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PostPosted: Sat Jul 09, 2011 9:10 pm
by DrDiana
Hi 1eye,

I must be having failure of my control systems. I'm not sure what you just said.

I'll sleep and try reading it again tomorrow. Hopefully, more brain cells will be firing in the morning.
:)

PostPosted: Sun Jul 10, 2011 12:57 am
by Johnson
(I used to have a diesel car that would start running on its crankcase oil)...


I had one of those too! A 79 Diesel Rabbit (bullet proof car that would run on its own crankcase oil!). The acceleration seemed infinite, and I had to stand on the brakes in 4th gear to stall it out - even with the ignition turned off. I had to disconnect the blow-by hose (collateral venous return) to prevent it happening again.

There is no real control system (other than basic physics) for such a primtive, but highly efficient design. It's operator-dependent.

PostPosted: Sun Jul 10, 2011 9:17 am
by 1eye
Johnson wrote:
(I used to have a diesel car that would start running on its crankcase oil)...


I had one of those too! A 79 Diesel Rabbit (bullet proof car that would run on its own crankcase oil!). The acceleration seemed infinite, and I had to stand on the brakes in 4th gear to stall it out - even with the ignition turned off. I had to disconnect the blow-by hose (collateral venous return) to prevent it happening again.

There is no real control system (other than basic physics) for such a primtive, but highly efficient design. It's operator-dependent.


Mine was a 77. Same deal. A bus tried to crush it, but it still would not die. The body shop man cut the engine mount in half, and my insurance company cut me off, but German ingenuity got it back on the road. Vampire diesel, I had tried the wooden-stake hood ornament, but no joy. Grew into a Tannenbaum. I had to have special silver impregnated sugar cubes placed in the gas tank.

You're both right: control systems are not simple; runaway rabbits are not a good example.

Anyway, anything more than zero positive feedback causes oscillation, and in that situation gain turns on you.