ATI Damper Discussion

[jgkurz]

I have an ATI 918310 steel  7" damper I was planning to use on my new stroker 427. After more research it seems I may run into timing mark and pulley issues.

According to ATI, I need a Chevy front pulley with a 3.200 bolt circle. What exactly is the issue with the timing mark? Any other installation issues with this damper?

THANK YOU

[blykins]

Some of them need to be honed to fit the crank snout. 

As for the timing marks, they are notorious for being about 7° off.  Easy to fix with some timing tape.

[jayb]

I just build my own timing pointer out of some aluminum angle and bolt it on to the timing cover in the stock position.  Before you cut the point on the angle, find TDC on #1, and then mark the angle at TDC on the harmonic balancer.  Cut the angle to a point at the mark, and you have a new timing pointer that lines up with the marks on the ATI balancer.

On the pulley, if you just drill the FE pulley holes oversize a small amount they will bolt right on to the ATI balancer.

[jgkurz]

I just build my own timing pointer out of some aluminum angle and bolt it on to the timing cover in the stock position.  Before you cut the point on the angle, find TDC on #1, and then mark the angle at TDC on the harmonic balancer.  Cut the angle to a point at the mark, and you have a new timing pointer that lines up with the marks on the ATI balancer.

On the pulley, if you just drill the FE pulley holes oversize a small amount they will bolt right on to the ATI balancer.

Thank you Jay and Brent. I appreciate the quick replies. Before I build my own, are there an aftermarket "bolt-on" adjustable timing pointers that work with Jay's timing cover?

[Falcon67]

If you use a dial back timing light, you only need to mark the balancer at TDC for the existing pointer.  You don't really need any other marks.

[jgkurz]

If you use a dial back timing light, you only need to mark the balancer at TDC for the existing pointer.  You don't really need any other marks.

I like using the marks on the damper. In the case of the ATI, it has marks the full 360deg.

[Falcon67]

Since the ATI uses black on white, you might actually be able to read it in practice.  Most others like the Summit parts, you can't.  I used locked out timing, so it's way faster for me to use a dial back.

[bill_396]

The stock FE timing pointer I had had enough material so I could file it back to the correct position. For the pulley I used a mid-sixties Chebby short water pump style lower pulley with the center bored out to match the ATI. Only needed a single groove and the lineup to the stock Ford water pump pulley and alternator was perfect without adjusting the space length.

[Rory428]

Like Jay said, not a big deal, just annoying. I used a stock FE single groove crank pulley, and just slightly filed the 3 bolt holes outwards a tad. The center register was fine.
For the timing pointer, once I established TDC, I just took the pointer to the bench grinder, and cut away the sheet metal until the new point lined up with the TDC mark on the ATI Balancer. Once I had the engine at TDC, I doubt that the 2 tweaks took more than 1/2 hour.

[jgkurz]

Thanks gents! This helps a bunch. I hear from several folks that the ATI balancer is the one to use so it's probably worth 30min of effort. : )

[jgkurz]

One last comment. I came across a photo from Barry Rabotnick's book that has a great picture showing the ATI damper with a trimmed stock timing pointer.