why not just bore out the cylinders?

[tonmarchelli]

if we want to get more displacement why not just bore the cylinder a little bit maybe up to say a 750 from a 600 or even higher. has this topic been covered before? it seems pretty simple. i have seen it done on cars a thousand times. why not bikes?

any input on this?

[paperairplane]

Start with a 750 - there are 771 kits available.

[tonmarchelli]

so in order to do that you need to start with a 750 motor, or you can go to 771 from 600. my kat is a 2000 600 if it helps.

[woobie]

I though the 600 Kat is a early GSX-R 750 engine that has had sleaves added to drop it to 600. So you can really bore it out because of the materials used in the sleaves in the first place.

Skip the 750 and get a oil cooled GSXR 1100 engine and drop it in . Special$k$ has/had one for sale.

[Mr. Clean]

The 98+ 600/750 cylinders have a ceramic like coating that can not be bored unless you get them deglazed and then reglazed after they have been bored. Very pricey, trust me I have researched it. Plus no one makes a piston kit for the 98+ bikes. Again I know what I'm talking about here.
Now what I did to build my late model 771 was to use a 2002 600 engine and swap the jugs with a set of 1992 GSXR 750 jugs, bore them 1mm over and use the Wiseco kit. I used a 1987 GSXR head because it is almost identical to a late model Katana 750 head(couldn't find a late model Kat 750 head). I reused my 600 cam sprockets and used cams out of a 1989 GSXR 750 because they had the most aggressive profile of the oil cooled engines.
The project took almost 2 years to finish.

[illinoiskat]

how did it tunr out?

[Mr. Clean]

It runs like a scalded Kat.

[BlackB12]

Boring it out also reduces the amount of heat-sinking metal there, so it will run hotter. As long as you don't go too far the engine will still cool adequately.

Mike

[paperairplane]

Am I crazy or is there also a 906cc kit out there.. if I remember right, it was pretty high compression and might not run on pump gas...

Where's Doug771?

[damic]

Am I crazy or is there also a 906cc kit out there.. if I remember right, it was pretty high compression and might not run on pump gas...

I don't know about a 906cc but wiseco does make an 815cc kit that works on a 88-89 Gix 750 with a 3mm overbore. These motors have a larger bore and smaller stroke than the other 750s. A trick thing I saw was to take the upper end of one of these motors and a bottom end one of the other 750s and end up with an 830cc. Then, if you added the 3mm overbore kit I mentioned earlier you would have that 900cc engine. The problem is you would have some excess machining to do too. The small end of the rods would have to be bored out from 18 to 20mm and a spacer plate would be needed for proper deck height. This would a fun project in itself but finding a gix 1100 or b12 motor and putting that in would be easier and cheaper in the long run.

[duff daddy]

why not buy a bandit 1200 motor, bore that out so its 1400cc's then stick a turbo on it, buil the bottom end so its like a rock, and i bet you could get a generous 230 hp out of it...

[Mr. Clean]

And where are you going to get a piston kit for that Duff?

[Dan Dubeau]

Out of a chevy big block

[tonmarchelli]

how bout putting a hemi in it. that would be cool

[SweetLou]

Well, Dodge made the bike with the Viper engine in it