Kip, Thank you for your observations and your input. Obviously you have put the objective eye on my project. My first reaction was yeah, yeah I know all that! However, when my ego subsided,....... I got to thinking about several of your comments. #1, My hairpin/drag link relationship is pretty close to parallel and the same length; however, they are not perfect. They do swing on an almost equal arc but,....not from the same center. #2, 'Tho my pitman arm is quite stout, it's longer than a stocker and the offset you pointed out does invite flex. I've put a big wrench on it and see almost imperceptible twist. Maybe an RCH worth. But, add those minimal imperfections to the item of generous vertical height diff. (pictured previously) at the steering arms and we're talking a number of less than perfect features that in concert certainly are suspects for my problem. I'm embarrassed to admit that I have installed the dampener. It's satin black so you can't see it unless really looking for it. The good news is I cannot make it shimmy after several hundred miles and a purposeful attack on the pot hole that started the whole freakin thing.
Well, Mr. Bill... Mixed feelings force me to say I'm delighted that dratted dampener worked! That is to say, considering all the preparation beforehand, this was the moment to try the 'solution to all front end woes'... Too often, the dampener is applied prior to replacing loose, ill-designed, and inferior components. This is an exemplary conclusion. I trust the classic pitman arm will stay. (Kudos!)
Those wrenches are called spud wrenches or structural wrenches, they are redily available with the offset in them already if anyone else is looking to use this set up.
Yes, the pitman arm stays. I'm thrilled with how the project worked out,....especially the appearance. And, in spite of what some will say, it's all about the look! However, there is a cost for cool. Sometimes it's dollars. Sometimes it's inconvenience. Different strokes, eh? Long's you don't kill yourself or anyone else.
Awesome! I'm glad to hear the stabilizer is working because the look of your rod is killer. I'll keep a mental note of your work and your solutions, thanks for sharing! Kipp
Just got back to this thread as reference for another that I am considering. If I don't forget, I'll post a few of the cowl steering project in the coming weeks. Anyone still watching.
before you go the cowl steering route, I would read this.... https://www.jalopyjournal.com/forum/threads/cowl-steering-just-stop.1101046/
Just did that. I know, I know! Life ain't perfect either but it's what I got and I've survived it for over 80 years. See my response.
To begin,....I don't have any quarrel with those who have a different point of view. If I have done something really stupid, I'll try to understand and learn from that. However, if I have done something just a bit controversial, "oh well!" * The project was completed about 25K miles ago. This is a refresh to provide images that have vanished The following is an expedited picture synopsis. Hope this tells the story, in brief, for those interested. If anyone needs clarification, just give a yell. And, as the original****le states,...this is a first time. I'm a decent hobbyist engineer and fabricator. And I can't stress enough the value of mocking things up to confirm or refute your****umptions. Otherwise,..."go for it", it's amazing what one can achieve by pushing your personal boundries. I have clocked over 80K miles on the car at this point (with Vega steering) but was concerned from the beginning that, I got the steering where I wanted it, the ratio was street friendly and the solution made a visual statement. mock ups to establish geometry and starting dimensions. Used up a lotta cardboard and conduit. sketched a monoque box to spread the steering loads to the cowl, firewall and door frames and started puttin stuff together from there.
Googled "cowl steering" and came up with a thread on the HAMB that documented using a 70 Ford pickup box. Liked that as the ratio was "slow", the pitman shaft was long and the mounting foot print was generous. Those done with a reversed Corvair box looked way too wimpy to me. The article went on to document how to reverse the Ford box. Way cool, way simple and a first for me. I spotted one of these "slug wrenches" some time ago at a swap meet and thunk what a cool pitman arm that would make,....been in the back of my head for some time. Cut the end off the Ford Pitman arm and****embled a custom arm that met the criteria.
Very nice work. I like you mockup and engineering. I didn't take any process pictures but this is what the install of the Schroeder in my 34 looks like.
I like this look a lot, but would be worried about strength as the wrench is pretty thin. I'd think about welding a doubler or stiffening rib to the back side, down the full length and especially in the area of the bend. You could do it in a way that won't show much (if at all). I tend to over-build things though. Nice fab work, and good call on the pickup steering box. It looks like it was plenty long enough so you didn't need to extend the shaft.
ok, everyone considering this needs to see Pete Eastwoods thread on why not to. here is a youtube video showing bumpsteer on a cowl steer set up https://www.youtube.com/watch?time_continue=13&v=5W-wl3p19e4
I'm glad you've found a satisfactory "fix" for your wobbling problem, and I think your craftsmanship is incredible. It sounds as if you attribute the problem to lots of minor transgressions from ideal. Regarding anti-bump-steer geometry, it is really off by a mile (well, maybe a foot). The goal for parallel drag link and radius rods only applies to 4-bar arrangements. For correct geometry, the bottom pivot on your pitman arm should be at the same height as the hairpin pivot (since they are both the same distance back from the axle). Of course, you would then have to spend a lot more time at your local weightlifter's club! The geometry you have would be nearly perfect for a 4-bar suspension. (I'm curious whether 4-bars are considered acceptable to the Traditionalist theme of the HAMB?) I don't think the pitman arm is flexible enough to contribute; it's probably a lot stiffer than the steering arm at the wheel, which hasn't been mentioned, and also is probably "not guilty". I wish you were nearby so we could swap some engine parts. I have a small Dodge Hemi, but am looking for an early Poly engine. To me, these are really cool and doubtful that you'll ever happen upon someone else running one. Do I understand correctly that to convert a Hemi to a Poly, you only need everything above the head gaskets (including push-rods) and the correct pistons?