Why do engines have a seperate cylinder head ?

[robinessex]

It's been done in the past. Integral cyl block. Brian Hart, turbo F1 4 cyl engine. https://www.highpowermedia.com/blog/3117/the-monob... Has many advantages. Cheaper, easier to sort inlet and exhaust tracs, no head gasket, no cyl head bolts, lighter, more rigid engine, better coolant flow etc.

[ging84]

if it was cheaper, they would be doing it

[glazbagun]

British Leyland made a bus (the 510) with an integral head. From wiki:

"The Leyland 510 engine had an unusual design, in that it featured non-detachable cylinder heads; any work on the valves required the crankshaft and pistons to be removed to enable access from the cylinder bore"

Seems like a nice idea, poorly executed.

http://www.aronline.co.uk/blogs/facts-and-figures/...

Edited by glazbagun on Monday 3rd November 22:42

[jmcc500]

Hard to manufacture, particulalrly to required tolerances I suspect. I believe old Bugattis had monoblock construction, but a separate head allows machining tolerances to be compensated for with graded head gaskets.

[McSam]

Simply put, it's astonishingly complex (and therefore prohibitively expensive) to mass-produce a monoblock engine. Purely in terms of machining/finishing access you can see how much more difficult it becomes, but you also lose a lot of opportunity to correct for small imperfections. Serviceability also becomes a nightmare.

Additionally, modern engine designs are very modular to allow interchangeability of parts or at least similar castings for different capacities etc. and this would get a lot more difficult with a monoblock approach.

Since the block/head format is so highly evolved, it would be a brave OEM who tried to do anything different..

[skyrover]

glazbagun said:

Seems like a nice idea, poorly executed.

The British car industry in a nutshell

[RobDickinson]

Suspect if/when 3d printing gets into mass production for this stuff we will see it happen more.

[Searider]

Steyr have been doing this for some time.

http://www.steyr-motors.com/automotive/

[glazbagun]

The Lotus Omnivore was a monobloc too. I wonder if they ever made any money from it?

http://jalopnik.com/5160933/lotus-completes-omnivo...