| LTx EWP, opti, timing set mod info |
Subject: LTx EWP, opti, timing set mod info by Notorious on 2008/1/1 15:48:20 Since this is an area of the LTx engines that differs greatly from other SBCs, even those of us who were familiar with SBCs had a learning curve when it came time for some internal mods. I hope this helps. And since I'm doing it from memory, please feel free to correct or clarify and I'll make any needed changes. First the electric water pump. It's popular for several reasons but for here I'm mentioning it because it's the only way you can added a true double roller timing set to your engine, if that's something you desire. This is because the factory water pump is run off of the cam gear by a smaller gear/drive. This doesn't allow the room under the timing cover for a double roller set-up. As a side note, can you install an EWP without going under the cover and eliminating the drive? Yes you can, but I don't recommend it. Without the mechanical pump at the other end of the drive to support it, I don't think it would be long until the drive seal in the front cover started leaking. Remove the drive and plug or weld up the hole. The early opti used in '92-'94 Vettes uses a different drive set-up than the later one. I'm not entirely sure if there's a double roller set-up made that works with it or not. I would definitely appreciate input from anyone who knows this. But for sure you can upgrade to the later opti and use the popular Cloyes 9-3145 timing set or similar. The later opti runs off of an extended dowel pin for the cam gear. On an early LT1 or other SBC this pin is only long enough to locate the cam gear properly to the cam. To use the later opti, this pin needs to protrude about .620" measured from the front of the cam (with the gear off). You'll also need the harness for the later opti which plugs into the engine harness under the right side fuel rail cover on the intake. You'll need to buy or make the vacuum harness the later opti utilizes to expel moisture. (This is one of the design improvements to the later design) You'll require the later style '94-'95 timing cover too. The '96 cover can also be used. Just plug the 3/4" hole for the crank sensor. It's also my understanding that on a '96 LT1 or LT4 that this sensor can be eliminated with a programming edit. Again this will be necessary if you want to use a double roller because you need to eliminate the trigger wheel for that sensor to make room for the DR crank gear. |
