requires a great deal of effort

[azz]

a. This cake requires a great deal of effort to make.

b. That scene in the movie required a lot of effort to get right.

c. This disease requires a lot of time to cure.

d. This disease needs a lot of time to cure.

Are these sentences grammatically correct?

I don't think they are. They sound wrong to me. I can't parse them.

I think they might work with the passive infinitive.

a1. This cake requires a great deal of effort to be made.

d1. This disease needs a lot of time to be cured.

But even (a1) and (d1) sound strange to me.

Many thanks

[Alan]

Re. a~d: while most natives would, I think, find these informally acceptable by analogy with '[be] difficult to make', etc., they would probably be flagged as substandard by careful users.

Re. 1a and 1d: structuraly acceptable, although (esp. 1a) not particularly idiomatic/felicitous.

They would more naturally lend themselves to an impersonal active construction:

A lot of time is required (in order to) make this cake.

or, better still,

It takes a long time to make this cake.