Being someone who builds the Hemi (modern gen) on a regular basis as part of my business, I feel the Hemi does have that reputation. Although it depends mostly on application. Nitro engines (of which I have built zero) are often tore down and refreshed after every single run. And at over $12,000USD per run, you can see why I don't touch that application with a 10 foot pole! It is also important to note the reason why that design was chosen for Nitro. Back in the 60's and 70's. There was a machinist and engine builder by the name of Keith Black. Keith Black (in my opinion) was a genius. He designed 426 blocks that could handle a few Nitro runs when most other engines could not even make it one run....including factory made hemi's. The engine was completely redesigned and reinforced and methods he invented are still in use today in all makes of and manufacturers. For an independent privately owned shop to produce its own heads, blocks and other internal parts with no other financial support or engineering input is pretty dam special. Even so, his engines also failed, but usually could handle much more than other engines. There really is no comparison between a nitro engine and other race engines. Nitro engines have no cooling system, the blocks and heads have no coolant passages or water jackets. This "solid" alloy structure makes them much stronger, but allows for only very quick duty cycles of a minute or two.
Today, the engines I build have very little in common with a nitro engine or early gen Hemi's for that matter. My engines are designed to be reliable street engines that pass emissions and still make very high power since I specialize in street legal engines in the 1000+ HP range. The modern Hemi including the 5.7L, the 6.2L and the 6.4L 392 cubic inch engines were the first generation of push rod engines with variable valve timing. Which is great for fuel economy and moderate horsepower improvements. That being said, the method being used can cause inherent weaknesses. So when I build a 1000 horsepower hemi engine, there is very little original parts remaining in it. Other than the block and external accessories, it is a different engine. In mine, the connecting rods and pistons are different, the crank and cam are different. The heads are different, the fuel system is modified, the variable valve timing is limited to half of its stock range and the list goes on and on. I would not even think of running a stock 392 with my nitrous systems, it would not be long before major failures happened. Also, there are certain engineering flaws in the latest gen Hemi's that make them unsuitable for horsepower mods over 250 HP without pretty much starting from the beginning.
If you compare the modern 392 Hemi engines with other manufacturers in stock form, it can more than hold its own against other unmodified manufacturers internal combustion engines. Only when a supercharger is added do they have a chance against a modern 392 with an experienced driver. So if you look at the Hell Cat (completely different 6.2L engine) and its output with its massive 2.5L supercharger, other manufacturers had to scramble to build something to compete (which they did, and did well). I find it interesting that we seem to be in a horsepower battle similar to the one that took place in the 60's and early 70's with the only difference being better technology. We can do so much more now with so much less than they had back then due to technology, and lessons learned from brilliant men like Keith Black.
The reason why I chose Hemi's is supply and demand. Not many 392's are out there compared to other muscle manufacturers. I think for every 10 Hemi's made, there is only one 392, even though they share the base platform. The Hell Cat does not count, it has its own special design that does not share the same platform as the 5.7, 6.2 and 6.4L. I can't make any judgements or statements about the new Demon, I know nothing of it.
So, according to my business model, not many performance parts are being made for the 392 just like back in the muscle era. The myth of the big hemi has followed this modern design with half of its appeal being the reputation for power, rather than numbers on a dyno.
By the way, this is not a "pro" Mopar post. I think all modern American made muscle cars are true wonders of efficiency, power, speed, and public road handling.
