Concept

[saygra]

I have built cars and motors for a long time, and have always loved KATS so when I made the switch, to building bikes the choice was a no brainer. I have posted a time or two about my concepts, and with the help of you guys, I have gotten some good tips. With that being said, here is my plan, and I would love any feedback. I am going with a combination of my original plan and your suggestions.
(Remember, this is my concept. I have the motors but have not tried fitting all the parts together, I am still finishing my frame work, so if you see any red flags, lets talk about them)
GSX 600F crank and and rods (46.7mm stroke)
GSF 1200 pistons and heads (79.0mm bore)
*will shave the head and install a big bore kit*
(BIGGER BORE/SMALLER STROKE, in this case huge compression ratio)
GSX 750F cams
GSF 1200 valves
GSF 1200 carbs
head ported and polished
MSD MC-3 Ignition/MSD Coils/MSD 8.5mm wires
D&D full exhaust w/custom mods to fit Turbo
NOS system (wet)

I have not measured anything yet, but I'm shure you will tell me what may work and what will not due to your trial and error, but I look forward to building a big HP "sleeping Kat"

Thanks

[WildKat]

Definately another FrankenKat in the works !! Sounds like you'll have your hands full with a great project !

[Pyro Lizard]

if you're turbo-charging the engine, why are you raising the compression?

[saygra]

Why not run the turbo, thats like asking a Top Fuel dragster, with all that compression, why run a supercharger, the reason, so he can make 6000 HP. HP any way I can get it, and the forced induction may end up being needed to help the Mikunis get the air/fuel into the motor that it will demand. I'm not certain the carbs will be enough, that will be a big problem when I tell my wife I'm going to lay down a few grand on some racing carbs or a fuel injection set-up. My goal is and has always been, to build a KAT with the most HP I can produce, and still keep the rideability. My love for these bikes and the ego of guys that laid down 14k on a bike because "it's whats cool", I live for the day that my wimpy, toy of a Katana shows them what my new clear alternatives LED tail light looks like at during a triple digit A$$ spank'in.

[SlipKid]

An 1127 GSXR engine might be a better place to start. You'll already have a good base to start from in a more rubust package.

[Mojoe]

An 1127 GSXR engine might be a better place to start. You'll already have a good base to start from in a more rubust package.

I agree. it will actually be cheaper as well, won't it? I think it would over having to fit all the parts together like you have planned.
I have no real experience in rebuilding bike engines aside from the research I have been doing with my 1100 V&H race engine (200hp), but I think you might run into a problem with the 600 crank and rods when paired up with the 1200 pistons and cylinders. before buying that one, I looked into a big bore kit. You can only go so large on the bore of an 1100 before it is required that you bore the crankcase as well....and an 1100 or 1200 has a bigger crankcase bore than a 600. I could be wrong about this, but let me know how it goes.

as for carbs, you can get a new set of FBG's (fast by gast) for about a grand.....or a good set of Keihin's or Mikunis used for about $500. You are going to want at least 40mm.

[SlipKid]

You can do a blow-through turbo design and get a single S&S Harley carb for it. Hey, I've seen it...:P

[Pyro Lizard]

yeah, higher compression yields more hp, but raising the compression, and turbo charging the motor seems a little redundant. Now, i'm just talking out of my ass here, because i have NO experience turbo charging motorcycle engines, but it would seem to me that you'd make more hp by lowering the compression, and raising the turbo boost.

if your engine can handle 12.5:1 compression, and 1bar of boost, it should handle 11:1 compression, and 1.5bar of boost, or something like that, right?

[saygra]

An 1127 GSXR engine might be a better place to start. You'll already have a good base to start from in a more rubust package.

I don't know a whole lot (bore/stroke/compression ratio/valve train) about the 1127 GSXR motor, so I can't really comment on why I would or would not use that power plant. I do have several reasons for my choice without going into all kinds of detail (I will if you want) and I already have some big cash invested in 3 motors (GSX 600 and 750F and a GSF 1200) and the internals plus MSD Ignition/Turbos/Pipes/NOS, the list is endless.

It's not about money, if I wanted to take the easy road and just haul A$$, I would go buy a new GSXR 1300 crate motor and stuff it into my KAT. It is about taking a KAT motor, that doesn't get any respect, and show people that it can produce some serious HP. Nobody that rides wants to ever say "yeah I got smoked by a 2001 Katana 600"

[saygra]

yeah, higher compression yields more hp, but raising the compression, and turbo charging the motor seems a little redundant. Now, i'm just talking out of my ass here, because i have NO experience turbo charging motorcycle engines, but it would seem to me that you'd make more hp by lowering the compression, and raising the turbo boost.

if your engine can handle 12.5:1 compression, and 1bar of boost, it should handle 11:1 compression, and 1.5bar of boost, or something like that, right?

Not redundant at all. The boost generated from the turbo and forced into the carbs only helps in the combustion process by force feeding this high compression monster. The compression ratio has no direct bearing on the boost generated, and the engine is only going to swallow the boost it can handle, or wants, thus the waste gate in a turbo set-up.

I really want to say I enjoy these threads and think this is what boards like this are for, exchanging ideas, theory, and help. Thanks for your contributions.

[SlipKid]

Hey, the 1127 GSXR engine is a Kat engine. On the Kat1100's it was anyway... The Kat engine (of all varieties) is based off of the original GSXR750 unit. Anyway, I'd say if you already have a Bandit engine, drop some 1127 cams in there and bolt it into your Kat! Special K did it (minus the cams I think).

[toobalicious]

saygra

i think what pyro is getting at is the impracticality of what you are proposing... it is not likely to run very well on pump gas, for example... it is also probably going to be very prone to overheating... is this a dragbike or a streetbike? dragsters arent very streetable, and typically arent very reliable either... aside from that, the average stock engine componets (like wristpins from a 600), with its forced induction paired with high compression *and* nitrous, arent likely to live for a long time...
take no offense... this *is* a discussion forum 8)
a

[Pyro Lizard]

saygra

i think what pyro is getting at is the impracticality of what you are proposing... it is not likely to run very well on pump gas, for example... it is also probably going to be very prone to overheating... is this a dragbike or a streetbike? dragsters arent very streetable, and typically arent very reliable either... aside from that, the average stock engine componets (like wristpins from a 600), with its forced induction paired with high compression *and* nitrous, arent likely to live for a long time...
take no offense... this *is* a discussion forum 8)
a

haha, yeah what he said!

i'm just b.s.'ing with ya here, by the way. but, anyway, you said you wanted to make a kat as streetable as possible. i don't think you would be anywhere close to streetable with the pressurization you're talking about. it would be better to keep the compression low, and rely on your turbo to give you the power. if it's running too hot, lower the boost. if you want to race someone, throw in some race fuel, and up the boost.

anyway, whatever you decide to do, i'm sure you'll haul some major a$$!