s4r engine rebuilt need help!!!

[Metzis]

Hey guys few km from the first ride after the restoration of my monster, probably the con rod failed!!!
I think the fault its on the power commander 004 map which has different set up on each cylinder :/...
Now because i am going to tear the engine apart i am thinking to boost it up a little bit so i'd like to ask what to do except fix it of course so i can gain few hp from the cheapest to the most expensive solution... I would also like to ask if i can use con rods, crank shaft or any other parts from a 998, 916 or 748 engine....

I was thinking for lighter crank and flywheel putting "if i can find something not extremely expensive" titanium con rods, "tune" the cams a little bit, new exhaust and a proper mapping on a dynometer i would love to go somewhere between 130 to 135 hp so is those things enough what else i have to do to go up to that numbers without loosing reliability....

[Speeddog]

Here's a pretty good recipe:

http://www.bikeboy.org/996SPS.html

I'm not sure about the life of aftermarket titanium rods.
The Pankl rods that are fitted to 'R' models do have a limited life, eventually the big ends go oval.

Be prepared to come up with a big bag of money.

[koko64]

Sorry to hear that P.
I hope it comes back even stronger.

[brad black]

put a 900 crank in it.  it gives 1026cc, which is somewhat irrelevant, but with an extra 0.6mm base gasket it should have 0.9- 1.0mm squish, 12.75 or so comp and no belt tension issues.  simple solution to 3 points.

if you really want to spend money on rods buy carrillos.  otherwise use std.

a 'std' crank used to weigh 4.5kg ish, an sp/r crank 4kg.  but the later ones are getting lighter due to drilled passages and no oil filled big end journal, etc.  just make the flywheel light and leave the crank as is.  cheaper.  unless you want to spend money.

996sps cams, which are hard to find s/h, are what you need.  or the schrick/msd/f1 cams that ducati kaemna use.  spend the money here if you want the power, don't buy some other cams because they're cheap.

if you want more power, get into the heads.  that's where the power hides.

fit a full system of some sort.  if using the original short bits near the heads, get rid of the formed step bit.  that will hurt it.

tune it properly, with a map for it.  not something from the dynojet site.  this is the most important bit, otherwise you just wasted a shit load of money.

[Metzis]

because there a lot of ducati tools misings from my collection i am not sure i am able to tare the engine apart by my self so the bike went into the shop today for diagnosis. Tomorrow i will be sure 100% about whats is exactly wrong with my bike. Right after the diagnosis i will have to make a long talk with the mechanic on whats is going to be next i told him of course that i want to gain few hp after this hole operation so i think he will do his homework, this specific guys was a member of a locals sbk drivers team and he was preparing a full ducati corsa 916 bike so i am sure he knows what to do!!!! As soon as i have any news i will update... Thanks all for helping i think i will touch my goal of 135 hp and why not few more than that lets see...

[Metzis]

hey guys does anyone know if i can use the crankshaft from the 916 motor to the 996 motor?

[brad black]

s4 or st4 yes, 916 no.

[Metzis]

may i know the reasons because i have two crankshaft a st4 oem one and 916 with titanium con rods both are in motors and i have to tear them apart of course... Why i can't use the one from 916? is not the same 916 motor in the st4?

[Speeddog]

916 motors were all single-phase charging, so the crank end is different from the S4R.

[Metzis]

So the crank doesn't fit neither from st4 2002 or the 916 or it does but it change the way that motor work? can i use the 3 way charge system to the single way charging of 916... I really want to use this titanium rods....

[Speeddog]

916 crank will not fit the flywheel/rotor of the s4r engine.

St4 crank will fit your s4r.

Those titanium rods will require different pistons, as their lateral position is controlled by the pistons.
Also would likely require the crank be rebalanced.
For a street bike, the benefits of titanium rods are tiny, while the drawback of reduced life is big.

Steel rods position are controlled by the crankshaft.

[Metzis]

copy that... ok i will tear apart the st4 motor to see in what condition is the crankshaft and the rods.... I didn't mention what happend to my motor so eventually the engine was opened and i notice that the con rod bearing of the horizontal cylinder spinned in its place... Does anyone hear anything similar?

[brad black]

failed big ends bearings is not uncommon, but it's not a regular thing by any means.  just something that happens.

all 996 and later 4v motors have small end located rods, even the steel rods.  so use rods to suit the pistons.

sell the ti rods to someone else who thinks they're good and buy a pair of carrillos.

[Metzis]

carillos don't need different pistons to guide their lateral position?

[brad black]

carrillos will either be "916" (big end located) or "996" (small end located) style.  the 996 big and small ends are 21mm wide from memory, 916 22mm wide.