620 motor swap for S2R800 - is it possible?

[davsheldon]

I'm trying to figure out the logistics of a motor swap for my 02 620. The frame is the same for the S2r and im assuming that this swap can be done without any modification. Would I need to swap the ECU as well? Anything else needed? Amazing the avenues 1 tooth off on a timing belt change will take you down... Any advice on the situation is appreciated!
-Dave

[davsheldon]

Bump. So the wiring harness and ECU would be included in the deal. I've looked around quite a bit and it seems like its doable. Motor should fit in the frame. I have looked into the ignition/red key/ecu immobilizer issue and I dont think that will be a prob. It seems like there might be an incompatibility issue with my old fuel pump... but I'll look into it more. I'd love some advice from anyone who has transplanted a motor like this. I find it hard to believe no one else has looked into this, I'm just having trouble finding any posts!
-Dave

[MingThe Merciless]

Judging from the dearth of response to your question, seems no one
has any experience with this swap. And frankly, I'd be surprised if
anyone did. This is the arcane stuff that only guys working in a
cycle salvage yard would attempt, as they try to make a hatchet job
from two totalled bikes. I can't image why anyone else would attempt
such a hybrid. It's always been my experience that these swaps are
always a nightmare, despite how simple everything looks before you
start. A real charcter building exercise. Let us know how it comes out.

[brad black]

the engines are externally identical, they're just variations of the same thing. it'll bolt straight in. your original 620 headers, mufflers, inlet manifolds, throttle bodies, etc, are the same as the 800, so you only need the engine itself and the oil cooler (if you want to run it).

you could run a pc3 over the 620 ecu, the only issue there might be spark map variations - it might not matter. cheapest option anyway and worth a try i'd think.

or get an 800 ecu - they did make 800m dp ecu, but no one bought them. your importer might be able to get one cheap from ducati if they still have any. remember you can't use a second hand original fitment - it's coded to the immobilisor. you need a new original ecu or a dp ecu or the ultimap u59.

you could also fit an injected 900 motor, but there can be engine bolt diameter differences - '01 onward had bigger bolts, plus you may need specific '02 900 headers as they are longer than 620/800 (i'd try forcing the 620 ones first) and 900 inlet manifolds. plus the ecu thing. the 800 goes very nearly as well as the 900 anyway, but if want to go further engine output wise i'd be starting with a 900 personally. the gearbox and clutch are stronger.

but the s2r motor with the APTC clutch has an amazingly light clutch lever.