Engine Swap

[kevingkruse]

So this guy is parting out his 1993 suzuki gsxr 600 and I'm seriously thinking about snaggin the engine, carbs, exhaust and electricals from it and fabricating them into my 400 frame. I wanted to ask if you guys think the 400 frame can handle it if I sturdy it up in some way? Should I look at getting the monoshock swingarm from the gsxr and swap it, or could it be stable enough with the 400 shocks and front end? What do you guys think?

EDIT: ha, I guess this has already been talked about before http://www.xs400.com/forum/showthread.php?t=8989 . In that post he mentioned cast wheels might work, I have spoked wheels though, would that be too weak? I am really getting excited to do this, so if anyone has any serious doubts that might throw me off this idea, please let me know.

 

[drewpy]

the engine will be a lot heavier so you need to uprate the forks and rear shocks.

I would also ensure the bushes are spot on for the swing arm pivot and think about bracing that too.

 

[Scorpio1963]

You would probaly have to use the entire electrical system from this bike also.I dont beleive the electrical system on a Xs400 would work since its not designed for the engine you want to swap with.

 

[kevingkruse]

I would use all the electrical components from the gsxr. I would really like to keep most of the frame and shocks and cafe it out really nice to keep a vintage look but with some kick. I think I might get the front end of the gsxr. Would it be ok if I got new gas shocks for the back with original swingarm? Also would the 400 spoked rims get totalled with the extra weight?

 

[Scorpio1963]

Alot of the older jap bikes with larger engines had spoked wheels so I would say yes your wheels would probaly be ok but Im not 100% sure as I never done what you plan on doing.It does seem like it would be a cool project.

 

[kevingkruse]

Oh it will be fun. I've never done any frame fabricating but I think I can figure it out. And drewpy, what do you mean by the bushes and the swingarm?

 

[Scorpio1963]

One thing Im glad to hear is that if you make bobber or cafe racer is it will be one with the proper balls.Just mop but when I see people chopping on xs400s to make racing bike its like using an engine with toddlers nuts cause it doesnt have enough balls to go fast enough.

Anyways nevermind my personal feelings Im sure you thought about using the gsxr 600 exaust.Also someone on my local Craigslist has 97 gxsr engine and frame 4sale.

 

[drewpy]

Oh it will be fun. I've never done any frame fabricating but I think I can figure it out. And drewpy, what do you mean by the bushes and the swingarm?

you will need to upgrade those standard plastic ones to bronze (oiltight) or needle rollers.

check the thickness of the spokes as there are different spoke gauges.
I would go with double butted spokes for the rear at least.

 

[kevingkruse]

@1982400xs - so are u saying it wouldn't have balls or it would, cas I think it should mob pretty nicely.

 

[xschris]

I don't think a 4 bolt sprocket or hub will take that much power. They put out between 80-100+hp also 4cyls would be too wide for the frame.

 

[Scorpio1963]

What Im saying is a cafe racer using the 400 engine doesnt have enough balls as a racer.Unless you dump a bunch of $ and make some serious engine mods your talking about a bike that will do 90mph.Now if I was to make a cafe racer I would use a bike that has enough horses to go 150mph.Thats a racer.

 

[xschris]

Get a gsxr 600-750 then it will work much better than a xs400

 

[Scorpio1963]

SXChris thats ironic cause on my local cl someone is sell 94 OR 97 GXSR parts bike.

 

[kevingkruse]

Well I plan on doing a good amount of fabbing to the frame. Would it be possible to drill and tap 4 more holes to make the sprocket stronger?

 

[16VGTIDave]

What about the brakes????? It is great that you want to put in a larger engine, that is heavier, and go faster. But will you be able to stop?

Projects like this get expensive quickly, even when being done "half-assed". Done right, they require cubic $.

 

[kevingkruse]

2 drum brakes should be good enough, lol. But ya, I was thinking about that, I'm thinking about just getting the front end, swing arm, and wheels from the gsxr, but it won't have as much of a classic look. It would still look a lot classier than the bulky newer frames though. I've been thinking about just buying a newer sport bike but what's the fun in that? I want something one of a kind.

 

[Liamthedevastator]

Definitely going to want discs (there is a reason they are dual discs on the front) for the bike as higher speed means more force required to calm'er down

XS400 is 400lbs wet which is fairly similar to GSXR 600 so I don't think you have to go apeshit on stiffening it up/upgrading the suspension. I think the only thing you need to be cautious of is extra speed + extra inertia + a slight increase in weight.

I started riding on an '09 ninja 250, then moved up to an '04 gsxr-600 recently. I was talking to a friend a little after the transaction and we got talking about weight, found out that my 600 weighed less than my ninja... i was confused..... and stoked....but mostly confused haha

 

[kevingkruse]

I would like to keep the swing arm and forks but they don't have the mounts for disk brakes, I wouldn't feel comfortable welding on my forks and I doubt they'll fit the gsxr wheels

 

[Scorpio1963]

I dont know alot about fabbing motorcycle frames especialy for the conversion you have in mind.Question I have is doesnt the Gxsr use a wider back tire and swing arm?Just my thought but I would also use the swingarm and wider tire from the other bike also.If Im not mistaken most bobbers or cafes use a wider and larger tire.Somebody can correct me on this.Im trying to visualise differences between the 2 bikes.You basicaly have one bike thats built for speed and the other that is a comuter bike.Since you want to combine the 2 into another I can see using the basic xs400 frame with a different swing arm from the other bike and racing style handlebars with larger engine.Intriguing project that take alot of time,probaly very expensive but worth the effort is your idea turns into a reality.

 

[bcware]

The gixxer engine would probably make too much power for our tiny rear tire; it would make one hell of a smoke show though.

found out that my 600 weighed less than my ninja... i was confused..... and stoked....but mostly confused haha

I experienced the same thing when I bought my gixxer 750; it weighed about the same as my ninja 250. The 750 feels a lot heavier even though it isn't. I think this has more to do with a higher seat height and much wider profile.