A firend of mine is telling me it will be fine to run my 454 on my 750lb capacity engine stand as long as I dont rev it....But my better judgement tells me thats not so smart. Is it ok to do this, or do I need a special stand to run it on..I really wont be much over Idle with it...maybe run it up to 2500...would the stand hold?

If you can do this,please send all of us pictures of the big block laying on the floor.There is no way you can do this.My friends have built stands for this.They use the engine mounts,rad.,gauges,fuel supply and everything that goes with it.It would be easier to fire it up in the care or if you are doing a frame off with it in the frame

People have done this many times. But I sure wouldnt dare try it with a 750lb. stand. You need at least a 1000lb. capacity 4 leg stand. It should work if you dont rev it. Try searching the subject, I know its been brought up before.

I wouldnt trust a BBC on a 750lb. stand in the first place.

At 2500 rpm, that motor would fly across the garage floor and thru the wall.
At 700 idle it would probably only fly halfway across the garage.
Can you say torque???

A firend of mine is telling me it will be fine to run my 454 on my 750lb capacity engine stand as long as I dont rev it....But my better judgement tells me thats not so smart. Is it ok to do this, or do I need a special stand to run it on..I really wont be much over Idle with it...maybe run it up to 2500...would the stand hold?

Have your video camera ready and ask your friend to stand on the right side of the engine when you fire it. That way you can send the tape to the Jackass TV show and maybe they'll pay enough for it to cover the damage to the motor, and your friend will lose a few toes, for tryin' to talk somebody else into doing something stupid and dangerous.

Disclaimer: It's a joke, don't do it.

LOL..yeah, thats what I was saying to him..But he's swearing up and down it can be done...Either way, I dont feel like picking my motor up off the floor, Was planning on just waiting till its in the car anyway. As for trusting the stand in the first place...A BB is around 680lbs isnt it?? Either way, Its on the stand now...Hodling fine so far...Plan on doing all the work without the heads on it anyway. Got the stand for free and figured it would work at 750lbs. What stand would you suggest?

Have your video camera ready and ask your friend to stand on the right side of the engine when you fire it. That way you can send the tape to the Jackass TV show and maybe they'll pay enough for it to cover the damage to the motor, and your friend will lose a few toes, for tryin' to talk somebody else into doing something stupid and dangerous.

Disclaimer: It's a joke, don't do it.

Oh, please.

Torque means nothing when you have nothing for it to react on. Don't install a heavy flywheel (or torque converter) and you'll be fine.

I broke in a 455 Olds on my engine stand. Flexplate, not manual flywheel. 2000+ rpm to make the cam happy. Never moved the stand--rock solid. Granted it's a 1K rated stand with wide-spaced front wheels. I won't own an engine stand that has three wheels or narrow-spaced front wheels. You don't need to run the engine to tip one of them...

As stated,Dont do it.Big blocks are too heavy to pick up off the ground.......

This might have to go into one of those physics threads in Bench Racing. I'm going to side with Schurkey on this one. If it has nothing to react to, it won't go anywhere. FWIW, I built a stand earlier this year to hold and fire up a 12-71 Detroit Diesel engine. Worked fine, didn't move around any, again, because there's nothing reacting to the flywheel torque. ;)

I agree in part with Shurkey,there would be no torque at any steady speed,but there would be torque present during any acceleration.

At 2500 rpm, that motor would fly across the garage floor and thru the wall.
At 700 idle it would probably only fly halfway across the garage.
Can you say torque???
Not if it's on a runway length conveyor that will match motion speed instantly...

Ever tried to turn an engine by hand? how about with the spark plugs in? The friction and compression will cause a reaction between the block and the rotating assembly, then there's the inertia of the rotating assembly... It will be minimal at idle, but still there...

While this may not cause a catastrophic engine flip, the vibrations from varying rpms (especially idle with a "lopey" cam) may cause other problems for the stand that was not designed for this... And all the weight supported by 4 bolts on the bellhousing flange, the bellhosing was not designed to support the weight of the engine cantilevered out like that... Asking for trouble, especially if you used cheaper or shorter bolts to hold it to the stand...

And with a new engine (untuned), a backfire could be really bad on a flimsy stand...

Maybe okay on a stronger 4-leg stand with a wider base, but really should have support at the motor mount locations (or somewhere toward the middle or front on the engine)...

750 lb stand, 3 leg? I wouldn't even put a BB on those (IMO, not worth the risk)...

Ever tried to turn an engine by hand? how about with the spark plugs in? The friction and compression will cause a reaction between the block and the rotating assembly, then there's the inertia of the rotating assembly... It will be minimal at idle, but still there...

We're back to the same scenario as the airplane on the treadmill, the frame of reference of the applied force...If you stand next to the motor and turn it by hand you stand a chance of flipping it over. If you stand on top of the engine and turn it by hand you will impart no torque to the stand.

oneofakind try your theory out,take a motor on a stand,put scales under each wheel,climb up on it and try to turn the motor over,and have someone watch the scales.

mmaver - It would make no difference whatsoever to the scales, unless you moved around a lot on the motor. To put this to the test, get on your bathroom scales with your tennis shoes on. Reach down and pull up on the laces as hard as you can. If you're really strong and can lift your own weight, what will the scale read? They'll read your weight no matter how hard you pull on the laces.

I think all the guys who think you can run a 454 on an engine stand should try it. With the confidence you expressed, stand in a tight circle around that big block, and fire that sucker up. Then when you get back from the emergency room, fill us in on how the test went..http://bestsmileys.com/clueless/1.gif

I think all the guys who think you can run a 454 on an engine stand should try it. With the confidence you expressed, stand in a tight circle around that big block, and fire that sucker up. Then when you get back from the emergency room, fill us in on how the test went..http://bestsmileys.com/clueless/1.gif

You've never started an engine just sitting on the garage floor? They just sit there and run, they're not flopping around.

Maybe I didn't post that the right way, put each wheel on an individual scale,the twisting force you create must go somewhere.The scales on one side of the engine stand will read heavier, and those on the other side will read less.

Its not like the engine is a jumping bean, its the accleration of the rotation parts that torques your motor over. Without a flywheel or converter this will be minimalized, but you will experience some toque by accelerating the crank and other rotating parts. Picture someone reving their engine while in the car and its in neutral, see the motor torquing over? That is because the motor is fighting to move the mass of the flywheel and converter. Now eleminate those and it will be lessened, but still there in a minor form. If you have a sturdy stand with some type of side supports or a four corner mount setup i would do it, but i have a 1K test stand and i wouldn't start my engine on that thing...

Daniel

Well, I never did it with a BBC, but I did it with a SBC. Fired it up on a 1000 lbs stand. At idle it was fine, but when I blipped the thorttle, the side of the stand wanted to come off the ground. That was a stock rebuild on a 350. I wouldn't want to do it with a BBC of any kind. I guess you can do what you want, but I sure wouldn't.

Chris

You've never started an engine just sitting on the garage floor? They just sit there and run, they're not flopping around.I can honestly say, I've never started any of my big blocks (and I've had a bunch of them) sitting on my garage floor. I've always put them in the car, then started them. http://bestsmileys.com/wink/2.gif

Got two bathroom scales? Put one foot on each and balance your weight. Reach up and push as hard as you can on the side of your head, generating as much torque as you can. Do you think that the scale readings will change?

How about this - sit in a swivel chair with your feet off the floor, reach around in back and grab the back of the chair and pull on it as hard as you can. How fast will you spin around?

I have seen this done at the 2005 Bike Week were I live and they took a big block on the ground and started it up Wide open till it blew up. It was a guess how long it took to seize up or blow up thing, they also do it to ricer motors. And the motor just sat their wide open till it Blew up was kinda cool to watch it smoking like crazy till it blew up. I wouldnt do it on a wimpy motor stand!! HMO
http://smileys.smileycentral.com/cat/36/36_11_13.gif

Please guys,

Thing about it like a drill motor, take your dewalt or makita or whatever you have and from a dead stop pull the trigger, feel it torque over in your hand? Its the forces generated by accelerating the internal moving parts. Same thing!

It will generate no force sitting there running, its starting and stopping it that are going to make it want to move. Now if you accelerated or decelerated it very slowly that is a different story, but the literal turning off/shutting down of the motor would make it want to move because it accelerated/decelerates quickly at those times!

Daniel

Honestly, Its not the flipping over im worried about as much as the Vibration caused by a running motor...The stand is fairly wide. Does anyone know once and for all the Exact Published weight of a Stock BB 454 with Cast heads??

oneofakind please read the responses from RedSS454 and Stickman33.

Somewhere on the internet I've seen stands meant specifically for starting and running engines. They have the rad and gauges and some sort of exhaust system. The engine appeared to be close to the floor and the frame base is wider than the engine. When quick reving the 396 in our Chevelle you can feel the vehicle torque over a little. An engine stand is a whole lot lighter. Who needs to take the chance of a disaster. If the timing is right and the fuel bowls are full of gas, the engine in the car will start clean and it won't be going anywhere except for a nice drive once the break in is done.....unless there was something done wrong in the engine build. If you have the equipment, pulling an engine isn't that big of a deal should something be wrong. I'd fire it in the car.

http://smileys.smileycentral.com/cat/10/10_1_118v.gif

Then when you get back from the emergency room, ...................

:) :D

I've ran small blocks on the floor to see if they were any good before buying them and it was no big deal but I never got crazy reving one up and didn't let them run very long without a radiator.

The last one sounded OK except for the open exhaust manifolds but two cylinders had low compression after I got it in the truck. :(

Lots of torque if you rev it, but mostly vibration from a lopy cam as stated before.

Ever see that v8 chainsaw?

http://www.compfused.com/directlink/154/

look how it pulls up when they rev it? think about the engine stand....

I started my 454 on a three legged stand
BUT, I also had the hoist holding a chain that I had bolted to the engine
although it never really seemed like it would have pulled
still safe than sorry

How about balancing a 502/502 on a small two-wheel engine stand and blipping the throttle repeatedly while sitting astride the motor? Will it throw you off or will you be able to sit there?

Interesting chain saw - a running V-8 that two guys can pick up. If they reversed the direction of rotation they wouldn't have to overcome the inertia of the acceleration in order to get the blade to the wood.

I know some of you older members may remember this,as I posted it before, but I went to look at a 427 some 20 or so years ago. It was in a lean-to shed, beside this guys shop. There were 5-6 of us there, and the owner says to us, " Good , we have enough to fire her up!" So, here we all stand, two of us holding the battery, one holding a gas can with a rubber tube hooked onto the fuel pump, one holding a cobbled up mess of wires,hooked to the starter, and distributor with a toggle switch somehow hooked into it, one working the gas, and the others there for the mere enjoyment of the show. I didn't believe it would turn over, let alone crank, BUT....she turned over twice, and shot flames out the headers as it cranked over. It had some wicked solid lift cam in it, and the only sound I've ever heard that resembled it was a pro-stock rail. The owner reaches over, and revs it up, and the flywheel grabs the dirt, and here goes the engine, out from under the shed, and across the yard..... spinning around in circles, and shooting up dirt about 6-7 ft. high. We all ran along, as it proceeded about 25-30 ft. across his driveway, towards the front yard. The owners son at that point was so scared, he dropped the gas can, and ran, and the engine eventually died, at the corner of the yard. This was almost 20 years ago, and man I wish I had a video camera. I'm sure I could have won some money with that one. So....if you do crank it, have it supported by some other means as well as on the stand, and BE CAREFUL!

I know some of you older members may remember this,as I posted it before, but I went to look at a 427 some 20 or so years ago. It was in a lean-to shed, beside this guys shop. There were 5-6 of us there, and the owner says to us, " Good , we have enough to fire her up!" So, here we all stand, two of us holding the battery, one holding a gas can with a rubber tube hooked onto the fuel pump, one holding a cobbled up mess of wires,hooked to the starter, and distributor with a toggle switch somehow hooked into it, one working the gas, and the others there for the mere enjoyment of the show. I didn't believe it would turn over, let alone crank, BUT....she turned over twice, and shot flames out the headers as it cranked over. It had some wicked solid lift cam in it, and the only sound I've ever heard that resembled it was a pro-stock rail. The owner reaches over, and revs it up, and the flywheel grabs the dirt, and here goes the engine, out from under the shed, and across the yard..... spinning around in circles, and shooting up dirt about 6-7 ft. high. We all ran along, as it proceeded about 25-30 ft. across his driveway, towards the front yard. The owners son at that point was so scared, he dropped the gas can, and ran, and the engine eventually died, at the corner of the yard. This was almost 20 years ago, and man I wish I had a video camera. I'm sure I could have won some money with that one. So....if you do crank it, have it supported by some other means as well as on the stand, and BE CAREFUL!
you might be red neck if...... just kiddin.. that is funny i AM LOL

I've fired a few motors up on dollies before and attached to a hoist..I can vividly picture what Doug described/experienced and I always had a scenario like that in the back of my mind if things didn't go as planned

Interesting ideas on the flywheel / no flywheel option mentioned here.

The flywheel weight does not determine the amount of torque developed, the flywheel stores inertia created by the engine. Adding a light flywheel allows an engine to rev faster because the engine torque does not have to accelerate the mass of the flywheel. Adding a heavy flywheel slows the engines ability to rev but the torque developed by the engine is the same with eather flywheel. Heavy flywheels allow for better low end (stoplight pullaways) because they have inertia which helps accelerate the car away from the light at lower RPM.

Light flywheel or heavy flywheel the engine is making the same amont of torque with eather one of the wheels installed. Torque developement is determined by a lot of factors in the engine. All of these factors are up ahead of the flywheel. Heavy flywheel, light flywheel or no flywheel, a given engine develops the same amount of torque. Application of that torque to a given job (moving a car, driving a saw mill, spinning an airboat propeller) will be different depending on the weight of the wheel that is installed but the torque developed by the engine is the same.

You would think the motor would stop as soon as the wires were ripped off. I don't think the battery would follow along.

Oh, please.

Torque means nothing when you have nothing for it to react on. Don't install a heavy flywheel (or torque converter) and you'll be fine.



Say what??? How exactly does the engine raise in a car when it's in neutral when you blip the throttle?

Say what??? How exactly does the engine raise in a car when it's in neutral when you blip the throttle?

With a manual trans, you'll have a 30lb flywheel reacting against the acceleration, and with an a/t, you have the torque converter and the front pump providing resistance. ;)

I've heard of engines that keep running with no battery, I guess it would depend if the alternator was tied in with the coil primary.

I always had to put a car in gear and hold the brake to get the engine to raise up.

With a manual trans, you'll have a 30lb flywheel reacting against the acceleration, and with an a/t, you have the torque converter and the front pump providing resistance. ;)

Hmmm, so I guess the rotating assembly would somehow be different????? I think somebody else's analogy of pullin' the trigger on a drill is a good example. Ever cranked an outboard motor in neutral (virtually no flywell mass, especially on the high perf stuff) and watched how they idle? There's a lot of motion at that point,m restricted only by the steering. Blip the throttle and watch. Take the steering loose and watch it at idle (bigger stuff much more dramatic than small kickers).

Just today I had to rig one of our RIB's with twin 50's to get it back in. Steering linkage snapped. (Obviously, some people feel it's okay to stand on the hydraulic steering ram. :rolleyes: ) FWIW, they're easy enough to move around in neutral, but in gear, look out, they're gonna try to take you for a ride. As long as you lock down your pivot bolt or pin on your stand, I'm still thinking it wouldn't be too bad. Now, I wouldn't go snapping the throttle wide open, but slowly opening it, bringing it up to speed, doesn't appear that it'd be a problem. There are limits. ;)

Back to the outboards, they move around alot due to rough idling characteristics. If you've ever fired one up on a mobile test stand, you'd know that you can crack the throttles hard on them, and they won't go anywhere. Never had one fly off the stand yet.

I always had to put a car in gear and hold the brake to get the engine to raise up.

To get the engine to raise up, sure... But even in neutral, you can see the engine move/rock when reving, just not as much...


I remember back in Physics class, we would actually stand on a "lazy susan" while holding a spinning bicycle wheel (handles on the ends ofthe axles)... Depending on which way the wheel was spinning, the person holding it would actually rotate on the lazy Susan due to the spinning wheel... Just with the inertial forces of the really light bike wheel... Like a gyroscope...


I guess we should just all talk "Chevelle Dude" into doing it, and then post back (with a video clip)...:D

I ran my 454 on a test stand before I installed it. I bought it used and wanted to make sure it was good before I put it in. I built a stand from square tubing, larger than the dimensions of the engine and transmission together. 3 ft X 5.5 Ft if I remember. The engine was mounted on solid mounts, no torque converter but used the old tranny to support the rear of the motor. I built a support for the radiator and even mounted the electric fuel pump and a couple of gauges.

I was afraid of the engine stand flipping as you suggest. When i ran this motor I revved the snot out of it through the headers and mufflers and then to thrill the neighbors and give them a taste of the future I pulled the mufflers and ran it again.

Not once during this test did the engine exhibit any tendencies to try and lift from my test stand, and it was not bolted tight to the supports under the motor mounts.

If precautions are taken with a safety chain and a cut out switch I would do it on an engine stand in a heart beat.