Well probably
a lot more than that but I dont want to discourage you it will depends on your background and how much of the course your already familiar with.
lets take a look : ct8 is split into 4 parts, heres the study guide on page 2 is a list of the chapters
http://www.acted.co.uk/Docs/2010/Study Guides/CT8 Study Guide 2010.pdf
so you'll probably love part 1 of the course and finish it easy with a smile on your face wondering what all this ct8 fuss is about
chapter 1 : efficient market hypothesis , look it up Wikipedia etc its pretty much the easiest question you can get on a ct8 paper , look at Aprils paper question10
http://www.actuaries.org.uk/__data/assets/pdf_file/0011/168491/FandI_CT8_201004_Exam_FINAL.pdf
a ten mark question woot , that is like 1/6 of a pass for an hours work.
chapter 2 : is new only added this year and there was no question on it in its first paper so I'd say a possibility for September also you can have a read of it right now cause its in the CMP upgrade pack starts on page 13
http://www.actuaries.org.uk/__data/assets/pdf_file/0011/168491/FandI_CT8_201004_Exam_FINAL.pdf
so thats a start the rest of part 1 of the course is very doable.
part 2 : stochastic calculus / models this is fairly tough alright and I'd never be able to say how long it will take to learn , there some easy questions on these chapter tho definition question etc. log - normal models you should have a look at.
part 3 : bit of ct1 knowledge required how did we price forwards and futures etc . Nice chapter called the Greeks then ,easy stuff ,another definition type question. Then very important chapter on the Binomial Model you can probably figure out how to do this quite quick too , have a look on google for some info , near guaranteed question.
part 4 : very tough in my opinion but for a more capable student than me part 4 could act to solidify what you've learned in part 2 and 3 . in principle the 5 step methods are incredibly simple arguments and it comes in nice step by step form which perhaps makes it easier to remember , however the notation and the abstract world that we are representing made it quite hard for me to learn .
OK to the point , hard course ,can be easy to pick up a lot of marks but getting those final marks to get you over the line , who knows how long that would take .
The papers can vary wildly too , if I looked over the past 10 papers I'd maybe pass 4 but would fail the other 6 .
To answer your original question : 298.25 hrs ish
