"Charles Talleyrand" wrote in message
...
On Aug 3, 6:34 pm, "Mike" wrote:
"Charles Talleyrand" wrote in message

...

I read that the O-540-A1A5 weighs 396 pounds, but that a IO-540-A1A5
weighs 437 pounds. Can the difference between a carb and fuel
injection really be 39 pounds?

Also, as I wrote an IO-540-A1A5 weighs 437 pounds. But an IO-540-c4b5
weighs 402 pounds, but produces 50 horsepower less. What did they
change about the engine that costs 50 horsepower but saves 35 pounds?

I'm not familiar with the exact models in question, but some
installations
require things like starter adapters, which add weight. Some engines are
also derated based on the application. The IO-540-AB1A5 used in the new
182s is a 230 BHP engine because it's limited to 2400 RPM. Other 540s
put
out as much as 315 BHP.

I actually knew all that. But why would the engine weigh more?
Lowering the RPM does not add weight.

As I said, some applications require extra parts like a starter adapter.
That alone weighs 40 lbs or so if I were to guess. I'm not sure if Lycoming
engines need a starter adapter, but it could be some other accessory or
necessary part needed or desired in one application but not another.