Split a crankshaft?

[Jordan]

The point I was trying to make though (and i did mention it in there) was that the arbor plate "bed" if you will of my smaller press wont hold the crank. 100 ton- wont fit at all, 200 ton will fit just barely, cant align it properly, then its on to the 600 ton dake at work

Why use a dagger when a meataxe will do the same job?

The advantage of a bigger press is not just to get enough working space, they are also more rigid. It's hard to control things when the frame bends, and then springs back and pushes your job possibly more than you planned.
A good quality 20 ton general use press should have plenty of overhead, in terms of both size and rigidity, for motorcycle cranks.

A vice made of cast iron doesn't flex like a steel one, by the way folks.

[Rick]

A typical 400 ton press will be 25 feet tall, weigh 100,000 lbs, and have a 75 horsepower motor running the pump. With 400 tons you could press that pin in sideways- wouldn't even need a hole in the crankshaft halves. I'm expecting there's an extra '0' in there. Working as a millwright in the eighties I installed a couple of 400 ton presses- I've never seen a 600 ton unit- 600 tons is some serious power.
If you've never seen a press this size, here's a Youtube video:
http://www.youtube.com/watch?v=YCgbQ30asr8

[joe46ho]

Rick, your right on the typo. Just rechecked that info...

But no i did not mean 60 tons
our small (old tire press) is 200 metric tons (which is 220 tons i believe)

our new tire press is 400 metric tons...or about 440 tons.

Also we arent comparing apples to apples here. that press you are showing isnt even the same type of press im talking about, its not all about how tall it is and how much it weighs.

The press you depict there is a die/forming press, no one ever uses those on a crankshaft, obviously i was refering to a standard h-frame press, and while a 200 ton h frame press is big, it is no where near that big, even our 400 ton press fits inside our building (20 foot cielings) it fits well, and was set in place with a 60,000 lb forklift, and doesnt weigh anywhere near the capacity of that truck.

Rick, a 20 ton press might work force wise...however find me a 20 ton press that will accept the o.d. of the crankshaft flywheels, not saying they dont exist, but i have tried several 20/40 ton presses at my shop and my customers shops (i work for caterpillar as a field tech, so i use many other peoples tooling at times) I have even tried our 100 ton, and it would work in a pinch, but flexes like crazy, and cant really be aligned properly to be used safely.

But...i digress the main purpose of this thread was to explain that you can not ASSUME that a ducati big-end is EVER in good shape. ANYONE HAVE A VALID ARGUMENT AGAINST THAT ?

AND THE MAIN REASON I USE THAT PRESS ? NOT ROCKET SCIENCE, ITS BECAUSE IT WORKS, AND ITS WHAT I HAVE THE USE OF. WOULD I CARE TO BUILD A CUSTOM TOOL THAT WAS ONLY USED TO DO DUCATI SINGLE CRANKS ? IF I DIDNT ALREADY HAVE A PRESS TO DO IT YES OF COURSE I WOULD (AS BILL DID) BUT I USE THAT PRESS FOR A WHOLE LOT MORE THAN CRANKSHAFTS, AND ITS AT MY DISPOSAL ALREADY, SO NO I WONT BE RUSHING OUT TO BUY/OR BUILD A DIFFERENT ONE ANYTIME SOON.

Jim, listen to whoever you want, do whatever you want...But if you dont at least have your crank disassembled and checked, you will most likely regret it.

Im off this topic, been beat into the ground now, if anyone wants to trade pictures of all the different kinds and sizes of presses, there is probably a industrial equipment forum around maybe we can get on there...

[Bevel bob]

Its likely that you will need new plugs (similar to core plugs) at each end of the pin plus a new sludge trap plug.My local engineer (not a Ducati Man) stripped my crank made the above parts and reassembled the crank with the correct side play and trued it to about 1 thou accuracy ,all for 40 pounds!! what a result! he also has vintage 30's singles so is well up to the job , am i a lucky boy or what?.I will have to treat him to a few beers.

[joe46ho]

Yes you do owe him a few beers

Bob is right, the plugs are odd, Ive bought them from lacey in the past, hard to find certain things in the u.s. 18 x 1.0 for the trap plug, the endcaps are metric welch plugs, also for a lot less $ than nos ones, you can find the roll pin/oil restrictor (simply a roll pin of the measured diameter 5.4mm x 12mm) considered a 5mm roll pin, in mcmaster-carr catalog page 3301 in mine, along with the endplugs for the crank, they are called an "extended point set screw" page 3064 in mcmaster-carr, havent been able to find them anywhere esle, they are actually better than the originals i think, because instead of the flat head, they accept a metric allen wrench, and come out way easier...

Joe

[Rick]

...Rick, a 20 ton press might work force wise...however find me a 20 ton press that will accept the o.d. of the crankshaft flywheels...:

I think most people do this above the press bed, so you don't need to have a gap big enough for the flywheels, like this:

crank fixture.jpg

This is my home made press- worked fine for 750 twin crankshafts:

press.jpg

I bought an electric pump, but prefer to do it with the hand pump- I get some feedback if things start to bind.
Rick

[joe46ho]

Rick,

Im not a big fan of using the elec. pump either, but I dont really have a choice on our shop press...

and I have seen that setup depicted, and your right if you had a setup like that, the size of the arbor plate bed wouldnt much matter, only problem i have is (and i realize some cranks will be tighter than others) i made 2 plates that slide between the crankshaft throws, they where notched/clearanced etc to fit very nice, and when trying to press apart my first crank they deflected badly, and bent... i ended up making better plates (with better steel) but still if it took this much force to press apart that crank, a setup like the one in the picture would just not work, it would be half as strong as what i was using at best, i was unpleasantly surprised at the effort/force it took honestly... Since I have no specs to go by i can only assume that some cranks where fit together to tightly at the factory (it would be nice to be able to verify this, or disprove it though) Without any specs to go by, i have simply cleaned all the parts, inspected everything, replaced what was needed, and gone on about my business....havent had any problems yet, but i really wish someone had the specs ducati used. Because even though they arent in the manual I have here...someone surely has them, because the factory had them at some point.

If anyone has any info at all about how Ducati did these at the factoy, and/or the specs. I (and a lot of other people) would love to hear about it....

Joe

[wcorey]

But...i digress the main purpose of this thread was to explain that you can not ASSUME that a ducati big-end is EVER in good shape. ANYONE HAVE A VALID ARGUMENT AGAINST THAT ?

Not saying you're wrong, I just don't like absolutes...
By your own reasoning the argument goes both ways, if the axial and radial movement is within spec and it feels smooth you can't assume it's not in good shape either... There are various opinions on this, a few respected professionals I've talked to have no problem using a clean in spec but unknown crank, though likely not on a race bike or for a high paying customer who expects near perfection. I'm sure if you try to nail someone down for a definitive answer, the reputation preserving, safe default response is going to be dis-assembly.
There are many judgement calls that can be made in doing a build, usually revolving around budget and intended usage. It's one thing if you're flying the bike to Italy for the MotoGiro but with the small amount of mostly easy miles the majority of these bikes see, even a marginal crank can last many seasons.
And the poor condition of a bunch of your "it feels ok..." ebay cranks qualifies little. Why do you think they're on ebay with somewhat ambiguous descriptions in the fist place...?

Bill

[joe46ho]

Bill, I dont disagree with you, maybe im being misunderstood here, I myself have used a crank without disassembly, but...(and this is a big reason) it wasnt of "unknown origin" and was from a trusted source, out of a running engine. The main reason I like to play it safe is because of the total disregard some previous owners have had, for maintaining there engines, which then leads to the whole problem of the crank packed with sludge/big end oiling problems, etc... And yes you are also right in that, if i build an engine for someone, there is no chance at all i would let it go, and not check it out. Simply because they are going to be paying me their hard earned $$ to see that its done right, and I would be sick to my stomach if It developed a rod-knock in a hundred miles or so... There are actually a lot of good parts on ebay that can be had (for a price of course) but this thing with people selling junk parts saying they are "in great shape" etc. is running rampant these days, luckily I have only been screwed over a couple times, and since I used paypal, I was able to recover my money...
All Im saying in the end is, err on the side of safety, never assume anything...

[Eldert]

i would say split the crank en inspect , replace rollers and remove endcaps and clean bigendpin inside .
clean out the slugetrap to

lots of bigends went out due to oil starvation from a bigendpin that was full of sludge and had
to oiling holes blocked .

BE pin endcaps are also available from Fabory in boxes of 20 and are called expension plugs



Eldert