I am confused on which route to go when it comes to a harmonic balancer/damper for my Small Journal 67' 327. I see them on Summit for $50-$400. My car will be used as a weekend cruiser and will see the drag strip maybe once a week in the summer.

I have a long edelbrock victor waterpump, and comp cams 2 peice timing cover. This will be a roots 142 blower engine. Should I go 6 3/4" or 8"? If you have a favorite brand, model, or size please share. Thanks :) ---

First Choice = Fluid Dampener
Second Choice = ATI
Third Choice = 6.75" dia OE replacement style.

ATI if you have the bucks, a good Pioneer stock replacement type if not.
Most performance builders I know won't use a Fluiddamper on anything.

I would suggest that if you do race the car that you buy something that is SFI approved. You may not need it at your ET but the SFI stuff typically has some mechanical backup to hold the outer ring on the hub in the event that the press fit or rubber between the two slips or fails. Some of the cheaper OEM replacement dampeners aren't as good of quality as the original product and are more prone to fail IMO.

From the research I did when I built my 383 and from talking to some really good engine builders of cup cars I went with an ATI. Fluidamper was one I looked into until it was one that caused the front snouts of the cranks to break off and were ban from all nascar vehicles because of that, there was an instance were it broke during a race and flew out of the hood and into the pit area luckely missing people but not a truck! If you are planning to have this motor blown or even if not don't skimp on parts and definately not on a balancer. You won't regret an ATI and if you are running an aftermarket crank give the manufacturer a call and see what they recommend, Scat recommends the ATI also.

ATI or Fluidamper. I've been running the same Fluidamper for 10 years. Until this year it was used on the same stock GM forged crank that saw 7,000 - 7,500 rpm quite frequently.

ATI super street damper. Upgrade over stock, but not an all out race unit. retails in the neighborhood of 160-180 bucks I think. 6 3/4" will be less rotating mass, freeing up more hp.

http://www.jegs.com/images/photos/085superstreetdamper.jpg

5800 max sustained rpm

7000 max rpm, like winding it up, shift, winding it up shift.....

Thank you guys very much, that ATI unit above seems like a great product.

I understand the 6 3/4" will be less mass, but I have heard the 8" units actually dampen better?

These SUPER STREET dampers come in 6" or 7" size. I dont see the 7000max windup anywhere...I will keep looking. I plan on shifting at 6500 ---

Thank you guys very much, that ATI unit above seems like a great product.

I understand the 6 3/4" will be less mass, but I have heard the 8" units actually dampen better?

These SUPER STREET dampers come in 6" or 7" size. I dont see the 7000max windup anywhere...I will keep looking. I plan on shifting at 6500 ---
True.
Even stock balancers will rev past 7k, i don't know why ATI said 5,800rpm on that balancer, I bet it could go way more, they just say that in case they make a damper with a higher limit and it fails, won't be their butts.

ATI is all I'll put on a good engine. Caution, they size the bore on the small side.


The little one for your engine is way good enough. But I'd call ATI if I was you. When I called them I got the distinct impression I was talking to an engineer who R&D'd the damthings, and he was nice as hell......

I called ATI when I built my 421, asked if my 6 3/4 could be rebuilt for the 421. He said yes, they could put 70 durometer rubbers in it, and it would be OK but they recommended the 7 1/4" unit for that much engine. So I bought a new one for the 421, leaving me with my old one for my ZZ which is what it came off of, any old how.

Thank you guys very much, that ATI unit above seems like a great product.

I understand the 6 3/4" will be less mass, but I have heard the 8" units actually dampen better?

These SUPER STREET dampers come in 6" or 7" size. I dont see the 7000max windup anywhere...I will keep looking. I plan on shifting at 6500 ---


I saw it on Jeg's website. http://www.jegs.com/i/ATI/085/917067/10002/-1 I'm using this one on my 406. The reason I didn't get the larger one was because I didn't know if it would clear or not due to using 327 frame stands and mounts. I heard the reason for the two different mounts was because of the 6 3/4" and 8" balancer size. So be careful when you buy a balancer

Heavier Larger Diameter Dampers are generally used for Road Racing and Marine use and Smaller lighter Diameter Dampers for Drag racing.

Personally I do not recommend Fluid Dampers. I've seen them fail. Living in a colder Northern climate may have a lot do do with that but I'm not convinced.

I recommend the SFI approved Solid BHJ Damper.

With any after market damper I suggest that you carefully do a test fitting. In most cases you will have to use a brake hone and increase the diameter in the ramp area a touch as they are usually very snug and may cock on the crank snout. If they do you have more then likely broken the Damper Installation tool - LOL