This is the Standard Crankshaft Version of the TRA Pro TRX-15 Engine. It is for those who want higher performance than a .12 size engine in their 1/10 scale kit. This Will Fit Standard Long Crankshaft Applications. One Assembled Engine One Air Cleaner (Rubber with Foam Element) One Full Instruction Book/Warranty Card One "TRA" Decal Sheet Two Replacement Head Gaskets One Installed Glow Plug (Standard Long--No Idle Bar) ABC (Aluminum Brass Chrome) Construction Precision Ball Bearings Oversized Blue Anodized Cylinder Head Black Recoil Assembly (This Makes it a "Pull-Start" Engine) Standard-Size Crankshaft Fully Adjustable Carb and Needle Settings Double O-Ring Seals On Each Needle Channelled-Beam Connecting Rod for Improved Oil Flow TRA Lifetime Engine Replacement Policy According to TRA, this engine will produce 20% more power than the TRX-12, which is approximately 9-11% more power than the OS CZ-Z. These figures are tested on a dyno (loaded) which provides power curves on a computer. TRA was unable to provide any numbers on BHP, bore, stroke, etc. Keep in mind that these figures are often useless, as they will vary from engine to engine. And there are other variables to consider: the kit, terrain, %nitro in fuel, etc.... Overall Length (from end of shaft to back of recoil): 92mm (3-5/8") Length of Crankshaft (from drive washer): 15mm (19/32") Length of Crankshaft (from crankcase): 22mm (7/8") Height (top of cylinder head to bottom of backplate): 93mm (3-5/8") Width: 51mm (2") Mount Holes (center to center): left to right: 31mm (1-1/4") front to back: 11mm (7/16") Overall Width of Mounting Ears (where the holes are): 40mm (1-9/16") ***Mounts the same as an OS .12 and .15 CV*** 1/10 scale Kit to put it into and 5%-20% Glow Fuel. For the Pro 15 with the Short Crankshaft, use TRAG4007. For the Pro 15 with the Long Crankshaft, use TRAG4009. The kits that this engine fits into are: 4007 fits: Nitro Rustler, Nitro Stampede, RC10GT, and the Losi GTX 4009 fits: Nitro Hawk, Nitro Buggy, and Nitro Street If you have any other kit, I would call that manufacturer or call TRA directly at 1-888-TRA. TRA engines run much hotter than "normal" engines (O.S., ASP, Thundertigre, etc.). Therefore, TRA recommends their Top Fuel (TRAP5010) and their glow plug (TRAG3230) to run the engine cooler. BBS 1/27/99 ir/jl &