Projects Building a Tube Chassis for my '36 Ford Sedan

Mumford is a lot of linkage, but it looks like it'd work pretty well for cars with fairly small wheel displacements.

However, as you can see (if you google it, many pics pop up), an extensive support structure in the chassis is required to mount the dual center pivots to. The Watts suffers from a similar drawback.

With a full length panhard bar, the roll center doesn't move all that much. Only exceptionally sensitive drivers in cars with high centers of gravity and very wide/sticky tires would ever feel the difference between RH and LH corners.

It's a trade off of perfection in exchange for simplicity, ease of construction, and efficient packaging.

The design I have puts the rear roll center plenty low enough, considering the CG and front RC height I'll be working with.

In all honesty, since I'm not constrained by any particular rule set, I would simply go to an IRS before resorting to such complex lateral control devices as the Mumford.

I am sure it works beautifully where you must run a solid rear axle, but IMO, if you're going to that much trouble with your locating linkages, you might as well take the next little step and go totally independent. The reduction in unsprung weight is enormous and the rear RC height become much easier to adjust (if they IRS is properly designed, of course).

That's just my thinking on it though.

If a customer came in and really wanted to do a Mumford, I wouldn't try to talk them out of it. Mostly, because it's his car, he can use whatever linkages he wants, but also 'cause they're really neat looking.

 

*Note* This post is to be read with a highly sarcastic tone.

Gee, thats cool but well...................... do you think its HAMB friendly.......

 

Will the floating brake mounts be getting something to prevent excessive wear on the axle housing? Or am I over thinking this? I have a habit of over thinking things.

Excellent work. I also vote for zinc chromate.

 

Well, they're set up for grease zerks, but they don't move hardly at all in relation to the axle housing. Less than 10 degs of rotation through the entire range of wheel motion.

It's not like a bearing on a constantly rotating shaft. The wear will be very minimal.

Some guys run them on dirt late models and modifies without any lubrication at all, and they run for years and years.

 

That is certainly true, but I have seen tall narrow hot rods with rear panhard bars only about a foot long.

I have only ever seen Mumford linkages at the rear of Clubman type racing sports cars. On most things, a rear Mumford would place the rear roll centre far too low to be useful.

But at the front, if you absolutely must run a front beam axle, a Mumford linkage would open up a whole new world of improved handling and roll stiffness tunability.

This is really the wrong Forum to try to discuss anything about suspension design concepts or vehicle dynamics. Many people here don't understand it at all, and don't like it.

 

awesome work,alot of thought and talent.what are you using for engine an trans?

 

Agreed.

Just as a note, the panhard rod on this car is 41" C to C. With a super short bar (like the 12" one you talked about), the RC is liable to be go over the place as the bar moves through its arc.

Thank you.

If I had my druthers, I'd build an aluminum block and head 434 Chevy mated to the road race geared TKO-600. However, that setup would cost many dollars that I do not have.

For expediency and budget's sake, I will probably be going with an LS6/T56 combo out of a late model GTO or CTS-V. That entire combo can be had for less than $6k ready to run, and makes 400+ HP reliably, on pump gas.

I know that choice won't be popular either, but I was going to use some kind of Chevy anyway, at least this way folks will have to guess at what it is.

I will, of course, have to do a good bit of cosmetic work on said LS motor to make it less ugly ('cause they are VERY ugly engines). Relocating the coil packs and swapping out the valve covers for something a little less plastic will help greatly, as will ditching the serpentine accessory drive in favor of a multiple V-belt system.

If I happen to get lucky and find some money I don't need elsewhere, someone makes a set of very slick Kinsler looking velocity stacks with individual butterflies that replaces the stock plastic intake.

There's a lot of water to go under the bridge before I get that far though.

Body work and body mounts will be the next items on the list, after I get the roller assembled and off the chassis table. If that ordeal takes less than a year, I will be profoundly surprised.

 

Maybe you should educate yourself a bit about the Forum you are on.

We have been having many Suspension related discussions, from a handling & cornering point of view.

( do a search...)

Funny you bring up Clubmans Race Cars, both of my Clubmans Racers ( a Mallock U2 mk6 and a Jasag ) are older though and both have Panhards.
And I can definately see the parallels between a Clubmans and a Trad Hot Rod

But I did build a single seater with a Wob Link.
Had I known about the Mumford at that time I would have done that instead.

Unfortunately I did not get to meet and talk suspensions with Arthur Mallock as many times as I would have wanted to.
But I feel very fortunate for the times that I was able to...

 

Just use whatever you can afford to get the car mobile and on the road.
It can always be upgraded to something a bit more exotic later on, when your finances have had a bit of a rest.

 

Love the frame. Is there art work or photos of the body mocked-up? Gary

 

Getting to speak with Mallock in person is pretty hard core, no matter how many times it happened. That's pretty cool.

My thinking exactly.

Thank you, no mockups or pics though, just what I've got in my head.

That said, I could probably draw something up, but that'd take a long time. I can do the artwork, but not quickly, so when it's not strictly necessary, I skip it.

I'm actually not thinking about doing any radical body mods. Smooth running boards, slightly flared fender lips (instead of dead flat sides), and likely some sort of different louver or vent treatment on the hood sides, but that's about it.

No chop, no section, I'm just going to channel the body over the chassis until the bottom edge of the running boards are flush with the lowest point of the chassis.

 

Yes, it was really very cool.

And when I say " talk suspensions ", I really mean me asking questions and listening...


Here are some pics of him, next to my car.

 

I would like to know more about mumford link theory and application but so as not derail this thread I started another.
http://www.jalopyjournal.com/forum/showthread.php?p=6127553#post6127553

The LS6 will be awesome with a six speed in that car. I am putting together a cammed 5.3 for the roadster and will back it with a t-45. Drive by wire throttle and all, it's gonna be fun!

 

Yeah, that's how it'd be with me as well.

I would really have liked to speak with Carroll Smith, but he died in 2004

I don't trust the "anything by wire" controls. Mine will be getting a high quality push/pull cable so I can close the TB manually if I have to (toe hook on the pedal).

Stuck throttles suck.

 

It's a roadster, if it all goes to hell I can just jump out!

 

You could always fit an ejector seat like the one James Bond had in his Aston Martin.

 

Thanks Coolhand,was wondering about body aswell.this thing is going to be a slotcar.suscribed

 

Ryan, If only threads like these existed in '73 when I built my 1st IRS/IFS tube chassis for an A coupe! You have raised the mark, a whole lot. Thank you, it encourages to learn what is possible. Your vision for this build will turn out to be a good driver, and that informs our group, we need the catalysts.

 

My plan with the body is to get it back straight and fix the rust on the outer skin, then basically totally remove the floor pan ('cause it's 90% rusted out anyway), then hang the shell over the chassis and build structure until the two meet in a satisfactory manner.

There is very likely to be a lot of "Pondering Time" spent in the process.

Got the suspension parts painted today, so pics of that in a bit when I've gotten them off the camera.

Thank you.

 

A good daily driver, something that stops, steers, rides and handles really well, but still has the old car mystique is my goal too.

 

From one ME to another.....Very nice work !!
Center of Gravity should be very low.......
Hope you scale the chassis to get F/R & L/R weight bias.
I have also built several "Home Built" Rnd Tube Chassis but I'm a straight line guy !

Can't wait to see the finished product.

 

If you combine passion and innovation, you've got someone who will improve all of our work/reputation. There are Hot Rods, then there are Rodders. Yes, billet was part of the baroque era of street rodding. Innovation is each of ours to explore as our budgets for time, skills and dollars allow.

 

Oh yes. Being an oval track guy, I've got scales and know how to use them.

I gotta get the big drive train bits in it and the body hung before I can tell anything meaningful though.

The design has been taking the mass of major components into account when placing them, so as to keep the chassis balanced laterally, and to keep the weight back as far as possible fore and aft.

The engine is set back ~13" from the CL of the front wheels, as are the driver and passenger seating positions. The rear seat has been deleted because of the huge rear suspension kickup and the setback.

If I can get 50%-55% rear weight, I'll be happy. It'll probably land around 51%-52%, cause a lot of the front sheetmetal is cantilevered out in front of the front axle CL, while almost no sheetmetal cantilevers out in the rear (the body is a slant back, and aptly named it is).

Just going to have to wait and see how it shakes out. There are several fairly large masses that I can play with to set the fore/aft weight balance.

EDIT: BTW, my degree is actually in Mining Engineering. I assume you're a Mechanical, right? I got more actual mechanical and practical design classes, at the cost of almost no thermo and only mining specific fluids classes (open channel incompressible flow, compressible closed circuit flow, no compressible open flow, no hard core CFD, etc). However, what I lack in Thermo training, I make up for with a minor in Explosives Engineering.

There are very few problems in life that cannot be remedied by the judicious application of high explosives.

 

I edited post #13 to insert the pics of the painted suspension parts, but I'll duplicated them here as well.

For what reason exactly, I do not know.

 

I will continue to update this thread until the chassis has reached the roller stage.

Then I will switch back over to the original build thread (Located HERE) to document the body and interior work.

 

Dude, I used to say something to that sorts for years whilst teaching neewbies in the military...nicely played sir!

Great build.....went throught the whole (both) threads.... keep on postin....cause even if it doesn't fit the "HAMB mold" it's still the true spirit of hot rodding....shit you fabbed your own farqin spindle for heavens sake!

 

Awesome engineering ! .... Have you been to http://www.dogfightmag.com/
Its another ATOMIC INDUSTRY forum , full of Hambers that love going round corners ...

 

I got that phrase from an English fellow who taught me about blasting.

His idea of a practical joke was 1/2lb blocks of C4 tied to a half dozen trees with 3/8" det cord, detonated to coincide with the ignition of the lifting charge of an experimental commercial firework mortar shell (an 11" dia shell IIRC).

Even from 300 yds, it sounded like the world was ending, and I'm pretty sure the guy shooting the mortar thought he'd lit his last squib.

When the smoke cleared, the fireworks guys were all under their trucks, and the professor was rolling on the ground laughing his ass off.

The mortar shell lifted and broke beautifully, the fireworks guys were issued new underoos, and the trees (which he wanted rid of anyway) fell over.

Then we opened the beer.

That guy knew how to party.

 

To quote Jim Belushi, "HOLY SHIT!"

That place is wonderful.

I have already registered and wasted at hour.

The historic F1 pics were most engrossing.

Thank you for the tip.

 

I noticed the L-Tec MIG welder with the MT-200 torch. I have the same welder and torch, which is the absolute best MIG welder ever made. I have had mine for 25 years now, in constant use and it has never failed once. I have built several dozen IMCA modified chassis with it as well as several hundred 9" rear end housings. Nice job on the chassis. I am a circle tracker myself, so everything on your chassis is very familiar to me. I was laughing when I read your DOM tubing rant, because I feel exactly the same way about it as you do. I have to deal with the DOM Nazis about once a month..........