anytime you, increase hp you increase the stress levels on an engine,you increase the heat it produces and the engine expected life span can be shorter, but increased rpm levels will put more strain on the valve train and connecting rods, etc, in a n/a build, than a supercharger thats properly installed and tuned, will on your engine.
lets look at a few factors, obviously theres a huge bunch of variations in components you can select,for any engine build-up so we will discuss the basic concepts
many, perhaps most engine failures involve either lack of proper lubrication, insufficient cooling, detonation or lack of valve train control, rod bolt failures
with a supercharger" insufficient cooling, & detonation" are the most common with a N/A combo youll need to operate at higher rpm ranges to make similar power numbers,so lack of proper lubrication, lack of valve train control, & rod bolt failures are more common
with a supercharger you can add a larger better designed oil pan, a larger radiator and learn to tune correctly.
stress can be managed and the low and mid rpm drive ability can be maintained as the engines basically going to increase dramatically in the torque it produces due the a larger volume of fuel/air mix being burn that produces a higher cylinder pressure.
with an N/A design theres not much you can do about the increased stress levels but select high strength parts and insure the lubrication is improved, as the higher rpms, are required to reach the higher hp levels if the engine displacement remains similar, or theres not a significant improvement in the flow rates of the components selected, in the engine build, but keep in mind many of those same increased flow components can be adapted to the supercharged version also.
rod bolts stretch on the exhaust stroke where, the loads are the greatest and theres little resistance to the piston,thru compression, slowing & reducing the loads on the rod bolts in tension as they play crack the whip with a heavy piston on the end. once rod bolts stretch the bearings fail to maintain the oil pressure and a rapid cascade of bad things in the engine result, if the bolts stretch enough to allow the piston to contact the cylinder head, valves or the oil pressure is lost as a result..
horsepower is the measure of the RATE at which torque or turning force can be applied, a supercharger , forces a larger fuel/air mix into the cylinders and as a result theres usually slightly greater compression and definitely higher pressure on the piston and rods over the piston, on the power stroke, but rods, are generally strongest in compression, as their beam cross section usually significantly exceeds the rod bolts cross sectional area.
ok lets say we take a common 350 sbc and add 7 lbs of boost with a supercharger, we have effectively increased the working displacement to about 48% at sea level, in effect we are running a 517 cubic inch displacement, and producing 600 hp is not out of the question at all.
now on a standard N/A, sbc you'll generally make about 1.1-1.2 ft lbs of torque , lets say 1.2 ft lbs, or 420 ft lbs
that will require at least in theory your going to spin the engine to 7500rpm to produce the same 600hp, but in reality your volumetric efficiency falls off rapidly after about 5700-6000rpm without much better heads and cams,and your stress levels skyrocket, so while the N/A 350 sbc engine producing 600 hp will be using very expensive components to stay together and dependable at that rpm level, and the low rpm driving characteristics on a 350 sbc N/A 600 hp engine are far more likely to be MISERABLE under 4000rpm as the compromises in the components used to reach 600hp will significantly degrade the low rpm performance , unlike the supercharged option
yes you can select 18 degree, or 2.2 sbc heads, and roller cams and reach that 600hp plus range with a N/A sbc, yes you can swap to the newer ls Chevy engines family and with the correct components you can make even better gains, and you can do the same thing with a supercharger or a turbo build up , using the improved heads, the correct cam, or the LS or even a BBC ENGINE as a basic platform,and add an inter-cooler, and double that hp.
its just basic physics, if you can stuff 50%-70% more compressed fuel air mix, thru an inter-cooler, with a turbo or a supercharger or use increased octane fuel, pushed into the cylinder and burn it efficiently , you can significantly increase the torque the engine produces, keep the rpm levels under 4000 feet per minute and your stress level will remain manageable with semi-reasonably priced components
lets look at a few factors, obviously theres a huge bunch of variations in components you can select,for any engine build-up so we will discuss the basic concepts
many, perhaps most engine failures involve either lack of proper lubrication, insufficient cooling, detonation or lack of valve train control, rod bolt failures
with a supercharger" insufficient cooling, & detonation" are the most common with a N/A combo youll need to operate at higher rpm ranges to make similar power numbers,so lack of proper lubrication, lack of valve train control, & rod bolt failures are more common
with a supercharger you can add a larger better designed oil pan, a larger radiator and learn to tune correctly.
stress can be managed and the low and mid rpm drive ability can be maintained as the engines basically going to increase dramatically in the torque it produces due the a larger volume of fuel/air mix being burn that produces a higher cylinder pressure.
with an N/A design theres not much you can do about the increased stress levels but select high strength parts and insure the lubrication is improved, as the higher rpms, are required to reach the higher hp levels if the engine displacement remains similar, or theres not a significant improvement in the flow rates of the components selected, in the engine build, but keep in mind many of those same increased flow components can be adapted to the supercharged version also.
rod bolts stretch on the exhaust stroke where, the loads are the greatest and theres little resistance to the piston,thru compression, slowing & reducing the loads on the rod bolts in tension as they play crack the whip with a heavy piston on the end. once rod bolts stretch the bearings fail to maintain the oil pressure and a rapid cascade of bad things in the engine result, if the bolts stretch enough to allow the piston to contact the cylinder head, valves or the oil pressure is lost as a result..
horsepower is the measure of the RATE at which torque or turning force can be applied, a supercharger , forces a larger fuel/air mix into the cylinders and as a result theres usually slightly greater compression and definitely higher pressure on the piston and rods over the piston, on the power stroke, but rods, are generally strongest in compression, as their beam cross section usually significantly exceeds the rod bolts cross sectional area.
ok lets say we take a common 350 sbc and add 7 lbs of boost with a supercharger, we have effectively increased the working displacement to about 48% at sea level, in effect we are running a 517 cubic inch displacement, and producing 600 hp is not out of the question at all.
now on a standard N/A, sbc you'll generally make about 1.1-1.2 ft lbs of torque , lets say 1.2 ft lbs, or 420 ft lbs
that will require at least in theory your going to spin the engine to 7500rpm to produce the same 600hp, but in reality your volumetric efficiency falls off rapidly after about 5700-6000rpm without much better heads and cams,and your stress levels skyrocket, so while the N/A 350 sbc engine producing 600 hp will be using very expensive components to stay together and dependable at that rpm level, and the low rpm driving characteristics on a 350 sbc N/A 600 hp engine are far more likely to be MISERABLE under 4000rpm as the compromises in the components used to reach 600hp will significantly degrade the low rpm performance , unlike the supercharged option
yes you can select 18 degree, or 2.2 sbc heads, and roller cams and reach that 600hp plus range with a N/A sbc, yes you can swap to the newer ls Chevy engines family and with the correct components you can make even better gains, and you can do the same thing with a supercharger or a turbo build up , using the improved heads, the correct cam, or the LS or even a BBC ENGINE as a basic platform,and add an inter-cooler, and double that hp.
its just basic physics, if you can stuff 50%-70% more compressed fuel air mix, thru an inter-cooler, with a turbo or a supercharger or use increased octane fuel, pushed into the cylinder and burn it efficiently , you can significantly increase the torque the engine produces, keep the rpm levels under 4000 feet per minute and your stress level will remain manageable with semi-reasonably priced components