I've built a few in my time and have gained some thoughts on the subject. On my MG I have a unequal length 4 bar. For my purpose it works great. On a Model A I would run the GM truck lower arms with upper arms running from the center outward. I just don't think that P&J's system looks that good. That is what I would do, it's just my opinion. Pat
On a typical A the 4 link is an unnecessary complication, the whole purpose of the Model A hot is simplicity. Stick to the tried and true suspension stuff and you'll be happier.
I've done countless customer A chassis and have good luck with Pete & Jake's Model A triangulated 4 bar set up with coilovers.
What ever 4-bar you settle on, I'd suggest a stout 'K' member to minimise any torsional frame twisting.
I know what the term generally describes, I even have them on hand for a project. However the reason I asked for a definition is because the “GM truck arms” are NOT used in a 4 bar configuration and the reference seemed out of place. They are used in pairs, one each, left and right, are rigidly u-bolted to the axle housing (no pivot point) so they do not require “upper arms” to control the axle housing …..as do actual 4 bar setups. They do require a Panhard bar to control axle housing lateral movement. Ray
Jaracer, what angle are the top bars and length compared to the bottom bars on your chassis, thanks Glen
@AccurateMike Just for clarification, the reference was contained in post #3 (see above), which was ‘quoted’ in my post #7, to which you responded. Thank you for offering assistance….no harm, no foul. Ray Ray
Im sure those who’ve contributed to this won’t care but are there pre-‘65 photos of 4- links? This is in the Traditional Hot Rod forum but this is still an honest question.
Triangler 4 link more eye appealing then model A 4 bar plus you need pan bar , I prefer to see one bar below the frame than two bars, I used 32 set up on stock boxed A frame made my own lower frame mount so It would be parallel to the ground at ride height , Street & Drag With high Hp .
Don't know what you already have, and if you just prefer the model A frame.....or just have one and thats why you are using it. They are pretty weak as original, and a lot of people put 32 frame rails under their Model A bodies. Just thought I would mention that. As far as the four link goes, they can look nice, and they definitely improve ride and handling. Something to consider is driveshaft angle. With leaf springs, people set the rearend on a lesser angle because torque causes the rearend to rotate upward as power is applied. With a 4 link the rear will move up and down vertically but does not rotate upward.......so initial angle will be different than a leaf setup. Here are some pictures of 32 Ford frames that might give you some ideas. I only have 32 Pics, so not pressing that point, just saying that they may give you some ideas no matter what frame you use. Anyway, maybe a little food for thought......... I realize these are not "4 links", but it would not be difficult to run them instead of hairpins. It just gives you a chance to see some well done setups and maybe help with your build.
The top bars are 17 1/2 and the bottom bars are 21 1/2. The car is all together now so I can't really tell you the angle on the top bars although I believe they point downward slightly. It's currently on the lift so the measurements were easy. The lift is a frame contact lift so the suspension is hanging down and angles aren't at ride height.
Cars that ride poorly, and have dangerous handling are traditional. Should we keep that tradition up? Where would one draw the line?
Isn't that trailing link? I never thought those to be truly a 4 link suspension but I'm open to learn. Our Camry is pretty comfortable and safe. Is there an adapter out there in a catalog somewhere? I didn't bring any of that up - just honoring the forum rules regardless of my opinions on safety. D
This thread is about rear 4-link setups. The photo that I posted is of a pre 1965 chassis with a rear 4-link setup, triangulated,even. You asked, I delivered. Yes, it is trailing link. All common rear 4-link suspension systems are trailing link. I am not aware of a rear OEM leading link setup. I have seen a few on custom mini-trucks, but have no idea how they handle. Jeep used a leading-link 4-link on the FRONT of may new-generation SUV's from about 1984-on. Prior to the chassis that I posted, there were common 3-link systems, with the third-link being a wishbone, with the two attachment points on the chassis, and the third on the axle. As this attachment point was roughly 20-inches to the right, it made for an offset roll center, and uneven handling. The fourth link was added to eliminate that issue, all before 1965.
Interesting. Thanks. My BMW moto has a leading link front end. Would be interesting handling in a car. Are there any pics of hot rod builds of the day using 4-link? Race cars maybe?
I am sure that there are. You would need to search for them, with the caveat that practical portable digital photography began in the 1990's. As for eyewitnesses, you should start another thread on the main board. I cannot help you here. I was manufactured in the 1969, to be released as a 1970 model.
Back in the 70's I saw a speedway midget with trailing link lowers and leading link uppers. This was with an open tube axle and the links were attached to "birdcage" floating bearings. The birdcages acted like a bell-crank on a watts linkage [basically a longitudinal watts link] This caused the axle to travel on a vertical path straight up and down. Rover had a similar setup with the P6 ,but with a De-Dion rear axle [The De-Dion axle had a slip centre to allow for articulation] On the front end of the Rover P6 they used a leading link upper A-Arm and a conventional "lateral" lower A-Arm