An exact time for engine replacement can not be made, in the course of replacing an auto engine, complications may occur. Every engine replacement job takes a different length of time. Different cars present different degrees of difficulty also. Old vehicles are much simpler in design and take less time to replace. A lot of untold and un-scene variables can change the amount of time it takes.
History demonstrated that the use of automotive conversionsin aircraft results in a higher risk of engine failure than when usingcertified engines or engines designed purposefully for aircraft use. Theprimary cause for the lower reliability resulted from the lack of adequatecommunication between fellow experimentalists. If one viewed the installationmethods used from the early Cessna 140 to the latest Mooney's, there isa common thread of proven installation technique. These techniques arereflected in the experimental community. The homebuilder who chooses toincorporate an alternative power plant is on his own when it comes to installationtechnique and one only has to look along "Auto Row" at Oshkosh to viewthe variety of techniques employed to incorporate an auto engine. It isthe exception rather than the rule to find a common design element betweenone installation and the next.
This page contains several cutaway automobile engines and car motor exterior drawings which are available for resale and licensing. These images highlight the engine's internal workings showing the pistons and crankshaft, overhead camshafts and valves, as well as timing chains or belts, intake and exhaust manifolds, oil flow channels and coolant water jackets.