A 4-bar front suspension question

[Zandoz]

Is there a minimum necessary angle between the bars and the center line of the vehicle? Summit's 4-bar kits have 7 degree ends on their rods, and sell 11 degree ends...P&J sells 5 and 9 degree ends. If I use a 3 degree angle, I can get another 6-7 inches more length on the bars.

 

[RESINATOR]

There would not be a minimum angle, although there should be enough of an angle to help keep the axle centered.. think of a seat of a swingset hanging straight down with the chains parallel, this would be somewhat easy to shift side to side. If you pulled the tops of the chains together or apart the seat would stay centered much more than if the chains were straight.
The degree will be based on width at the batwing, width at the frame and the length of the bars, these companies have set degrees because of specific popular setups ; 11 degree would be specific to a 32-34 Ford, with maybe a 22" c to c bar
7-9 degree would be maybe a Model A, depending on axle width with about a 24" c to c bar
we use a 3 degree on the front (frame side) for our 4- link and radius rods, but we use a 51" bar on a 26.5 frame.

 

[Wild Mango]

There would not be a minimum angle, although there should be enough of an angle to help keep the axle centered..

I expect that you would still use a panhard rod or somesuch to retain the axle..

 

[Zandoz]

There would not be a minimum angle, although there should be enough of an angle to help keep the axle centered.. think of a seat of a swingset hanging straight down with the chains parallel, this would be somewhat easy to shift side to side. If you pulled the tops of the chains together or apart the seat would stay centered much more than if the chains were straight.
The degree will be based on width at the batwing, width at the frame and the length of the bars, these companies have set degrees because of specific popular setups ; 11 degree would be specific to a 32-34 Ford, with maybe a 22" c to c bar
7-9 degree would be maybe a Model A, depending on axle width with about a 24" c to c bar
we use a 3 degree on the front (frame side) for our 4- link and radius rods, but we use a 51" bar on a 26.5 frame.

What prompted this question was I had planned on using a complete 4-bar spring-over-axle front end "kit" from a supplier. When I found out they were the questionable Magnum cast axles, I looked around and found a good deal on a forged axle locally....but the local axle is a 46" wide, instead of a 48". The original kit was supposed to fit a 26"-30"wide frame, and had 21 1/2" bars with 7 degree ends. As planned, my frame would be 29 1/2" at the attachment point. With the narrower axle, the rod angle worked out to 3 degrees.

I've since revised the plans to use the narrower axle, and 27 7/8" bars, but still ended up with the 3 degree angle. With the revised design I could shorten the bars and get back some angle, but I'd like to keep the longer bars if at all possible. I will be using a Panhard bar (or if I can work it out, a Watts link).

 

[Zandoz]

There would not be a minimum angle, although there should be enough of an angle to help keep the axle centered..

I expect that you would still use a panhard rod or somesuch to retain the axle..

Yup!

 

[grazza]

Drill your mounting holes through the chassis at a 4* angle.

 

[HenrysT]

Drill your mounting holes through the chassis at a 4* angle.

Shouldn't the bolt holes be parallel/inline with each other to avoid binding? http://www.lucky7ent.com/images/L71084_and_L71084C_Multi_Link_Adjuster.jpg