Some people have told me I can remover the counter balancer in a blaster and pick up a few extra horse power? But they also said there would be a slight vibration? Wat are your thoughts on that?
removing the counter balancer?
- Thread starter strokedblaster4
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You do not want to do that. The engine will vibrate real bad. There's no real power gain to be had by removing it.
Mmm, I don't have any experience with doing that mod, but I would prefer my engine to be as balanced as possible. A ballanced engine keeps internal stresses at bay and makes it much more reliable, especially at higher revs.
All my 4stroke race motors(cars) are ballanced better than factory spec!
I was actually amazed that the 2jzgte supra engine was amazingly well balanced from the factory!!! One of very few engines I've come acrossed like that.
I would understand the power robbing potential of the blaster ballance shaft, but could it cause more bad than good???
All my 4stroke race motors(cars) are ballanced better than factory spec!
I was actually amazed that the 2jzgte supra engine was amazingly well balanced from the factory!!! One of very few engines I've come acrossed like that.
I would understand the power robbing potential of the blaster ballance shaft, but could it cause more bad than good???
Unbalancing an engine has never increased horsepower in any application. There are lots of bigger displacement engines out there that aren't counterbalanced, but they achieve balance through the crank throws as well. HP isn't increased by reducing rotating mass, mass stores energy. How quickly you feel acceleration will be affected by it. I'd say the tradeoff for vibrations isn't worth it in this case.
Actually, yes it is. Torque is a measurement of the ability to move a given amount of weight over a given distance. If an engine produces "X" lb.ft. of torque and is measured at the crank with a counterbalancer, it will produce less torque than if the counterbalancer is removed because the force produced has to accelerate the counterbalancer. Since horsepower is a byproduct of torque, lightening will produce an increase in horsepower.
The argument of a lightened flywheel being an undesirable addition to a trail quad is similar. A lightened flywheel will produce a small, yet measurable, increase in torque. The seat-of-the-pants dyno says otherwise because of the decrease in rotational inertia which means that there is less momentum, yada yada.
There won't be the wear on the crank, bearings, etc. that you'd think, however. The crank is going to do what it does (accelerate in the direction of instantaneous travel) with or without a counterbalancer. The counterbalancer just acts to counteract the motions of the engine produced by the crank, aiming to neutralize the net vibration. In the end, you're going to see harmful vibrations which vary in severity, but are nonetheless there.
In short, a counterbalancer will give you more power, but it would be negligible and definitely not a win/win scenario. Time and money would be best spent elsewhere. My vote is "no".
I could probably come up with a figure if I knew the weight of the counterbalancer. It likely isn't much, though. I want to say that a Blaster makes 15 lb.ft. torque, which equates to having 15lbs pushing down on a one foot bar at that is at 90°, or 30lbs pushing on a 6" bar, 60lbs on a 3"bar, etc.
This is a hypothetical set of numbers as I don't know the specifics for the counterbalancer, but you'll get the idea. When you reduce the weight of anything that rotates (in this case, a counterbalancer), you are reducing the rotational inertia. Inertia is the ability of an object to maintain it's current speed, whether it be 0mph or mach 4. If you take 1lb of material and add it to the outside of the lobes of the CB (I'm not typing counterbalancer anymore), it would have a higher rotational inertia than if you added it to the shaft.
Now this is where my math starts to become hazy as it's been quite some time since I've done all of this. If your CB lobes weigh 1lb each and the center of mass for each of them is at 1.5", they would require .25lb.ft. or torque to move. Also, you have to factor the weight of the CB shaft, the resistance of the bearings, the air resistance against the lobes, and the mechanical losses between the gears into the equation, although it would be much less significant. I wouldn't estimate more than .05lb.ft. loss there. Even then, you'd be only sitting at 15.3lb.ft. at peak.
So if the lobes weigh 1lb (total of 2lbs) and have a center mass that is 1.5" from the axis of rotation, you'd see a loss of about 1.6%.
This is a hypothetical set of numbers as I don't know the specifics for the counterbalancer, but you'll get the idea. When you reduce the weight of anything that rotates (in this case, a counterbalancer), you are reducing the rotational inertia. Inertia is the ability of an object to maintain it's current speed, whether it be 0mph or mach 4. If you take 1lb of material and add it to the outside of the lobes of the CB (I'm not typing counterbalancer anymore), it would have a higher rotational inertia than if you added it to the shaft.
Now this is where my math starts to become hazy as it's been quite some time since I've done all of this. If your CB lobes weigh 1lb each and the center of mass for each of them is at 1.5", they would require .25lb.ft. or torque to move. Also, you have to factor the weight of the CB shaft, the resistance of the bearings, the air resistance against the lobes, and the mechanical losses between the gears into the equation, although it would be much less significant. I wouldn't estimate more than .05lb.ft. loss there. Even then, you'd be only sitting at 15.3lb.ft. at peak.
So if the lobes weigh 1lb (total of 2lbs) and have a center mass that is 1.5" from the axis of rotation, you'd see a loss of about 1.6%.
You can remove it BUT then you have to have the crank balanced. Which, if this were a cost effective mod it would be right up there with porting and head mods. Which on a single cyl might not be as good of balance.
It won't make more power, but you will eliminate the parasidic drag of two gears and two bearings.
Sorry, I would have to see an SAE paper or article from Hot Rod magazine (etc) stating that it would make more power.
When the Blaster broke the balancer gear & bearing, it took less than 5 seconds run time when my son brought it home to know something was horribly wrong. Shook worse than a whore in church.
It won't make more power, but you will eliminate the parasidic drag of two gears and two bearings.
Sorry, I would have to see an SAE paper or article from Hot Rod magazine (etc) stating that it would make more power.
When the Blaster broke the balancer gear & bearing, it took less than 5 seconds run time when my son brought it home to know something was horribly wrong. Shook worse than a whore in church.
Don't get me wrong, I don't believe in removing the counterbalancer, but it is a factor that you can calculate. The math is there if you search for it. It's the same as crank and wheel hp, except the counterbalancer is much, much less significant.
We did a bunch of research with counterbalance shafts a couple of years ago. No dynos, no math, just 5 guys with a free day and an idea. The goal was to remove (or reduce) the balance shaft from a Blaster and keep the vibration down to that of a stock engine. We started by drilling a hole in the back of the head and welding brackets to the frame for a head stay. We removed the shaft in a fresh engine and bolted it up. The vibration was unbearable. We pulled the engine and counterbalance shaft. The counterbalance shaft was reduced in weight by cutting the outside diameter. The engine was assembled and installed several times that day. I don’t recall the exact amount we removed off the shaft but it was significant. We were surprised to discover that even after removing significant amounts of material from the shaft, none of us noticed an increase in vibration but we all noticed a faster reving engine. The bottom line is we never found a point where removing material from the shaft would cause a vibrating condition unless it was completely removed. I’m sure if we continued to remove additional material, we would have found the point where vibrations were noticeable. It was late, Tarmo was hungry, Dave was driving me crazy, and I was sick of splitting cases. I’ve had almost every possible combination of Blaster engine and have performed this modification on all of them with no problems. We now offer this service at the shop.
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