I was at the Air Force Museum today (my favorite place) checking out the Allison Engine. I noticed that basically the whole engine had a texture to it. Nothing, even the valve covers were a little rough. The painting wasn't done like a show car either. You could see some runs, streaks and graininess on just about every visible part. The point? For those of you who want to tackle the TDR When You Build the TDR Allison Engine Allison, your sanding When You Build the TDR Allison Engine doesn't have to be absolutely perfect like an auto engine. That should help the job go a bit easier and less time consuming. I also checked out the Packard Merlin P-51 engine and the textrure on that one was worse than the Allison. Hope this helps some of you. It definitely helps me.