1000DS motor vs "Built" 900??

[kevincg]

Since I have had trouble finding a donor 1000DS motor, I was wondering how well a 900 motor would work in a dedicated track bike. I would probably have it balanced and add con rods and do major head work. Certinly a big bore kit.

Would it be close to the power of the 1000DS?
Would this be an unreliable option?
Any significant difference in weight?

I can locate 900's easliy, so I may consider this if I feel comfortable that I am not building a potentail grenade.

Thanks for any input.

[RichD]

There is no replacement for displacement, so the 1000DS would be nice.
But then the 1100DS would be nice too.

The 900cc engine is plentiful, powerful when built, and reliable...
When I was racing (not bikes) there was a saying regarding spare parts:
"Have a pair and a spare"
Parts for the 900 are typically less $$$, from pistons to timing belts.

I bet the 900 would do you just fine. On a bike it typically isn't about power (especially if you are on a tight track).

Just opinions...

[duc97sp1]

There are plenty of built 904 motors out there; 944, 966 & 10?? kits are readily available. You can top 100hp at the wheel and get well under 400#. Just depends how deep your pockets are.

Here's a good place to start: www.ca-cycleworks.com

[bruce19]

FWIW, I took my '96 SS/SP and did the 944 kit w/HC pistons, 41MM FCR's, on Malossi short stacks. I bought the parts from Bruce at BCM and happened to be there when Doug Lofgren was visiting. The ensuing discussion about my project resulted in their estimation that the rear wheel HP on my bike would be in the high 80's or low 90's for HP. The bike was purely a street bike and pretty tractable. And, it was definitely strong.

bruce19

[markg]

I have limited experience withthe 1000, but I do have a 900 with hi comp pistons, matched ports, and Keihin smoothbores with staintune cannisters. Aso have a 39 tooth rear sprocket. Coming out of second gear corners you can roll it on hard and the front end will get very light to lifting a bit. The Keihins were the last thing added, before them I never saw the need for a steering damper, now I do. If you use staintunes pull the tip silencers for track work, leave them in for the neighborhood if you want to be invited to block parties

Up until 7500 rpm or so I think its a match to slightly better than a stock 1000 supersport, more so vs. the sport classics. The problem at the top end; it still has the long manifolds, and two valves, (also true on the 1000, but the valves are bigger and set at a narrower angle) so after 7500 rpm or so the 1000 might be stronger.

As the previous poster mentioned, there are ALOT of after market parts around.

Good luck and have fun.

[rz33v4]

If you want a 900. get the F.I. motor, as these are capable of about 10 HP more with the same mods as a carbed version. As an example, my '99 SS gets 95 RWHP from a 944 kit (10.5:1 CR), ported heads (C. R. Axtell), opened airbox, replacement mufflers and a PC II. Plus, the F.I. + PC II is easier to tune for mods than the old jets/needles of carbs.

To me, the big advantage of the 1000 DS is the twin-plug heads, which should allow for higher compression ratios without detonation, though that advantage may be nonexistent with racing fuels.

[kevincg]

Thanks for the great feedback.
I was concerned that the 900 may not hold together when pushing 100hp, or if 100 was even possible. It sounds as though the durability is not a huge concern, so I may persue this motor instead of the DS.
I am familiar with BCM, and I plan on speaking to them to get some ideas as well.

[1fast750ss]

Remember, HP is obtained by several factors, one being efficiency. If you build the bike right, you will not have a problem.

You can easily obtain 100+ with a 900. Find a set of ST2 cams, then talk to Doug at ARC Fabrication(good friend of Bruce Meyers) about doing a set of Downdraft heads. He will put all of the good bits in it, with bigger valves, and redesigns the inlet port to be more downdraft.(By 56 degrees) He can adapt the inlet manifolds to accept the 50mm 748 TB's too.

All that said, a 944 with the above said heads, running at about 12:1 comp ratio and a lightweight flywheel and balanced crank(you will HAVE to go to Carillo rods) should net you little more than 100hp at the wheel.

Add that to a package weighing in at less than 400lbs wet and you have a rocket, if properly tuned. If you live by one of the great tuners(the Meyers', Lofgren's of the world), have them do it.

BTW, if you do the 2 plug set up with HiComp pistons, be careful of the possibility of detonation. It CAN happen if your ignition map is not set up proper. Trust me, I know from experience.

[FM_Ducati01]

Does anyone recall the racing team from Wisconsin that ran a 2v air-cooled (almost certain a 904+2mm or more?) against I4's in a middleweight class... Was it late 90's or early 2000's. It ran pretty good, however at a certain HP figure (somewhere in the 95-110 range, I think?), they started having recurring issues in the form of broken cases... Not saying at all that you would have the same case issues with yours, using it as a 'dedicated track bike' (track days....) But, definitely something to conscious of.

PS - if you go for it, find the newest motor out of an SSie or a Monster 900ie 00-02 lump with the close-ratio trans...

[riversbikes]

My 2cents:

I have a 98 SSFE with 41 mm carbs. I sent the heads to Doug at Arc -- he didn't do the full monty, but matched the long intakes with the polished ports. I initially bought one of his simpler undertail exhausts -- not the spaghetti type. He replaced a few valve guides and a rocker. While that was going on, I got my stock jugs bored by Millenium to accept Martin Brickwood's Mahle 966 kit. Left the bottom end stock, and just replaced the upper end stuff. Even left the flywheel alone. Bike ran like shite when I added the Nichols flywheel (at idle, now I know better) -- the local Dyno has me at a solid 85hp at the rear. I'm faster than all the SVs at the local track, and the Ninja 650. There's a yank who comes up and whups my ass, but that is due to skill, rather than outright hp... although his engine is built, and he has tire warmers, and (whine whine). Doug is nearly finished making me an under-engine exhaust, similar to the 749 one he has on his "what's new" page. I'm also planning on running velocity stacks, because the intakes foul on the 748 tank... which I converted to work with my carbs... which fit on the modified Monster frame I built... that carries the 748 forks and Marvic Mag wheels I have... geez, I should post a picture!