mounts

[needenginerunnin]

evening all

i was wondering what sort of anti-vibe mount to sit my cs genset on?
with there being a fair bit of energy to control something like land rover engine mounts several of them to start of with.
the set will be close to my neighbours so, i am thinking that a second layer of protection.
what is anybody out there using?
lenghts of hydraulic pipe, rubber door stops, hose pipe, axle bump stop.......
my guess is that if you get the wrong sort of rubber or what ever, it would make it worse and bounce about like a jack rabbit.

cheers needenginerunnin

[Stan]

Just don't ask how many tons of concrete to set it in!   

There's lots of varying opinions here, I like 6x6" wooden beams some guys like to bolt it down to concrete, others put it on metal I beams, some put it on rubber mats, the only consensus is that you have to try it yourself and see how it works.  There's lots on the site if you care to peruse the back messages, or do a search using various mounting words.

btw...I don't know if you have a roid or a Dursley Lister.  There seems to be a big difference in how much they hop, with the roids hopping the worst.  That will be your determining factor in mounting.
Stan

[SteveU.]

And a Good Morning to you too.

Use this forums Advanced Search function with key words of "mounting" " rubber mounting" "viberation mounting" "wooden mounting" ect.
Try to avoid making a decision on just the speculitative talk.
 Focus on what people are actually using and their reported results.
You will find people clustered into groups of styles. You will have to make your own desision.

Me?  I believe my engine is always tring to hop-a-round and kill me. Wants to Hop up and down enough to break off a crank arm, losing a flywheel to roll the 300' (100 meters) to kill one of the nieghbors children.
So I'm a bolt it to concrete person to anchor it down and mass dampen the unwanted up and down energy and redirect it to rotating the crank shaft where I can harvest it for productive use.
And cage the damn thing in  a chain link cage. Good enough to stop RPGs, should hold in a loose flywheel.

SteveU.


 

[compig]

Just been reading about engine foundations and the important factors are , mass and isolation. Imagine a concrete slab , 2ft thick , much larger than the engine , with a rectangular hole in it ,but not extending through , like a bathtub if you will. Then the actual slab the engine is bolted to, is cast in the hole with a gap of about 3" around all sides , and this slab rests on a 2" thick layer of  heavy rubber sheet. This engine slab can be higher than the outer slab , thus increasing it's mass without consuming alot more concrete for the whole slab. The gap between the 2 slabs can be covered with wooden planks or checker plate loosely resting in a recess. This method was accepted practice for vibration isolation back in the day the engines were in normal use.

[xyzer]

btw...I don't know if you have a roid or a Dursley Lister.  There seems to be a big difference in how much they hop, with the roids hopping the worst.  That will be your determining factor in mounting.
Stan

Same question here....I have delt with the oids only and before you rubber mount one you have to tame the beast otherwise call the cement truck! I spent / wasted time and money on the jumping issue and after having one professionaly balanced and have a close idea what % they need to be balanced at 65-68% Here is a video of my 6/1 with no cement....it ran for 5 days and stayed in the same spot  http://video.google.com/videoplay?docid=-9194771268947755783 No matter what you do it will have some movement....But they can be tamed well enough you can stand next to it and no pounding is felt without cement.
Dave

[needenginerunnin]

evening again
i will be running a 6/1 dursley cs with som flywheels, i would like to bolt to the concrete floor in the out house/shed in which it is to live but soil conditions 'very heavy wet clay' transmit real well and with next door so close its not an option.
hence the reason for this post.
i will be bolting the cs to thick a thick angle iron frame mounted on land rover engine mounts, which in turn will be sat on a wooden frame 'floor joists' and then its what i put between joists and the concrete floor?
hope this helps, off to read the old posts section.

cheers needenginerunnin

[Quinnf]

Steve,
 
Re: your engine being a "hopper," take a look at the extensive discussions on this forum regarding balancing.  Nobody has come up with the ultimate technique to achieve the best overall balance, which has to be, at best, a compromise, though several techniques have been proposed. 

But one thing is known, and that is, if your engine lacks sufficient counterweight on the flywheels, it will hop.  And if it has too much counterweight, it will tend to slide back and forth along the ground.  You keep saying you have a hopper.  If'n I were you, I'd play around with adding several ounces of modeling clay to the flange in the region of the flywheel counterweight (on each side) and see if that quiets the beast somewhat.  Keep track of the weight, and stay out of the path of any clay that gets launched.  The counterweight appears to weigh about 46 ozs. as near as I can determine.

Quinn

[sailawayrb]

Wife/neighbors would not tolerate ANY engine sounds or vibrations, so I went with the resilient mount approach for my 6/1 and I am extremely happy with it.

Make the mounting structure that the engine reacts against as heavy as possible to maximize the attenuation into the local environment and to minimize engine motion. The engine and generator should be mounted on stiff structure to prevent any relative motion between the engine and generator.  Once you know the combined weight of your engine/generator/structure, you can calculate the proper resilient mount parameters using equations such as:

http://www.karman.com/selectvibro.cfm

You really need to get the parameters right in your design to get good results. I suspect this is beyond most folks.  You should also take appropriate safety precautions to ensure that any failure event is safely addressed.  This might include having backup steel cables to restrain the structure in the unlikely event of a sudden engine seizure.   My setup is just sitting on garage floor of my suburban house and I can put my wine glass on floor next to it without getting a ripple.  The engine/generator/structure moves about 2/10 inch during startup/shutdown and about 1/10 inch during normal 650 RPM operations.

[compig]

Any chance of some pix of your rig to show the details ? What did you do for exhaust ?

[ronmar]

My 6/1 and generator are bolted to a thick wall 4X4 steel box tube frame(with 3X6 box tube crossmembers).  This whole affair is bolted to a 1300# block of concrete roughly 10" thick and 3'X 5'.  The block of concrete is setting in my generator room(old pump house with concrete floor and cinderblock walls) on a 1/2" thick rubber mat.    I have fairly sandy soil with lots of round rock(old streambed deposits), and I can only really feel it at full load for about 20'. 

Yours being a dursley engine, I would hope it will be pretty smooth, but there is no balance in the world that will overcome the massive torque pulses under load.  The greatest thing you can do for this is to make the frame as solid, heavy and most importantly as rigid as possible.  Triangles are your friends when designing.  There is an old lesson I have learned and tought repeatedly on the ships I have worked on.  It is far easier to hold something in place, than it is to stop it once it has been allowed to move.   

Equine supply stores usually stock the mat in 6'X 6' or 4'X 8'  sheets for stall mats.  I saw some in a farm store the other night for around $34 a sheet. 

[sailawayrb]

Any chance of some pix of your rig to show the details ? What did you do for exhaust ?

Exhaust is standard diesel flex pipe like used on sailboat inboard diesel engines...which are also on a resilient mount.  My exhaust goes thru a wall thimble and then 10 feet underground into a 7 cubic foot concrete cistern for decompression...and then 100 feet via plastic yard pipe to ground surface in by backyard.  Here is photo I just posted in our new gallery.  Hopefully the link works.

http://listerenginegallery.com/main.php?g2_itemId=357

I apologize for the weight lifting set being somewhat in the way.  Engine just occupies a small corner of my two suburban car garage and my teenage boys need to workout frequently so the weight lifting set is in the same corner.  Our two cars also still live in garage too

[mobile_bob]

after argueing the merits of resilient mounts for about 6 months on this forum some time ago, i ain't going down that road again.

i figure it like this,

much of this AE/RE is akin to being a religion to a lot of folks,

folks are going to believe what they wanna believe

if you believe in a ton of concrete, you will use it and do what is necessary to make it work acceptably in your install

same goes for the resilient boys

what amazes me is the lack of at least doing some research into either method by most folks
they just do what feels right and if it works does it really matter?

however if you are concerned about vibration, one would do well to do the research
it isn't rocket science, it is well laid out technology that has been around since way the hell back there
surely by the late 1930's resilient mounting was fairly well understood.

just as with concrete there is a right way and a wrong way,, and a bunch of ways in between

either way you pick, what can it hurt to research a bit and do it the right way, maybe then you get a better result?

looks like sailawayrob among others have done an excellent job of applying the technology to provide a solution to the problem.

i know i have as well, and am very happy with the result
bob g

[t19]

2 cars still in the garage?

That is just so sick on so many levels

[compig]

I have 1 car and 5 motorcycles in one garage and 5 motorcycles in another !!! Nothing else will go in !

[GuyFawkes]

Then you have 8 motorcycles too many.