BobK207 wrote:
On Mar 14, 2:10 pm, (big e lewis) wrote:

I am building an engine hoist framework, to hang a chainfall. I will be
using it to pull and install engines and trans in my racecar and other
various vehicles. I planned on using 4x4's for the uprights and the top
crossboard. The crossboard, that the chainfall will hang from, will be
10' long. Is a 4x4 strong enough, or should I use a 4x6, or something
else entirely? I figure the engine/trans combos shouldn't be more than
700 or 800#. Plus maybe a momentary higher weight when a mount hangs up,
and the front of the car lifts up a little with the engine. Any
comments/thoughts are appreciated! Thanks, Big E


Big E-

I would suggest that you look for a small A-frame style gantry on
Craigslist

Take a look at mcmaster.com under floor crane to get an idea of what
the design looks like in steel.

Timber is pretty variable material & the strength from piece to piece
can vary a lot.

A 4x4 is way undersized ... a 4x6 is getting closer.

The connection details are very important to performance of the
system.

Wood though easy to work with isn't ideal material for this
application.

Several 100's of pounds of auto components suspended chest high off
the ground is a non-trivial activity that could seriously hurt or kill
someone if it falls.

Lifting systems are required to have substantial safety margin....your
home brew solution, while doable (if you know what you're doing),
could be a disaster waiting to happen.

cheers
Bob

I'd design for at least 1500#, for example, a Studebaker V-8 weighs over
600 lbs. fully dressed with clutch and bellhousing but without
transmission. I'd imagine if you work on 4x4s you could conceivably
pull an engine, automatic transmission, and transfer case as a unit,
which even with a modern, lightweight engine and trans case could weigh
over 1000# all up. like Bob says, you don't want to find out that you
underbuilt the hard way.

nate

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