Hi all new to the forum and looking at the knowledge here I think I'm in the right place... I've owned and worked on my 916 for some time but decided it's time to delve further and try an engine rebuild......... I bought a spare 916 engine some time back but the front engine mountings have been cut Gould only knows why?????, I have started to strip the engine down and all in all it seems in pretty good nick so my dilemma is do I get the engine mounts repaired? (I should be able to make the bits and hopefully get them tig welded on) and check the rest of the bearings etc out and rebuild it OR As I have a set of 996 cases (though the engine number says 916 the 996 barrels fit), barrels, pistons and heads (which I think are 996SPS), strip the whole 916 engine down and put the crank, gearbox etc etc into these cases and make a 996 engine........ I know the 916 con rods won't fit the 996 pistons but have been told that 996 con rods will fit the crank....... will it work? I'm going to have to buy new big end bearings, gaskets, belts etc which ever way I go...... Any thoughts? Thanks in advance
I Would be hesitant to weld more than one engine mount onto an engine and even then.... I have no knowledge of Ducati engine casings and someone may say otherwise but I guess as most casings are cast, which usually means made with some impurities and or tiny air pockets they are not always easy to weld well, i.e. to give the same strength they once had. I've had a F1 tig welder repair casing and it leaked. I had a coded tig welder repair a car gearbox and it broke. I do however know someone who welds fittings into cast sumps for dry sump kits on race engines (although these are now all cnc made from scratch) - I doubt he would even agree to do it for safety reasons. The guys I know have motors rebuilt all the time so that would be the route they would take. It's the importance of the engine mount, the stress and forces Others may have had work carried out successfully, but for me, even though tig provides very localised heat, I'd be concerned about possibly changing the properties of the metal the weld binds too. Something like that would probably be x ray'd or similar if it was a mod for racing. This might be OCD, Hope you get sorted.
I had front and back engine mounts welded up after track damage. The engine went on to race with no issues in those areas.
Thanks for the replies, it's both sides of the front mount and it's like they have been cut down (don't have pic at hand) the centre section is still there so would be like having 2 spacers but would weld them in.
is the original engine not rebuild-able? Failing that I would think the 996 cases would work, but I'm not sure on that due to the alternator/crankshaft differences?
Hi it should be rebuildable it's just the engine mounts, I was just thinking if poss would transfer all the internals, alternater etc over to the 996 cases and make a 996 engine...... Not sure if it produces much more power etc than the 916 etc etc etc but the 996 heads I have I'm sure are SPS heads
OK, I had understood that a replacement engine had the mounts missing not the one in the bike? IIRC the 916SPS was the first 996cc model homologation for racing? which maybe why the engine no. is still 916, so it should be a bit better than the standard 996 (different heads & cams?). AFAIK the 996 stroke is the same as a 916 so, as long as the crank fits? you should be good but the 996 (don't now about the 916SPS) had a different alternator and fitting for it on the crank, I reckon it would work as there is a lot of mix/match with Ducati engines but someone on here should be able to confirm. 996 should make a few more HP and lb/ft than a 916, especially in SPS guise.
Thanks again, yeah I think if I remember right as I've had the cases a long time the guy I bought them off said they were 916sps but could be wrong and the heads which I'm sure I bought as just 996 have got T1 cams in them.
Well finally split the cases today only problem was the gearbox refused to stay in the right hand case an I found a spring......... It's approx 50mm long and same internal diameter as the selector fork pin......... Where does it go?? Good job I split it though the big end bearings were shot
Yes mine had a gasket as that was how they made them back then but it was reassembled with just threebond.
Unscrewed the plugs out of the crank shaft tonight and found it full of black crud could this be why the big ends were shot, or is it the big ends :grimacing:
Oh right well it had deff trapped some sludge all be it dried, should the plugs be locktighted back in Cus the big plug was loose :0/
So now it's time for the big decision, I've got a pair of 996 con rods to fit the Pistons so do I try repair the 916 cases and rebuild that or go with the 996 idea looks like all but bits will fit......... The con rods are the same weight but the 996 Pistons are 10grams heavier, I've read a few wrightups to do with piston weights on 748's etc and after market or high compression Pistons and the opinion seems to be 10 gram should not need the crank to be rebalanced. Any thoughts??
