ramermanz28

OK, here is the situation. Putting the car back together after years in the garage. I am running 383 ci LT1 with Callies crank, EFI Connection 24X conversion utilizing an ATI Super Dampener and the ATI supercharger hub that has the small block i.d with the big block o.d. Vortech T-Trim, Trick Flow heads, etc. When I first installed the setup years ago I was not running the 24X system so no crank reluctor wheel therefore I was using the .100 shim that came with the hub. I never noticed if the accessories lined up years ago and only ran the car from the shop to the garage. Fast forward 10 years and I am installing 24X setup vice OPTI. I have removed the .100 shim and installed the 24X reluctor wheel (same thickness as shim from ATI). I have reinstalled the hub and verified a dozen times that the crank gear, reluctor and hub are fully seated. Sent pictures to EFI Connection and they said the reluctor looks properly seated. My crank pulley is approximately .250 forward of my accessories? There is no way the crank gear, reluctor and hub could seat another .250 so that can't be the issue. I hate to machine .250 off the hub if I am missing something simple, but I can't figure out what it could be. Please if anyone can help am I at a loss. Thank you, Robert.

ACE1252

Before you do any machining, do some measuring. Pull the hub and measure the depth inside the hub to the end that contacts the reluctor, then measure from the reluctor to the end of the crank snout. Those measurements will tell you if the hub is too long or if the crank snout is too long.

If I'm not mistaken, the 96, 97 hub is shorter to accommodate the crank reluctor on a stock engine.

Are you using your stock LT1 hub for the aftermarket damper or is it different? I don't have any experience with the aftermarket dampers so others will need to chime in.

How are you determining if it's offset? Known straight edge flat against the damper leading up to one of the accessory pullies?

ramermanz28

Thank you for the reply. I have measured everything multiple times. Callie's said their crank snouts are 1.860, the crank gear is a Cloyes Billet so it measures .543 compared to a stock timing gear of .526. I measured from the face of the crank gear to the front of the crank snout and get right around 1.312-1.317 (dial calipers) so I know my crank gear is fully seated, repressed it on just to make sure, same measurements. The 24X reluctor is .100 (same thickness as ATI shim that comes with ATI hub) so I am not using the ATI shim otherwise I would be another .100 forward. After doing some more measuring tonight might straight edge might not be so straight, but I am still off by approximately 1-2 ribs on the belt. I am thinking with all the aftermarket drive train components my hub sits further forward than a stock setup. I am going to keep measuring and possibly shim the accessory bracket to align with the crank pulley. Really don't want to machine the hub. I am hoping it is more of an optical illusion making it look so far off, but it is definitely off. Thank you again, Rob.

Chimera96

Contact ATI. The hubs for the B, F & Y body for LT1, IIRC, are different depth to accommodate the placement of the accessory bracket different on the 3 body types

ramermanz28

Chimera, thanks for the suggestion. Called ATI with high hopes. Turns out the F-Body LT1 hub is the shortest of the three hubs. The Corvette and Impala hubs are actually longer. ATI said the hub has enough material to mill down what I need without affecting performance, I just wanted to rule everything else out before I did that. Thanks again, Rob.

Chimera96

well you either machine off .250 from hub or use .250 spacers and stand off the accessory bracket

modding motors, different manufacturers...sometimes something has to be changed so both parts work well together

ACE1252

Based on your measurements, looks like the timing set is the cause and you have already found the issue.

Just make sure the hub has enough depth to it to take the amount needed off without bottoming out the hub. Would suck to take off 0.25 and only have something like 0.125 left in the hub before bottoming out against the crank snout.

ramermanz28

Update: I spaced out the accessory bracket .250 and everything is lining up correctly. Now I need to decide whether to take .250 off the hub or just have some .250 shims made to space out my accessories and supercharger. I have plenty of room on the hub to mill out .250, nowhere close to bottoming out. Any thoughts or suggestions? Thanks again guys for the help.

Chimera96

I would be inclined to stand off the accessory bracket. If you ever remove the SC...you could just delete the .250 spacers on the accessory bracket. A good nut/bolt hardware store should have 1/4" spacers. I got them for my 70 Ford 302 for a similar reason

ATI does sell hubs separately so you could always buy another if you did cut your current one and later decided to go NA for that motor

Injuneer

There's quite a few people who have done the 24X conversion on another site I hang out at. I can give you the link in a PM if you want. Although most of them are probably on the way to the LTx Shootout at Beech Bend in Bowling Green this weekend.

ramermanz28

Thanks Injuneer, that would be great for future reference since I am sure this will not be the only hiccup I experience. The main thing I was worried about was the crank gear and reluctor not being properly seated. Now that I have verified that the measurements are correct I feel more confident. I spaced out the accessory bracket .250 and everything lines up perfectly. I then spaced out the supercharger bracket .200 and now the crank pulley and blower pulley line up as well. I ordered some spacers to make the install look more professional. Great site for spacers is aluminumspacers.com if you ever need spacers they have thousands in stock. Once I verify the belts don't squeak I might remove the hub and mill it down so I can remove the spacers. Thanks to everyone for the help.