This may be a silly question but Do I need a particular perch angle on this set up? I had to set my perchs mounted angling up because I face them down my rad would come too close to the axle. ????
No, because your not using them like stock anyway. BTW the spring has no weight on it yet already looks too long. Like that the tension in the spring should pull the shackles horizontal. I'm also thinking the radiator and shell will be way higher than the cowl.
Actually, the perches are upside down...the reason for their design bias is geometrical: If the spring length increases over a severe 'bump', there is room for the eyes to still clear the perch. Additionally, your main leaf is excessive in length; the shackles should hang in a 45 degree angle when loaded, not the vertical angle I see here. Get a shorter main leaf, (2" or so) and reverse those perches. Alternately, if 'too low', you could have the spring re-arched, possibly getting by with the length it is now.
True, when used in a stock location, but sticking sideways out of the bones like he's got 'em, the eye wouldn't hit either way. At least we agree on the spring
So what I need is a more narrow spring, turn the perch pins down, which in turn will correct the shackle angle???
Is your perch perpendicular to the wishbone, or parallel to the axle? In the pics it looks like they may be at a 90 to the wishbone, which is at a slight inward angle. Thus making the perch eye skewed from the spring eye. Not a good thing.
Currently, perch is more perpendicular to the bones!! Thanks for the advice fellow hambers. Keepm coming. All this helps.
Not sure why these springs are so confusing, but they sure seem to be. The spring is mounted in tension. That is to say, if the car's axle ***embly were removed the spring is in so much tension that it pulls the shackles in a straight line. The springs pre-loaded tension is significant!! As weight is applied to the arched spring, the arch decreases and the eyes get further apart. When that happens the shackles angle MUST change for the springs dynamic ends to still fit within the perches fixed ends. As far as those perches go, the way you have them mounted in that angled plane- it wouldn't matter which orientation they were in as far as contact or spring operation. H O W E V E R - rotating them will change the C/C measurements and the length of the spring. Rotating them will also change your ride height. Mounting them on that angle puts a different set of rules into play. I can't say that I've ever seen that before but I like it.
That perch bolt is made to support a "stack" load, being pushed down, not carrying much of any side load. Now you're using it in single shear to carry the entire weight of the front of the car with 11/16 inch bolts, in a side load. If that perch bolt fails, and the aftermarket ones do frequently, on the ground you go.
There's got to be a bazillion perch bolts mounted with the shafts of the perches thru the bones, shafts 90* from their original orientation to the load. Just like his spring behind suicide front end Beefing up the radiator mount and it will be an axle catch for the suicide front end should the perch or spring break.
From what I'm gathering, I may need a more narrow front spring to give me a better shackle angle (45*).loaded that is(weight of flatty) Which in turn,will dampen the force applied by bumps in the road????
To be clear, your shocks actually do the damping. But w/shackles @ 45* the spring will maintain/center the axle position, and be able to deflect due to load changes.
In addition to what 31vicki said, how much room is there between the axle and bottom of radiator? Looks to be about 4". It may be sufficent? You could also add a rubber snubber to the u-bolt plate.
Just a thought here. There are perches that are straight and much shorter, I believe Speedway sells them, they may solve your spring length as well as putting the shackles at the desired 45 degree angle. I've seen them on a roadster before.
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