orbital valve

Rockwells607 · Jun 8, 2011

lookin for some advice for an orbital, psc has several different options but im not sure what to get, using ag ram and stock gm pump for now and will prolly bump the pressure on the pump, i would like to get 3 turns lock to lock or close to that anyways, any input on what ya'll are runnin would be apreciated

gomer pyle · Jun 8, 2011

probably a 7.3cc. what size ram?

5BrothersFabrication · Jun 8, 2011

I run an orbital off a Nissan forklift. Find your local forklift shop and ask for a used unit and a rebuild kit. CHEAP and it works!

Elliott · Jun 8, 2011

You can call Psc but they are going to tell you that the tractor ram isn't going to work tho,they are wrong.I usually run the charlynne valves. Just don't get to big of a valve.I tried a 12 ci. Psc valve on my jeep and the stock pump wouldn't hardly make it turn.

Rockwells607 · Jun 9, 2011

yea psc told me that when i put full hydro on my jeep, i have a 2x10 ram on that and a charlynn valve but i dont know the specs of the valve, i bought it used, it takes almost 5 turns lock to lock wich isnt bad on that jeep but i got a Jimmy Smith Chassis and its gonna have alot more woo pow so i wanted to make this steering 3 turns or so, i am going to use the same 2x10 ag ram on the buggy

gomer pyle · Jun 9, 2011

probably need a 9.6cc. 11.x will be faster but i don't think you pump will move enough fluid

TBItoy · Jun 9, 2011

pretty simple to figure out your displacement and size your orbital to your ram.

On the "big side" (the side that doesn't have the shaft on a single ended ram) you use the area of the piston x the length. So: 3.14 x (diameter/2)^2 x length

So a 2"x10" ram would be: 3.14 x (2/2)^2 x10 = 31.4 in^3 (cubic inches) of fluid to go from lock to lock. So a 10 in^3/rev valve (moves 10in^3 of fluid per revolution) will put you right at 3 turns lock-lock one way.

Now on the "small side" you have to subtract the volume of the rod. Say the rod is 1.25" and the same 2x10 cylinder.

3.14 x (1.25/2)^2 x 10 = 12.265 in^3, Now you gotta subtract that from the cylinder volume so: 31.4 -12.265 = 19.135 in^3,

So with the same 10in^3/rev orbital, you'll be a little more than 3 turns lock-lock one way and a bit less than 2 turns lock-lock the other.

TBItoy · Jun 9, 2011

gomer pyle said:
probably need a 9.6cc. 11.x will be faster but i don't think you pump will move enough fluid

Pretty sure daniel means 9.6 cubic inches, not cc (cubic centimeters or mL) that would be a 157 cc/rev valve.

Elliott · Jun 9, 2011

You won't need 10 inches unless you are running rocks, most axles only need a 2 x 8 cylinder unless you go down to yota axles which I doubt your doing with a smith chassis

TBItoy · Jun 9, 2011

Dude, his screen name is "ROCKWELLS607"... :gtfo:

Rockwells607 · Jun 10, 2011

i know this, however i have two 2x10 ag rams on the jeep for front and rear steer, so my thought is to use the same ram on the buggy in case i have a fail on a trip, i can swipe one off the jeep and lock the rear steer out and use on the buggy, its nice to have interchangeable parts if ur only gonna carry spares of certain things, im runnin an hp 60/14bolt in the buggy...and the wife is takin the jeep over when its done so i will haulin both rigs around...just trying to make trail fixes and weekend trips easier if something breaks

Rockwells607 · Jun 10, 2011

its lamberts old chassis, i will get some pics around and start a rebuild thread on it, gonna change a few things but it should basically look the same

cheroking · Jun 10, 2011

Little off Subject but I am looking for a new orbital as well. I have a double ended set up on my 60 and I am running a stock chevy pump on a 6.0. The current orbital takes like 10 turns lock to lock and I was looking at getting a new one because I get a little nervous when running WOT.... What kind of displacement should I be looking for in an orbital. I am pretty sure it is a 2"x8" double ended.

TBItoy · Jun 10, 2011

Rockwells607 said:
i know this, however i have two 2x10 ag rams on the jeep for front and rear steer, so my thought is to use the same ram on the buggy in case i have a fail on a trip, i can swipe one off the jeep and lock the rear steer out and use on the buggy, its nice to have interchangeable parts if ur only gonna carry spares of certain things, im runnin an hp 60/14bolt in the buggy...and the wife is takin the jeep over when its done so i will haulin both rigs around...just trying to make trail fixes and weekend trips easier if something breaks

if you run your tie rod in the stock knuckle holes and mod your knuckles for more steering (make sure your shafts clear too) they you could run a 10" ram.

Or you could just limit the travel of the ram with an internal or external stop on the rod.

Elliott · Jun 10, 2011

But if you start "making". The knuckles turn farther your going to be eating stub shafts. Always better stopping a little short

Rockwells607 · Jun 10, 2011

sounds like its 6 of one half a dozen of the other...i was just trying to make the most sense of what i have and what i haul around for spare parts on any given weekend