[Namor]

I'll be rebuilding an engine from the 999S engine that I picked up. I managed to salvage everything but the pistons.

I am going to stroke it with a 66mm or 68mm crank, more likely the 66mm, for some more torque.

Since everything is apart I wonder at things worth doing -

Difference in shift drum between 999S and XX98? (don't need the neutral light to work)

Primary gearing between the 2 & 4 valves engines?

1098 primary gears b/c they are lighter, don't cost much, or are they prone to failure?

I'll turn down the flywheel.

And since I've never run Ti-rods and the lightened crank, is their much of an argument for it over a heaver 66mm balanced crank?

Between a 999S and a 1036/68 what size exhaust system are we looking at? 45mm seems too small even for the 999. Was thinking 52-54mm

Power is not that big of a deal to me. The Time Machine is enough for now, so a properly timed, and squished S engine will be a please gain as is.

 

[xracer]

My 1198 engine in the 999 runs a slightly modified 57mm system with more power than the big system that you can buy for an 11. 54mm will be good enough. Throw some bigger intake valves while your at it.

 

[Namor]

That's all you got Rob? Surely you don't have something better to do than to answer all of my questions. I am really upset. I am really upset. After all the time I took to write all those words. I made myself vulnerable and open. I expressed my concerns. I mean, I feel like you don't understand me... do you? I feel like I am getting mixed signals.

I am sorry.


There was fresh bait in there and I got nothing from that. The exhaust information was good. I'll run the xx98 OEM system with a tune first then go from there. The 1098 ran 52mm?

 

[TomTom]

Difference in shift drum between 999S and XX98? (don't need the neutral light to work)

1198 drum wont fit as its a 7-speed box

 

[xracer]

1198 drum wont fit as its a 7-speed box

That made me laugh Tom.:laugh:

 

[Namor]

Why are ya'll being mean to me?

With regard to the drum selector, I recall or miss-recall that channels for the shift forks were smoother than the previous model drums and so provided smoother shifting. Pictures do not confirm this. Perhaps one of you tyrants can.

 

[TomTom]

Id say its more like 11-1 Namor-TomTom in stupid comments over the years ;D

The serious answer is that 1198 drum in a 999 gearbox wont do well as the gears in the 1198 box are different width, it would cause the forks to bend in best case.
996SPS oem drum and 999R gearbox works, that I have tried (likely any close tranny 916-999 follows that (anything with the same gear width)).
1098 drum may work, but I have no input confirming that. If the gears are the same width it 'should work'.
I know for sure 1098 and 1198 drums are different, not for the same width gears.

In any case Id check if Ducati made revsions of the 999 drum. If they have five of them like they do for the 1198 you may want to get the latest and try that.
If you dont have connections to check let me know and Ill look it up for you.

Edit: A freind has a 1098 box in the open so I can measure those gears, and if you have some of your ole 916 bits its possible to make an educated guess.
Plus I wouldnt bee to keen to see an improvement, shifting works or not. There are drums with smooth turns but I think that is just eye-candy as the work is being done else that portion (different manufacturers).

 

[seven4niner]

Awwwww man, the lil' 100mm bore puts the mockers on any decent increase in cubes without big $$$. Same hassle either way with 66 or 68mm crank but at least you'd net a few more cubes (70 odd cc's) with the 68mm crank. Same 68mm crank in a 104mm bore 999 gives 1155.

But if you're only doing it for shits and giggles, here's an idea: use a 54mm 749R crank for an "848S" that would smoke an OEM 848. 999S has similar size valves as 749R (40/33 vs 749R 39.5/32) and decent cams, albeit not quite as much lift as the 749R. The upside of the S cams is you'd actually be able to rev it without worrying too much about battering the valve gear, and the bigger valve sizes would go someway to compensating for less lift. Rather than being something marginally different to a stock 999S it would be something completely different in nature, much more fizzy. She'd be a lil' ripper, a more modern version of the classic 853.

As for the heavier crank, after racing the 749R I picked up an old 851 Strada as a classic race bike project and holy moly, the speed (or lack thereof) with which it gained/lost revs felt like a Harley in comparison. I really did wonder what I'd got myself into, thinking how the hell is this considered a race engine?! Fast forward a disturbing amount of time later (6 years, whispered under my breath) and it is finally a much more purposeful bit o' kit with a balanced crank, H-beam Ti rods, Pistal 96mm pistons, Nichols alloy "washer", oops, I mean flywheel, and the difference is night and day. Sorry, just my way long winded way of saying you'll love the reduced reciprocating mass. My 999RS engine has even lighter internals again than the R, and it is just a lovely thing, with no downsides that I can notice. These are gyroscopic forces after all, so it's not just engine but handling improvements too.

If you haven't already, check out Brad Black's info on the 999S/998S (and other) combo's, there is some interesting exhaust stuff there that might help you out. BikeBoy.org

 

[TomTom]

Just dont overbore 996 to 100, stroke is fine!

 

[belter]

what chassis is it going into? what exhaust configuration are you going to use? what's your intended rpm range?

none of the 66 or 68mm cranks have a splined primary drive. 1098 and 1198 do, maybe see if an 1198 crank fits. you'll need to make sure the pistons aren't coming too far out of the bottom of the cylinders though.

 

[Namor]

916 chassis.

Have not decided on the exhaust configuration.

RMP? Around 7.5-10k. But if the 999S doesn't flatline at 10k like the 996, then I would like power up to 11k or 11.5k

The 999 cylinders are 110mm top to bottom and the 996 are 112mm top to bottom. On both cylinders, the portion that slides into the cases measures 42mm. My logic is that if the 68mm crank runs just fine in the 996 stroke (+2mm stroke), then the 999 will be fine with the 66mm stroke. But 2mm more for a 68mm crank, I would have to purchase one then have a look with crank in and one of the cylinders absent. My thought is it will be fine.

 

[xracer]

After working the 999 it flatlined at 10,500 and only dropped 3-4 hp at its 12k redline.

 

[mrfurry]

The 999 100mm bore engines, are more difficult to stroke than the 999R 104 mm bore engines.
As you have to make special pistons/conrods to make the stroker crank fit. and 70cc extra makes about 5hp? much effort for not so much hp.

i would search for 749R heads.
My blueprinted 999S makes 136 RW HP (on the rear wheel), on the same bench test my 749R makes 125 RW HP.
what would happen if the 749R gets 250cc more?? Or equal the 999 gets 749R heads?

 

[Jyrki]

what would happen if the 749R gets 250cc more?? Or equal the 999 gets 749R heads?

My current plan is to throw in a 999S crank with titanium rods, 100mm Pistals and 749R heads. It is (or was) a 749s from 2004 with the big bore kit. I might port the heads too, but we will see. So far the project hasn't moved a bit, but will be done before late spring 2019. Exhaust would remain same which is Zard 2-1-2 system.

 

[Namor]

The 999 100mm bore engines, are more difficult to stroke than the 999R 104 mm bore engines.
As you have to make special pistons/conrods to make the stroker crank fit. and 70cc extra makes about 5hp?

Why? Because the timing shaft getting hit by the outer edges of connecting rods? If that the case, then the shaft can be turned down to make clearance.

If not that, then why? Beyond the sand casted material and a couple minor things, is the difference between the Base/S and R cases stud spacing?

 

[mrfurry]

999R 104mm bore has more available pistons see pistal racing. The last racing models did use longer conrods. Therefor you can use an longer stroke and use standard lenght conrods. or shorter 1198 conrods.

 

[TomTom]

If it was me Id take the effort of making the cylinders sit in the oem position, else throttle bodies wont fit well and belt covers wont fit properly, it kind of escalates pretty quick.
The 749R heads have a tiny chamber (just 28cc) so do the calculus to avoid too high compression

 

[Namor]

749 base/S heads different from R heads? Or are we only looking at the cams?

The 999S cams can fit the 749 heads with minor modification?

 

[mrfurry]

each head has different valve spacing. 749 smallest with 90mm bore, 749r 94mm bore, 999 100mm bore has the biggest valve spacing. in other topics this is explaned, and some have put 749R cams in 999 heads.

here is lots of info:

http://www.bikeboy.org/performance.html

 

[TomTom]

What you recall as valve spacing is actually bore per that, valve spacing per def is way diffrent, I have ground cams to fit actual valve spacing
Valve spacing is the center between valves.