GASSER MUST HAVES and cant haves?

X2... on the ladder bars....


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Marty. I think he imay be referring to post #17, but only guessing. Congrats on the 55 on the cover of Street Rodder. I have not been able to read the write up as 2 pages had been torn out of my mag when it arrived.

 

Here are the ones I built for my 31 Chevy. The front rides in an aluminum bushing so I didn't have to have housing floaters. They look short, but they are mounted at the transmission cross member.

MELTDOWN DRAGS
JULY 18-20 2014

 

Scott here's a link to the build thread on my car. This link should take you to post # 68 where the ladder bars were started. http://www.jalopyjournal.com/forum/showthread.php?t=729572&page=4 The ones that I did for Cromers car were totaly different there is pic's of them somewhere in his build thread.

 

Here's a link to Cromer's traction bars this should take you to page 18 the bars start on post # 356 http://www.jalopyjournal.com/forum/showthread.php?t=730747&highlight=quain+stott&page=18

 

These are the ladder bars I built for my falcon. If I remember correctly they're 1.25" round tube with .125 wall.

 

What is "the math" on where the front end of the ladder bar mounts (length of ladder bar)? How do I determine best point? Is it a measurement or frame specific by model, or both? Longer the better?

 

It's pretty complicated, but I guess it boils down to mount the bars where the rotational force tries on the front ladder bar mount tries to lift the whole car instead of one end more than the other. LOTS of books and computer stuff about it. They talk scaling cars, instant centers, rise/run and a bunch of other theories.

I think the theory of the long ladderbars was to lift the front end to get weight transfer to the back on acceleration. It's not the most efficient way of doing things, BUT it is traditional.

With the newer tire compounds and track prep, I don't think getting a car to hook up is near as hard now as it was in the 60's.

My old Anglia with bars to the firewall always lifted the frontend, but the rearend would drop. If you think about it, the rearend dropping is really unloading the slicks. But the tires hooked good enough that tire spin wasn't much of a problem.

 

I think the old rules said the length could be no more than half the wheelbase length? Seems I've seen old cars that were much longer, so not sure why they chose a certain length. I just picked an arbitrary length for my Falcon and built them. I think they're about 48", with a 109" wheelbase. The ladder bars on my Austin are only 34" long, but the wheelbase is only 89" also.

 

notice in the old pics of SWC and MAZ ---SWC rises in the rear while MAZ squats and smokes the tires, we thought that was horsepower but now it seems like poor chassis design---traditional ladder bars help control wheel hop and that is about it...

 

love those!

 

Thanks Dave. One of my winter projects is reworking the rear mounting points. I am moving the rectangle box tube forward so I can shorten the top and bottom tubes, which will allow me to install a heim on the top, and a heim with adjuster on the bottom. This will allow me to easily adjust pinion angle preload without removing the mounting bolts. The heims will be solid style, as I don't want or need pivot heims.

 

If y'all get tired of me being picky just tell me to shut up. With solid joints in the rear or front with a ladder bar set up the housing can't move from side to side with out something bending or flexing. Think about it as a square with the corners welded. This is a problem of you use a pan hard bar because if there is any up and down travel at all it pulls the housing from side to side. Not much if made right but it does move. A wish bone type don't make it move but they don't look right on an old school gasser. This was a problem on the way I built Cromers bars (Solid on all 4 corners) but I had to keep it as original as possible. Anyway after a lot of driving or hauling on the tailor bouncing down the road it will brake something. If the ladder bar is made from thin material it will flex enough if your lucky and never cause a problem.

 

Quain, mine has a upper wishbone, has since the late 60's, but you're right, it would not look correct on an earlier car.

 

The Comp ladder bars on my Austin gasser use solid mounts in the back with a panhard bar, and coil over shocks (I know, not traditional) but the front is a regular heim with pivot ball mount to allow the panhard to move the axle slightly sideways through it's motion. I've got about 12,000 street and drag miles on it now.
Been using this system for years, and guess I'm lucky, as it has worked well. Unless you were referring to ladder bars in conjunction with leaf spring suspension?

 

I'm definitely not 100% on this but I don't think coilovers are taboo on late 60's builds.




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I don't know how to explain it with out drawing a pic or something but I'll try. imagine you had the housing laying on the floor with the ladders bars bolted to it with the solid joints in place. Now slide the housing side ways on the floor 1 inch the front of both bars will move the exact same amount. Now image what would have happened if they were bolted to the brackets under the car (that won't let them move) something has got to flex and if it flexes it will eventually brake. Like your car it's working fine but I have seen it cause problems and they blame it on bad welds or to thin of a bracket. Like I said earlier I sometime get to picky about little things that very rarely give trouble.

 

Right coil overs were legal in 1967

 

I have heard that there were some cars built back then with wish bones on top. I guess they didn't show up in pic because they were on top. A lot of them even the early 60s built cars had a watts link it would not cause the housing to pull from side to side unless it traveled a lot.

 

That's a relief!


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Quain this 62 Vette was built by Butch Elkins (cylinder head guru with Diamond Racing engines and worked his magic on many cylinder heads with Maskin and others for years). I spoke with Ron Reader, owner of Midwest and he partnered with Butch on this car. Believe it was built in 64 with a watts link according to Ron. He said the watts link worked well. This car was driven most of the time by Al Maynard. This picture is at Milan in the mid 60s (blue with a silver top).

 

One inch would certainly break or bend something, but I can't get anywhere near that amount of side travel in the suspension on my car. I've moved the suspension up and down and checked travel of my panhard bar to see how the length changes, and it's plus or minus 1/4" for a total of 1/2". Probably why it's working, and not bending or breaking anything.

 

I was using 1 inch as an exaggerated example, 1/2" total is about right for a pan hard that is installed right with about 4" total up and down travel.

 

One of the famous willys of the early 60s had a watts link but I can't remember witch one it was.

 

Comp Engineering sells a lot of ladder bars set up with fixed rear mounts. I guess they have enough flex built into the tubes to not break with just the front heim pivot point. This is what I am running in my Austin:

 

I think the front heim is at risk, not designed for 90° shank loads but push/pull..A encapsulating bracket is used in current day applications for that reason...Now I realize that there can be speculation as to how much bend/lift vs push/pull during use, I also seen posted a nicely twisted ladder bar from speedway so there is some stout required...Also I think the adjuster should be at the top so it is not under compression but the ones pictured are at the bottom....AND I don't type fast, sorry!! .

 

I asked this same question in a call to Comp Engineering before I purchased mine. They told me the adjuster is built to handle the load whether it's pushing or pulling, and the strength of the adjuster wont be different one way or the other. But that is just a picture from Comp, so as you see it's not on a car.
Not sure that any heim can handle extreme side loads, as they weren't designed for that. But I've seen some crashes with heims in suspension systems, and I don't remember many ever snapping off. They are 3/4" heims, which should take a fair amount of abuse, or impact. I would expect the rear mounts welded to an axle could give as soon as the heim would.

 

I used these S & W bars on my 55. They are 42 inches long, 1" x .156" wall, DOM tubing. Being a street driven car, I like the poly front bushings. The bars still do there job, and I don't have to listen to Heim joints banging away under my seat.

 

You've touched on something that I don't like about the Comp bars. The noise of heim joint rattle when I go over those stutter bumps. A single bump doesn't seem to make them rattle, but get in rough road, traveling at 35 mph or more, and they do rattle!

 

This is my build. More 2010 than 1965, but I still wanted an earlyish feel. I built a watts link. Post #46 shows some piks.
http://www.jalopyjournal.com/forum/showthread.php?t=722751&page=3