996 Engine Into 748

If you are using your 748 throttle bodies the bore of those is smaller. They used to mod twin injectors to run on one. You will need someone like CJS to set the fuelling up for single injector and get a machinist to bore the bodies

 

I put a 748R engine in a 748S frame, which means using stock 748 air box, injector stubs, a different coolant hose etc. and 748 injectors, which are smaller than 748R ones.

You can use the stock 748 Injectors but to get it to run properly you will need a custom chip in the ECU to get it to run and fuel correctly.

As suggested CJS is one place you could look at to do this. I did use Chris and my bike is perfect and just a half BHP down on a full 748R setup.

You could also use 916 injectors which are bigger and do not have twin injectors or, again, as suggested, you could get the throttles bored out. Personally I would go with stock injectors and save some cash as the likely performance increase would not be that great.

Any other tuning like bigger exhausts should be done prior to the setup otherwise you would be in potentially for another remapping session.

If you wanted to modify the frame to 748R\998 spec. then another option is to use 748R injectors and airbox, some racers of 996's have done this and it is a straightforward conversion, the real problem being the frame which will need modifying or the use of a 748R\998 or ther others mentioned below.

Note the difference in the size of the mounting bolts. In my case I machined bushes which I inserted into the 748R engine to reduce the spindle diameter to match my frame. The other option is to drill the frame

Frame details here.

"All the same until the Foggy rep SPS in 1998, 748R 2000, 996RS 2001 and 2002 998 which all had a modified frame member for a larger airbox, called the "Kyalami" frame.

Then there was a change of tubing, 1998 SPS, 2001 748R, 2001 996R in cro moly.

From 2001 onwards they increased the engine mounting bolts up from 10mm to 12mm"

 

Personally I wouldn't go that route and would opt for a custom map, which would release the full power of the engine. After that then you should select a chip that would be suitable for the engine, or get as near as possible.

The FIM company used to do chips that converted the twin injector 996 setup to single injector, I would say this would be as close as you could\may get to it working on a smaller single injector setup. However this company is now defunct so any secondhand chips are likely to be at a premium.

Another option would be to try a 916 chip, this is meant for slightly bigger (single) injectors but may work.

Final option is to go for a Powercommander and put a map in from that. The drawback with a Powercommander is that it only has a very limited number of steps that you can alter to adjust the fuelling.

A custom map will\can give you fuelling for each individual cylinder and also a rev limit can be incorporated into the map. For me it is the only sensible option and you could find changing chips etc. may (or may not!) be hit and miss.

My final take is why change for a bigger engine and not make the most of it? but I appreciate cost issues as custom mapping is expensive, mine was about £400 but did take a whole day to sort out.

 

The 748R frame takes the larger engines, but the standard 748 frame means you are compromising. You "might" find it an expensive business and maybe cheaper getting a 996?

 

You would need the relevant loom as well, the notes below might help. These are from a US site that used to supply engines for such conversions.

Note the comments about an oil cooler, which is not on the 748 standard models and also about wiring looms.

The conversion is quite doable but you would need to cover all the items mentioned depending on what route you decide to take.

My 748S was purchased as a rolling chassis which was from a track bike, although it had a V5 etc. it originally had a 996 engine but that was run a single injector bike using the 748 loom.



"Ducati 748/916/996 Superbike are more similar than different, but there are differences besides just displacement. I have tried to list some of the differences below.

The throttle bodies on 748's and 916's are single injector while the 996 has dual injectors. Although the 748 and 916 both have the single injectors, the 748 has 45mm intake manifolds while the 916 shares 50mm intakes with the 996. The rear ECU wiring harness that connects the ECU to the injectors is also different. The 748 and 916 harnesses have connections from the ECU to the single injectors while the 996 wiring harness has dual injector connectors.

The ECU's of all 748 / 916 / 996 Superbikes from 1997 onwards use the same Magnetti Marelli 1.6M ECU. The 916's from 1996 and earlier and the SPS models have the P8 ECU and a P8 specific wiring harness. The 1.6M ECU does not have to be changed if converting between a 748, 916, or 996, however, the EPROM chip inside the ECU, is specific to the bike. Therefore a 916 or 996 EPROM chip for the 1.6M ECU would be required if converting from a 748.

748's don't come stock with oil coolers while 916's and 996's do. The radiator and the rest of the cooling system is the same though.

The years of both the recipient bike and donor engine also matter. The 748's and 916's from 1998 and earlier have 2 phase alternators / regulators and have 19 pin connector wiring harnesses. The 748's and 996's from 1999 onwards are 3 phase and have 22 pin connectors on the wiring harness.
So if you are installing a 996 engine into an early 748 you will need the 3 phase set up and wiring harnesses.

In 2001 Ducati changed the timing sensors and clutch slave cylinders. Also in 2001 the frame / motor mount bolts changed from 10mm to 12mm on both the 748's and 996's. So if you are installing a 2001 motor into a 2000 or earlier frame you will need to either use the 10mm bolts with sleeves through the crankcases or use the 12mmm bolts and bore out the frame mounts 2mm. If you are installing a 2000 or earlier motor into a 2001 frame you will need sleeves in the frame. I would not recommend boring out the crankcases 2mm.

So what does this all mean? IMHO if you have a 1997 or 1998 748 with a blown motor you should consider either another 1997-1998 748 motor or convert to a 916 motor. Of course you can convert to a 996 but it will require more parts and more work. If you have a 1999 or later 748 with a blown motor you should definitely consider the 996 conversion but you still need to keep in mind all the differences between the years and parts.

Other things to consider. The internal gearing of the motors is different so you might want to think about this when you choose sprocket sizes. Also, one added bonus of upgrading engines is that depending on your state, your insurance will most likely stay the same even though you effectively have a different bike.

You can also do conversions from 748 to 998 or 999 motors but that requires more modifications / parts and is beyond the scope of this guide. Some of my customers have done those conversions though so it is possible. "

 

Go for a 1098 engine and make it worthwhile or sell the 748 and buy a 996, it will be cheaper, more reliable, easier to do and will not lose so much in value?

 

And you would have to change your username too.