Comments by "Golden Croc" (@GoldenCroc) on "The Best Way To Compare Car Engines - BMEP" video.

  1. Depends on what you want to know. The BMEP value is all about the combustion efficiency per stroke.
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  2. Probably mustang.
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  3.  @m.morininvestor9920  About 12.45 for a 2020 370z. Youre welcome. Its an older engine design than the mustang.
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  4. @Roderick Voordouw  BMEP is mostly about the inlet airflow efficiency and pressure wave managment. Port your heads, switch your cams and grind off a bit from your cylinder head. And get a good tuned exhaust and you bmep will be up about 2-3 or so.
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  5. Bmep is about combustion efficiency, not about power.
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  6. I calculated it for you. Its about 19.5 bar. Dont know the max boost, so you will have to divide by that number if you can find it, to compare with the other turbo and NA cars.
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  7. Good head and intake design does wonders. Generally if you take the effort to have those, you also take the effort to make the engine rev high. Its a correlation, not a causation.
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  8. Wait til you hear about them newfangled camshafts. Sorcery I tells ya.
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  9. This video is more about the efficency than the performance.
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  10. Those engines are all about thermal efficiency, so they have sacrificed BMEP to gain in other areas.
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  11. It is a valid, apples to apples comparison, since they both use the same fuel. The diesel on the other hand gives bad numbers compared to modern engines for a multitude of reasons. Its probably about average for its fuel, age and induction type.
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  12. No, not really. Its because its an older engine design. Its about average for its age.
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  13. That is not true unfortunately. You have taken a correlation as a causation. More BMEP does not mean shorter engine life in isolation.
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  14. Na, as an average of all cars produced, Id say german cars rules using this scale.
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  15. Yes, more BMEP is theoretically better for mpg, but it is a weak correlation to say the least, since mpg depends on so many other things in an engine. Also, if you really want mpg, then maybe you will make it an atkinson cycle engine, in which case the BMEP will be comically low.
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  16. Dont know where you got that from, thats not the case at all, as you have written it. You have misunderstood some things unfortunately. In fact, more torque equals more horsepower at the same rpm.
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  17. BMEP does not impact reliability at all unfortunately. The old engines are more reliable becuse they have less things that can go wrong. Diesels are well know to have much more BMEP for example, and they last a very long time. No, your value of 10 just reflects the age of the engine and its relatively primitive intake system Im afraid, no other upsides just from that factor. It still is a great car in doing what it was designed to do.
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  18. Its an old design that has been surpassed long ago in this metric. Not really any more complicated than that.
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  19. The vast majority of engines of cars on the road are still NA, so I dont think so.
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  20. Not really.
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  21. Neither has a direct correlation, really.
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  22. Not bad!
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  23. One could say what you are asking is already being done in practice, and for many decades. Look up "thermal efficiency" and enjoy the rabbit hole.
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  24. Not really.
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  25. Depends on what you want to know :)
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  26. Fanboys dont know such terms as BMEP. Anyone with enough knowledge to know this term is not likely to be a fanboy. Also, this video is not about what you are talking about at all. This is a pure engine design comparison.
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  27. Heh, it is, more or less.
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  28. Not very good these days, but about average if its an older one.
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  29. Durability depends on so many other things which are more important, that it is impossible to compare. Generally, no, that is not the case in theory or practice.
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  30. Its creeping up nicely over the years as one can see :)
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  31. Its not, they are correlated somewhat.
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  32. Not really, these pressures are very low comparitively.
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  33. But you have to divide total displacement by the cylinder number, giving you the same number in the end.
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  34. Not really. They give more torque becuse of their big displacement and high boost compared to cars.
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  35. Its built to a cost. No shame in that. It does the job. Optimised airflow costs money.
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  36. They ones you are thinking of probably flows more air, and revs more.
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  37. In just a miata 1.6 Engine. Newer Engines are already more optimised generally and does not have the same scope for improvement. There is a physical limit at play here at higher BMEPs. BMEP does not translate to extra hp more than maginally.Yes, it is correct that it is not a cost effective way to increase power, compared to other methods, but that was not the question I attempted to answer. It is not technically hard for any reasonably competent engine builder to get a over 200hp from this engine without forced induction. It is expensive though, and increasingly so with every extra hp. Thats why almost no one does it. It also affects the drivability and longevity.I attempted to answer how one should go about to increase BMEP in the miata 1.6 Engine in my prevoius comment. But it will as a sideeffect also increase the Power, because of the increase in airflow allowing higher revs without starving the Engine. Hope this helps.
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  38. Is it a side valve? Side valves are terrible for BMEP unfortunately. Dont know enough about those rules to give an answer unfortunately, sorry.
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  39. I dont think it will be that bad. Its about the airflow efficency of the engine, not the size. And this engine is quite modern, so it should be ok, for a turbocharged car.
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  40. I think it probably is a marvel of engineering compared to some smog engines, do some calculations of them, Id wager they are shockingly bad!
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