brillant explanation. I always wanted to know how an engine really works.
Internal Combustion Engine
111–120 of 415 posts
Re: Internal Combustion Engine
#112Earlier quoted context omitted.
The raw materials may continue to cost more for EVs. Motor windings are generally copper, and batteries contain lithium and (usually) cobalt and nickel. Permanent magnet motors sometimes contain rare earths. One could make an EV with aluminum motor windings and electrical cabling, no rare earth magnets, and lithium iron phosphate batteries. That would keep expensive materials to a minimum. EVs don't need a catalytic…
cmon man. the total weight of pricey metals in a car is so low, there is no way its going to offset the cost of precision machining. tolerances < 1 thou and callouts for surface finish and perpendicularity are expensive!
I'm sure a motor is cheaper than an engine (less steps to make), but they still require precision manufacturing, and all the other parts aside from the motor (driveshaft, axles, brakes, etc.) are more or less the same.
Plus, the cost of those other materials is going to increase if demand for EVs goes up.
Re: Internal Combustion Engine
#113Earlier quoted context omitted.
I built an LSX (Aftermarket GM) iron block engine (V8 LS) for a CTS V. I had to get some very precise tools (Have to measure to 10,000ths) or they were useless for bearing clearances and verifying cylinder diameters. My cylinders were 4.155 bore, and the bearing clearances were around 1.8 thousandths. Forged pistons, rods and crank. I had cracked a cylinder/piston on the original LSA. I did not trust anyone to do the…
Yes you are right as far as LS engine builders there's loads. I could have ordered a crate engine from Texas Speed and been done with it. And yes for hours of my time spent vs hours of money saved I lost a ton of money. But all it takes is one very small mistake to make an engine short lived with these exacting tolerances. I'd rather blame myself than deal with someone kicking the blame back. It was also a personal s…
I have a buddy that is adamant about not flushing transmissions if you dont have a issue because he think its guaranteed to have an issue after, from his experience. lol
Re: Internal Combustion Engine
#114aaaaaa
Re: Internal Combustion Engine
#115I just built an engine for my car. One thing I gained an appreciation for was how CHEAP cars and engines are. There's probably nothing else with as precise machining that is as inexpensive. Engine cylinders are honed to accuracies that are less than 1 thousandth of an inch. Crank journals as well and rod journals. This is all precise machine work with metal. I use inches here because in machine work thousandths of in…
Nice! What engine did you build? >The distance between a crank bearing or rod bearing is less than 2 thousandths on modern engines. A small amount of oil in that tiny space is all that keeps your engine from having metal on metal seizure. The BMW S65 and S85 engines are prime examples of what happens when the wrong tolerances are chosen. I can't think of another engine family where rod bearings are considered a maint…
I thought once you replaced the crappy OEM bearings you were all set on these engines. I guess it is not the case?
Re: Internal Combustion Engine
#116Earlier quoted context omitted.
Nice! What engine did you build? >The distance between a crank bearing or rod bearing is less than 2 thousandths on modern engines. A small amount of oil in that tiny space is all that keeps your engine from having metal on metal seizure. The BMW S65 and S85 engines are prime examples of what happens when the wrong tolerances are chosen. I can't think of another engine family where rod bearings are considered a maint…
Any race or high power engine, especially those that rev quite high will need rebuild - not just in bottom end but often with piston rings and valves as well. You don't really hear about those other engines much because their buyers understand that a race engine needs more maintenance than any other road car. Also, not beating on the engine until oil has warmed up to temp will elongate the bearing lifespan quite a bi…
> Also, not beating on the engine until oil has warmed up to temp will elongate the bearing lifespan quite a bit.
I am curious if there is proof to this. I've always felt the same way. I know in the "old days" with iron pistons, if you you simply started up a cold motor and and drove it hard without a warm up period, the pistons would expand quicker than the block and would start to scour the walls and/or lock up.
But other than that, the only other "proof" I have is from people in high school that like clock work at 3:30 everyday, would smoke tires leaving the parking lot everyday. They seemed to go through motors every 6 months. I'm talking knocking bearings and lifters cracked in half. I've never gotten rough with anything I own until after a 20 minute "warm up" and all has been well (so far).
Re: Internal Combustion Engine
#117Earlier quoted context omitted.
Any race or high power engine, especially those that rev quite high will need rebuild - not just in bottom end but often with piston rings and valves as well. You don't really hear about those other engines much because their buyers understand that a race engine needs more maintenance than any other road car. Also, not beating on the engine until oil has warmed up to temp will elongate the bearing lifespan quite a bi…
The S65 and S85 are road car engines, not racecar engines. They're also hardly BMW's highest performing motors. Even Dinan built engines don't suffer from that problem.
They're meant to be dual duty. There aren't any road car engines I'm aware of that use individual throttle bodies or 12+ compression without direct injection.
Re: Internal Combustion Engine
#118Earlier quoted context omitted.
People have hard time grasping how much energy chemical bonds can hold. 15 gallons of gasoline store 500kWh of energy. That is 5 tesla model s worth of energy. Efficiency plays role for our day to day car tasks, but when you have to deal with external forces or higher requirements of momentum, then you need more energy period. Towing, beating high-speed drag / waves, climbing high, cannot be addressed with smarter de…
> 15 gallons of gasoline store 500kWh of energy. That is 5 tesla model s worth of energy. Yes. However, the Carnot efficiency means that most of it is lost as heat. Suddenly the advantage is not that large anymore.
Not even close. An electric motor is 4 times more efficient than ice. An ice car can easily store 10 times more energy than an electric.
F150 can tow 13,000 pounds and has a 27 gallon tank (almost 10 Tesla’s).
Re: Internal Combustion Engine
#119Earlier quoted context omitted.
Tesla already uses aluminum for power cabling because it’s cheap and lighter weight. Tesla Model S were induction motors (at first at least) with no rare earths, and Tesla is partnering with CATL for lithium iron phosphate batteries in lower cost versions of, if I believe, Model 3 and Y.
I thought CATL makes lithium iron phosphate batteries, and lithium sulfur hasn't been commercialized yet. Unless there's some news on that front I missed? I think induction motors tend to be less efficient than permanent magnet motors (and thus require more cooling). The Netgain Hyper9 (a popular motor for conversions) is a permanent magnet motor which doesn't use rare earths. It's very efficient but not particularly…
Yes, I meant iron phosphate. (I’ve had sulfur on my mind from Bye Aerospace’s 925km range 8-seat electric aircraft, working with Oxis Energy.)
Re: Internal Combustion Engine
#120Earlier quoted context omitted.
Your fuel tank was only allowed to hold a certain amount of fuel because if you had more, you could go farther between pit stops, thereby covering more laps while the other drivers were stopped for gas. He would temporarily meet the small tank regulations during inspection, but under race conditions, the ball would burst, allowing for more space in the tank, which would get filled up with more fuel than his competito…
How was he "caught" if thats the term?
By the mere fact that the car wasn’t pitting as often. Car was likely inspected afterwards.