Well THIS was exciting... and unexpected... and dangerous!!!

[Kern Dog]

I borrowed a home made engine hoist from a friend that seemed robust but had a small hydraulic ram. As I pulled a 400 and 727 over the core support, the ram bent like a taco similar to this:

The engine and trans slammed to the floor!

By the way, I didn't not mean THIS taco....

 

[DeltaV]

By the way, I didn't not mean THIS taco....

Yeah, right!!

 

[Krooser]

What ram?

 

[Pops1967GTX]

Do I see a cigarette in your picture?

There's nothing logical about smoking. At any point.

https://va.media.tumblr.com/tumblr_subzzwHMyz1y10rdd.mp4

 

[1KoolBee]

I’m glad no one was hurt! Hopefully you can salvage most of the engine parts.

Flat stock is very strong in tension, just not compression. Old bridges use flat stock (large scale) in the same application. Looking at the orientation of the hoist the straps are always under tension, as previously noted it takes the stress off of the mounting bolts. Without the straps it’s trying to twist the nut/bolt head off.

The fact the bolts were undersized is a double whammy.

View attachment 1945898

Exactly! Chicom pickers and engine stands have little safety margin. Don’t compromise the structure by jury rigging it. Those straps can probably support 1000 lbs in tension. The fact that your picker failed on a 318 should be cause for pause and reflection!

 

[thehemikid]

In engineering terms, without the straps, your mast is under shear stress, with the straps, it’s under compression, and the straps under tension.
I would bet you could lift an engine without any nuts on the bolts of the mast when properly assembled.

On your last statement, I was thinking the same thing earlier in the thread.

A few day ago I was in the process of putting the 6.1 block back onto the engine stand when I remembered that scenario. So I lifted the block high enough to put some wood blocks under for safety then loosened the bolts of the mast's bottom plate but left the nuts on the under side with a full nut just in case.

With both bolts/nuts loose, I could pull the bolts up or spin the heads with just my fingers showing there was no vertical or side load for the moment. Shook the motor pretty good but not violently to see if the plate would shift and create a small side load on the bolts but it didn't. But I believe it could if rolling the hoist with a load and say one of the wheels snag a small rock on the floor.

So I thought maybe the paint had stuck the mast plate to the square cross tubing it sets on. Pry bar'd the plate up and sat it back down showed they weren't. I could've taken the bolts out but there was no need to go that far.

Appears to me as I've thought for a good while,...that the base bolts are mainly to keep the base secured from moving, left, right, fore, or aft. Their work is in shear not tension.

I rest my case, ...on the base bolts.

 

[WS23U1]

Glad you posted this. It should make everyone look over their tools of the trade for safety reasons. Thank you.

 

[Daves69]

Way back early '80s, I built my hoist to fit between the wheel wells of my pickup, assemble / breakdown quick, and lean against a wall for storage.

The mast only slides over a length of 2" X 3" tube that locates it without bolting.

I

 

[thehemikid]

Woop, there it is!