Engine Swaps?

[Honclfibr]

I was poking around Ebay and noticed a ZX9R engine for sale on there, real cheap. Got me thinking because the damn thing looks so much like my ZX6R's motor...not that I would ever do something so crazy, but I know some of you have done engine swaps, what is it that makes a bike/engine pair a good candidate? I've heard mostly about the ZX7/9 swap, that it's basically a drop in. Any others like that? Are there problems with frame stress and adding all that extra torque to a cycle not designed with all that extra horsepower in mind?

Just curious...

[Stoneman]

Heh, heh...show me an engine that you can just 'drop in', and I'm swapping a few engines!

Especially with bikes, a just 'drop in' engine is a rarity when putting something other than what the bike came with in it. IE; shoe horning a 900 into a 750 frame, stuffing a 750 into a 600 frame, etc...

[TLRMan]

Originally posted by Stoneman
Heh, heh...show me an engine that you can just 'drop in', and I'm swapping a few engines!

Especially with bikes, a just 'drop in' engine is a rarity when putting something other than what the bike came with in it. IE; shoe horning a 900 into a 750 frame, stuffing a 750 into a 600 frame, etc...

How soon you forget....
Ask Rye what he's running in his 7r.....

[Zero]

It all depends on how the company designs their bikes. For example Suzuki's are known as a parts bin bike. Oil cooled GSXR's as well as Bandits and Katanas for that matter can swap motor's easily. Mount points and cylinder spacing are all the same. Water cooled GSXR's also swap very easily. My RF is getting an 1100w motor this winter. The TLS and TLR motors are interchangable. A small company like Suzuki tends to use the same cases for their motors to save costs. It is my understanding that a GSXR1000 is just a bored and stroked 750.
Depending on the swap weight may be an issue. I don't see torque as a huge concern because wheels, chains, and sprockets are usually the same. You may want to beef up the swingarm. To go from a 600 to a 900 would make for a totally different bike though because 600's are generally known for their ability to rev and turn quickly and the 900 may not have the same properties with a heavier crank and longer stroke. Most of my knowledge is in the Suzuki lineup though.

[Stoneman]

Originally posted by TLRMan
How soon you forget....
Ask Rye what he's running in his 7r.....

Ah, Old Grasshopper. How soon YOU forget. Ask Rye how long it took him to get it in there and all sorted out...

I've even done an engine for engine swap in my truck. 'Just pull out the old TREE-FIDDY and drop the new one in...'. Yeah, okay. Took me THREE fuggin' weeks! Again, that was for an even GM crate motor swap. NEVER 'just drops right in'. Always turns out to be quite the project...

[beet]

Originally posted by Stoneman
Ah, Old Grasshopper. How soon YOU forget. Ask Rye how long it took him to get it in there and all sorted out...

I've even done an engine for engine swap in my truck. 'Just pull out the old TREE-FIDDY and drop the new one in...'. Yeah, okay. Took me THREE fuggin' weeks! Again, that was for an even GM crate motor swap. NEVER 'just drops right in'. Always turns out to be quite the project...

[Rye]

Actually it only took an hour. As mentioned, the cases on the zx7 are identical in mounting points to the zx9 (except the 2 head mounts). Those required me to relocate the holes by 5mm or so. The zx9 motor is in essence like a stroked zx7. They run the exact same head though. Couple of minor things to take care of but the base frame is retained and not fucked with (good thing)By far, the BEST, most reliable way to bump hp by 20-25 #'s. You can talk boring, stroking, flowing, lightening and balancing but you will never do all that for the money you'd spend on a drop in motor of larger cc. It's safe HP. There are a number of bikes that you can do this with. A few are a Honda 900rr in a 600 (but I think it takes some fab work), the Gixxer 7/11 (run by Emgo/Valv Suzuki in FUSA a couple years ago....180 hp monster), tillers, and obviously the stunning ZX7/9.

BTW, for those 96+ zx7 owners that want a fairly cheap bump in hp (say up to 20)......run a 93-95 crank in your bike. Yes 793cc ZX8!!! Drop in mod that will give you roughly 15-20 hp tuned(I've seen 1). This will in effect stroke the motor! Nothing changes except the crank. The only complicated part is the cases need to be split and there are some tight tolerances down low that may require a trained eye, instead of a shadetree mechanic. But dropping a motor and sending to a Kawi builder like Zlock or Superbike Mike would be a good move. As for a crank......$35 off ebay.....see them all the time. My quess is about a $750 mod since it's basically all labor. But now you've got a ZX with power to compliment the stellar handling.

[Rye]

Oh yeah, and another thing to think of is wiring diagrams and CDI's. Alot of those bikes run similar if not identical wiring diagrams. ZX7 and 9 being absolutely identical with the exfception of a lower redline on the 9, which is why it is better to run the 9r cdi as I do.......or get a programmable ignition like a Powerpack which allows you to set rev limiter.