Hi, I’m Jay from Real Street Performance. Today, we’re going to talk about harmonic balancers, and why an aftermarket one is better suited than your stock one. The harmonic balancer is a weighted pulley that mounts on the nose of the crankshaft to absorb the inherent vibration that happens when you’re running your engine. Your factory harmonic balancer consists of 3 pieces: the hub that slides on to the nose of the crankshaft, a piece of rubber that wedges between the hub and the outer ring to absorb vibration, and the outer ring that typically drives the drive belt. As the factory balancer ages over time, the rubber deteriorates. And it will allow the ring of the balancer to slide off of the hub. The factory balancer could also fail by changing the frequency that the engine operates in. So if you change the reciprocating parts in the engine: pistons, rods, things like that, it changes how the engine was balanced and what vibration it makes. High RPM can exceed what the factory balancer was rated for, creating the condition where it can swing the ring off also. Your engine needs a harmonic balancer because there’s inherent vibration in the reciprocating parts. So what happens when the engine doesn’t have a balancer on it, if you have an engine that is a single speed like a generator that just ones that runs at one speed or a lawnmower that runs at one speed, there isn’t a wide range of RPM to tune the harmonics out of. But with an automobile engines and drop ratings from a 1,000 RPM to 10,000 RPM. You need something to pull that vibration out as the engine frequency changes. It’s important to tune out these vibrations because it can hurt the oil pump, if you have a crank snout driven oil pump. It can drive the valve train into harmonics if you’re using a timing chain engine where the vibration is transmitted from one side of the engine to the other. It can rattle the flywheel loose. It can split the hub. You can see vibration on the face of your bearings and your main bearings if the engine is vibrating a lot. You can also see it in the main caps if there starts to be some micro welding. On the nose of the crankshaft, you can see some prints where the balancer is actually shaking on the nose of the crank during severe duty. Because again, we’re not treating these engines nice. We’re making 2, 3 times their designed power output and with that comes additional stress that needs to be dampened. A quick example of an OE manufacturer combating this problem is the 2000 Ford Cobra R. Ford had been building the modular Ford for years. And when they decided to put together the Cobra R, which would be a road race style vehicle, they had to add weight to the crank balancer [to the harmonic balancer] to help absorb the vibration that was being driven back into the oil pump and to the other reciprocating parts. Because the factory balancer deteriorates over time, you should consider buying an aftermarket balancer. The aftermarket balancer doesn’t necessarily add a lot of flash. It doesn’t necessarily add a lot of horsepower, although it can add horsepower by reducing the vibration in the engine. It’s basically about longevity. When the stock balancer fails, things break. If you’re racing your car in a sanctioning body, they normally won’t let you race under a certain time or class with a stock balancer because they know they fly apart. And that ring can become a projectile in addition to its problems that it gives your engine. The aftermarket dampers are constructed differently. One of them is for safety to have good containment so the isolator is mounted inside the balancer where it cannot exit the balancer. They also have a tighter tolerance on the hub of the crankshaft. So the fit from the hub to the crankshaft is going to be a bit tighter. And that’s going to allow more vibration to be transmitted directly into the balancer instead of lost through a loose fitting balancer. As an example, I have an ATI ring here. This is the dampener. They use different durometer o-rings that will isolate the hub of the crankshaft to the ring of the balancer. And they are tunable in some degree for different engines, but they generally have a good safe setup for engines that are over the factory power level and will meet a class or NHRA rules. A quick installation tip if you’re installing one of these balancers is you’re going to want the engine cold. And you’re just going to boil this hub in water. So get this hub over 200 degrees. Put some oil on the snout of the crankshaft, and you’ll be able to slide it on that way. If you try to put this on cold or put this on cold with the hot crankshaft, that’s not going to fit. There’s too much interference between the 2. So this has to be hot, engine has to be cold. This will get on the nose of the crankshaft. The harmonic balancer is not a flashy fun part. It’s not something you’re going to brag about to your friends that you’ve just purchased. However, it is a key component in your build. And you should definitely budget for it. The price of the balancer versus the risk of not having one, it’s a no-brainer. So just put it on the list of things that you need to purchase for your build to make sure that your engine can live a long and healthy happy life. Thanks. See you next week.