crank hub that adapts an ATI scrub damper to the flathead crank.

                 The big question, how close is the F.H. crank snout to the "Y"?

          This would open up more avenues for us "y" guys......

                                          Bill

Bill. My replies to your email keep bouncing back so I’ll just post the answer to your email question here.

The crankshaft snout diameter on the Flathead Ford V8 is 1.311” which is considerably larger than the Y so you can effectively rule out using the aftermarket dampers made specifically for these engines on the Y.  The small block Fords are also out of the question as the snouts on these are 1.375”.  The least inexpensive option for an aftermarket and SFI approved damper is to use the small block scrub damper as the crankshaft snout for that engine is ~1.247” or ~0.003” smaller than the Yblk snout (1.250”).  Just a slight bit of honing of the scrub damper hub and it fits fine on the Y crankshaft snout but be sure to use a hone designed for bores with keyway slots.  You’ll have to look at the damper key and decide if you want to broach the keyway slot to the Y size or take the Y key and machine it so the exposed portion is 3/16”.  I’ve been both ways and it’s two in one hand and a couple in the other (no preference).

If using the standard 6.325” O.D. scrub ATI damper, pricing looks to be around $280.  But because the hub on this damper is too short to use as is on a Y with a stock timing cover, a sleeve that fits both the crank snout and timing cover seal must be machined and placed behind the damper.  Another option is the LT1/LT4 damper which does have a longer snout but pricing also jumps up another $100.  On this one, I can’t say if the snout is long enough without having one here to measure.  I’ve used these in the past for the Y but always with the marine covers which required the damper hubs to be machined shorter than what was supplied to get the damper moved closer to the cover.  Another option which is viable but I haven’t pursued myself is to get the 6.325” damper and simply machine a new hub from scratch with the required length on it.  This option could potentially work for any aftermarket damper that has a removable hub.

          to. Using you std. hub with measurements from Ted or Tim or ?,

           you could probably design something. I know a couple of guys with

           CNC machines that may could do the work , with the correct drawing.                

                  Do it and WE will purchase them..............

                                            Thanks Bill

Charlie.  That damper would work.  Just do a search on this site for ATI damper regarding the other nuances regarding pulley bolt patterns and spacing as the damper thickness is still an issue with the correct hub.  Here’s just one discussion that’s not too old.  Damper discussion 

The pricing of the Y specific ATI damper with its corresponding hub has skyrocketted in the last couple of years.  It’s become completely out of the normal buying range compared to the prices of the normal catalogue offerings.  Blame that on being a special order whenever trying to get one as its not a stocking item.  But I will talk to them and see what it takes to get the pricing down to where it’s more affordable.

As far as the hub measurements go, I’ve got a Y specific ATI damper here and will take the hub loose from it so I can get the measurements.  As far as duplicating the threaded holes in the hub, using a set of center finders for the holes with the damper semi installed on the hub as it’s being reproduced will be easier than reverse engineering those particular measurements.  I’ll try to post this early next week as this sounds like a Saturday afternoon project.  And here’s a print that shows some of the measurements but may be too small to be easily readable for the site.

No.  The dampening portion of the ATI damper is simply wider than that of the Y damper.  With a belt pulley installed on the front of the ATI damper, the belt itself ends up being forward about ~ ¼“-½” more than the stock Y belt car and truck location.  Accessory pulleys will simply need to be spaced forward the appropriate amount to accommodate.

Here are the basic dimensions for a hub to use an ATI damper shell on the Y engine.

Side View

Top View

TDC key location

...sorry my metric dimensions on picture.

Bill.  Received your email but not sure if you are getting mine back as I’m getting failure notices on the replies.

My material of choice for making hubs is ‘cold roll’ steel and go out of my way to not use ‘hot roll’.  Aluminum is also an option for the hub itself.  The bolt circle for the damper attaching bolts is 3.250” but one hole is offset so it’s easier to simply use transfer punches to locate the damper holes to the semi-finished hub than go to the trouble of indexing the holes in the hub on a rotary table or lathe.  Here’s a couple of pics of the hub that allows the ATI damper shell to be used on a Y.