How do you know that a particular harmonic balancer is better than another?
09-22-2009, 09:04 AM
#1
TECH Enthusiast
Thread Starter
iTrader: (2)
Join Date: May 2005
Posts: 516
Likes: 0
Received 0 Likes
on
0 Posts
How do you know that a particular harmonic balancer is better than another? I'm looking at getting an upgraded harmonic balancer but was wondering how would you know if one is better than another. Can you actually feel your engine vibrating less? I wouldn't think so. With my lumpy 306 cam I'm almost positive I'm not going to know a difference.
Could you tell me why I should go with one over another? Also these don't have to be balance right? I just throw it on correct?
Could you tell me why I should go with one over another? Also these don't have to be balance right? I just throw it on correct?
09-22-2009, 09:35 AM
#2
I'm looking at getting an upgraded harmonic balancer but was wondering how would you know if one is better than another. Can you actually feel your engine vibrating less? I wouldn't think so. With my lumpy 306 cam I'm almost positive I'm not going to know a difference.
Could you tell me why I should go with one over another? Also these don't have to be balance right? I just throw it on correct?
Could you tell me why I should go with one over another? Also these don't have to be balance right? I just throw it on correct?
And yes you just "throw it on" unless you arent internaly balanced.
10-04-2009, 07:37 AM
#3
Teching In
Join Date: May 2008
Posts: 14
Likes: 0
Received 0 Likes
on
0 Posts
Harmonic Balancers On some externally balanced motors, the harmonic balancer plays a roll (it actually heavier on one side).
Just bolting one on will not (unless you get damn lucky) improve the balance of your motor.
To achieve the best balance - your pistons + rings+ pins need to all weight the same. Connecting rod big and little ends need to weigh the same. Now the part most forget, the crank needs to have throws that are 90 degs appart and the block's bores must also be 90 degrees apart.
At that point you can adjust the balance by removing or adding weight to the crank.
The harmonic balancer's job is a bit different. Imagine the crankshaft as a big torsion bar. As the back cylinders fire, the front may be on compression stroke. So internally the crank flexes one way. As the crank turns the force reverse. This variation in stress on the crank shaft causes all kinds of harmonics and in the extreme case will crack the crankshaft. Harmonic balancers prevent that.
The factory balancer is probably the best below 3000 rpm, where your engine spends 99.9% of its life. The Fluidic balancers tend to be a pretty good compromise for both low and high rpm, but if you are bolting stuff on to the balancer be careful, there are reports of supercharged owners (mostly Ford 5.0) getting a slight crack near the threads and leaking the fluid out. TCI is like a stock balancer the way you wish the stock balancer was built. SFI approval is something you need to watch... The "Rattler" is pretty much a high rpm only balancer. Leave that one for your weekend racer.
I will note that I have been corrected before about using the Fluidic balancer on the small blocks. Lots of people claiming no problems what so ever.
Just bolting one on will not (unless you get damn lucky) improve the balance of your motor.
To achieve the best balance - your pistons + rings+ pins need to all weight the same. Connecting rod big and little ends need to weigh the same. Now the part most forget, the crank needs to have throws that are 90 degs appart and the block's bores must also be 90 degrees apart.
At that point you can adjust the balance by removing or adding weight to the crank.
The harmonic balancer's job is a bit different. Imagine the crankshaft as a big torsion bar. As the back cylinders fire, the front may be on compression stroke. So internally the crank flexes one way. As the crank turns the force reverse. This variation in stress on the crank shaft causes all kinds of harmonics and in the extreme case will crack the crankshaft. Harmonic balancers prevent that.
The factory balancer is probably the best below 3000 rpm, where your engine spends 99.9% of its life. The Fluidic balancers tend to be a pretty good compromise for both low and high rpm, but if you are bolting stuff on to the balancer be careful, there are reports of supercharged owners (mostly Ford 5.0) getting a slight crack near the threads and leaking the fluid out. TCI is like a stock balancer the way you wish the stock balancer was built. SFI approval is something you need to watch... The "Rattler" is pretty much a high rpm only balancer. Leave that one for your weekend racer.
I will note that I have been corrected before about using the Fluidic balancer on the small blocks. Lots of people claiming no problems what so ever.
Trending Topics
10-04-2009, 10:38 PM
#9
The one I bought happened to be keyed and 10% underdriven, so I used a shorter belt.
It comes with the washer you need to hold it in (standard SBC crank hub washer)
I like the ARP crank bolt, but you can use the stock one if you want to.
10-05-2009, 08:56 AM
#12
http://www.google.com/products?sourc...-8&sa=N&tab=wf
You can sometimes find them on eBay cheaper. (no tax, free shipping)
Or have your local parts store order them in for you (free shipping)
None, same crank snout.
