Delegating tasks to helpers/partners for hourly work on Odesk/Elance?

Question

Freelance

I have several clients that I work with on an hourly basis. Lately, I've been finding that there isn't always enough time for everyone. Naturally, the idea arose to delegate some tasks / subtasks to some assistant. Or take and lead larger projects.
The question is, how to do this when working on Odesk/Elance, where the time is calculated automatically using the time tracker? How do you, dear colleagues, get out of such situations or negotiate them with clients? I mean how to include additional budgets and justify them to the client.
PS Naturally, I would like to have some "interest" when delegating tasks, in addition to my own payment.
PPS key point - projects are NOT fixed price.
PPPS had an idea to dig in the direction of organizing their own team, but so far I don’t quite understand how it works.

Answer 1

You can always score time with pens.

Answer 2

Hire a new person to the team (the client on odesk sends him a job offer) and be his team lead. Explain to the customer that an assistant is needed. His rate, of course, should be lower than yours.
This situation also arises for me, but it’s not easy to find a suitable assistant in my field, plus controlling his work is also not an easy task. Therefore, we have to refuse new projects and rather bring the matter to an end on the simplest project.