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View Full Version : SFI balancer or not?



ricardoa1
04-04-2007, 04:07 PM
What are the possible issues with the SFI balancers, being tha they are one piece, what could happen.
Is one better off with the ones that are two piece or it doest matter.

I am not looking to know what the bennefits are from the SFI certification, but simply to know if the original design is better for harmonics.

ricardoa1
04-04-2007, 10:16 PM
Any one?
Any one?

XR7 Dave
04-04-2007, 11:05 PM
The SFI unit has more damping capability at higher rpms. The SFI unit is 2 piece with an elastomer.

ricardoa1
04-05-2007, 12:05 PM
The SFI unit has more damping capability at higher rpms. The SFI unit is 2 piece with an elastomer.

The description on Victors site describes it as being one piece. So I guess they are two piece just like the original one.
Do they still rust like the earlier ones.

DrFishbone
04-06-2007, 12:05 PM
Yes, they will still rust if you don't clear-coat or paint them first. I'm not for certain, but the original BHJ's don't have timing marks on them do they? - the SFI certified ones do.

I just received my SFI BHJ from Victor, and is sure is purdy. :D Now I just need to get some good durable clear-coat, so that it'll stay purdy.

As far as the differences: I've never really inspected them to figure the differences, but besides being made of different materials than stock (alum and cast iron) the SFI versions are put together differently. (I can't really comment on the orginal BHJ's) I don't believe I could actually SEE any elastomer without really searching. I think it has a shroud covering it or something...but if Dave says it's there, then it must be.

XR7 Dave
04-07-2007, 01:58 PM
I don't believe I could actually SEE any elastomer without really searching. I think it has a shroud covering it or something...but if Dave says it's there, then it must be.

My saying something does not by any stretch make it so.

BHJ (http://www.bhjinc.com/2dynamics/dynamics-landing.htm)

But BHJ says they use an elastomer.

It stands to reason that in order to be a harmonic damper it has to have a dampening material. To even think for one moment that it would be a solid chunk of steel demonstrates a large lack of understanding as to how a damper works. If it is solid steel then it is a flywheel and not a damper.

ricardoa1
04-07-2007, 02:20 PM
"These SFI approved dampers are all-steel, one piece and are lighter than the OEM units they replace." From Victors Ad.
This is why I started this thread, and why it raised a consern with me. Its all clear now. Thanks

DrFishbone
04-07-2007, 11:50 PM
Isn't it pretty much incorrect to call them "balancers" as well? All that they are balanced in relation to is the pulley that is installed with them - not anything within the engine. If it was simply a "balancer", then it could be made of one solid piece of steel..but in order to be a damper, it has to have some material that will allow it to absorb unwanted vibrations: the elastomer. Am I anywhere near correct in saying these things?

By the way, Happy Easter everyone! :)

XR7 Dave
04-08-2007, 02:34 PM
Isn't it pretty much incorrect to call them "balancers" as well? All that they are balanced in relation to is the pulley that is installed with them - not anything within the engine. If it was simply a "balancer", then it could be made of one solid piece of steel..but in order to be a damper, it has to have some material that will allow it to absorb unwanted vibrations: the elastomer.

Some harmonic dampers are also balancers such as on an NA 3.8. Ours are not balancers but the wording often gets mixed up. Some engines have a balancer and a damper bolted together, but most combine the two which is what leads to the misnaming.

ricardoa1
04-08-2007, 06:55 PM
Struts and Shocks. :)