Ducati Sporting Club UK > Model Specific - Discussion, Technical Problems and Help > 998 / 996 / 916 / 748 > 916 Pistons in a 748....

[nelly]

Yep. Pretty much is that "simple"

DC, the cases don't need any work. 916 pistons are the same diameter as the ones Sigma fitted in your motor. They're heavier though hence the bottom end'd need balancing, and you'd more than likely inherit the 916's rev limit.

Nat..........you've got all the ingredients to do the job, basically you'd just need the balancing done on the bottom end and the barrels machining to compensate for the differing piston heights. Ducati Kamna are in Germany and have the info/parts on their site. Look like they know the game. Maybe worth a call??

[nathanhu]

thanks Nelly,
would i be better off with the different pistons and leave the bottom end,
only asking as the standing cylinder base gasket has started to leak and needs the lot taking off and re sealing ......a nice swop and power increace would take the pain out of it. if you know what i mean.

[nelly]

IMO yes. I'd go for lighter pistons and get the barrels decked.
It would definately take the pain out of having to do the job

[moto748]

I thought Ducati did an "official" kit. Is this not the case?

[DC]

allo Nelly,


"DC, the cases don't need any work. 916 pistons are the same diameter as the ones Sigma fitted in your motor. They're heavier though hence the bottom end'd need balancing, and you'd more than likely inherit the 916's rev limit."



Perhaps I am getting confused with 955 pistons and the size etc.


What about the idea of fitting some hotter cams from the 748R or SP. Also, I have always fancied putting 916 injectors on if they would supply more go juice!!

DC.

[nelly]

DC, it is the 955 kit you're thinking about..........unless you have a 916SP.
The SPS or R cams would go in OK. You may/may not need to machine the piston pokets, but you'd fuel it OK with an eprom change. I'm 95% sure the injectors are the same.
No need to swap them for the 855 motor I'm building, even with big valves and a gas flow
The 916 throttle bodies are 50mm whereas the 748 are 45mm downstream of the butterflys. I'm thinking of taking those out to 50mm or swapping for 916 items

[bolds]

problem with fitting SP pistons is they have 21mm gudgeon pins and also barrell have 100mm skirt into crankcases because if you fit a 955 kit to a SP you dont have to machine crankcases out unlike 916BP

[DC]

Originally posted by nelly
DC, it is the 955 kit you're thinking about..........unless you have a 916SP.
The SPS or R cams would go in OK. You may/may not need to machine the piston pokets, but you'd fuel it OK with an eprom change. I'm 95% sure the injectors are the same.
No need to swap them for the 855 motor I'm building, even with big valves and a gas flow
The 916 throttle bodies are 50mm whereas the 748 are 45mm downstream of the butterflys. I'm thinking of taking those out to 50mm or swapping for 916 items

Nelly,

I must make the trip up to see one day. I feel a winter engine mods list coming on!!!!

DC