The engine will come way sooner than 6 months. They scheduled it to be live in Q1 2018 so it will be there before May.It would take 6 months to make a new engine from scratch but it won't be the case.

Here comes a quote from Mong Suan's interview regarding the engine release:

"To be honest, building a new engine from scratch would take a long time, probably close to 6 months. But we can build with what we already have which will be much faster. We can work in stages and replace what we have step by step. We call that refactoring. By doing so we would be able to release improvements regularly. Our architecture right now is based on services, and we can easily replace them one by one. That is the best solution in my opinion."

You can see the entire interview here: https://medium.com/@raphaelblouet/interview-with-mong-suan-yee-engineering-director-at-coss-io-f03df1095228

Edit: formatting