Found some time to get the LT4 in the chassis. My first primary concern was to make sure none of the engine components hang below the frame rails. You cannot pass NJ safety inspection if any part of the drivetrain is below the rails.
As of now it looks like I have about .5” clearance but need to make sure the engine is level. Since I did not weld the caps onto the engine mount yet, I can fine tune the height of the engine by trimming the vertical engine mount tubes then have it welded up and either plated or powder coated to finish the job.
Very excited to get to this point and very satisfied how the LT4 fits.
Getting the engine in the frame, it was a little nerve racking since I’ve never done this before. Also, because of the geometry of the engine lift arm I found out that the engine shifts as you lower it so you can’t just place it where it needs to be and just lower it. So you lower it and adjust it, then lower some more and adjust it a few times but I got it in without swinging the engine into the frame rails.
Video of the engine installed in the chassis...
Lifting the engine above the frame...
Lowering the engine...
I decided to rest the rear of the engine on a wood rear engine mount stand. Since I am planning to make custom rear engine mounts that shift the engine back a bit I’ll use this to calculate exactly the shape and size of the rear mounts I’ll need to fab up. Plus having the car on a lift and the front engine mount in the chassis will easily allow me to get the engine perfectly level. Raising the lifts tilts the engine down in the back and vice versa.
The whole point of getting the engine in the car is that I know there are some fitment issues with the LT4 in the SL-C chassis. These being:
1)The need to fab up an intake elbow to reverse the throttle body
2)The alternator fouls the top frame rail
Most supercharged SL-C builds require a V cut in the rear bulkhead brace to make room for the throttle body intake elbow extension. I’d like to avoid that so my current thinking is to shift the engine back a little to make enough room for a custom elbow. By shifting the engine back about 1 to 1.5” I think there is enough room for the elbow. Since I am not building a track car the impact on handling should be minimal and not be a problem.
I have almost 4” clearance to fab up the intake by shifting the engine back slightly...
Lastly, I thought about how to overcome the fact that the LT4 alternator fouls the top frame rail. Turns out the Sanden AC compressor has enough room, so I am going to swap the alternator and A/C compressor locations and everything will fit fine.
The wet sump version of the LT4 uses a low mount alternator. I ordered the alternator bracket just to see how it fits and it interferes with the water pump on the dry sump version so sent it back. It won’t be too difficult to fab the necessary brackets up. Wegner makes a top mount Sanden bracket for the Wet Sump LT4 with a dry sump water pump so I’ll check that out to see if it will work.
Pic of the alternator interference..
Pice of the Sanden compressor and show there is enough room...