LED Turn indicator for Motorbike

Hi Everyone,
I'm new to this forum and joined to get some help from all the geniuses here.
I'm making  LED turn indicator for my 100cc bike. My present Factory installed flasher rating is 12v 10W X 2bulb. I want to add total of 48 ORANGE LED, 24 in front indcator and 24 in rear indicator. The current drawn would be much less for the flasher to work as the LED would not flash. I want to make 4 parallel set of 6 LED in series. as the total volt would be 2.2v*6 led =13.2.

I've achieved the above so far but how to make them blink?
Flash would be better then blink !!

So can anyone suggest me a simple circuit which I can put in place of factory installed flasher and work the same way.
I've 12v 7.2Ah Battery on board.
and one thing more If I hook up a 55w/55w headlamp directly to the above battery how long will it last.
I'll be grateful for the pain you take for me...

Thank You
Gurdeep