The Elephant that was a Duck

[onformula1]

Sweet bike! Desmodromic engines are very cool.
I had a street bike magazine editor friend connection where we got to "break in" all kinds of bikes before shootouts or tests.
I revalved & respunged a bunch of these bikes.
The 916 & 996 were my favorites.
Keep up the great work.

[onformula1]

Forgot, I love the D&D's

[El Camexican]

Sweet bike! Desmodromic engines are very cool.
I had a street bike magazine editor friend connection where we got to "break in" all kinds of bikes before shootouts or tests.
I revalved & respunged a bunch of these bikes.
The 916 & 996 were my favorites.
Keep up the great work.

Sounds like a dream job. I've never ridden a 4V Duck, but I'll bet it's a blast. FYI, D&D seems to have has a falling out with the Ducati's. I called to see if they had a couple replacement parts to allow me to run the stock head pipes with the upswept cans and got a very cold "we don't do Ducati's anymore".

[onformula1]

Sad for them to ditch a iconic bike, soooo much cooler than a HD...LOL

[El Camexican]

Sad for them to ditch a iconic bike, soooo much cooler than a HD...LOL

Gotta follow the money and the Harley market has plenty. Vance & Hines went that way too. Besides, when you build Harley accessories you don't have to change your tooling very often

[onformula1]

Gotta follow the money and the Harley market has plenty. Vance & Hines went that way too. Besides, when you build Harley accessories you don't have to change your tooling very often

Very true, same boat anchor motor for ever!

You know about these guys right?

http://www.ferracci.com/

[El Camexican]

You know about these guys right?

http://www.ferracci.com/

Yea, but I recall they were into the 4 valve bikes. Loved watching their Superbikes honk around the tracks back in the day.

[El Camexican]

With Trikefest behind me I finally got around to tearing this thing down for a facelift. The plan was to gusset the frame, remove any unneeded brackets, add a battery box, set the valves, powder coat the frame and add a little bling to the fairly new engine. Well that was the plan... The first issue was removing the frame from the engine (no I didn't say that backwards) So a stand was build that allowed it to be installed while the bikes is on stands and then lowered an 1/8" to the ground where it remains until it is stripped to the engine.

The good news is that the valves are within spec. The bad news is that the crank bearings are shot after 6,500 street miles and a couple track days. It also sat on the dyno a couple times, so that may not have helped either. This engine is going to be the most intricate rebuild I’ve ever done. A bunch of proprietary tools are needed to take it apart and the assembly process involves at least one pre-assembly of the cases to determine axial pre-load on the crankshaft bearings and transmission shafts.

I managed to split the cases yesterday, but I’m holding off on removing the transmission until I have everything I need to put it back together. Lots of little parts that look almost the same as other little parts on these engines. I guess some people would say they’re simple and I’d agree, but simple with the addition of dozens of shims, clips, pins and retainers added to the mix. I literally have a 2 cylinder engine spread out over 40 sq. feet of table tops and 3 large plastic bins and the trans is still in it! I haven’t had to take a bike engine to a mechanic for assembly in my life, but if it ever happens it may be with this one. Fortunately I’m taking lots of reference photos, but some things are not in the manual.

For example the crankshaft; It’s a Falicon Super Light with Carrillo rods. Cool would be an understatement, but the left end of the crank appears to be from another engine as does the flywheel. The manual says to line up the key slot with the dimple on the flywheel, so I pulled it off without a thought only to realize mine doesn’t have a dot

Then there’s the worn-out crank bearings. I was feeling a slight intermittent “ing” sensation in my crotch when I rode it briefly. Mostly around 4,000 to 6,000 rpm, nothing under or over that from what I could tell, but not having ridden the thing for 20 years I figured maybe it was just a carb syncing issue.

The first oddity I found was that while still assembled the crank had zero axial play which is exactly what it’s supposed to have. In fact they should have .002” of preload in them when cold and fresh. However, it had enough radial play to make a “clunk” sound when moved up and down. My first Internet search (before I split the cases) came up with a theory that the synthetic oil had caused the ball bearings to slide in the groove instead of turn and flat spotted them, but that seemed like an old wives tale. The story went that some poor SOB lost his Ducati warrantee for using synthetic oil, but there are way more posts on the Internet about Ducati’s coming off the showroom floor with incorrectly shimmed bearings.

After splitting the case and pulling one bearing it turned out that the balls seem perfectly round and that there is no visible scoring in the inner race (I haven’t cut it opened yet). No large bits of metal in the oil either. They seem to have eaten themselves up at a very slow rate. Oddly enough the removed bearing has about the same axial and radial play, but the crank had no end play? WTF? It should have had a bunch of end play as well. I’m thinking they put too many shims in there. There is one shim that measures .020mm on the RH side and two that combine for .063mm on the LH side, but with the bearings worn out there is no way to know what it was originally. BUT, get this. There is evidence that the bearing had turned a few revolutions inside the steel housing that is pressed into the cases at the factory. The bearings are a snug fit, they can be tapped out easily with a little heat and a , they are not a high pressure press fit, so what would cause them to turn in the casing? I’m thinking excess lateral pressure would do it.

So next I start looking for replacement bearings. Seems Ducati specified one RPH bearing and one NSK (same manufacture) These are angular contact bearings and come in a variety of load angles. Supposedly 18 degrees for Ducati, but the one bearing in this engine that I’ve removed is a KOYO bearing and all indications are that it has a 40 degree load angle.

I pulled out the shop bills from 1996 bills and they show a Ducati part number as well as an industry part number and they cross over to RPH and NSK respectively.

In short it looks like the shop supplied cheaper non-spec bearings and/or may have installed them incorrectly. Unfortunately I don’t know which it is, so I can’t risk installing SKF or KOYO bearings. Hell, at this point I’m not even sure I want to trust an RPH bearing if it doesn’t come in a Ducati wrapper I guess I’ll see what the dealer quotes me for OEM and go from there. No other issues I can see so far. I guess the bushings on either side cover held the crank in place enough to keep it from tearing up. I’d rather not pull the rod caps, but likely should while I’m in there.

Meanwhile all the bare aluminum bits went out for chrome including the swing-arm and the same place is striping and plating all the hardware in yellow-chromate zinc. The frame was coated on teh weekend and it looks great. If it ever runs again it will be an eye popper

More pics to come.

[big specht]

Lol I wounder who dug this old thread up. It's good to see you didn't give up on it.

[tripledog]

I love V twins and I can't deny, though the crank bearings have been fried.
It's a curse, can only type one verse, please don't axe me why.


I'll be watching.

[Jmoozy27]

Not sure how I ever missed this. That's one helluva build, nico. If anyone is up to the challenge. It be you sir.

[El Camexican]

Received a quote on engine bearings and seals today. "Gulp" is a word that comes to mind.

Here's a few more for now...

[bkm]

That is such a cool bike. Remind me to never buy one.

Sent from my SM-G900V using Tapatalk

[El Camexican]

That is such a cool bike. Remind me to never buy one.

Sent from my SM-G900V using Tapatalk

Ditto. It will be my last. Starting to remind me of those well used "cheap" Lambo's you see pop up once in a while that seem affordable if you could just cut back on a few luxuries like eating and a roof... till you realize a tune up and an oil change will set you back about the same as the car.

Ever hear the expression: "Beautiful Italian piece of sh*t" ? Or how about: "Titanium fasteners, the final stage of Ducati inflicted insanity" Let me tell you, its a real thing!

[YTZ drew]

The closest I'll likely ever come to owning a duck is the original Honda voltage regulator on my '06 599, which has "Ducati Energia" inked stamped on it. That's an amazing piece of engineering you have there Nico. I look forward to pics of the final result. I'm sure it will be astounding.