I’ve read enough magazine build threads where they pull some motor out of a junkyard for very little money and then with a cheap EBay turbo the heck out of it making really silly horsepower.
What I wonder is how long do they last?
Could you get a season out of it? Say LeMons or Chumpcar, er Champcar?
i would say a race or 2 at best at that horsepower. There is 1000hp dyno runs and then there are 12 hour endurance races
No, none of them will last for an enduro. The life of those motors is measured in drag passes.
They might last a race or two...quarter mile drag races. Maybe.
I can't imagine the size of radiators you'd need to shed a thousand horsepower worth of heat.
Why would you want 1000 horsepower for a road course in a E36 M3 box car?
Streetwiseguy said:They might last a race or two...quarter mile drag races. Maybe.
I can't imagine the size of radiators you'd need to shed a thousand horsepower worth of heat.
You can reject quite a bit of heat from 'normal' sized radiators if you make sure to match it with a similarly sized oil cooler and use the oil to help cool the engine. Also need more cooling system pressure (higher boiling point).
Lemons is the wrong venue for that sort of build. You should go to a race before you make any car or engine choices.
Most cars can't make high hp for long periods because they can't shed the heat. Cooling systems and intercoolers (and oil) all work the same in that they can absorb heat a lot faster than their heat exchangers can shed it. So, they are all sort of 'heat sinks' and you can throw crazy amounts of heat into them for a few seconds, but not minutes because in the longer term you're limited by your ability to shed that heat to outside air. You can even be limited by the ability of the piston to shed heat to the cylinder wall and oil below it ( add oil squirters etc) or by the ability of the exhaust valve to shed heat to its seat and guide (put moving sodium inside it to help carry heat up to guide etc). This is also a reason why super fast drag cars switch to fuels which are lower in energy density. You have to spray more of them, but that's the point because you're using the latent heat of vaporization of a larger amount of liquid fuel to remove more heat from the engine through the exhaust system than you would with gasoline. They wouldn't live 4 seconds on gasoline, because of temperatures inside the chamber causing detonation.
An example of this heat-shedding limit is the recent articles talking about how Jeep was struggling to hit a 7000 lb tow limit with the Gladiator because they had limited cooling real estate in the narrow Wrangler front end. Also the same reason that they've never put their v8s in it from the factory, although they don't say that. It would live for drag passes but it would have a time limit and wouldn't be 'normie-proof'.
With proper cooling and the correct air/fuel ratio, there's no reason such an engine couldn't be reasonably durable. People tend to think of boosted engines as being far less reliable than an n/a, but the failures can almost always be traced to some commonsense need of the engine that wasn't met, i.e. controlling heat, and providing sufficient fuel.
Patrick said:Why would you want 1000 horsepower for a road course in a E36 M3 box car?
I hardly think this is the place to ask such a question.
In reply to Vigo :
Agreed on everything above. I was involved in making sure the Champ car engines would cool sufficiently when we prepared to race in Denver and Mexico City in 2002. Just your basic 800hp turbo engines. The real trick is making sure you have the two things radiators (water and oil) really need, good thermal conductivity and good airflow to drag that heat away. Granted those were not your run of the mill junkyard engines, but the numbers all add up the same way: more power requires bigger/more efficient cooling.
Texas-mile would be a great reason to build something like that. I would love a 1000hp bi-turbo v12 Mercedes inspired by cotton!
1988RedT2 said:Patrick said:Why would you want 1000 horsepower for a road course in a E36 M3 box car?
I hardly think this is the place to ask such a question.
...nor the PERSON to ask such a question!! 
The rods will show themselves at this kind of power in a junkyard build before it overheats.
SVreX said:1988RedT2 said:Patrick said:Why would you want 1000 horsepower for a road course in a E36 M3 box car?
I hardly think this is the place to ask such a question.
...nor the PERSON to ask such a question!!
I'm not THAT obsessed with all out speed.
Patrick said:SVreX said:1988RedT2 said:Patrick said:Why would you want 1000 horsepower for a road course in a E36 M3 box car?
I hardly think this is the place to ask such a question.
...nor the PERSON to ask such a question!!
I'm not THAT obsessed with all out speed.
nimblemotorsports said:The rods will show themselves at this kind of power in a junkyard build before it overheats.
Not according to Corky Bell in "Maximum Boost". Something about tensile load and power load and like, vector dynamics, man.
1988RedT2 said:With proper cooling and the correct air/fuel ratio, there's no reason such an engine couldn't be reasonably durable. People tend to think of boosted engines as being far less reliable than an n/a, but the failures can almost always be traced to some commonsense need of the engine that wasn't met, i.e. controlling heat, and providing sufficient fuel.
Plus there is no reason you would have to pull 1000 horsepower out of the engine for the whole race. Pop to the front of the pack and then cruise using a fraction of available power.
I agree that boosting an engine does not shorten its life if used rationally. Million mile diesels are all boosted.
Of the 4 strokes of a motor. Only the intake is trying to pull the rods apart.
Compression, the piston is being shoved down against the rod.
Power the burning fuel is pushing down on the rod.
Exhaust the rod is pushing out the waste.
In those three strokes the load is where the piston rod assembly is the strongest.
Only on the intake stroke in a normally aspirated engine is the whole assembly trying to pull the rods apart. Where the bottom of connecting rod and the two rod bolts is trying to be pulled apart is the force working against the strength of the rod assembly.
Under boost that doesn’t happen. This piston is more or less getting out of the way of the fuel/air mixture instead of creating a vacuum to draw it in.
Oh, and one major thing. Sufficient end gap in the rings. Heat under boost expands the rings until the ends connect and then are forced up or down to accommodate that expansion popping off the ring land, bye bye motor.
Perhaps this can be the next GRM event. The $2000 1000HP 24-Hour Turbo Challenge
frenchyd said:Only on the intake stroke in a normally aspirated engine is the whole assembly trying to pull the rods apart.
While you are correct that the intake stroke is the only time the rod is in tension, look at the forces.
A 5.3L engine making 370lbft of torque has a BMEP of 172psi (force applied during power stroke).
During the intake stroke if its pulling a perfect vacuum, its pulling 14.7psi. Obviously if the motor is running correctly, it has open valves and the goal is to have as little resistance as possible, in which case the only force generated is from ring friction.
In reply to frenchyd :
I'd think that rods only fail under tension in an overrev situation, other than that they'd fail under compression on the power stroke or compression stroke, and fly out the next time the rod moves down.
slowbird said:Perhaps this can be the next GRM event. The $2000 1000HP 24-Hour Turbo Challenge
Endurance landspeed racing used to be a thing...I think the popular car would be '90s Cramits with janky twin turbo setups.
I remember Matt Happel's turbo 6.0 LS Colorado. On the dyno it made 1000hp to the tire on a stock bottom end but at one point he was quoted saying "it probably won't survive a full 1/4 mile pass this way"
For lemons there is also the issue of making everything else in the car survive that kind of power. Brakes, tires, differential, axles, etc.
FIn reply to ProDarwin : filling 662.5 cc during the portion of a second the piston is in the down stroke would require more than 14.7 psi. At peak RPM
I’m drawing a blank here because the piston goes from dead fuel stop top to dead full stop bottom during that time. While I’m math challenged I can usually figure out the required formula but I’m hung up on inertia of the air/fuel mass.
Then Too I’m ignoring overlap trying to keep it simple.
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