- Credit: Motoring Weekly

H-Engines explained

In this article, I will be explaining what this type of engine is.

An H-Engine is a type of reciprocating engine with two flat/boxer engines together. The meaning of "H" would mean the engine blocks looking like a "H" went you view the front of it.


H-Engines were mainly used in aircraft. The Lotus 43, a F1 car, used a 16-cylinder H-Engine. It won back from the 1966 American Grand Prix. Powerboat racing boats had 8-cylinder H-Engines.

Who uses them nowadays?

Porsche is probably the only car brand to manufacturer H-Engines. as well as Subaru. The Subaru flat engines are referred as "H4" or "H6". From the old days, other car manufacturers uses them, like Saab,

What does "H" means?

"H" would mean horizontally-opposed, which would likely be an alternative term for flat/boxer engines.

How do they work?

It'll pretty much do the same as flat/boxer engine, but with two engines combined, just like "V" or "W" engine with two or three inline engine.

A note!

I will still be editing more of this article and correct me if some of this is wrong by the comments!

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Comments (9)

  • This is lamest explanation yet. Not to mention it's wrong. Neither Porsche or Subaru make H engines. They make boxers/flats.

      1 month ago
  • Not explained! It’s quite tricky without drawings, but horizontally opposed is not the same as H

      1 month ago
  • This article is, how can I put this nicely, rubbish.

      1 month ago
  • But isn’t the main picture an H engine with the cylinders top and bottom as well as having blocks on both sides, hard to describe but Porsche and Subaru use a typical boxer engine

      1 month ago
  • his is a wonderful article. I can see that you have done a lot of research and your subject knowledge is good and impressive.

    This is Nitin, I also like to write for an education blog www.cleariitmedical.com - This is an online blog for students who want to prepare for India's most difficult entrance exams - IIT JEE and NEET This is a free blog and provide free study material, quiz and notes to those who can't afford to pay hefty fees of coaching institutes. I write free of cost for the good cause. I know you must be busy with your work but if you could take out some time from your busy schedule and have a look at it. I saw a good collection of articles. If you only write a few words about this blog then it can help a lot of students out there. Thanks

      1 month ago