I like where this is going, but if the model is still just over 600 tris you should add in the extra 400. If you've got a budget of 1024 you need to hit that.
Hey mate, just dropped in to check your progress, but I'm getting the '403 Forbidden', looks like ImageShack took your image down (booo!), unless it's just me.
lolno why don't you use a larger texture, and drop that polycount by half. 40k is obscene. also pointless to spend tris on areas that will be so small they will be mere pixels in game.
Caterpillar that i did few days back for my company Little Red Zombies. Special thanks to Ankit and Sriram for the Art Direction. Tricount : 40k Texture size : 2048
Do you mean it revs at 1rpm, or 1000rpm? If it's 1, it might be a broken fuel pump. It happened to my old truck, it was about $400 after parts and labor I think.