Is the engine's bottom mount rod where it's weight is balanced?

[Smeggy]

I would imagine the designers of that time, on deciding to put a mounting rod underneath somewhere, would prob run it under the engine's lateral 'pivot point', or whatever it's called. Anyone know?

Maybe I've just got a little OCD.

 

[TwoManyXS1Bs]

Good engineering takes into account "load paths", how to resolve internal force dynamics, so that things don't fly apart. But, there's always compromises in designs. Can't have multiple things occupying the same place at the same time, like the crank bearing seats, sump filter, and bottom engine mount. Plus, there's the "ideal" expensive ways, versus "good 'nuff" cost effectiveness and manufacturability.

Gets really interesting when the marketing guys take charge.

But, to answer your question specifically, we'd need to find the guys on the original design teams (probably need a shovel for that), and quiz them (with an army of translators nearby).

Just for fun, you could take a rod and pass it thru any engine mount, rotate the engine appropriately, and maybe get it to balance...

 

[Signal]

I have been told to use the crankshaft as the centre of gravity for parallel twins and across the frame inline fours / triples. It seems to work out near enough for our purposes.
When it comes to other engine layouts I have no clue.

 

[TwoManyXS1Bs]

Aircraft engines use the "dynafocal engine mount" system. All the mounts are aimed inwards, in a pyramid fashion, towards the crank center of mass...

 

[Smeggy]

Thanks for the replies. I'm building an engine stand out of some old box tube. I'll be attaching it to a large slab of discarded kitchen worktop (about the size of a sink!) so it deff won't fall over, but looking at the examples of stands available in the TECH area of this site got me wondering if there was a magic ratio, or 50/50. It's been a long time since my engine was in it's frame, but thinking on it, I'm now picturing it falling forwards when all supports but that big rod were taken off.

 

[TwoManyXS1Bs]

Oh! Hahaha. For an engine stand!
Man, did I go off on a tangent...

 

[Smeggy]

Interesting though.

 

[gggGary]

CG is towards the front about at the crank like Signal sez. without a stand or block under the front, an engine on a flat surface flops forward.
If I had to guess I'd put CG about 2" ahead of that bottom mount bolt. ie have your countertop stick out well to the front. um the stuctural integrity of chip core is very low when dry, water or oil soaked it approaches nil. It's basically sawdust and cheap glue.

 

[retiredgentleman]

If you're going to do a top end re build, all you need is a flat bench to work on. With the sump plate removed, the engine will sit very nicely with one 2 X 4 under it. Also the bench allows you to rotate the engine forward so that it's resting on its nose. The "on the nose" position is very handy for installing the cylinders/pistons.

 

[Smeggy]

Thanks again.