another 900SS engine swap; high comps + light flywheel edition

[Rudemouthsky]

   I think it was fate, as I was browsing around the 'web looking for a certain something...found it, along with the rest of it.... The beginning of a 1996 900SS part out by a dude that's local to me, Mark from WoundedDuc.net. Gave me an offer I couldn't refuse, $600 for a mostly complete, SUPER clean engine with 14k original miles. And since a certain company of asshats pulled my heads and jugs off anyway, leaving me with a fukn basket case of unorganized hardware ( ) I sez why the F not I'll start over and do a better job of it this time, with a better product. Spent all day driving to central OH to pick it up and bring it back.

I'm also going to document the crap out of the swap this time with lots and lots of pics, something I did a sucky job of my last build thread, and enlist my good friend and former Porsche/Audi tech to play a bigger role. There's a few mistakes I'm embarrassed to admit to that I don't wish to repeat.

I will do JE standard bore high comps, and a lightened flywheel as well this time. I would appreciate anyone who has this combo to chime in and tell me a little about how they like it.

Leaning toward the Fast Frank flywheel for $100, both for the cost savings as well as a less dramatic experience. If anyone would like to tell me why I should go with a Nichols or another "ultra light" brand instead I am all ears. The FFFW is 2.6 lbs, about a 50% reduction. The Nichols weighs well under 1 lb which is considerably more dramatic. I'm probably gonna run a standard clutch and either put my Ducabike slipper in the classifieds or shelf it for my future Streetfighter. Orrr...stick with it, as a slipper combined with a light flywheel sounds really intriguing. My riding style is...kind of @ssholish. (err.. hooliganish?  ) I like goosing the throttle... doing wheelies... and going fast from light to light. That's why I think I'll enjoy the light flywheel.

I really don't wanna jack this up folks...the very best resources for installing the pistons (squish, proper clearances, etc) and retarding timing via the flywheel are highly appreciated. I think I have this covered with Brad Black and Chris Kelly's various write ups but these 2 are WAY smarter than me, so some "for dummies" references would be great. Otherwise I intend this to be more of a documentary than anything else hence the "Accessories and mods" section.

I'll update tomorrow with some pics of my new-to-me engine. 'tanks ya'all.

[joshuajcrouch]

Yipee!  I will be watching this one.

[koko64]

I dont know the weight difference between the Nichols and Yoyodyne flywheels.    My  M900 bike has an oem flywheel machined down to 900gm.  A previous bike of mine (SL900) had a DP flywheel which looked identical to the Yoydyne (someone will confirm that or not).
 The DP flywheel was alloy and significantly lighter. Both have FCRs and hi comp pistons, but with well tuned and balanced carbs, and tuned ignition maps (Igmitech), they run quite smoothly.
The Nichols flywheel looks possibly lighter again. I think there is a used one for sale by Motowheels.
Maybe a fat flywheel helps hide rough tuning, so I would opt for a tuned ignitech unit and careful, patient carb tuning.
So go for it I reckon.

High comps and a light flywheel will increase engine braking which some like and some hate, so dont sell the slipper clutch without trying it.

[ducpainter]

A glutton for punishment you are...

[Howie]

http://www.yoyodyneti.com/ProductInfo.aspx?productid=T11502

http://nicholssportbikes.com/products/NFLYCARB90_98.html
http://nicholssportbikes.com/products/NFLYCARB98.html

[Rudemouthsky]

I just ordered that Nichols from MW, it was marked down to $120. I can't resist a bargain, thanks for the tip Koko!

[ChrisK]

Good luck with it all! 

[ducatiz]

I have a 2000 900ssie that I am tearing down to put the engine into my 95 900sp. 

[Rudemouthsky]

Just thought of something.. would it be possible to retard my timing for the high comps simply by moving the metal pickup on this Nichols flywheel, and if so, how?

[koko64]

Dont mess with it, dont mess with ignition pick ups either.!
Just get a preprogramed Ignitech and plug it in. There are people here who can suggest a safe set of numbers to use for a nice, progressive advance curve.

[Rudemouthsky]

lol, thanks for the vote of confidence!! haha.

I'm still a bit confused tho, I can't change the ignition timing on my bike with the Ignitech bc I don't have TPS or MAP...you and Brad are altering the advance curve with it, and that achieves the same desired effect? I get how retarding the timing will reduce or eliminate knock/ping but I still don't quite understand what you're suggesting I have the Ignitech do....explain it like I'm an idiot, because I pretty much am. I'm still trying to absorb Brad's article on it.

[koko64]

I was just trying to give you the best, easiest option. 

I would just program a unit now without messing with pick ups, etc. Brad explored the aspects of the oem ignition system to understand how it works and the tuning parameters. He was doing the science, documenting the process and sharing the knowledge. We all benefit from the outcome.

The Ignitech unit can be programed via laptop with the right software to alter the ignition curve. If your unit came with a disc you can do it, if not, the vendor may have the software. You dont need a TPS. A TPS offers extra ignition tuning dimensions, but dont worry about it. My carbs dont have a TPS and most FCRs on Ducatis dont.

I would suggest getting the unit programed for a hi comp motor by someone on the forum with the correct software. They can set the rev limiter, etc.

[koko64]

Besides retarding the max advance, the ignition curve can be made more gradual. Because the oem curve maxes out early at low revs, the curve ramps up real quick which is too much for a high comp motor.
Someone might have charts.

Anyway, a good ignition map (and fuel) will protect your motor and improve performance.
You can custom map the ignition to suit the motor mods as they evolve. Someone up there will be able to do that for your unit for low$$ or beer while your motor is built.

[memper]

 

[Rudemouthsky]

Flywheel's OTW.



Pistons...Would have liked to give a sponsor the biz but they're insanely cheap (JE for 900, $250/std or big bore!!) on eBay. Sorry but that's $70, and I need to buy useless crap like this with the savings...a DP alloy "spoiler"? to match my DP alloy fender 








The creeper van just got bondo'd and is getting hit with gloss black, prob gonna do my Monster while I'm at it. The matte/flat is gettin old.