[Vwdiesel] Crankshaft talks --- ( cranky geezer stuff )
H.Hagar
h_hagar at prcn.org
Tue Jun 22 19:12:08 EDT 2004
The highly loaded crank-pin, at cylinder 4, ?
Strengthening the crankshaft --- why ? suddenly I understand.
I never before gave a thought to the fact that all the torque has to
be transmitted through the crank pins.
So if we run a VW at 100 hp ... pin # 1 handles 25 HP # 2 50 HP and so on.
Ideally # 4 should be fatter. than # 1.
If VW had to improve the 1.6 L NA crank for the turbo , there are many things to
consider. ---- most desirable would be a forged crank of best available alloy.
Then shot peening ---- then x-ray and magnaflux inspection. All costly. so I
expect they compromised. Do cranks break ? sure do --- as many GM rocket
owners found out. I have 2 broken cranks from 5.7 GM V8 diesels right here.
I have seen John Deere cranks broken (2 cylinder) dozer. Airhead cranks break.
James Hansen some time back explained the difference between a cast and a forged shaft.
One thing I know for sure , is that a forged crank is way more expensive.
I never shot peened any rods or what not but I have the shots and the machine.
Am I wrong in thinking that a lot of VW cranks are forged ? I saw a film from Germany
showing how they made a crank at VW the whole procedure. Very impressive
show. Discovery or history channel ---- a show called Automobiles or the likes.
What it showed was forging.
Question : Does anyone know if VW use cast cranks at all ?.
Hagar.
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