Gang, I've done a search but can't find much on rear 4-bars. Any HAMB refs or links appreciated. Looking for some advice on front vs rear spacing (ie slightly non-parallel, eh?) with regards to good pinion angles. Thanx in advance, Gary
I think they should have equal spacing to keep the arc's more or less the same. I have a set and the front and rear brackets have the holes centered 5 1/2 inches apart. I'm in the process of bolting the front brackets to the frame, to let them float a bit until I get the rear brackets where I want them. If they are set up equally spaced then the pinion angle should remain constant, where ever you set it. If you space them differently, then you may be able to tune it so that the pinion angle changes enough to keep the nose of carrier from wanting to push itself upwards. (just my opinion) I'm going to set mine inboard a bit rather than on the outside of the frame. I hope that when the thing articulates, it won't bind on the bushings as much. Look at Dodgerodder's posting about his powdercoating issues. He has a 4 bar set up on that, and his are not running on the same centers. Maybe he can elaborate on it. Good Luck!
Dave, thanx for your views. I've been told that if the bar mounts on the frame are a tad closer together than those on the diff, and / or the top bar is shorter, that you can control the rise of nose and tilt the diff downward as it rises under compression. But I'm FAR from an expert and really need some voices of reason to keep me on track here. I'm in the same point in my build... we want to start the clip on Monday AM! Perhaps I should have asked this question last week? Thanx, Gary
I am building the 4 lind under my 28 sedan right now, and am goin to make it parralell and equal......this took some studying for me, my back ground is in dirt racing and on a dirt car the 4 bar's are usually quite different since there is so much suspension travel......I think I read on here that normal movement on a rod is like 2-3 inches....I hopw so or my arms will be crashing into my frame!!! I am still undesided about steel hiems Vs rubber bushings......again thats the stock car racer in me
Mine are equal length, but I have seen late model cars with very short bars on the top, unequal length. They really ride nice, a lot more travel than ladder bars, etc.
<CENTER>[SIZE=+1]Hope this helps[/SIZE]</CENTER><CENTER> </CENTER> <CENTER><HR></CENTER> <CENTER>[SIZE=-1]MODEL "A" TRIANGULATED 4-LINK[/SIZE]</CENTER> <CENTER></CENTER> <CENTER></CENTER> <TABLE cellSpacing=5 cellPadding=0 border=0><TBODY><TR><TD vAlign=top colSpan=3></TD></TR><TR><TD vAlign=top colSpan=3>[SIZE=-1]Frame should be boxed at least 4" on either side of the front frame bracket mounting area.[/SIZE]</TD></TR><TR><TD vAlign=top>[SIZE=-1] [/SIZE]</TD><TD vAlign=top>[SIZE=-1]A[/SIZE]</TD><TD vAlign=top>[SIZE=-1]Center of hole in front frame bracket is located 2-1/4" behind the center of the top running board bracket mounting hole. Bracket is mounted flush with bottom of frame.[/SIZE]</TD></TR><TR><TD vAlign=top></TD><TD vAlign=top>[SIZE=-1]B[/SIZE]</TD><TD vAlign=top>[SIZE=-1]Rear axle brackets are located 38" apart measured from center to center at the coil-over mounting holes. Make sure that both brackets are the same distance from the end of the axis housing. Position the front face of the axle housing parallel to the back face of the axle brackets. Bars are ***embled with adjusters at front.[/SIZE]</TD></TR><TR><TD vAlign=top></TD><TD vAlign=top>[SIZE=-1]C[/SIZE]</TD><TD vAlign=top>[SIZE=-1]install angle brackets on adjuster end of short bar and housing tabs on opposite end. Housing tabs are located 15" from center to center. Angle brackets may require slight t******* for correct fit. Check for floor pan clearance before final welding.[/SIZE]</TD></TR><TR><TD vAlign=top colSpan=3></TD></TR><TR><TD vAlign=top colSpan=3>[SIZE=-1]Brackets should be tack welded and the ***embly should be checked for square and alignment before final welding.[/SIZE]</TD></TR><TR><TD vAlign=top></TD><TD vAlign=top></TD><TD vAlign=top></TD></TR><TR><TD vAlign=top colSpan=3>[SIZE=-1]All welding should be performed by a qualified welder.[/SIZE]</TD></TR><TR><TD vAlign=top></TD><TD vAlign=top></TD><TD vAlign=top></TD></TR><TR><TD vAlign=top colSpan=3>[SIZE=-1]Please note - Kit is shown installed on our Model 'A' ch***is with tubular crossmember and kick-up. All measurements also apply to stock Model 'A' ch***is. Coil-over shocks and mounting hardware are optional.[/SIZE]</TD></TR></TBODY></TABLE> <HR align=left> <CENTER>[SIZE=-1]'32 TRIANGULATED 4-LINK[/SIZE]</CENTER> <CENTER></CENTER> <CENTER></CENTER> <CENTER><TABLE cellSpacing=5 cellPadding=0 border=0><TBODY><TR><TD vAlign=top colSpan=3></TD></TR><TR><TD vAlign=top>[SIZE=-1] [/SIZE]</TD><TD vAlign=top>[SIZE=-1]A[/SIZE]</TD><TD vAlign=top>[SIZE=-1]Center of hole in front bracket is located 30-1/2" forward of axis housing center. Bracket is positioned on inside of boxed frame rail flush with the bottom with the ears facing up. Frame brackets may need slight t******* to fit flush.[/SIZE]</TD></TR><TR><TD vAlign=top></TD><TD vAlign=top>[SIZE=-1]B[/SIZE]</TD><TD vAlign=top>[SIZE=-1]Rear axle brackets are located 38" apart measured from center to cents at the coil-over mounting holes. Make sure that both brackets are the same distance from the end of the axle housing. Position the front face of the axle housing parallel to the back face of the axle brackets[/SIZE]</TD></TR><TR><TD vAlign=top></TD><TD vAlign=top>[SIZE=-1]C[/SIZE]</TD><TD vAlign=top>[SIZE=-1]Install angle brackets on adjuster end of short bar and housing tabs on opposite end. Housing tabs are located 16-1/2" from center to center. Angle brackets may require slight t******* for correct fit. Check for floor pan clearance before final welding.[/SIZE]</TD></TR><TR><TD vAlign=top colSpan=3></TD></TR><TR><TD vAlign=top colSpan=3>[SIZE=-1]Coil-Over shocks and mounting hardware are optional[/SIZE]</TD></TR><TR><TD vAlign=top></TD><TD vAlign=top></TD><TD vAlign=top></TD></TR><TR><TD vAlign=top colSpan=3>[SIZE=-1]Bars are ***embled with adjusters at front[/SIZE]</TD></TR><TR><TD vAlign=top></TD><TD vAlign=top></TD><TD vAlign=top></TD></TR><TR><TD vAlign=top colSpan=3>[SIZE=-1]Brackets should be tack welded and the ***embly should be checked for square and alignment before final welding. All welding should be performed by a qualified welder.[/SIZE]</TD></TR></TBODY></TABLE></CENTER>
This may help. http://www.cach***isworks.com/cac_technical.html And this: http://www.cach***isworks.com/cac_technical.html Do a Google on Instant Center to learn about unequal vertical angles on the 4-bar/4-link.
this is a pretty good link - I am going to lay mine out and see what I have I've been told the rear of my car appears to jumps up when I lay the hammer down. My car has pretty good traction. I don't know if that is good or not. I have a 4 link rear and the bottom links are twice as long as the top bars. I've laid it out to scale on graph paper and the differential link appears to travel without rotating the pinion at all for the limited travel it sees. it says if your instant center is below the neutral axis acceleration will cause the front of the car to lift under acceleration. http://www.swracecars.com/Files/pdf/95_022.pdf
The Jalopy Journal
