GS550 with GSX-R Engine

[Guest]

I know, this will probably sound bad to many here.
But I was wondering if it is possible to fit a GSX-R600 engine or something with less power on the 1978 GS550 frame. I know it would cost way more than just rebuilding the 550's engine or even a 550/650 hybrid.

This is crazy, I do acknowledge that. lol
Would the frame be able to contain that beast ?
But what do you guys have to say about this ?

[steve murdoch]

With new mounting brackets, possible frame modifications and some ingenuity you could probably shoehorn the motor in place.
But i would think the GSX engine would have approximately double the horsepower of the GS and if the frame wasn't overwhelmed, the suspension and wheels would be.
I would certainly follow along if you give it a whirl.

[Hybridan]

Alright, sounds like a challenge.
This will pretty much take me some time to gather the engine and parts needed for that.
Thanks for the post.

[Buffalo Bill]

Seems like you're gonna want and need so much from a donor GSX-R, GSX-F, or Bandit 600, like swing arm, front fork complete, cooling system, headers, front & back wheels.
What's gonna be left of the GS? Just the frame I think.

[tkent02]

A quick search shows the older GSXR 600s at 80-100 horsepower depending on the year model, as compared with the 550's 49hp, or maybe 65-70 or so hp with the 650 top end. Probably not too overwhelming if proper frame bracing, wheels, suspension and brakes are used. Don't know what the 550's frame would do at the speeds allowed by that much power. Is your idea to get top speed like a GSXR or just amazing acceleration up to the speeds a 550 was designed for? The 550 feels pretty twitchy at it's highest speeds with the 550 engine, not sure I'd want to go a whole lot faster than that on it. If you want the higher top speed I think the frame geometry would need to be altered for more stability. Don't know what that would take, different rake and a whole lot of extra bracing? Dunno. If you want to gear it for lightning acceleration to a top speed that the 550 frame can handle that would probably be a lot easier.

Not sure if it will fit in the frame without major surgery, don't know how much lighter the GSXR engine is, it's probably narrower and shorter, but I bet it's quite a bit taller?

If you do it keep us posted, sounds interesting to say the least.

[tkent02]

Seems like you're gonna want and need so much from a donor GSX-R, GSX-F, or Bandit 600, like swing arm, front fork complete, cooling system, headers, front & back wheels.
What's gonna be left of the GS? Just the frame I think.

I think I'd just put a 550's seat and gas tank on a Bandit 600 and call it good.

[Hybridan]

Seems like you're gonna want and need so much from a donor GSX-R, GSX-F, or Bandit 600, like swing arm, front fork complete, cooling system, headers, front & back wheels.
What's gonna be left of the GS? Just the frame I think.

True. That could be very unprofitable

[Hybridan]

Yeah, I think this sounds like a better option. I wanted the power of newer engines compared to older ones like the one in the 550.
Also the advantages of EFI if I could find a "could-be-compatible" engine with all the other advantages that comes with it.
The frame would probably need a lot of work since GSXR engines are taller without forgetting the cooling system too.
I guess it would be easier getting a more recent bike then give it the old/classic look with tank swaps etc..
I'll be thinking on these options.

[Buffalo Bill]

If you already have a GS550, one cool option is a bigger GS or GSX engine. Like a GS750 8 valve or 16 valve.
You can keep the look, and such a similar engine would mount easier.
Another challenging option is swapping the pistons, cylinders, head and carbs with a GS650 for an extra 25 HP.
If you aint got a 550 yet the GS650 has as much power as the 750.
A GSX750 is a sleeved down GSX1100, so that's almost a direct bolt in swap.

[akckhim]

An oilcooled 600 bandit engine would be great way to go. Or even a 750 katana

[Ace07]

Hey guys, I have a 1981 GS550T that I bought a few of years ago. I have taken this bike on a nice 2000 mile cruise to the gulf beach and back, and used it as a daily driver ever since I got it. Now I would like to upgrade the bike a little bit, new paint, tires, lights and motor. I was thinking about going with the with a GSX 600 katana motor any where from 1998-1999, then I found this forum and got lost in the information a little bit. So will a GSX 600 Katana motor work in my bike? If so, how much frame work will I have to do to it? This bike has alot of sentimental value to me and I would like to make it a nice bike again, so I am not that worried about sinking a little money into it. I like all the information I have gotten so far, but if you guys could help straighten this out for me that would be great.

thanks

[Hayabuser]

A Bandit 1200 engine would be the same amount of work to mount as the Katana 600 mill.... just putting that out there.

[Buffalo Bill]

For a lot of people it's all about the challenge and building of the project, not about making sense in today's world.
Make it happen.
Just Sayin!

[Ace07]

Yeah I am up for a challenge. ha ha It would be awesome to have that 1200 engine inside the 550, but I am afraid the frame and other parts wont be able to take that much power.

[Buffalo Bill]

Yeah, I would not put that much power into a 550 frame, but the Katana 600 or GS750 only make 70- 75 HP, and that will be plenty. 75 HP is 50% more than 50HP.