1199 Big Bore Engine

Seth Vo · Mar 29, 2023

I am currently building a 1199 motor and considering using the 1299 full crankshaft assembly within the 1199 case and heads set-up....

This would include the 1299 Crankshaft, rods, pistons, and liners all matched and balanced with new bearings and seals. The main journals are identical and even call for the same part number (if you have the same pairings).

I've done a full compare of the heads and other then the valve cover changes the intake, exhaust valves are identical along with the head combustion chamber. Cam profiles from what I've researched are identical.

Has anyone has heard of this being done before? If I do I'll double check every clearance including the "valve to piston" clearance as given the difference piston profiles this still concerns me however the 1299 dome actually has a lower profile then the 1199.

bp_SFV4 · Mar 29, 2023

Seth Vo said:
Seth Vo said:

however the 1299 dome actually has a lower profile then the 1199

Click to expand...

Did they drop the compression ratio and bump up displacement to maybe keep power and lower heat? Engines with more stroke in the American V8 style may require grinding some clearance into the crankcase for rod clearance, but it's nothing to be worried about.

Seth Vo · Mar 30, 2023

bp_SFV4 said:
Did they drop the compression ratio and bump up displacement to maybe keep power and lower heat? Engines with more stroke in the American V8 style may require grinding some clearance into the crankcase for rod clearance, but it's nothing to be worried about.

The heads combustion chamber is identical so that means you have less cc's with a 4mm wider piston so it has a smaller dome to keep the same compression ratio as they are both 12:5 to 1.

The more I've compared these parts while there are a number of minor differences between the two it really seems like they only focused on the bore size and missed a big opportunity to improve the flow of the heads themselves...?

On the crankshaft there is a significant amount of machining done to the crank to allow for the size of the wider piston skirt to travel in full rotation without making contact and then they've added weight to the counterweights to replace what was removed. The con-rod journals are also slightly wider but the main journals are identical.

1199 Big Bore Engine

Help Support Ducati Forum:

Seth Vo

bp_SFV4

Seth Vo

Similar threads

Register CTA

Recent Discussions

Recent Discussions