How many automotive engines use offset cylinders, and can they be used in flat engines?
Do you mean offset cylinder bores or offset piston pins in pistons?
I was thinking offset cylinder bores but I guess the same thing could be accomplished with offset wrist pins. Is that a common thing in modern engines?
Thank you for making me look up the concept…
Offset piston pins have been used in every type of engine including flat-4 VW and Porsche engines.
As for offset bores… The Desaxé engine is an old concept used on steam engines as well as automotive engine in the early years. It means the crank centerline is offset from the bore centerline. It is done to reduce friction. It was common in the US in the early 1900s. The Ford flat-head V8 used this principle as do the modern VR6 and VR5 VW engines as wel as the Toyota Prius engine. This seems to be making a comeback in the motorcycle and outboard motors as well.
Apparently modern Hyundai engines are doing this. No reason it would not work just fine in flat 4s and 6s.
A friend of mine ran a 273 Mopar in a stock 280 class hydroplane in the 60s and early 70s; the piston pins were offset to the outside of the V to give quieter running and less piston flutter at idle. he swapped the pistons and rods from side to side which gave him a little more power due to a straightes push and less friction. It has to be a completely stock 2 bbl carb engine. He was using all stock parts but th sanctioning body made him put them back in the stock location. He won a lot of races against the usual 265 Chevies.
Steam engines were double acting so a Desaxe offset that reduced friction on the push stroke would increase friction on the pull stroke. Perhaps it was used to equalize the push and pull stroke of the engine because the back side of the piston had less area exposed to high pressure steam due to the diameter of the piston rod.
Oil well pump jacks have offset cranks. I was out in an oilfield because the owner of an oil well was having trouble with the electric motor kicking back into the start winding at the beginning of every upstroke due to motor overload. (single phase service) Me and my partner checked everything over, tried different sized run capacitors and stuff, and then I studied the action of the pump and noticed that it dropped the sucker rod slow but jerked it up real fast. I then said, “I’ll bet if we reverse the direction of the motor, it will lift slow and drop fast” so we reversed the motor and…PROBLEM SOLVED!
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