Due to so many people asking how do you run an engine here is an explanation of what is what below.
On a fresh engine the main areas you are looking to break in or run in are the piston rings to bore, to do this actually needs the engine put under load , this then puts extra heat in to the liner and rings and allows them to wear together (which is what you want) the idea of bedding the components in is so that a minute amount of oil remains present on the liners to reduce friction between the piston and rings but not too much that the engine smokes, the absolute worst thing you can do at this stage is pussy foot the engine for 1000miles as you will glaze the bores and scuff the pistons as they will not expand correctly !!! Engines built correctly need very minimal time to run in these days due to machining being so good and the oils being synthetic.
if your engine has new cams then you have to follow the manufacturers instruction but it normally entails running the engine at no less than 3000rpm for ten minutes or so, the reason for this is that if you run it too slowly the lobes do not polish or bed to the rockers correctly and you get premature wear!
cranks and conrod bearings do not need bedding in as the bearings should never ever contact the crank, the idea is the oil separates the two surfaces and absorbs the shock load from the engine running.....if you have any sort of contact they normally fail very quickly.
so in summery the best way to run an engine in is to get everything set up and checked correctly on first start up, use the normal oil you are intending to use and drive the car as a normal car or run it in on the dyno......doing 1000miles using mineral oil driving like a pansy on an engine not set up properly will not run your engine in!.........if an engine has an inherrant fault or has been built incorrectly you will know within a few hundred miles of the first start up, so if you are building a super fast engine for your car, when you first start it have the timing and fueling checked by your tuner if you cannot do it check for leaks,check coolent levels and get on and drive it.
On a fresh engine the main areas you are looking to break in or run in are the piston rings to bore, to do this actually needs the engine put under load , this then puts extra heat in to the liner and rings and allows them to wear together (which is what you want) the idea of bedding the components in is so that a minute amount of oil remains present on the liners to reduce friction between the piston and rings but not too much that the engine smokes, the absolute worst thing you can do at this stage is pussy foot the engine for 1000miles as you will glaze the bores and scuff the pistons as they will not expand correctly !!! Engines built correctly need very minimal time to run in these days due to machining being so good and the oils being synthetic.
if your engine has new cams then you have to follow the manufacturers instruction but it normally entails running the engine at no less than 3000rpm for ten minutes or so, the reason for this is that if you run it too slowly the lobes do not polish or bed to the rockers correctly and you get premature wear!
cranks and conrod bearings do not need bedding in as the bearings should never ever contact the crank, the idea is the oil separates the two surfaces and absorbs the shock load from the engine running.....if you have any sort of contact they normally fail very quickly.
so in summery the best way to run an engine in is to get everything set up and checked correctly on first start up, use the normal oil you are intending to use and drive the car as a normal car or run it in on the dyno......doing 1000miles using mineral oil driving like a pansy on an engine not set up properly will not run your engine in!.........if an engine has an inherrant fault or has been built incorrectly you will know within a few hundred miles of the first start up, so if you are building a super fast engine for your car, when you first start it have the timing and fueling checked by your tuner if you cannot do it check for leaks,check coolent levels and get on and drive it.