C1 Rear Spring Arch - Article?

[Keith R.]

Re: C1 Rear Spring Arch - Article?

Hi Stew,

Guessing that what that means is that the rebound straps were lengthened to 29.9 inches.

Corvette V8 1955 - 1962 complete owners hand book.
In 1960, further development resulted in a truly '' dual - purpose machine. New front and rear stabilizer bars vastly improved vehicle stability making unnecessary the use of heavy duty springs and shock absorbers for competition. At the same time, riding comfort in normal touring use was not sacrificed.
Other changes included adding an inch to rear suspension rebound travel for better wheel adhesion under severe road conditions.

It states that GM has added an inch in rebound travel to the 1960 car. If I'm reading it correctly wouldn't an inch in rebound give the car a higher stance at the rear. Stewy

[Steven B.]

Re: C1 Rear Spring Arch - Article?

Corvette V8 1955 - 1962 complete owners hand book.
In 1960, further development resulted in a truly '' dual - purpose machine. New front and rear stabilizer bars vastly improved vehicle stability making unnecessary the use of heavy duty springs and shock absorbers for competition. At the same time, riding comfort in normal touring use was not sacrificed.
Other changes included adding an inch to rear suspension rebound travel for better wheel adhesion under severe road conditions.

It states that GM has added an inch in rebound travel to the 1960 car. If I'm reading it correctly wouldn't an inch in rebound give the car a higher stance at the rear. Stewy

Stew, I have the same book----got it when the 1st ed. came out. I competed with my '57 way back when and used both suspensions on the car at various times, the standard and the HD. There was a noticeable difference in the handling between the two. The HD handled better and I got faster lap times. Although I didn't have the '60 set up a friend did and after alot of tweaking, changing springs, shocks, and bars, the best performing set up was the complete factory HD over the standard on his '60. The extra rebound travel does not refer to ride height, but rather to the available movement of the axle. Over the years these old suspensions sag and the height changes considerably.

Steve

[Stewart A.]

Re: C1 Rear Spring Arch - Article?

I better go back to school and learn how to read again sorry about that. Although I was positive the 60 cars sit higher, all the pictures I see they seem to show more tire at the rear ?
John Hinkley is extremely sharp on Corvettes and I think he is correct with the car heights. Sagging springs and re tempered stuff could make the car sit at any height.
So what is the correct height for a 58 - 60 from top of rear arch to ground be ? Is there documentation on the heights of the cars.

[John H.]

Re: C1 Rear Spring Arch - Article?

So what is the correct height for a 58 - 60 from top of rear arch to ground be ? Is there documentation on the heights of the cars.

GM has never published any dimensions from ground to the top of the wheel openings, as that varies depending on tire size and inflation. They DO publish suspension heights, which are independent of tire sizes - look in UPC 3 or 4 in your Assembly Manual, and you'll find a published dimension "B" from the top of the axle tube to the bottom of the frame rail directly above it, which is the design suspension height.

[Gary C.]

Re: C1 Rear Spring Arch - Article?

Tom, only dimension drawing I've seen is reference in Noland Adam's C1
book. Scan attached. Gary....

[John H.]

Re: C1 Rear Spring Arch - Article?

Tom, only dimension drawing I've seen is reference in Noland Adam's C1
book. Scan attached. Gary....

Gary -

See the '57 Assembly Manual, UPC 3, sheet 4.00, View "C".

[Mark P.]

Re: C1 Rear Spring Arch - Article?

I just bought these 1960 springs and it is believed they came off a 25,000 mile car.

I will check the dimensions when I receive them but was wondering if they look like they need re-arching ?

If they have the correct dimensions then would you not have to re-arch them ?

I plan to restore them but would like to avoid the re-arch expense if I can.

[John H.]

Re: C1 Rear Spring Arch - Article?

I just bought these 1960 springs and it is believed they came off a 25,000 mile car.

I will check the dimensions when I receive them but was wondering if they look like they need re-arching ?

If they have the correct dimensions then would you not have to re-arch them ?

I plan to restore them but would like to avoid the re-arch expense if I can.

Mark -

If they're close to the dimensions noted in post #2 in this thread, I'd just clean them up (or restore them) and use them.

[Donald H.]

Re: C1 Rear Spring Arch - Article?

I just bought these 1960 springs and it is believed they came off a 25,000 mile car.

I will check the dimensions when I receive them but was wondering if they look like they need re-arching ?

If they have the correct dimensions then would you not have to re-arch them ?

I plan to restore them but would like to avoid the re-arch expense if I can.

I am by no means an expert, but my springs were pretty sad on my 1960. I have already posted photos in another thread at the link below. Look at the before and how the Main Plate curves back on the front end of the springs. The after is a photo after I got them back from Eaton where they did the shot peening, rearch, heat treating, etc. I have painted, installed the liners but not the bindings yet. For reference the measurement I got was 49 3/8" on center eye-to-eye and 5 1/2" from Main Plate at center bolt to center line of eyes. Using the method from link above to Eaton, I got "Divisional Lengths" of 26 3/4" and 23 7/8"

https://www.forums.ncrs.org/showthread.php?t=82830&uid=7785

[Mark P.]

Re: C1 Rear Spring Arch - Article?

Donald - any pictures of the springs before they were re arched ? Do you know their dimensions at that time ?

Thanks,

Mark

[Gary C.]

Re: C1 Rear Spring Arch - Article?

If springs and body are on the car with reproduction tires. Nominal rear fender center opening height is 28 1/2" from the ground. Gary....

[Donald H.]

Re: C1 Rear Spring Arch - Article?

Donald - any pictures of the springs before they were re arched ? Do you know their dimensions at that time ?

Thanks,

Mark

Here's a couple of pictures, one while the springs were still on the bare frame and shortly after removal. The red circles show the spring curving back the wrong way. As explained to me in a previous thread, this was probably for a lot of wheel hop in its past life, i.e. lots of drag racing. I did not do any measurements before I had them rearched.

[John D.]

Re: C1 Rear Spring Arch - Article?

Tom -

Per the late Dale Pearman's notes, the C1 spring main leaf was 51" long from the center of the front eye to the center of the rear eye, and the correct unloaded arch (the drop from an imaginary line connecting the centers of the two eyes to the top of the leaf) is 5-1/2" to 5-3/4".

john
The drawing for 3751438 shows a developed length of 51 +/- 0.12". It does not have a spec for free arch but it states " .08 negative camber under load of 545-605 lbs." at a point at the center

[John H.]

Re: C1 Rear Spring Arch - Article?

john
The drawing for 3751438 shows a developed length of 51 +/- 0.12". It does not have a spec for free arch but it states " .08 negative camber under load of 545-605 lbs." at a point at the center

Thanks for the info, John. Spring design is more art than science, and I've found that objective measurements in the free state (as indicated in the late Dale Pearman's notes) or as-installed per the Engineering "Z" and "D" ride height dimensions in the A.I.M. can at least move you in the right direction.

Not many of us have access to spring load/height/deflection checkers, although Eaton Detroit Spring has several of them so they can correlate to the original drawing load rates.