Hi Steve,
Typically, I cant seem to find the exact video I found before. This one shows the concept:
It's method number 2 in the video, except I did it horizontally, rather than vertically. I did it in stages, starting from near the center of my car, using a side-view and and end-on view profile, over-laid at 90degrees to each other... select the end-view profile face, push/pull it to around 10cm deep, resize and move the resulting new face (leading edge only) so it lines up with the side-view profile, then push/pull that new face another 10cm and repeat. I hope that makes sense, but feel free to PM me if you'd like to talk it through on a video call or something.
Here's a link to the engine model:
https://drive.google.com/file/d/1QRbW1YaWH-Rrv45uTSG24WuWuPCRQy6y/view?usp=sharingI put an image over-laid onto it, showing the dimensions (from the Honda website, I think), so you can check the scale is set correctly for you, and then delete the image.
Hope that helps,
Konrad