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Seized 748.

Discussion in 'Technical Help' started by luckymarine, Apr 30, 2013.

  1. On a brighter note I think my crankshaft oil galley plug is fine!

    [​IMG]
     
  2. Will there be hat eating? :biggrin:
     
  3. Ha!

    I believe so!

    From its symptoms, and what I can see. One of the bolts holding the big end together worked its way loose, and then came out all together, snapped the big end in half, shed the big end bearings and then parted company with the crankshaft.
    I ran on 1 cylinder till the floating conrod lodged in the other cylinder locking up the crankshaft at 70 mph...

    Not so uncommon it would appear.
    http://www.brighthubengineering.com...087-operating-faults-in-connecting-rod-bolts/
     
    • Like Like x 1
  4. How do you determine the condition of the bottom end you have seen for sale ?

    I bet there is at least one complete engine available from someone on here or a known reputable engineer.
     
  5. At £70 it would have been ideal to strip down and rebuild so long as everything was there and nothing was locked up/eaten like mine.

    Ah well.

    I see it as an opportunity to.... tinker.
     
  6. ouch :frown:
     
  7. So, is it an entire new complete motor you are looking for now. As mentioned someone will have or know of one for sale somewhere.

    In the meantime are you totally overhauling the rest of the bike ?
     
  8. Turns out I also have a front fork oil leak so the front end will be stripped off the bike so might as well do a bit of an overhaul.

    Just depends what I can pick up on the cheap. saw a 748 with a 1098 swingarm that looked interesting....
     
  9. Found this while trawling the net, did not know if it would be of any use to you in your search for a replacement engine,

    DUCATI 748 / 916 / 996 Engine-Motor Conversion

    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
     
    • Like Like x 1
  10. That'll be scrap then! How much debris has contaminated the rest of the motor?
     
  11. Cheers iang27 I think I stumbled across that on a site whilst looking for exactly what would fit in the 748 frame.

    Am going to get the motor split by the dealership as it looks like a right epic to get into.

    Will salvage what I can/laugh and take pictures of the mess.

    If the casings are fine then at least I have something to build on, hopefully the gearbox etc will be fine. As will anything outside the conrod flailing radius.

    Heads are fine, thankfully.

    One of the cylinders is shot probably both.

    If I'm going to get new crankshaft (I assume) conrods, pistons and cylinders it would be a shame not to up the displacement a small amount...
     
  12. I got a couple or so of 748 bip barrels sat on a shelf :upyeah:
     
    • Like Like x 1
  13. and if you need a piston or two,i have them. :upyeah:
     
    • Like Like x 1
  14. Luckymarine, thanks for a great thread with wonderful pictures. I would not wish what happened to your bike on anybody but over the last week the soap opera of your bike strip down has been unforgettable. I really hope the sound of a Ducati once again resonates around your neighbourhood.
     
    • Like Like x 3
  15. 748 engine 003.jpg 748 engine 002.jpg 748 engine 001.jpg if you need any bits,i have all these from a 748 mate. :upyeah:

    748 engine 003.jpg

    748 engine 002.jpg

    748 engine 001.jpg
     
    • Like Like x 1
  16. I wouldnt bother to get it stripped you will be wasting more money than its worth . You have just seen a whole , good? , 748s bottom end sell for £70 . How much do you think your knackered 748 bits will be worth . Get a 748/916 full motor it will be best, cheaper , in the long run .
     
  17. If you really want to go raving mad , i have a pair of brand new ferracci stroker pistons and a crank to suit. Go 1026!
     
    • Like Like x 1
  18. I would but I don't think there are any cylinders to match, I'd have to get a set of 748 cylinders bored out so that everything would line up!
     
  19. Lucky how much do you think your going to end up spending, theres a 748r motor on ebay now for £1000 , no workshop costs of new parts labour etc. Will your Ecu work with this ,maybe its a better bet option.
     
  20. Cant afford £1000 at the moment, am spending all my pennies on the whole of a mortgage I never planned on paying by myself! Ha! life huh! what a bitch.

    Can afford £100 or so here and there, thats why I'm pissed off I missed out on that bottom end at £70! :mad:

    So, I know "Ducati" and "shoestring" are not exactly cosy bedfellows, but this rebuild is going to be done on the cheap. Doesn't mean I'm going to scrimp on quality, I'll be doing all the work myself. If I can pick up the specialist tooling to pull gears, split the engine casing, time up belts/crank etc then I can just use my limited funding on the actual parts.
     
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