Shortening coil springs

I need to shorten front coils about an inch. I don't want to increase the spring rate, so cutting is not a good approach. It is an oddball spring, could never find anything fit and I'm not going to have custom springs made. This leaves me with heating the spring, but that seems to be way out of favor for reasons that sound legit, but I'm thinking way overblown. What do you guys think? I'm especially interested in hearing from guys that have gone this route. Good or bad results, I want to hear them.

Bill

 

I don't think one coil is going to change the spring rate much, if any and heating would remove the temper. I'd cut 'em.

 

I agree with Landseaandair...........however, on the typical A arm suspension the amount of drop will be one and a half to two times greater than the amount the spring is shortened.

 

You're right. O.k., maybe half a coil, but an inch doesn't seem worth all the work.

 

I read in a suspension book about clamping the spring to it's new "free" length, and putting it in an oven for a while....I think it was the Fred Puhn book?

 

Yeah, but it does not work. Seriously, 300 degrees isn't going to do squat to anything made of steel. I wonder how high the temp would have to be in order for the technique to work. Might try it at the oven's max temp.

Bill

 

I know it is a lot of work, but can you extend the upper spring pocket depth by this 1'' ?

 

heating the spring will make it ride like ****. so will cutting it. no matter what you do to "shorten" it, it's going to compromise the ride quality.

that being said, and since it's an "oddball" spring, why not use a set of those cheapo little spring clamps? that way you aren't destroying a set of springs you won't be able to replace easily.

 

I would cut the springs, cutting them enough to lower the car 1" won't screw up ride quality enough to be a problem. But I think most old cars ride too soft...so what do I know....

 

A lot of 'the sky is falling', by some that might not even have a car.

Heating to lower it an inch would my way to do it. In 1957 on a '51 chivvy. In 1966 on a '56 Ford.

Odds are you won't even notice the difference in the ride. Of course there's a right way. You have to take the shock out. Heat the extreme bottom coil until it relaxes. If it breaks later where you heated it and half a coil at the end falls out, the result is the same as if you had took it out and cut it. DUH?

Look at this thread http://www.jalopyjournal.com/forum/showthread.php?t=226917&highlight=torch+coil+spring&page=4 and find the posts by FADED & Groucho on page 3 and Crusty Nut and Rpmrex on page 4.

If I had any more questions I'd pm Groucho and FADED. I haven't read any bad advice from either of them, anywhere.

 

Well, I tried it. Compressed the spring 2 1/2", baked at 550* (oven max) for two hours. Came out stock height. Don't know what Puhn had been smoking, but evidently it was good sh*t.

Bill

 

I've cut more coils than I can remember. Unless you go crazy and cut a lot off, you have to have some mighty fine sensors in your **** to feel any difference in ride quality. Coil springs aren't rocket science; it's more rule of thumb on how they are selected.

 

You're only trying to lower the car by an inch...so cut the coil and end the discussion. It's not difficult. You can cut 2.5 coils off a 50's front spring and still have a good ride. Most people are too cheap to buy shorter shocks or shorten their bumpstops so they complain about the ride quality after they cut springs. Either that or modify the spring saddle 1". Either way, it sure seems like a lot of work to get the car down 1"...something that is hardly noticeable.

Heating a spring is not an option. You'll realign the molecules in the tempered and hardened spring steel and make the spring brittle. Not only are you taking the 'spring' out of the spring, but you just made a ticking time bomb...which WILL break in due time. Basically a heated spring is like winding up a piece of round bar and expecting it to act as a spring, or using a piece of flat strap as a leaf spring...it won't do the job, and it won't last long in it's attemptto be something it's not.

 

I agree, cut it, but not more than half a coil. Also, there was a post here on the HAMB about 6-8 months ago on how to do this without removing the springs from the car. Do a search, but as I recall -- jack up the front end. Remove the shock, ***uming it goes up through the center of the spring. Put a heavy, flat bar horizontal through the spring. Put a bottle jack up through the middle of the spring where the shock was, and jack up the bar, thus compressing the spring. Use an angle grinder (not a torch!) to cut 1/2 coil off the bottom of the spring. Let the bottle jack back down, remove the bar, and re-install the shock.

 

X2 on what he said.
I won't knock you for wanting 1" out, sometimes it's those little changes that make it sit "just right". I think you could cut it with a cut off wheel without introducing too much heat. If you're worried about heat, use a porta saw, band saw, or even a hacksaw....if you have that kind of time.

 

I agree with most on cutting the coil but not baking a coil .

Have you considered lower blocks in the front end .

RetroJim

 

First off, I want to remove 1" of spring, not lower the car I". The springs are out of the car. Extending the coil tower is an excellent idea, but beyond what I am willing to tackle. The upper A-arms attachment points are welded to the coil tower. I will cut the springs.

Thanks all for your input. I truly appreciate it.

Bill

 

I've done several with cutoff wheel. No problems. Just did my '62 front (1.5 coils) will be doing the rears next week. Probably same amount. 1.5 coil on the '62 is a pretty good drop (maybe 3 inches or so at the bumper) but now the lower A-arm is level and the shock doesn't bump at the top over dips, etc. It must of had wagon springs in there or something. (Sat pretty high all the way 'round).