fzs600 --> yzf600 engine swap??

[Krystek]

Simple question, would be difficult to swap engine from yzf to fzs ??
Any tips welcome
Thanks

[noggythenog]

Yes it would


Different engines

[kebab19]

Not an easy swap if at all. Engine mounting points probably in different places. Not sure if cylinder barrels / head are also canted further forward than the Fazer's.
And nowhere for the downdraft carbs to fit above the cylinder head either, unless you carry over T'cat airbox & petrol tank.
No Ramair either (unless you make your own front fairing) so no real power advantages to be gained. You might be able to fit everything in below the cylinder head, but with plenty of Fazer 600 engines available, it's a lot of hassle for minimum gains.

You'd be better attempting the 660cc 'big bore' using an early FZR600 crank that I might get round to next year if I can:
a) Track down a spare engine.
b) Be bothered... as another 6 - 8 ponies is not a huge gain for a lot of hassle

[Krystek]

Just asking, I was thinking that would be easy plug`n`play swap, but is not. My engine is 52.000 miles and is still good so if there is so much work, there is no point to change anything. Probably in future I will buy  fazer 1000 when I grow up to bigger/faster bike.

[jonest27]

But isnt the fzs a detuned thundercat engine? A Thundercat is still an R6 right? so couldnt you just put a Thundercat engine in thats fully tuned?
Or have I completely lost the plot?

[Paulfzs]

But isnt the fzs a detuned thundercat engine? A Thundercat is still an R6 right? so couldnt you just put a Thundercat engine in thats fully tuned?
Or have I completely lost the plot?

the fzs and thundercat share near identical internals, however the externals are quite different the intake for one is a different angle.


there is a nats wisker of room getting the fzs engine in and out so anything marginally larger would not fit.


you may get away with it if you change the cylinder head but then youre still in a world of trouble trying to make it all run right...


best idea: get a cat

[Krystek]

I was thinking the exact same thing that Fazer and Thundercat have the same engine, but differently tuned. As Suzuki gsx 600, 750 and 1,200, you can change them almost plug`n`play

[kebab19]

I prefer to think of a family tree.
If you check a few part numbers, the 'Grandfather' is the early FZR600, the 'father' is the 2nd Gen FZR600R engine and the FZS600 and Thundercat engines are it's two 'sons', sharing a lot of mechanical DNA but also having quite a few differences. The Fazer engine has the most recessive genes as the other three are from sporty designs with beam frames, downdraft carbs and air box hoses going to the front fairing. 

JonesT27: No, the R6 engine was a completely new engine compared to the above 'family tree', although it has itself gone on to spawn the FZ6 engine

[wraith600]

fzr & fazer same bore /stroke  been looking at this though wicesco used to do a big bore to 660 this is no longer available but a set of pistons from a 98/99 cbr600  is 65mm with the same pin of 17mm which gives 658cc might look closer over the winter if i can get the ash together