 stroke will be a bit faster. Nice round approximate figures for good out of the box engines for absolute maximum top speeds, a typical 49cc 4 stroke kit can achieve about 35mph whilst a 66cc 2 stroke would be about 40mph. Note, these are just approximations and either can be within a couple MPH either direction, and to reiterate his is with the best quality kit in the best state of tune in the best conditions with both setup for "top speed" as the main goal.

Now, which one has a higher potential top speed? The 2 stroke, hands down. These cheap little 2 stroke engines are nowhere near optimal in their ports, exhausts, etc. The 4 stroke engines will be more consistent, more reliable, and more practical for a bike that may need to be used for commuting for the vast majority of people. That doesn't mean they aren't without their own problems that require a bit of tinkering either, but as a whole are a bit less involved on the user end, which many problems coming more from the driveline side (gearboxes).

The 4 strokes also have forced air cooling, which really does make a difference for practical use as the 2 strokes are static/motion cooled an can be much more prone to overheating in hot weather. There are forced air 2 stroke engines that could also be used in a similar function, but don't come in a kit form, don't really make a whole lot more horsepower (1.8-2.5), and would require fabricating a mount system. On the plus side, they do use the same clutch system the 4 stroke engines use, so the same transmission options can be applied.

I am looking to do my own 4 stroke build after a decade of playing around with 2 smoke bikes. I've done 50mph on a bicycle because of it and enjoyed the tinkering endlessly, and I even used a 2 stroke as my main form of transportation for a couple of years while I was going back to school and on a tight budget (why I joined this forum back in 2014). I have learned that 30-35mph is plenty on a bicycle

I meant the 49 is also a 2 stroke. And I’m getting the 80/66 cc stage 3 performance kit from bikeberry

 

[cloakedvillain]

Dont get from bikeberry. Bicycle-engines.com or ebay/amazon for a cheaper kit.

 

[ImpulseRocket]

I meant the 49 is also a 2 stroke. And I’m getting the 80/66 cc stage 3 performance kit from bikeberry

Don't fall for the gimmicks. "Stage 3" really doesn't mean a whole lot. This industry is full of hype advertising used to sucker people into spending their money on "performamce."

 

[Brian31520]

Why haven't they water-cooled the jug or even just the head being wc would be a significant benefit. Heck my 13700kf CPU has a 360mm radiator and pump. They been wc engines long before CPU's they just don't want to because they sell more engines.

 

[ImpulseRocket]

Why haven't they water-cooled the jug or even just the head being wc would be a significant benefit. Heck my 13700kf CPU has a 360mm radiator and pump. They been wc engines long before CPU's they just don't want to because they sell more engines.

Because these little engines are made to be cheap. Water cooling a head and/or jug requires R&D work, design changes to castings, and more parts. These engines would go from costing 100ish bucks to 800 bucks for a minor benefit.