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fighter transplant in NC
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14,319 Posts
Discussion Starter · #1 ·
I have what I think is an old kat 600 motor. I think it is from an 88-93 gsx600f. it has a bore of 62.6 mm.

it is in pieces. I would like to rebuild it for my poor gpz550 that is in my shed. it will be used as a drag bike.

a while ago I bought a spare jug and a set of srad pistons. the srad pistons are for a 72mm bore. with a stroke of 48.7 mm, that would get me a displacement of 793.

I've never rebuilt an engine before. none the less one that isn't going to be stock.

I don't want to do anything too crazy. I know I'll need to re-sleeve the jugs, and possibly make a set of custom con rods. honestly, that scares me less than rebuilding the engine.

if I'm going to be tearing this thing down to bare nuts and bolts, what else should I look at? should I get a head from a different oil boiler and not even mess with the 600 head?

what about cams? is there a stock cam that I should be looking for?

is this going to be a money pit? is this whole idea idiotic? lol. if its looking like its going to be too costly, I might just have to pick up a bandit 1200 motor and go from there.
 

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ShamanFighter
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22,340 Posts
first things first good luck finding a b12 motor.

second things first talk to bill aka mustapha dump... i wish old skool suzuki archived their shit before taking a dump because they had shit on lock... i would honestly try for a b12 if i were you because id rather build a loose motor than a tight one. what i mean is if you Over bore that much you will run into motor problems...then again you said drag bike so i hope you plan on rebuilding often anyways...the clutch atleast.

i cant for the life of me remember if the 750 jugs and head will go on the 600... it would involve machining the cases to fit the bigger in width jugs. not too sure if its all the same.

basically what i would do is find a b12 bottom end. get a ******** gsxr head (or kat750 head with the dot) and put GSXR750 cams from 88-89 one of the kat 750 cams is the same. and get 1999 hayabusa pistons...

basically bill wrote it up how to do a 1216 kit without taking alot of meat away from your jugs. its in my thread on b12 hop up stuffs. you dont want paper thin jugs unless you plan on rebuilding frequently.
 

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fighter transplant in NC
Joined
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14,319 Posts
Discussion Starter · #3 ·
first things first good luck finding a b12 motor.

second things first talk to bill aka mustapha dump... i wish old skool suzuki archived their shit before taking a dump because they had shit on lock... i would honestly try for a b12 if i were you because id rather build a loose motor than a tight one. what i mean is if you Over bore that much you will run into motor problems...then again you said drag bike so i hope you plan on rebuilding often anyways...the clutch atleast.

i cant for the life of me remember if the 750 jugs and head will go on the 600... it would involve machining the cases to fit the bigger in width jugs. not too sure if its all the same.

basically what i would do is find a b12 bottom end. get a ******** gsxr head (or kat750 head with the dot) and put GSXR750 cams from 88-89 one of the kat 750 cams is the same. and get 1999 hayabusa pistons...

basically bill wrote it up how to do a 1216 kit without taking alot of meat away from your jugs. its in my thread on b12 hop up stuffs. you dont want paper thin jugs unless you plan on rebuilding frequently.
b12 motors are out there. just looking at $800+. other problem is that they are too tall for my frame. the 600 motor only has about 1/4" of clearance. the 1200 would require surgery to the tank and frame.

I think the jugs have plenty of room to resleeve, and if they don't I am 90% sure that I can use jugs from certain years of 750s

this is a quote from katriders
OK easiest way to get more power out of a Kat 600 is to take the 600 top end off and swap in a 750 top end. I'm not kidding, that is what I did. I took a 2002 600 and put a 86 GSXR 750 head, 92 GSXR 750 jugs, and a 1mm Wiseco overbore kit for a 92 GSXR for a total of 771cc and about 12.5:1 compression ratio.

Try to avoid 98+ katana 750 jugs. They *can* be overbored but you have to go through the whole deglazeing/boreing/reglaseing the cylinders and then getting the expensive rings from wiseco (or JE) for your pistons. A 98+ 750 head is great though! You can even bolt your 600 head up to a set of 750 jugs, it will be a PITA to tun the carbs and your compression ratio might be off the chart but it will work.

But before you go nuts buying old 750 top ends make sure you get your years right! The 88/89 GSXR 750 and the 88-97 Kat 750 were the "sling shot" 750s. Those are the big bore-short stroke 750s. You can actually use them to make some monster 813,816, and 900cc engines but you are going to need to do A LOT of research first!

Goodluck!
this statement has problems though. I thought the 92 gsxr was water cooled? oi, this is all so confusing

I'm not planning on running a full season or even being competitive on the track. I just miss being in some sort of competition. I'll go do some runwhatyabrung nights at MIR. I don't want to have to rebuild the motor constantly. I don't mind the clutch.
 
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