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Senior Narcissista
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Discussion Starter #1
This is a short report on an engine I just finished, its merely meant to show what can
be done with relatively cheap parts if you happen to split your engine.

It all started with a 1098 engine that got a rod bearing sheared, when inspected it
turned out the crank was damaged too. So I got pretty much free hands to come up
with something fun while the engine had to come apart. This is a streetbike so
absolut topend wasnt too interesting but a wide spread and strong mid was.

As I like K.I.S.S I went for Ducati oem parts only, so every bit is 1098 oem but
1198 crank, 1198 cams and 1198 pistons (already bored prior).
Crank is a straight fit, we used 1098 rods but I recommend 1198 rods as theyre 1mm
or so shorter making up for the additional 2mm stroke, same weight.
I modified the heads in the exhaust port as they suck a bit there, intakes
just blending port to seats, nothing fancy or advanced.
Bottom end got new bearings and everything set to specs (blueprinted).

I was hoping for 120hp at 7k and 150 at 8k, and it did a tad better actually so Im
quite pleased the way it turned out. 136Nm equals 100lbft and its with the SAE
correction, in DIN its 3.5% more.

Comparison with an untouched 1098 with full 70mm in the same dyno.


 

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wow very nice.

1- does 1198 cams are direct replacement over the 1098? How much benefits do you think they are?
2- How do you think this engine would do with slip on only (not full line)
3- stock pistons?
 

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Discussion Starter #5
wow very nice.

1- does 1198 cams are direct replacement over the 1098? How much benefits do you think they are?
2- How do you think this engine would do with slip on only (not full line)
3- stock pistons?
1. The 1198 cams dropped right in, even the valve lash was identical on all valves, pretty amazing precision.
However with the 1198 cams the mapping gets way rich on part throttle, not sure why.
2. Not sure, we did a back to back on the 1142cc config this was and no change.
3. Evolve please, not sure what you mean?
 

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I thought it was 1098 pistons. Now, I realize it is 1198 pistons. Can the 1098 sleeves be bored out to accommodate 1198 pistons?

so
1198 crank
1198 cams
1198 pistons (in 1098 sleeved)

sounds pretty close to a 1198 engine lol!
 

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Discussion Starter #7 (Edited)
I thought it was 1098 pistons. Now, I realize it is 1198 pistons. Can the 1098 sleeves be bored out to accommodate 1198 pistons?

so
1198 crank
1198 cams
1198 pistons (in 1098 sleeved)

sounds pretty close to a 1198 engine lol!
Id personally skip the 106 bore, this one came bored so thats what I had at hand, infact its a very nice one.

1198 crank
1198 cams
104mm Pistal piston
-Is my tip, and should be very close to this one, yet less messy.
The crank is an easy one and it does 50cc, no brainer to me, 106 bore is much more hassle for return. Id settle with crank only any day.

For later this spring Ive got a 1098 stroked with 1198 crank, R-cams with 104 pistals, it will be a smidgeon behind this.

Its the combo that does it, 1198 cant stand a chance to the one I did today, not even a 1098R with dialled cams will, although they all share the same bore and stroke.
I do measure all the heads by cc and and port dimensions and then I do calculations from that and use simulation programs to get in the ball park, seems ok so far.

Point with the thead is to say, the 1098 as such isnt dead, far from it.
 

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Discussion Starter #9 (Edited)
No, it came in as a 'tuned' 1142, but turned out to be very wrong in my eyes at 157/125.
So while at it I tried my turn on making it better.
Likely you can get a good buzz from doing this on a 1198 too, Im not keeping any secrets, I just do and tell.
You try that and let us know, will you?
 

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"It all started with a 1098 engine that got a rod bearing sheared, when inspected it"
"No, it came in as a 'tuned' 1142, but turned out to be very wrong in my eyes at 157/125."
"You try that and let us know, will you?" Is this a challenge or a put down?
What would you like me to try????? And what should I let you know?????
 

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Discussion Starter #12
"It all started with a 1098 engine that got a rod bearing sheared, when inspected it"
"No, it came in as a 'tuned' 1142, but turned out to be very wrong in my eyes at 157/125."
"You try that and let us know, will you?" Is this a challenge or a put down?
What would you like me to try????? And what should I let you know?????
All Im saying is I tried this and wrote about it can be done, you try 1098 heads on a 1198 engine and let us know the result, thats all, relax buddy.
 

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mmm ... thanks for this post it's really got me thinking, i have a 2nd track 1098 to build up but the motor has no history so i was planning to work it and swap it into my current track bike .

I understand this build was for a road bike so let me ask .... using the same KISS principle what would you change on this engine for a dedicated track bike?
 

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I enjoy that you have kept it simple by, removing the engine, splitting the cases, swapping out the crank, etc. while some have trouble installing slip-ons.

The post made me smile when it started with KISS, and then I read on to everything else that's involved. Thanks for the post.
 

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just thinking out loud
The benefits of the increase in displacement is undeniable for power output. But I would like to know how much better the 1198 cams are.
160HP/1.1L = 145.5 HP/L
170HP/1.2L = 141.7 HP/L

interestingly, the 1098 makes more power per liter than a 1198 stock for stock; so I don't expect to see MAJOR lift-duration differences, as the extra power might just be the increased displacement. I understand that everything has to work in together to get good power, so changing only one parameter is not the absolute solution.

Also for the rods (still thinking out loud):
I think I would personally go with the longer 1098 rods. I understand that longer rods are slightly heavier and requires 1mm thicker base gasket, but longer rod reduces the cylinder wall pressure because of the (rod ratio); which is a good thing

What is your feeling on that?
 

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If you guys think you're going to get more power out of a what, 1-2 mm longer rod you've spilled a significant portion of your bong-water!!
 

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Discussion Starter #19
I enjoy that you have kept it simple by, removing the engine, splitting the cases, swapping out the crank, etc. while some have trouble installing slip-ons.

The post made me smile when it started with KISS, and then I read on to everything else that's involved. Thanks for the post.
Why couldnt a big job follow KISS you mean?
 

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Discussion Starter #20
About moving cylinders up; this means a lot of unwanted practical side effects, like TB wont fit straight, the belt covers wont fit straight, belt rollers needs latheing, new foot gaskets needs manufacturing or use 10 original at 7 euro a piece.
So I wouldnt recommend that.

Note: 1098 and 1198 rods weigh the same. 1198 and MTS/Diavel are the same rods.
 
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