Bigger engine - buy or bore?

[Commodus]

The GS1150 is a gooder engine. If you're spending that much money and don't care about the classic looks of the old two-valve engine, buy an 1150 motor. You're rebuilding it anyways, so you're ending up with a new engine regardless - so it doesn't matter what the condition of the engine is (to an extent).

[80GS1000]

Diggin' on this GS(XR)1000 with an early oilcooled GSXR 1100 motor installed. Bet the thing accelerates like a beast, has the handling to match, and love the classic GS styling.

[Commodus]

Yes, lighter and better ground clearance too. If you're willing to forego a GS series engine, the GSXR1100 is definitely the right choice.

[80GS1000]

Seems to be for sure.

The early (86-92) oil boiler GSXR 1100 motors are 128-145 HP stock. They look like a late model GS engine. Performance pipes are available. Would be cheaper and easier to buy a complete, reliable Gixxer 1100 engine than build up the stock GS motor. Even with the GS engine hopped up, it'd still make less HP than the Gixxer motor and be more prone to breaking down from the extra stress. My GS engine leaks oil pretty bad, so it's either rebuild or get another engine. From a performance and reliability perspective, the Gixxer motor seems to be the way to go.

[Big T]

Thanks for all the tips and advice guys - much appreciated.

Let's go down the engine swap road for a minute.

I have a line on a 1980 GS1100E parts bike for cheap ($150). It's complete, minus the headlight, carbs, and airbox. The guy says it makes 120 psi dry, 140 wet on a compression test. The motor appears to be leaking some oil, but so does my GS1000 motor. It's unknown how long it's been since it ran. What kind of questions should I be asking from the seller?

Who knows, maybe the 1100 will turn into a restoration project.

The GS1000 is my first project bike and first effort at motorcycle mechanics - it's been a lot of fun and very educational so far but I've barely scratched the surface. You guys are the gurus. :-D

Here's some pics of the parts bike and engine:

Okay, remove everything not necessary to have it function, get one of those racy seats off Ebay, rebuild that motor, and make it a track only bike, You'd have the best of both worlds.

[NoBars]

That R motor 1000s is what I am talking 'bout. It looks right and makes good power. Notice how the motor is pushed to the front, leaving the gap in the back to weight the front tire (R engine is a couple inches shorter).
Even the oil coller looks good.

[NoBars]

I'd score that 1100 and part it, good deal

[80GS1000]

That R motor 1000s is what I am talking 'bout. It looks right and makes good power. Notice how the motor is pushed to the front, leaving the gap in the back to weight the front tire (R engine is a couple inches shorter).
Even the oil coller looks good.

Agreed on the looks of the motor matching and complementing the bike. Is weighting the front tire a good thing?

[Dink]

Weighting up the front end gives a more secure feeling and allows higher corner speeds, notice that sports bikes are all hunched up over the front?

Dink