View Full Version : Old School Tech Question.

extreme racing
March 26th, 2010, 09:16 PM
Ok i have had this question i was hoping i could figure out but its not looking like it. Ok Here it is, I have all ways wondered what the old leaf sping trucks used up front for the ladder bar/Traction bar to help dampen the the front axle when its moving rearword after an impact. It looks like a basic hyd ram, That part is understood...I thought.. I went last week before i flew out to vegas to speak with my local hyd builder an i asked him about if he's ever heard of anyone doing such a thing an he said no i was hoping to pick up a couple smaller rams to put on the front on the mini for a classic touch of old school but he said a hyd ram will not work due to hyd fluid is not compressable, He said you would need a nitrogen shock to get the effect im looking for, To help dampen shock load. I showed him a few old pictures i brought along he said they look like hyd ram but doubt's it so does anybody know what these cylinders were??? I have an old pic of the monster jeeps/rockstar an it looks like jeff bainter used old motorcycle shocks??? Can anyone answer this old school tech question??? an any specs on these cylinders if possable.

http://www.monstermayhem.org/forums/images/imported/2010/03/414.jpg (http://img208.imageshack.us/i/img4010l.jpg/)

http://www.monstermayhem.org/forums/images/imported/2010/03/415.jpg (http://img444.imageshack.us/i/dscf3480n.jpg/)

Fat Brian
March 26th, 2010, 10:33 PM
He is right about hydraulic fluid, it doesn't compress. The dampening of a shock comes from its valving not fluid compression.

extreme racing
March 26th, 2010, 10:55 PM
ok so could you change valving internaly an make a hyd ram work is that what these old school trucks had?? I seen an old digger pic were the out/return ports have a solid hose tieing them together.

March 26th, 2010, 11:51 PM
What you see on the old RockStar setup is an actual motorcycle front fork. With a leaf spring setup that has the shackle to the rear the axles natural movement is slightly rearward. So a solid traction bar would stop almost all suspension travel. But with such weight some sort of locating device is needed. Using some sort of shock like device in the traction bar allows the suspension to hopefully move some while still keeping spring wrap under control.

March 27th, 2010, 12:34 AM
You could use a Hydraulic cylinder if one was to put an accumulator in the system. I believe that's how the old Blue Thunder used those cylinders as ride height control and as shocks.

extreme racing
March 27th, 2010, 12:52 AM
Thanks for the post jim yea i know some sort of ladder bar is nessary in order to settle down the axle wrap just as marty explaned in his artical-http://www.therangerstation.com/Magazine/winter2007/monstertech.htm

I guess my question was, what is inside these hyd ram's to make them work as far as a dampener as from what S.J. posted an accumulator in the system may work? Im unshure what that is mabey someone on here can shed some light on that or just use some old dirtbike shocks? Motocross shocks have nitrogen i assumed the old drivers/builders just made a bypass line from port to port an drilled a hole for a fitting an filled the rams with nirogen....Thanks for everyone's help.

March 27th, 2010, 05:29 AM
whoever said you couldnt leave it empty?

March 27th, 2010, 02:58 PM
-didn't one of the first 2 or 3 Digger trucks use a coil spring, instead of a hydraulic? I think the coil was green too.

Christian Riedel
March 27th, 2010, 03:25 PM
Fat Brian answered your question, dampening comes from fluid (either gas or air) moving through an orifice, the faster it tries to move, the greater the dampening force. Yoda...I mean the all knowing one...I mean Marty Garza already wrote an article that answers your question. http://www.monstertruck.terramail.pl/budujemy.html

extreme racing
March 27th, 2010, 06:10 PM
I understand how the dampening works. So i just pick up a ram an put it on the truck an end of story?? I dont put anyfluid in it? Do i need to have one of these valves installed into the ram?? Was there hyd fluid inside these short rams or what???? Thats all im trying to get to the bottom of, It is never mentioned in the articals what is inside these rams.

April 12th, 2010, 02:43 PM
Bypass tube from one end to the other. Can't be FULL of fluid because the shaft will take up some volume as it compress into the cylinder. Fill with some fluid, but leave enough air volume to allow for the shaft.

Sinister '32
April 12th, 2010, 05:41 PM
You could put some fluid in, but don't fill it full. Bascally, position the ram to it's "compressed" position and put fluid in. Then put the bypass line on the upper and lower ports like you see on all the trucks. This way you won't be getting into the situation where you are trying to compress fluid.

September 20th, 2010, 02:37 AM
Bigfoot #6 at one point had a rubber spring on it's arm. It's in the 89 TNT video with Kramer giving a tour of the truck after it got the smaller 472 engine.