GSXR and Katana 750 engine????

[Swift1]

What is the difference? What makes the GSXR model different and more powerful? They look the exact same on the outside what's different in the inside? Thanks.

(BTW I'm talking about the 92 or so model of GSXR engines)

[WyredHardware]

coating on the cylinder walls, cams, not sure if the crank is though

[arsenic]

no crank is the same. It's all about the cams and the jetting. A 92 GSXR 750 is shim type valves a Katana 750 is tappet. The Katana 750 is 36mm carbs the GSXR is 38. So yeah, looking the same on the outside means absolutely nothing.

[Swift1]

I figured they where different inside but didn't know how exactly. Thanks.

Would you guys know about how much horse power each is pushing out and is it a big difference if you don't have numbers?

[arsenic]

yes it's a BIG difference, certainly in top end, above 8K the GSXR engine really comes to life. It's not so much a difference in power it's were the power is in the RPM band. The Katana is really torquey the GSXR is just reall balls to the wall fast.

[Swift1]

Long story short, I have a 2000 600 Kat with a Slingshot 750 motor. Bike has been out of comish for a couple of years and right now it seems so much easier to find a 750 Kat motor and drop that in there while I get the Gixxer motor running again. Any suggestions?

[arsenic]

pre 750, yes they are easy to find, Katana engines do not sell.

[Swift1]

BTW you're right about the power band around 8k :mrgreen: I remember it well Was one of my favorite parts of my then sleeper

[arsenic]

I know I'm right, nice of you to tell me though

[Swift1]

pre 750, yes they are easy to find, Katana engines do not sell.

Where do I look? Ebay?

[arsenic]

ebay, local paper, local motorcycle salvage shop. Try to find one local, shipping a 200+ lbs engine is a lot.

[Swift1]

I've looked on ebay a few times, but I guess I'll keep trying. Thanks.

[zspencer]

I picked up a Pre's 750 CC engine on craigslist for ~$300... No carbs though ...

Go to crazedlist.org every day, type in "katana" and click the surrounding area.

Eventually you'll find smething.

[The CyberPoet]

I thought 92 was one of the years they offered the GSXR750 specifically as a sling-shot motor. The sling-shot motors had a narrower bore and longer stroke, causing the engine to make a larger amount of torque earlier in their rev-range than their shallow over-square cousins.

If that is the case, the bore & stroke of the 92 GSXR 750 would be different than that of the Kat, and would explain the differences in the carbs as well (piston falling with a narrower bore over a longer stroke would change how the vacuum built at the carbs).

EDIT:
90-91 GSX-R 750 had bore/stroke of 70 x 48.7mm (as did the 89 GSX-R750R homologation special-edition)
while the Kat 750 of the time used 73.0 mm x 44.72 mm

Cheers,
=-= The CyberPoet

[arsenic]

so, by those measurements, The Katanta 750 has the same bore x stroke as an 88-89 GSXR 750. Which is correct according to Haynes.