"Lieutenant Scott" wrote in message
newsp.wdo8ojpuytk5n5@i7-940...
On Wed, 02 May 2012 21:30:17 +0100, John Williamson
wrote:

Lieutenant Scott wrote:
On Wed, 02 May 2012 20:45:48 +0100, Rod Speed
wrote:



"Lieutenant Scott" wrote in message
newsp.wdoz0r10ytk5n5@i7-940...
On Wed, 02 May 2012 08:21:07 +0100, John Williamson
wrote:

Lieutenant Scott wrote:





Work out the torque at the driving wheels, which will let you work
out
the acceleration, then compare that with the force required to
decelerate the mass of the car at about ten times that accleration.
For
most cars, maximum acceleration is well under 1G, while the
deceleration
when you're snatching a stump is at least 5G. The safety margins are
on
the order of 100%, not 500%.

Well the tow bar is still on the car.


Then you must be driving a tank. The towbars on most cars are
fastened
to metal which is less than 1mm thick. Even my Land Rover has a
chassis
which is less than 3mm thick at the point of attachment, and that's
reinforced for kinetic energy recovery, which is a posh name for
doing
to bogged down vehicles what you were doing to trees.

I'm thinking of the steel tubes which run from the towbar itself to
the
chassis, they're pretty thick.

I can't believe those are fastened to metal 1mm thick, that would bend
with the weight of the towbar, and definitely if you for example
stood on
the towbar, which simply doesn't happen.


Still safe. I left London a decade ago. London's also big enough that
you can always find a fool who'll buy anything you want to sell. ;-)

It had LPG conversion. Don't. Petrol engines were not designed to
use
LPG, and shouldn't be made to do so.

Works fine for all the taxis in my town for decades now
and quite a few other cars too.

According to my LPG fitter, certain Honda engines have "softer valve
seats" (where the word "seats" could have been something else).

It was a 1999 Honda CRV 2 litre petrol.

I find that a little odd.

All engines capable of using unleaded petrol should be able to use LPG
without any problems. All Honda engines made after 1985 are compatible
with unleaded. Soft valve seats are normally only found on vehicles
which use the lead in the petrol as a lubricant for the unhardened
valves and seats. Replacing the valve seats is often done when the
cylinder head is off for other reasons.

I was told it was due to the higher burning temperature of the LPG. In
fact the first fitter I asked refused to do it at all.

But presumably he doesn't refuse to do it to all cars,
so its likely that just that car wasn't suited to it.