ATI OEM 4 BOLT DAMPER

I'm looking into having a few 429-460 oem style dampers made in a 4 bolt pattern to match OEM pulleys instead of buying one of there shelf big block dampers that utilize a modified chevy big block pulley. This damper would also use the OEM spacer that rides behind the hub normally. any interests if I have more made? These could be 6", 7", steel shell or aluminum shell. I would need to know interests before I commit to a quantity to have made.

something like this in 4 bolt

http://www.jegs.com/images/photos/0/085/085-917620.jpg

thanks
Jim

what kind of pricing are you looking at?

Why?

Depending on QTY, as a custom unit I'm trying to do $599 for 7" aluminum shell version, and maybe $549 for 6" steel shelled versions. Both on a steel hub.

Jim

"why?"

to make it easier for the average guy to press the damper on, bolt on their stock or stock style pulley, trigger wheel, mandrel, etc and call it done.

This is a good alternative for the everyday street motor that has an OEM damper on the way out the door.

just trying to get an idea of interest....

Jim

Why not use that Powerbond 460 damper, it's already got the OEM 4 bolt pattern.

The Romac balancer I have uses the factory four olt pattern with an aluminum shell.

DaveMcLain wrote:Why not use that Powerbond 460 damper, it's already got the OEM 4 bolt pattern.

And the FRPP A460 and A521 units also.

Just personal preference I guess.

Look at every Nascar engine built from builders such as Earnhardt-Ganassi, Childress, Hendricks, Richard Petty, Penske, etc, and every other top engine builder for drag, dirt, etc... Shaffiroff, bill mitchell, steve schmidt, larry morgan, Katech, Bischoff, Sonny Leonard, they all use ATI. Even some crate GM and Mopar engines come standard with them. I have tried Romac, Powerbond, Fluidampr on other engines... nothing compared to the quality.... they are rebuildable, tunable, and offer many different options.

just trying to get interests.... if none is here thats fine.

Jim

How do you select how you're going to tune the damper? What do you go by?

I've had guys use those ATI dampers on mud racing stuff and they are awful, they quickly fill up with dirt and become a solid hub so they are not perfect.

TALONMAN69 wrote:I'm looking into having a few 429-460 oem style dampers made in a 4 bolt pattern to match OEM pulleys instead of buying one of there shelf big block dampers that utilize a modified chevy big block pulley. This damper would also use the OEM spacer that rides behind the hub normally. any interests if I have more made? These could be 6", 7", steel shell or aluminum shell. I would need to know interests before I commit to a quantity to have made.

something like this in 4 bolt

http://www.jegs.com/images/photos/0/085/085-917620.jpg

thanks
Jim

i talk to them years ago, they use to make a 4 bolt, becareful on the back spacer if using a belt drive,and if using a boss snout this will also change things

[quote="TALONMAN69"]"why?"

to make it easier for the average guy to press the damper on, bolt on their stock or stock style pulley, trigger wheel, mandrel, etc and call it done.

This is a good alternative for the everyday street motor that has an OEM damper on the way out the door.

just trying to get an idea of interest....

Jim[/quot


most make a mandel the bolts right on the 3 bolt,peterson for ex. same for the tri wheel,msd's wheel fit 4 or 3 bolt, pulleys can be redrilled to 3 bolt, thats why they quit making the 4 bolt

[quote]BOSS 429
"i talk to them years ago, they use to make a 4 bolt, becareful on the back spacer if using a belt drive,and if using a boss snout this will also change things"

they make a damper for the Boss and Bryant snouts currently, but those are a standard 3 bolt chevy front also.
standard chevy accesories will not work "properly" with there current 429/460 design damper with out modifying.

I could see them filling with mud.. so maybe that could be a pain... although they are modular and rebuildable so they can be easily taken apart cleaned and bolted back on without ever pulling the hub portion off.

they can be tuned for stroke, HP, RPM, weight of crank, etc by using different size damper bodies, Elastomer O-ring number, and by durometer (hardness) of the O-rings. Apparently the larger the inertia weight and the more O-ring contact the better dampening/protection it will offer.

Jim

they can be tuned for stroke, HP, RPM, weight of crank, etc by using different size damper bodies, Elastomer O-ring number, and by durometer (hardness) of the O-rings. Apparently the larger the inertia weight and the more O-ring contact the better dampening/protection it will offer.

I've read that in the instructions but they don't give you any selection criteria. When do I go to a harder or softer O ring? How do I know which one to use? That's always been my question with this sort of stuff. From what I've read personally, the lighter the hub can be relative to the inertia ring the more effective the damper will be at the point where the assembly wants to resonate but how do you know where in the rpm range that occurs if at all?

I've had circle track engines ruin a new stock damper in one season yet net break a stock cast crankshaft. Does this mean that the damper(by taking a beating) is actually being quite effective?

DaveMcLain wrote:
I've read that in the instructions but they don't give you any selection criteria. When do I go to a harder or softer O ring? How do I know which one to use? That's always been my question with this sort of stuff. From what I've read personally, the lighter the hub can be relative to the inertia ring the more effective the damper will be at the point where the assembly wants to resonate but how do you know where in the rpm range that occurs if at all?

I've had circle track engines ruin a new stock damper in one season yet net break a stock cast crankshaft. Does this mean that the damper(by taking a beating) is actually being quite effective?

durometer is best left to the techs @ ATI. Their COO runs many tests for the Nascar teams and other large engine builders and he specs all the changes in O-rings when necessary. I found this out when I called and the first thing out of the salesman's mouth was what engine, stroke, RPM, HP, and what sort of racing. Sometimes if you want to go further they can take weight and material of the crank shaft into account... but I didnt go inot all that. The durometer of O-rings in there stocked PN dampers are designed to cover most application, but usually when HP reaches 2000, and RPM starts going over 8K is where they look at changing them. Of course this would be different on a 1.5L honda making 190 hp turning 11000 RPM....

The salesman had a good point that most OEM manufactures use an Elastomer bonded rubber strip to hold the inertia weight on the damper, and for stock HP and stock RPM do EXTREMELY well. ATI takes that theory and improves on it by moving the inertia inside where it cant come off the damper.

Jim

What I've always wondered about is this: Let's say a guy takes his stock 460, offset grinds the crank to a 4.140 stroke and builds a stroker engine using whatever rod and piston. In the same process he decides that it would also be a good idea to reduce the main bearing speed so he grinds the mains down to 351 Cleveland diameter and runs a spacer setup. Now the rod throws are .300 under and the mains are .250 under size. Stroke has been increased and the crank is now a lot more flexible and thus resonates at a lower frequency and possibly with a greater amplitude. What's the best choice in this situation?

ATI might make a certain recommendation but based on what? I wonder how they are getting their data and what criteria they are using to make their selection. The reason I'm saying all of this is because I've been thinking about a simple kit that could be used on the dyno to determine the effectiveness of a given damper on a given engine combination. I have not come up with a simple way that this could be done but I'm working on the idea. Wouldn't it be nice to be able to say, "that's working" or "that's not".