1.5" X ? X ? cylinder? Pump? Specs? Pulley/drive ratio? Steering gear ratio? Pitman arm length? Line sizes? Reservoir? Cooler? Overall system design? Cooler location and line orientation? Reservoir? Location? A lot of questions, right? My suggestion before asking questions about re-inventing your steering, is understand what you're working with right now. Otherwise you're going to be guessing again when it doesn't work out the way you want. Folks don't usually complain about 1.5" cylinders. I can't comment about full hydro, but I'd sacrifice strength over speed when you're talking about hydraulics. Last thing you want is unresponsive steering when you need it most. It'll be strong enough just about any way you spec it. I'd look to other avenues beyond the reaches of this forum if you want to put pen to paper and design a new steering system. Research what's proven. Don't ask. There's a few gems out there from a time when folks weren't utterly annoyed by the masses of the internet and cared enough to share straight talk. My point is asking about cyl diameter only is setting yourself up for failure.
Try these calculators and links to get your feet wet.
http://www.baumhydraulics.com/pages.php?pageid=4
Steering gear threads
http://www.pirate4x4.com/forum/gene...ring-box-tech-thread-size-power-strength.html
Mine but incomplete
http://www.pirate4x4.com/forum/ford...t-side-hydro-assist-pitman-reversal-tech.html
I'll drop some stuff on you now just to get an idea
Ford steering gears run a generous 3.18" bore. Massive. That's why they have pinky steering. 17:1 ratio also decreases the effort however yields 4 turns lock to lock. The piston is 5" long riding inside a 7.40" long bore and the ball Race measures .75". Currently I run a Saginaw TC pump. Only way to go. Rollerized and good to 8,500 rpm shaft speed. This allows you to overdrive them. Most run a 1:1 drive. IE 6" crank pulley 6" pump pulley. Anyways it's a 1,300psi and 3gpm pump. My assist cyl is a PSC 1.75" x 8" x .75". It's very strong and fairly responsive unless you quickly change directions. As in: after you catch the ass end, keeping up with Newtons law can be a bitch unless you can increase pump speed with the skinny pedal. Not feasible if you're hooked up. Currently my pump is underdriven. I need to gain valuable pump shaft speed and I need to gain volume and pressure. Monday a PSC 1200X arrives at my door. 1,650psi and 4.5 gpm. This will help dramatically. Another thing I will consider is increasing my crank pulley diameter. Take a look at my numbers.
Cyl strength
Bore Psi Rod diameter - Push force Pull force
1.75" 1,300 .75" 3,127 2,553
* 1,650 * 3,969 3,240
Cyl speed
GPM Bore Stroke Rod - Ext speed Ret speed
3 1.75" 7.5" .75" 4.8"/Sec 5.9"/sec
Extend time: 1.6 sec - Retract: 1.3 sec - cycle 2.9 sec
4.5 * * * -
Extend time: 1 sec - Retract: .8 sec - cycle 1.8 sec
Steering gear
Bore Psi Rod Push Pull
3.18" 1,300 .75" 10,325lbs 9,751lbs
* 1,650 * 12,708lbs 12,001lbs
1.5GPM increase shaves 1.1 seconds from the cycle time of the steering piston following the same calcs above used for the assist cyl.
I run Parker 471ST -6 pressure hose, PSC 8.25" reservoir with a -10 feed line, Ford stacked plate transmission cooler from a 90s F-250.
