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Engine Stand Bolts

tnfastback

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Getting ready to put my short block that the machine shop assembled on the engine stand. I think I remember somebody telling me or reading to use 4 long SBC starter bolts to mount on stand. Is this correct?? Sorry this is my first Mopar build.
 
Doesn’t matter a whole bunch. Try to spread out the arms and make sure you have 1-1/2 - 2x the diameter of the bolt in thread engagement. Even for a crappy bolt the weight of an engine isn’t much load.
 
You realize we'll need pics of the progress, right?:thumbsup:
 
Will post in my build thread. Going to get engine in then put wheels on so we can set her on the ground and adjust the ride height.
 
Getting engine a position so it isn't bottom heavy or top heavy when heads are on is important. I like cam plug to be even with where stand rotates on a Hemi. May different on yours.
 
Doesn’t matter a whole bunch. Try to spread out the arms and make sure you have 1-1/2 - 2x the diameter of the bolt in thread engagement. Even for a crappy bolt the weight of an engine isn’t much load.
I find it amazing that a 550 lb engine can be cantilevered out only being suspended by 4 little 3/8" bolts.
Those manifold lift plates with 4 even smaller 5/16" bolts seems reasonable but the lateral load of the engine on 4 small bolts just standing out there boggles the mind.
 
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550/4=137.5 lbs per bolt, not so hard to believe.
 
I find it amazing that a 550 lb engine can be cantilevered out only being suspended by 4 little 3/8" bolts.
Those manifold lift plates with 4 even smaller 5/16" bolts seems reasonable but the lateral load of the engine on 4 small bolts just standing out there boggles the mind.

Good to ask! If
I find it amazing that a 550 lb engine can be cantilevered out only being suspended by 4 little 3/8" bolts.
Those manifold lift plates with 4 even smaller 5/16" bolts seems reasonable but the lateral load of the engine on 4 small bolts just standing out there boggles the mind.

Always good to question people about this. Here's the detail on my reasoning. Let's figure it's a 1000 lb engine just for comfort. Let's also say it's 2' long with the center of it 1' from the stand. This gives us two basic forces on the stand, a downward force of 1000# and a torque of 1000 lb-ft. The downward force is pretty easy, just figure it's 1000#/4 bolts so 250# of shear per bolt. The torque is a little more difficult. Has a lot to do with the spread of the bolts on the tranny flange. Let's say you get them 9" apart from the upper ones to the lower ones. The lower ones are getting all compression, nothing for the bolts to do except the shear from the weight. The upper ones are trying to get ripped out though. 1000lb-ft/9" (.75 ft) = 1333#, but there are two of them so 667# of tension each plus 250# of shear each. sqrt(667²+250²)=712#. Then we have the 3/8-16 bolts. Tap drill for that is 5/16, so: .312²*3.1416/4 = .0765 in² of steel. Now figure it's really crappy steel, worse than some aluminum, and has an ultimate tensile strength of 40000 ksi. 40000*.0765 = 3058# to break the screw against the 712# you'll put on it with a 1000# engine. So you've got a safety factor of 4+ which should be just fine to handle head bolt torquing etc. The important things here like in my original note are getting that spread, you can see how if 9" went to 4.5" you'd double the tension, and getting enough thread engagement so you don't pull the threads out. 1-1/2x diameter or greater is a good guideline. I hope this helps.
 
Don't let any chevy bolts violate your block.

Measure the width/depth of the support arm spacer, add a thick washer and get bolts that are 1/2" to 5/8" longer.

Or chase the threads in the block and measure how deep a bolt can go then factor that into your measurements.
 
Holding a weight on a bolt along it centerline is a simple straight forward thing indeed, when momentum (Force X Arm) becomes involved things can get tricky fast.

I just used grade 5 studs and cut to length as needed.
 
I usually cut a 2"X4" or 2"X6" about a 1/2" longer than the front since the whole stand tends to bend forward.
Lift up and stick it between the front of the block and the stand.
It sure makes me feel better when moving it around or working on the top.
I had my son weld a knee brace on the upright of my brothers stand which helped him greatly.
 
Good to ask! If


Always good to question people about this. Here's the detail on my reasoning. Let's figure it's a 1000 lb engine just for comfort. Let's also say it's 2' long with the center of it 1' from the stand. This gives us two basic forces on the stand, a downward force of 1000# and a torque of 1000 lb-ft. The downward force is pretty easy, just figure it's 1000#/4 bolts so 250# of shear per bolt. The torque is a little more difficult. Has a lot to do with the spread of the bolts on the tranny flange. Let's say you get them 9" apart from the upper ones to the lower ones. The lower ones are getting all compression, nothing for the bolts to do except the shear from the weight. The upper ones are trying to get ripped out though. 1000lb-ft/9" (.75 ft) = 1333#, but there are two of them so 667# of tension each plus 250# of shear each. sqrt(667²+250²)=712#. Then we have the 3/8-16 bolts. Tap drill for that is 5/16, so: .312²*3.1416/4 = .0765 in² of steel. Now figure it's really crappy steel, worse than some aluminum, and has an ultimate tensile strength of 40000 ksi. 40000*.0765 = 3058# to break the screw against the 712# you'll put on it with a 1000# engine. So you've got a safety factor of 4+ which should be just fine to handle head bolt torquing etc. The important things here like in my original note are getting that spread, you can see how if 9" went to 4.5" you'd double the tension, and getting enough thread engagement so you don't pull the threads out. 1-1/2x diameter or greater is a good guideline. I hope this helps.

Now that will get your mind gears turning first thing in the morning :thumbsup:
 
I use bolts at the top and studs at the bottom of my engine stand. The studs at the bottom are 7/16 so they are much stronger. I use ARP head studs since they were the correct length.
stand.jpg
 
Yeah, but the lower bolts see the lightest load.
The weight of the engine is split over the 4 bolts. (say 500lbs total = 125lbs per bolts)
But if you think about it, if you remove the 2 lower bolts (or studs) the engine will still hang there on the top ones as long as the brackets are solid.
But that also shows the top 2 bolts hold the engine from tilting down, and that force is the more invisible one and get out of control fast is the "arm" becomes longer.
So the arm in this case is the center of gravity in the engine, if that moves away further from the stand mounting face, the load on those 2 upper bolts increase. (load = stretch on the bolts)
 
Thanks......I like your engine stand mounting set up :thumbsup:

Thanks. I built that 30 years ago and have it used on dozens of engine builds over the years. I'm not a fan of the floppy four arm setup. I designed a billet mount that works for SB engines but I don't do much SB work anymore so it mostly gathers dust.

engine plate.JPG
 
Thanks. I built that 30 years ago and have it used on dozens of engine builds over the years. I'm not a fan of the floppy four arm setup. I designed a billet mount that works for SB engines but I don't do much SB work anymore so it mostly gathers dust.

View attachment 950214

That is also a nice piece of engineering :thumbsup:
 
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