What is the best charging and ignition system for wide case 450

[LaceyDucati]

Responding to:

I was interested in this post when it switched to cranks. We messed up the first 900SS crank with a gube on my part - one that was corrected - no more crank problems. The absolute best combination of rod length versus bore and stroke is 6" rod center to center - 4" bore and 3" stroke or any combination using that formula.. I first saw this in the late 60's with the Z28 Camaro. Later racing an SV650, I learned that the same formula was applied by Suzuki on many of their later sport bikes. I believe most of the drag racers and other types of race engine builders still adhere to this formula or close to it.
I seriously doubt the reliability of a crankshaft has anything to do with the Italians quality of materials or precision in manufacturing. There are too many other variables. Example - most folks think that any name brand oil is of a reasonable quality or they couldn't sell it - not true. The way I learned this is a tale for a different day.

Not sure what the relevance of a plain bearing Suzuki SV650 or car crank has to do with the issues of a roller bearing crank. Also statements regarding 6" rods and various other measurements have little practical relevance to a Ducati single either. Many other modern performance 4 stroke singles using roller bearings, fall well outside these dimensions without issue.

On the basis not all original Ducati singles had premature failure, variable quality of components and build are quite likely.

Regarding oil, that you seem to be suggesting is the issue. I will add that of my customers using my cranks and new rod components use a vast array of different oils, of different grades and makes and there is as far as I can see no obvious advantages of one particular oil regarding bigends (30 years continuous experience of bevel Ducatis) Cams and rockers in race use are however probably a different subject.

I know we are well off subject here, but of further evidence of OEM quality I will share my days inspection of a low mileage 350 crank, my guess would be hundreds of miles rather than thousands. This crank has most definitely not been stripped from the factory.

Firstly on removing the first wheel it can be seen the non chamfered oil hole on the crank pin has broached the pin bore. As can be seen, the main oil feed is loaded with swarf ready for "long life" The swarf was loose and easily removed from the hole, adding further evidence that there is not any great flow or "pressure" (as I've previously stated this is not a high pressure or even volume feed design) to the bigend.

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Next as can be seen from the following the pin and cage is near new, no wear on the pin from the side shims and the cage is nearly unmarked.

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Next you will note the swarf from the crank pin is sticking to the rollers...That's because the rollers are magnetic! Niether the crank pin or the crank thrust faces are magnetic. The only other part of the crank that is magnetic is the drive side shaft from contact with the flywheel. Why the factory thought magnetic rollers would be a good idea....I jest! I will add here that I spend time checking and demagnetising all rod components on my kits and it is another good reason to use non ferrous side shims.

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To be continued...

[Duccout]

Wow! Obviously cleanliness was not a priority at Ducati.

[LaceyDucati]

Finally, the bigend eye still sporting it's honing marks.....and the start of the surface hardness beginning to fail.

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I'm not saying all OEM kits were crap, but many were clearly not likely to last long.

Any amount of: fancy oil, straight oil, synthetic oil, caster oil, filtration modifications, oil changes, warming up, etc, etc, will not overcome poor components and after 30 years of working on these engines I'm "buying into" the evidence I see. This crank is one of many hundreds I've inspected. This one is just an example of some failings that will lead to premature failure of the bigend. To be fair the pin on this kit was parallel, but that certainly wasn't always the case.

I will add many other manufactures the world over successfully manufacture motorcycles with not to dissimilar configurations of: bore, stroke, rod length, using roller bearing bigends without significant issue. I will also finally add (as I've stated before), using quality well assembled components, I haven't experienced any real issues with bigends. I'm not promoting my own products here as I've used various other manufacturers kits that check out okay without issue either.

Regards Nigel

[Duccout]

Nigel, here's a question for you: do you think that Mototrans big-ends were any better made, or about the same as the Italian ones?

[LaceyDucati]

Wow! Obviously cleanliness was not a priority at Ducati.

Having stripped some new unused engines and cranks I was fairly horrified what I found: missing shims, loose parts in the sump, general grime and swarf...crossed threaded sludge traps, rod thrust shims trapped under the crank pin step.....I could go on! Generally the earlier the bikes the better and towards the end of production someone really did'nt/could'nt give a dam at the factory. Again it's not hard and fast and I don't really know how widespread the issues were as I probably only ever saw the failed engines/components.

I also have a suspicion that after production of the bevel single engines ceased, quite a lot of faulty miss machined parts escaped in factory clear outs into the European market as NOS parts. That can be the only explanation of NOS cases where you can't get a gearbox in them because the bearing pitch is to tight. Also NOS Desmo heads that lock up solid and won't turn over because the spindle positions etc are so far out. Maybe some of the above NOS cranks and engines were also failures not used at the factory and hid in dark rooms....

Regarding Mototrans, I think the build quality was much the same on the stuff I've seen and of course all the 1975 Italian single engines were made in the Mototrans factory anyway. I certainly wouldn't say Mototrans bikes were intrinsically overall any worse than the later Italian bikes for build quality (some parts better some parts worse)

Regards Nigel

[Duccout]

Hi Nigel,

I imagine that as Bologna was the centre of Italian Communism, and the Ducati factory was state-owned, a situation comparable to British Leyland existed, and workers had a 'couldn't care less' attitude. If only Italians were Germans or Japanese...... But then the bikes would not have that intrinsic Italian flair and passion. You pay's yer money and makes yer choice......

Thanks for the insight.

Colin