Hot Rods Split wishbones, hairpins or 4 bar front end?

I have a dropped and filled axle in my current car, and I haven't died yet. But yes, you are going to die.

 

Not trying to jump on the cast axle bashing, but a friend of a friend just got hurt really bad when his cast axle broke while on the freeway.

 

Haha... would you happen know when it will happen? I want to run up my debts!

 

different gearbox possibly, or have they previously run a different motor that necessitated it.
Or some think that they handle better as they act partially as a stabiliser type bar….
or they think that it’s the way to do it because others have done it……

 

If you drop the car by using the spring the wishbone can get close to the frame.

 

Ok I’m finally back at it. I have bought a forged axle and all the stuff to put my front end together. But the wishbones I have already have the holes in them . I want to fill the holes with tubes and weld them in . I don’t like the looks of the open inside of the wishbones and think this will be stronger and better looking. Is there any draw backs from this?

 

I'm welding mine up also.
Don't see any problems.
Terry aka dirt t

 

You will be fine sleeving the holes. Hundreds have done it over the years

 

Back in times past, the holes were made with the idea of weight reduction. Adding sleeves to the equation probably makes them heavier than original. Gets me thinking sleeves is a "modern traditional" thing; kinda like pinched frames.

 

Sure, 6 one way, half a dozen another. I don't really care. They look right on certain cars.

 

Here's some simple maths to consider using nominal dimensions -
Holes - 1" OD x 1/8" thick x 2 each = 0.196 cubic inches.
Sleeve - 1" OD x 1/8" thick x 1" long = 0.344 cubic inches.
This shows that the sleeve is substantially heavier than the two holes drilled ...... and that doesn't include the welds etc.

 

Model A’s usually sit a little higher than a deuce. So, with a non fendered Model A hot rod, un-split bones look the best. If running split bones, I would mount them to mounting brackets on the inside of the frame rails so the bones sort of visually disappear under the frame rails. Mounted to the outside of the frame rails, they sort of hang down quite far...like dog balls! Just a thought.

 

Stock wishbones are best, then 4 bar, then split wishbones. Stock everything pivots on the ball, 4 bar up and down movement puts some forward and aft twist in the axle, split wishbones cause the axle to bend more.

 

In my opinion, the only reason hairpins exist, is so that you can run a 37-40 front spindle on a dropped axle without having to drop the steering arms, as the tie rod and drag link travel through the hairpin.
Why else would they exist?

 

Race cars.

 

Easily adjustable for length and caster.

 

'cause they look good?

BTW unless you use bolt on arms you still need to bend stock steering arms to swing; even if you have one of those modern artistically styled aftermarket dropped axles.

 

Lots of good advice so far, but some don’t really touch on your questions.

The choice of front suspension comes down to a balance of being period correct, having a period flavor, or having optimal suspension geometry. Period correct would be not to split the wish bones unless you have to suit to the engine and/or trans used. If you split them you might consider what kind of rod end to use - some are more period than others. For example, a heim joint would not be period correct for a traditional car. If you split them you might also consider hairpin radius rods, which would be a little later in time. Split bones and hairpins both have some down sides in terms of suspension geometry, but have been commonly used for a long time (my car has an I-beam axle with hairpins). Pete and Jake’s invented the parallel 4-bar to solve the geometry shortcomings of the split wishbones and hairpin styles, but represent a later evolution and are not ‘traditional’. However, people use them on all sorts of cars (to the pleasure of some and disgust of others!).

The Pete and Jake’s online catalog has a nice section about front suspension geometry and steering choices.

In the end it comes down to your vision for the car you are building and how you want to incorporate traditional and newer designs into it.

Hope that adds…

John

 

Whew , lots of info from friends & members here. My professional opinion overall is ; it's a hot rod , do it your way ! I still install & build chassis with split wishbones (etc). I doesn't matter standard (stock) drop or 5-6" drop. Where the wishbone goes is of course not changed. I prefer 35-40 wishbones or even the cool looking 46-48 bones. the hot lick is to use 35-40 , turn them upside down (because they look better with out factory weld.), & have a little more room for tierod/draglink. You'll have to get the chassis at ride height & loaded to fit the wishbones. I V cut them where the tubing fits against the "yoke" that slides on the axle. Remember, it's all about ride height (degree of angle) usually 3 + -. I tack the v cut together & take to a welder friend who is way better than I. About the tube verses I beam. I manufactured tubular axles with forged steel ends for 15 years. NEVER had a failure, even when we ground the weld off ! All that propaganda about can't use hairpins etc on a tube axle is all B/S ! I drove my 5" chopped 3 w with wishbones for many years before selling to a friend in Wa; Bruce Giesler. I even ran that hot rod at Maxton (125mph). We did (90's) a test on axles for Hot Rod Magazine . We bent them till they bent or broke. Best one was the Chassis Eng. Forged I beam (now sold by Pete & Jakes). Our VCW tube was next, then the Super Bell Ductile I beam. The "forged " I beam from China land was similar to the cast axle. Some tubular axles are not worthy ie: MAS bent tube etc. Previously Total Perf. style axles too. Filled axles are cool & lots of work too. The test was never published by Hot Rod because wouldn't use names. Sorry to run on but all is true. Contact me if have questions. text ok 336 302 6091. Hi & best wishes to my friends that posted here ... Alan the "Flatlander" NC (Norfolk : 1978 - 2006)

 

That's not strictly true, but they did develop it into a hot rod application form, to address the issues you mention.

 

Not sure where the text went, but to cut to the chase…what is this mess on my 36 project?

Spring hangers say Pete & Jakes, and I think it dates to the early seventies.

Probably going to ditch it and go with another 36 axle & bones I hav, or a 39 setup.

Curious what this is, though.

 

Looks like a homebrew 4 bar with the batwings made out the front piece of a '35-'36 wishbone, '33-'36 axle with the spring perches welded on. Looks like it could have GM rubber panhard bar bushings in the ends of the 4 bar. Might not be that sharp looking; but probably works well.

I don't remember aftermarket 4 bar set-ups being commonly made for fat-fender cars; maybe because the spring hangs off the front.

 

Thanks, you’re right!. I looked at their catalog again and it says they just put a trademark on the term “4 Bar” for their parallelogram front suspension.

John

 

I disagree. Angles and distance between load points are extreme and the length of the bars real short. When the parallelogram moves up and down, the distance between the axle and rear pivot points shorten, an amount you want to minimise. To do this, the bars need to be as long as is practical. Same as all the locating methods in this discussion.

It's a home brew fail, I'd change it.

 

That’s what I’m thinking. The back of the four bar is pinned to the frame roughly under the firewall feet.

I don’t thing there are modified 36 wishbones here. The batwing and front link looks store bought comparing the welds and finish to the booger welds elsewhere on the car. I suspect this is some early aftermarket kit. It looks like the pictures speedway has for their 34 kit, to some extent.

I suspect early P&J, but it could just incorporate their hangers.

problem with going back to 36 split wishbones is the x frame has been heavily cut up. I do have a partial x member for parts, though.

the car’s a mess, all in all.

Don’t want to hijack this thread, but the op was asking about bat wings, so…

 

Finn, I bet the only P&J parts on that home brewed setup are the shackles. Usually the batwings have the front pivots of the 4 bar close to he axle. Yours are really far back. Might induce leverage into the bars, especially since the axle is already hanging off the back edge of the spring rather than under like an earlier car.

 

Yep.

 

You’re correct on the setback batwing. Looking at online pictures of the Speedway 37-40 setup, the batwing is at the axle, and splayed forward and outbound to catch the shackles. That avoids the brackets welded to the axle.

They don’t have anything for the 2” 35-36 axle, though.

Leaving for Tucson next week, so I have six months to figure out what this is and how to salvage some of it.

 

That Speedway 4 bar set up looks kinda clunky and a headache to me.

If you are happy with the height of the front end you could easily remove the 4 bar stuff. Get a '35-'36 wishbone, cut off the spring hangers, and split the wishbone to the inner legs of X-member with something like a Chassis Eng AS-2085 split kit.

If you wanted to lower the the front, get another axle and send it out to get dropped and keep the spring hangers on the split 'bones. Your spring and stuff should all be compatible with this.