high hp/cylinder engines... 3

[mitsoulas]

Hello to everyone...

Lets say that we have a 4cylinder engine(for example 4g63)that produces 1200hp...
How many kilometers do you believe this engine can last?or it is better to say...how many full throttle passes can handle?

Do you have any examples with such type of engines that has lasted for long??

I'm talking about material strength...we assume that cooling system,oil system etc are the best we can have.

 

[Lou Scannon]

Well, near the extreme end of the spectrum are the top fuel engines, which I believe have now reached 10,000 hp territory, but are only used for one burnout and one 1000' pass before being completely torn down and rebuilt. I think the number of revs they go between rebuilds is counted in the 1000s, if not 100s.

"Schiefgehen wird, was schiefgehen kann" - das Murphygesetz

 

[BrianPetersen]

300 horsepower per cylinder is peanuts for an engine in an ocean-going ship ... just saying.

If you re-cast your question in terms of BMEP (brake mean effective pressure) at peak-torque RPM and mean piston speed at redline RPM, it might give a better frame of reference.

There are turbocharged two-litre 4-cylinder engines in current production that are approaching 400 horsepower, and those meet OEM reliability and durability requirements. (200 horsepower per litre)

The current 1000cc Superbikes are making near 200 horsepower without forced induction, and the mean piston speed at redline is near 25 m/s, and those meet their OEM reliability and durability requirements - probably less than automotive, though. The Kawasaki H2 (derestricted) and H2R are supercharged and make near 240 horsepower from 1000cc.

I suspect if you go much above this threshold, you are going to get into an area where the engine can handle "intermittent" power output at that level (for a few seconds at a time) but is not able to provide "continuous" output at that level.

I know that the Kawasaki H2 engine is calibrated to run very rich under load, in order to protect itself from meltdown.

Plenty of the newfangled downsized and turbocharged automotive gasoline engines are getting a reputation for being thirsty under load (e.g. trailer towing) for this same reason - and it means they're pushing the limits of what thermally can be dealt with.

 

[PackardV8]

Not exactly a new question or new concept. War Emergency Power was designed in and prohibitions against its use widely ignored by pilots.
Maximum normal power would be limited by a mechanical stop, for instance a wire across the throttle lever slot, but a more forceful push would break the wire, allowing extra power. In normal service, the P-51H Mustang was rated at 1,380 hp, but WEP would deliver up to 2,218 hp. The Vought F4U Corsair, not originally equipped for WEP, later boasted a power increase of up to 410 hp (17%) when WEP was engaged. Several methods were used to boost engine power by manufacturers, including water injection and methanol-water injection. Some earlier engines simply allowed the throttle to open wider than normal, allowing more air to flow through the intake. All WEP methods result in greater-than-usual stresses on the engine, and correspond to a reduced engine lifetime. For some airplanes, such as the P-51D, use of WEP required that the engine be inspected for damage before returning to the air. 5 hours use of WEP on the P51D required a complete tear down inspection.

jack vines

 

[BrianPetersen]

The Kawasaki H2 (restricted to 200-ish horsepower from the factory) has a standard-issue Kawasaki maintenance schedule and requires nothing special in terms of engine oil.

The H2R, which is the same bike except de-restricted and with different camshafts and a 14,000 rpm redline instead of 13,000 rpm, (240-ish real world horsepower from the factory) requires the use of synthetic oil and calls for a major inspection after 15 hours above 8000 rpm and a bottom end overhaul after 30 hours above 8000 rpm. The ECU tracks the amount of time spent above 8000 rpm for you.

If you were to ride the bike at top speed continuously, that 15 hours would cover about 5000 km. If you were to do it a quarter mile at a time, that 15 hours would represent about 5000 dragstrip passes.

I'm no expert on the Mitsubishi 4G63. Google tells me that the hottest original-equipment version made around 270 horsepower. I think it's fair to say that asking this engine to make more than 4 times that much will at best only be possible intermittently (seconds at a time) and certainly not for very long.

 

[mohawk2]

I think you will find that the available main bearing area + heat management will be the main issues with this. A 4x power increase is much worse than 4x the load, that said how often does an engine see max power applied ? Likewise power at load is the killer, a max rpm burn in a low gear is much easier on the components than the same at max load in a high gear, as in max speed, combined with maximum aerodynamic resistance !

Best to do some research on what others have extracted & determine if reliability or max power are your main targets. Steel components normally have approx 30% over strength built in by the manufacturer & are very reliable within that envelope. Alloy or Titanium components have much less predictable stress failure limits.

Drag machines are the only things that usually add 3x+ power to stock engine blocks & their lifetimes are reduced to minutes at full power. The use of the H2 Kawasaki above is slightly off base, as it was designed to cope with those loads as standard. Your 4g63 was only rated to 270hp stock & 300hp in rally form, so 4x rally power is not gonna last well

YMMV

 

[Tmoose]

How many kilometer can it last while developing 1200 horsepressure?
Somewhere between zero and 50 is my guess.

What are the internal parts used?

http://www.themotorhood.com/themotorhood/2014/12/9/how-do-you-build-a-1000hp-4g63

Sounds like a stock crank will develop cracks pretty quick at the "mere" 1000 HP level when drag racing.
So a well prepared stock crank would work, but the engine would have to be disassembled regularly, and frequently for wet fluorescent mag particle inspection.

If the engine tune is not safe, or the engine builder was not thorough and experienced, or the chassis builder did not provide systems to adequately support the engine's requirements, or the driver is a bone-head, I don't think any engine would survive the first "full throttle pass."

 

[mitsoulas]

I was wondering...do we halve materials that can cope with 1000hp/litre (for example bmw m12/13 f1 engine)?
This engine could withstand this hp level for only a few laps..
Top fuel's pistons and rods can last up to 10 runs...they blow often because they make the fuel adjastement and when they add more fuel the extra pressure in the cylinder must go somewhere...and it cracks piston rings or even the whole piston...
WRC engines can go with 1000 celsious for 1000km...really impressive...
F1 engines can go 2.500km with full throttle all the time...

In conclusion...is it a science fiction or how far is the day that we can have a reliable 200hp/cylinder engine?

 

[mohawk2]

We have the materials, but no one willing to pay for it ! The cost for run of the mill production engine putting out that power would be astronomical. But keep an eye out for "Metal Glass" in the near future, its regular glass but fired by electrical induction & produces a high tensile ceramic that it tougher than steel but lighter & extremely heat resistant !

 

[BrianPetersen]

You can have 200 hp per cylinder if you make the whole engine BIGGER so that there is enough material to spread out the stress and spread out the heat.

What, at the end of the day, are you attempting to accomplish?

Fixating on excessively high BMEP (extreme torque from small engine) will result in an engine that requires exotic fuel, consumes it at a prodigious rate, and doesn't last very long before breaking something.

Formula 1 is not near the power output per litre that you are suggesting. But they are making the power that they make with high revs, short stroke in order to keep piston speed and acceleration manageable and thus, stresses on everything involved manageable, plus materials that the rest of us can't afford. The flat-pancake shape of the combustion chamber in a F1 engine is not ideal but they make do with it.

Drag-car engines have very high power output, but at that level they require exotic fuel, consume it at a prodigious rate, and don't last very long before breaking something.

What's wrong with just making the engine bigger, so that your target power output can be reached without all this trouble?

 

[utkuselamoglu]

it's related with the materials, the atmosphere and the usage, You can not have any prediction about this question I though.

You can pass:

1000 passes without any trouble with reduced cylinder charge, reduced and cooled cylinder pressure, good lubricants, good mechanical stress and etc.

10 passes only with not enough good materials, mechanics, chemicals, etc.

the main question should be like this, how to build long life 1200 hp 4g63 engine? not how many passes of my unknown 4g63 engine can do?_

it's all about the target that you want to achieve. all modifications are dark but possible.

 

[SwinnyGG]

Formula 1 is not near the power output per litre that you are suggesting.

The BMW M12/M13 was an engine used not only if F1 but also in touring cars, F2, and basically any form of racing BMW entered in the 80s.

It did actually approach 1000 HP/L in F1 qualifying trim- the F1 version was 1500cc, and in qualifying trim made approximately 1400 bhp.

Of course, during this era of F1, exotic fuels were used and it was not against the rules to use a brand new engine for qualifying and then throw it away.

The touring car version of this engine was used all over the world and won championships in DTM, Australian Touring cars, Italian, British, and European, and WTCC in the late 80s.

 

[BrianPetersen]

Yep. Uses exotic fuel, consumes it at a prodigious rate, and didn't last very long before breaking!

How did they manage piston and exhaust valve temperature?

 

[Lou Scannon]

Most likely steenking rich AFR...; perhaps overscavenging as well, though less likely.

"Schiefgehen wird, was schiefgehen kann" - das Murphygesetz

 

[SwinnyGG]

My guess would be AFR as hemi said.

During this era of F1 the only real limiting factor to engine performance was fuel consumption- cars were limited to 195 liters of fuel for the race. Fuel consumption during practices and qualifying was unlimited- so the BMW powered cars were capable of 1400-1500 bhp for 5 laps or so in qualifying, but were detuned to 800-1000 bhp on race day so that they could make the required distance on the alloted fuel.

 

[DuncanM]

I'm a little late in commenting, but you may find some useful information in the below linked thread, and others across the internet by the same fella. Its a long time since I read his posts though.

He twin-charged his 4G63 evo to great effect, although only reaching around 750bhp as I recall.

http://www.eng-tips.com/viewthread.cfm?qid=267889