600 Engine in a NC23

[hannakournikova]

CBR600 engine fits into the NC29 without a problem

nope! nc29 is too thin. all the examples are in nc23 frames.

there are also probs with airbox and downpipe clearance...

but please prove me wrong, would save me having to buy a 600rr lol

[drew70]

290249279419

Nc29 on ebay with 600 engine

Nice feedback

[Cammo]

There's an nc29 in Aus with a 919 fireblade lump in, what a handful!

It required extensive frame surgery and more.

[garyboy_palaboy]

There's an nc29 in Aus with a 919 fireblade lump in, what a handful!

It required extensive frame surgery and more.

wow!!!! i hope someone can post a picture of that monster bike, hehehe!


.

[drew70]

Pics of project cbr64
Cut the frame to fit engine before it goes off to be welded and braced.
I will keep updating as it progresses .
There were other options for where to cut the frame bit i took the easiest option.

[Aido_400RR]

Squirrel_hunter: your friend is correct, that is indeed a 600cc engine in that bike. A few of the tell tales signs if you look closely are the cut & weld marks along the frame spar which need to be cut off and rewelded back a bit to line up properly with the 600's engine mounts, whoever welded it did a decent job looking at the pics.

Secondly when you put a 600 into an NC23 the airbox always presents a bit of a problem..its taller then the NC23 airbox which means that the fuel tank sits up higher off the frame then usual which you can also see if you look close at the pics.

And finally..he has left the bellypans off the bike not just to show us the engine in the bike..but because they wont fit onto the bike anymore without significant modding to make them fit.

One gripe i always have with people that do this mod is that they never do it cleanly!.. i mean is it too much effort to clean the engine block and cases before fitting the engine after going to all the work of making the frame welds all nice and factory looking..Arrrgh!

[squirrel_hunter]

Drew70, many thanks for the pics. The cutting of the frame is what bothers me the most but at least I can now see where I would have to do it. Again pic's once it comes back from the welder please!

But I still can't see any welds on the frame of the original posted bike. So I'm still not 100% convinced that frame surgery is the only option. Drew did you have a go at lining the engine up with the frame unmolested, if so what did you find were the problems and could there be other ways around this?

I know I'm asking the same questions again, but I really don't want to cut the frame. Not least because I doubt I would be able to weld the frame myself (though I did just by an Arc Welder, but thats another story).

I have seen the odd CBR600FL on eBay and I have been tempted to buy one and have a go with the engines myself. However at the moment I simply don't have the room and can't find one in a running condition for the right money to make the inconvenience of space worth it. But I will keep looking.

As a final point as Adio_400RR brings up fairings not fitting is a consideration, but I am willing to forgo this as I have my own plans for that... And yes if I would do it then I would tidy the engine up before final fitment unlike the original bikes engine.

[drew70]

The bike you seen on ebay had the front legs cut along the frame spar,It makes it a neater job but a lot more work. As ive said before i went for the easy option. Mine is going to be a track thrash tool so im not being too anal about it looking as honda intended. I will be fitting cbr600rr bodywork the same as my 400 racebike which will sort out the width problem.
Back to the frame there is no way the front legs will fit over the engine unless you buff/grind a lot of material from the inside of the front legs, but even if you do this it will only be the crank case bolts that will line up, the cyl head bolts are out a fair bit. Unless you dont want to use them .
So in theory if you grind a lot off the frame and only use the front bottom crankcase fixings( and both rear also ) there is no need to cut and weld the frame .

[squirrel_hunter]

Cheers for that Drew, it all becomes clearer. I might look around and see if there are any other options for a larger engine before making a final decision, but do keep us updated on your build.

But staying on that subject... Along with the 600 engine I take it that you would require the carbs, airbox and exhaust (although I would wonder if the 400 would fit still)? The wiring loom, CDI, reg/rec would also be required as I understand it, but how does this fit in with the fuel pump and switch gear etc? Admittedly your building for the track so lights and signals won't be as big an issue for you, but I'd still be interested in your thoughts.

[zimm]

from my experience with a 600 engined zxr400, i think its easier to think of it as re-framing a 600, than changing the engine in a 400, as by the time you've fitted

engine
exhaust
loom
carbs
airbox
fuel pump
clocks

and uprated

forks
brakes
rear shock

and changed/hacked about the bodywork

and fitted some trick bits. because, well you might aswell..

there's not an awful lot of the original 400 left.