An inmate with a spare set not on their bike offered theirs for us to try so probably in a few weeks we'll be able to post an actual dyno comparison back to back of the 39's vs the 41's so we can see exactly what the differences in the curves are. I suspect that we'll see an increase in top end but at the expense of bottom end but on my 990SMR engine it might be better suited and help to flatten out the torque curve. Now that I feel that I'm on top of the engine I'm encouraged to actually look for a bit more. I've even asked Chris to take a look at my old 950 mill and see if he might be able to build/offer a bolt on big bore kit for the bike. Who needs the new 1190! Gregor
The 950 had so many great features that disappeared in the new models. Gone seems to be a kind of simplicity and elementalism, that some hated, but I love. I'm extremely curious for these updates. I'm sorta meh on my Superenduro these days, of course I love it, but I also kinda want more. If your investigations bear fruit... I'm interested!
Gregor, Not sure if I missed a discussion about it earlier but have you guys thought about using some Power Blade / Power Now type inserts in the carbs and your new intake stacks? I don't think it will make a big difference in top numbers on the dyno but in actual drive-ability in my experience they give a noticeable improvement. My KTM engine guru in Belgium says the best way to do it is to start with a 39mm carb and then blend and port everything nicely, to make sure there are no steps or ridges that disturb the flow. This is a single carb but the same should be doable for your twin setup: Overall airflow should be somewhere between the 39 and 41 due to the blade, and you get increased velocity when you don't open the throttle all the way.
I'm sure Chris will have something to say about the splitters. I believe they're supposed to create a smaller venturi for partial throttle openings but I think there's some expense as well. For those of you interested in the velocity stacks Chris has redesigned them and is offering them in the vendor forum so you can check him out there. Once he's got his first production stacks I'll shoot some photos as I hope to have a set from the first batch for my bike. I'll be curious to hear feedback from those of you who get them. I'm going to continue to do more work on my bike to see what I can discover about the 41's and I've given Chris my old 950 engine to see if he can create a big bore kit for the 950/990's. He's built his own V-4 Moto2 engine and created the molds to have his engine sand cast so he's certainly got the chops to do it. It might not be possible due to case restrictions but hopefully he'll figure it out when he opens up my old 950 mill. I am all for being a guinea pig for this kind of development and besides, this thread is called Mission Creep. Gregor
The upcomming 1398ccm SXS KTM Adv Kit. Love the coolness. Gregor, its a pleasure to wake up in little Denmark to read this fantastic thread. The video on the dyno with all the boneheads where great. Really nice to see some bike roaring. Your take on unknown terrain with this engine/carb combination is brave. But i´m sure there is room for at turbo... Mikael
Oh it's possible. Paul from OZ built his SE into a 1090cc. "STD 950 Se Motor is 100 x 60 Mine will be 105 x 62.4 Custom made forged pistons, HC Crankshaft from 990 (62.4 stroke) 40mm Titanium Inlet Valves Heads ported and flowed Balanced and lightened bottom end 990 SD R Camshafts It made 122.4 RWHP, up from 94 STD. Most importantly, an extra 15 Nm through the middle... It wheel-stands in 4th gear, no shit... It's apart again, being treated to 50mm Akra headers and EFI. 140 here we come!" Keep in mind before beeing rebuilt this bike was ridden 43.000 km across all of Africa and then across Asia to Magadan.... :eek1 (www.donkeyandthemule.com.au) More info here: http://www.advrider.com/forums/showthread.php?t=328225
Mikael thanks - I've enjoyed watching your thread as well. It's nice to finally realize some gains from all the work so far. Now I'm trying to push Chris to keep the momentum going. My bike is still in NYC for the foreseeable future and there's a spare old 950 engine just sitting there waiting to taken apart. Lukas, I just found that last night. It's super cool and the build is very clean. There's also the German company that took a SuperDuke to 102.2mm so it seems that you don't need to modify the cases to go oversize. I would love to put this on my bike and see it go to 1089cc's because every little bit larger I go makes those big ports of mine all the more useful. Plus, I did threaten Flanny over a year ago: Really, there's little I won't do or spend to continue opening this can of whoop ass on Flanny. Gregor
Welll...you know what they say huh? (At least in Canada). Better to have your ass whooped on the dyno then on the trail....
Lots to cover! OK, on intake splitters I am undecided. They can induce turbulence and other flow characteristics to increase fuel mixing and burn quality but also decrease overall flow area, not just by the thickness of the plate but by introducing 2 boundary layers (on top and bottom of splitter plate). I think the more modern the engine design (more downdraft ports than sidedraft) the less a splitter will help. It also goes to show why a lot of these are done on singles with a horizontal carb. The flow having to turn 90 degrees to get through the valve introduces a lot of flow compromises that a modern v engine with its largely straight ports do not experience. On the big bore kit I have to see what the inside of the 950 looks like. The 990 superduke engine cases may be machined differenly than the 950 engine. Ducati does it with the various 7xx thru 10xx engines. I also want to make a kit that is bore only, no stroker crank needed. That would keep kit and install price down. Reboring existing cylinders is nice but if new castings are needed it is not a big problem. Will find out and let you all know. Gregor, did you do a photoshop drop shadow curved text addition to the engine in a crate picture?
Yes, well, a little more than that but like I said... there's nothing I won't do, blah, blah, blah. That includes photoshop. Of course if we do a big bore kit I would like to suggest we incorporate that into the casting somehow and then offer it to everyone but Flanny. In fact we could offer these kits in "Flannymobile Killer Level 1" etc. I think that might prove popular. That was a low blow Mr. Flanny. There will come a day when I will actually ride my bike again instead of just work on it endlessly. It is a difficult to imagine day, I will grant you that, but one that will come sooner than you'd like. You will know that day has come when you find your bike sand blasted down to the primer from the roost I will throw your way. Just sayin'. Gregor
Hope the dyno room and bike projects are safe from the storm surge!! Best wishes to those affected...
Fortunately our shop is on the third floor so while I haven't heard anything directly I'm pretty sure it's all fine there. However a friend who has a motorcycle garage across from my old East Village apartment (and where I used to park my 950) sent me a few photos from last night... This is near the intersection of 8th Street and Ave C so not all that near the water. Pretty amazing the devastation and when you see this and realize that it's up and down the whole coast the cost to repair/replace the homes and cars and property will be beyond staggering. Gregor
Thanks for the update and I am very thankful to hear there is no physical loss or injury! Of course, I am very sad to see the poor ponies in their stable, up to their axles in salt... All the best to anyone affected and reading this!
So Chris is fine but the shop has been without power for the last week so everything has been on hold back there. My job that was supposed to start next week got postponed until the week after Thanksgiving so I'll be flying in on my birthday and will get my bike swapped over to the production intakes then and spend the week riding it while I'm there and then do the 41 swap the following weekend so I get a day to see what that feels like. Gregor