I'm swapping an Lt4 into my 93. What ive read is there are 2 different hubs for vette and fbod 93-95 and 96/97 because of the change to obd2 and its crank sensor whatever.

Am I good to swap my 93 hub and damper and it should clear the crank sensor and all that?

Does GM still make a stock 93 damper? Mine has 180k.

 

The reluctor gear requires a shorter hub. See Shoebox “differences” chart:

http://shbox.com/1/4th_gen_f-body_ye...onversions.pdf

If using the 93 LT1 accessory bracket and all the 93 accessories, it would seem using a longer hub from a 93 would cause the pulley to stick out a bit too far.

On the other hand, what computer are you using? If you are going to run the engine with your 93 ECM, the crankshaft sensor/reluctor serves no purpose and the reluctor could be removed, allowing use of the longer hub. In fact, if you are using a 97 F-Body PCM the reluctor could be eliminated with the only impact being the loss of misfire detection.

How are you handling the differences in the water pump?

http://shbox.com/1/lt1_water_pumps.jpg

The LT4 also uses a dual-mass damper, to reduce stress on the crankshaft at high RPM: An ATI Super Damper may be a better choice.

https://www.grandsportregistry.com/lt1vslt4.htm#DAMPER

And is this swap going to be legal in CA? The LT4 does not have an EGR system. Might create a problem with a visual inspection. On the other hand, a newer CARB certified engine in an older chassis might be acceptable. But the LT4 does require dual cats. Relocation of the cats may not be allowed.

 

I need to update my info but I'm up near Seattle where emissions aren't reqd. Also planned on using an fbody waterpump and using the 93 computer and brackets.

Excuse my lack of understanding, I don't mean to come across as argumentative. With regards to the reluctor wheel, if its removed and the longer 93 hub could work at that point, did the reluctor just take up space on whatever the hub mounts to?

As far as the damper, this is where it gets weird. Some LT4s had balance issues. Ones with issues had some white paint on the flywheel. My LT4 motor didn't come with its flywheel, BUT It does have a white paint dot near the rear seal. Now, it seems the LT4 balance issues only seem to affect some 6spds. LT4 automatic C4 conversions don't seem to have vibration balance issues. So my assumption was use the stock 93 hub/damper, and since I'm automatic hope and pray it balances fine like the automatic C4s. I only found 1 thread in regards to the 97 fbody Lt4 dampner, where it had weights inserted for balance issues, but again a 6spd.

 

See the diagram in this thread:

https://www.camaroz28.com/forums/lt1...nstall-496663/

The nose of the crank sticks out of the front of the block. First the timing set crank gear slides on, up against the block, then the crankshaft position sensor reluctor slips on the crank, against the timing gear. I believe their is a different “key” that positions both the timing gear and the reluctor.

Then the timing cover goes on. Then the crank hub gets mounted, butting against the reluctor. The “short” hub allows for the thickness of the reluctor. The “long” 93-95 hub will not slide in all the way, meaning the pulley on the damper will stick out just a bit too far and cause problems with the serpentine belt.

The literature indicates the LT4 damper is specific to the fact the LT4 engine is designed to operate at higher RPM than the LT1. The damper (LT1 or LT4) is neutral balanced and has nothing to do with balancing the engine. Its purpose is to dampen the cyclic twist that the crank experiences as the cylinders fire, to reduce fatigue and possible fracture. I would use the ATI damper (have one on my build) because it performs better at higher RPM than the LT1 damper. ATI makes hubs in various lengths to accommodate the different locations of the Corvette and F-Body serpentine belt, and they can provide one for a 96/97 F-Body with the reluctor.

 

That makes more sense now. Thank you. It should work. Its amazing the differences of 3 car lines can have on a motor and its accessories.

The closer I come to starting this swap makes me kind of want to do a build thread.