I solved my jackstand problem......

overkill · 01-30-2002, 09:49 AM

I bought ramps!

They look very sturdy and dont look like they would collapse. I can use them for the front and back of the car. I can use the jackstands for extra support. If I need the car completely off the ground with tires hanging....I bought 16 35lb. cement bricks that are four inches thick. I place pieces of wood in between them to create even pressure between the brick so they dont crack. I went to HOME DEPOT and was trying to break one there(without anyone knowing about) and i haad alot of trouble doing it, so im very comfortable with that....and guess what I thought it up all by myself

Leadfoot · 01-30-2002, 04:25 PM

excellent idea, good thinking 99....Leadfoot

AFJuvat · 01-30-2002, 08:00 PM

Not a bad idea in theory.

One thing to consider though is (assuming these are solid cinder blocks) that to get the car up high enough to do certain things, you would have to stand the blocks on top of one another. This will raise the CG of each block AND the car. A strong enough lateral (side to side force) could cause the bricks to tilt and collapse with you under the car.

Something else to consider would be the ability of the bricks to withstand compression without developing cracks. The lowest brick in the stack will sustain the most compression

Just a few things to consider before you trust your life to a few pieces of cast concrete....

AFJuvat

overkill · 01-31-2002, 02:52 AM

Ok, think of it this way....if 16 of these 35 pound bricks(4" thick, like 10" wide and I think 14" long)cant hold up a 2800lb car...why would they use them to construct buildings? I mean come on

Plus, ill have the jackstands under the car too so if they do break they will be there. might have the jack under there too. The more the marrier! The most important thing is that I have to maintain an even amount of pressure between the bricks. Thats what the wood is for. I actually want somthing softer but I think that will do. The ground has to be even too. If I can maintain the bricks properly then they should be fine.

ribs · ribs's Garage

All right, so about 4:00 this morning, I jack my car up to start working on it...1/3 the way up each side at a time so the jackstands don't get wobbly. Then I realize I need to lower my car back down because some of the stuff i have to do (remove intake manifolf, fuel rail, air box, cap/rotor/wires, etc) can't be done with the car in the air because I can't reach it. So I jack one side off of the fully extended jackstand, lower it to about half way down, go to the other side, and....my piece of shiite 2 ton mini floorjack quit on me. With the airscrew tightened as much as possible, every additional pump to try to get the driver's side up far enough so I can pull the jackstand down some just hissed out of the floorjack.

So...I am waiting for an autoparts store to open so I can go purchase a 3 or 4 ton floorjack with the twist release handle instead of the crappy airscrew that my POS has. I also hope my car doesn't fall on me when I am working on it. Wish me luck. Later.

kenny · 01-31-2002, 03:51 AM

I'm an engineer, though not a licensed professional engineer (P.E.). It's not required for the type of work I do. I do structural analysis of aircraft. I'll give you some comments and hopefully they will help you make a more informed decision.

Your set-up may work and the wood is a good way of taking out some of the stress concentrations caused by the brick surface being slightly uneven. Having said that... Would I do it that way? No -- and here's why.

The wood is also softer than the brick, and as the wood deflects [due to the weight of the car] the bricks may be exposed to some tenison type loading. See here is the gig: bricks are great in compression (as OVERKILL has suggested). They are terrible in tension applications (that's why concrete has rebar in it -- the rebar is what takes the tension load -- not the concrete). Bricks don't have rebar [or any other fiber] to carry this tension load. They will carry the weight of the entire car and more if they are loaded as intended -- but that is dificult to due in this case.

Now here's the other deal. Porsches are very low to the ground (even with the tires on). If the car comes off your stack of stuff... we're talking injury or death. Whats the cost of a couple of jack stands [with wide bases for stability] that are designed for the express purpose of holding a vehicle up. It is your life! There is a fair chance that your set-up won't kill you. In the south here (TX) too often used is the expression "hey y'all watch this" just before the Darwinian event occurs. I'm pretty good at math and I just wouldn't take the odds. Use the bricks to make a book shelf and go get ya some jacks.

That's my $25 bucks worth (we ain't cheap!)

Eturbo924 · 01-31-2002, 04:16 AM

I would not use the bricks. As the other engineer had noted about the limits of their ability to react to dynamic loading. Yes I am an engineer also.

Anyway if you have the jack stands you can use your wood set up with the stands. Just make sure you have a good thick plywood. It is also good to have plywood under the jack in order to keep it from sliding or sinking into a tar driveway.

Oh on your jack. You may have backed that screw out to far and got some air into that jack. Try bleeding it. Of course I would not want a leaking jack raising my car... but before you trash it... try bleeding it.

I have the 1.5 ton jacks.. (two of them). More than enough power to jack a 924. You do not need 4 tons of lifing power. That is overkill... ha ha

overkill · 01-31-2002, 05:44 AM

Fine Ill just get like 6 ton jackstands! There like $90 for two of them!

kenny · 01-31-2002, 05:56 AM

overkill,
We love ya man (you still can't have my bud light!) $90 bucks is the cheapest life insurance you'll ever buy!!! We wern't trying to get preachy just keep you safe.

Mike B · 01-31-2002, 07:58 AM

EEEEK...I got two 6 ton jackstands for 39.00 CDN at the local Princess Auto Store...