Frame / Springs: Another... MOOG CC-655 front spring question

[wittsend]

I know there is a lot of information on the forum about these springs. But, I don't know if this has ever been asked? Are the MOOG CC-655 springs a direct replacement for all the GM cars they fit? Or are they a variable rate upgrade for those GM cars? Being a CASO I have looked at these GM cars in Pick A Part (where I'll be tomorrow for their 50% off sale). Visually there is nothing to indicate the GM original springs as variable rate. I see no alteration in the coil spacing, taper windings etc.. On the other hand, if they actually are variable rate OEM spring (regardless of appearance), then I can get a comparable set of MOOG CC-655 "like" springs for very cheap. Thus, why I am asking the question

Which brings me to another point. My '64 Daytona was originally equipped with the Studebaker engine. Internet information lists that engine at 650 pounds. At some point prior to my purchase the engine was swapped to a Chevy 283 and subsequently I swapped that to a Corvette 350. Most of the engine weight charts list the SBC at 535-570 pounds. Being that I have an aluminum intake, water pump and what are often referred to as light weight iron head castings I'm incline to say my engine is no more than 550 pounds and likely less. I have no PS, A/C etc. This is a 100 pound weight reduction. I also swapped out the cast iron B/W A-12 transmission with a 700R4. The B/W A-12 was 200 pounds and the 700R4 150 pounds. So that is an additional 50 pounds reduction. Lastly I may swap the battery to the trunk and that would shift another 40-50 pounds off the front end.

I'm looking at close to 200 pounds of weight reduction from the front of the car. Has anyone else had a similar configuration with the MOOG CC-655 springs and can comment on the front ride height?

Thanks, Tom

[irish]

I have the Moog CC-655 springs installed in my 62 Daytona and my 64 Cruiser. Both of these cars have a Studebaker 289 V-8 and the ride height appears to be identical to the original height. So with that said, I think it's safe to assume your car will sit too high with those springs. I know people have used the lark 6 cylinder springs in a situation like yours. You can contact eaton spring and tell them what you have and they can make springs for your car. Hope this helps.

Joe

[junior]

Tom, how does the car sit with the stock springs...is there a need to change them? I`ve read a lot about 6 cyl. springs not being up to the task of having a Stude v8 rest on them, at least in the c\k series. My C car has 6cyl. springs and they are more than up to the task of supporting the weight of a sbc chevy with cast iron intake, and exhaust manifolds, either with auto or standard trans, battery in trunk...in fact the car sits at what appears to be stock 6cyl. ride height, and I have never bottomed them out while driving. Point being, seeing how you are a caso, why not try the stock ones first...I`m thinking they`re going to work for you. regards, Junior.

[wittsend]

Junior this is how the car sits now.

Note that the tires are 225-60-16" on Crown Vic Cop Car wheels. The car has a slight forward rake that I visually prefer. However, there is no spare or jack in the trunk and the gas tank is virtually empty. I know on cars like my '73 Valiant the ride height is generally how I prefer it, but with a full tank it drops lower than I want. I guess I could always cut the springs.

I was most interested in whether the Moog springs were a direct replacement (meaning the GM cars they fit were also variable rate from the factory). Or, are the Moog's an upgrade to a variable rate spring and the GM cars came from the factory with a standard (non-variable rate) spring. Reason I asked is if the factory springs are variable rate, and I could get them from Pick A Part for $8 each, that is a lot cheaper than the going rate of the Moog's. But, if the factory springs aren't variable rate then there was no need to get them.

Thanks to all who replied, Tom

[Paul Keller]

Check the RockAuto site - They have a way of checking for application to a specific car model (often will state at the parts info/price or you may need to dig a bit deeper). Otherwise your friendly (?) Buick parts may be able to help.
Assume (?) that you have read thru' all the Forum sites re springs - Lots and lots of info, including the original TW article.
Paul TK

[Skybolt]

Tom, PM sent.

[wittsend]

It is now nearly two months since I posed my original question asking if GM made a variable wound spring and if it equaled the Moog CC655. I have some information to add, but I'm not sure if it answers anything, - but here goes... .

I was at Pick A Part today and found a 1986 Buick Le Sabre that has progressive wound springs. From my searching I don't recall seeing other GM cars that are the correct late 80's early 90's application (Le Sabre, Olds 98, Bonneville) - with a variable coil wind. This spring had a part number of 25525303. I did not assume them to be the exact Moog CC655's, but the GM progressive equivalent of. After I got home I did some searching and found some differences.

The Le Sabre spring is almost an inch longer. The coil diameter is about .050 smaller. I was disappointed to find this. However, with my 350 Chevy engine and 700R4 transmission I have 150 pounds less weight on the front end. So, maybe this won't be too bad. Also I prefer a slightly lower (not slammed) car. So, if I need to cut any coil, it will favorably increase the spring rate.

Yes, GM does appear to make a variable rate spring similar to the Moog CC655. But, No, the spring rate seems to be reduced (based on the .605 vs .656) coil diameter. What gets lost in the discussion (and maybe no one knew..., I didn't) was that the "CC" in CC655 stands for "Cargo Carrier." Moog rates this as a stiffer "cargo hauling" spring, not an exact replacement spring. I assumed they were similar. Since these spring were happened upon they were just described by a part number CC655. With stores wanting an application the vehicles of application was then mentioned in other posts. I tried to "back track" that data thinking I would find an wrecking yard priced equivalent. At least as an exact spring that logic failed.

Moog does list a direct replacement standard spring which is 5713 (for the application late 80's early 90's, Le Sabre, Olds 98, Bonneville). What I don't know is if that is a non-progressive spring spring or not. Visually at the Moog site the image does not show a progressive wound spring nor is "progressive" or "variable" used in the specifications. The 25525303 number on my springs brought nothing in a Google search. I pulled the RPO tag off the car (1986 Buick Le Sabre Limited, 3.8) the springs came from. I spent a good hour decoding the numbers. The closest I could come by was possibly 6DZ or 7DY were the spring numbers. The code just returned the term "computer select spring." The 7DY seems to be the rear springs. Google search on those codes weren't helpful.

I'm just going to try the springs. Who knows, they may work better than CC655's. With my reduced weight the CC655's might have been too stiff. It is just a hunch, but maybe these spring might provided a variable rate spring suited for 6 cylinder cars.

Tom

[Skybolt]

Sorry for the late reply.

Try this: Go to a site like O'reilly's Auto parts, because they have compatibility software, and put in the part number CC655. Then look at the cars it will fit. For example a 1988 Buick Lesabre base model. Then start again with entering a search for a coil spring and add a 1988 Buick Lesabre base model as your car. Choose the rear coil. You will find it will bring up two springs, one a CC655 and the other is a 5713, both Moog products. This spring, the 5713, is the standard coil spring and will be for lighter duty use.

Spring #

Inside Dia

Bar Dia

Install Height

Load rate (lbs)

Spring Rate (Lbs/in.)

Free Height

End Type

CC655	4.187	0.656	11	827	355	13.63	Square Ends
5713	4.218	0.593	11	825	241	14.5	Square Ends

As seen here from the Moog spring chart the 5713 might be what you want. Therefore a standard spring from the wrecking yard from a matching car would give you a start and if found to be compatible you could always get them new from Moog for about $50 a pair. There are other cars, about 40 models, that these springs can be used for and found in. A used set will give you a lower ride from the start as it will already have set in. Just an idea. If you want the Moog chart it is online but I have it so PM me and I can shoot you an email with an attachment. As I have it as an excel file it can be edited easily. This way parts that are out of the question can be discarded and closer ones examined. This is how I came up with the CC655 springs for my car. There is some math involved, but it is simple, to work out installed height vs weight etc... But because it has already been done to arrive at the CC655 one just has to work either side of those to get your desired result. Notice the ride height of the 5713 will be the same as with the CC655 but with a lighter load. Although we are not using the same weights, installed heights etc... but the math proved the spring rates and installed heights for a Studebaker to be usable. I hope this helps somewhat.

P.S. Standard spring are used for the rear of most of the GM cars. I have no idea if the HD variable rate springs were used from the factory, or at least I can't recall off hand, as it has been a while since I was working on the replacement front springs. Moog offer them as a HD option so that's all I can tell you. Also, the CC prefix designates variable rate and the others are a constant rate.

[wittsend]

Thanks Skybolt. My GM issued variable rate springs are a bit of a mystery (yes, I did buy them, $12.59 each at Pick N Pull). While not Moog CC655's (diameter too small) I'd think they are an improvement over the 5713. I think they are in the "ball park" for my application. I just wish I knew the spring rate. All I can do is try them. With the the Chevy 350 and the 700R4 reducing weight (150 lb's) they may be a better option than the CC655's.

Anyway, since the subject comes up from time to time, I thought I'd relay what I had found. Maybe it will be pertinent to someone else.

Tom

[wittsend]

It's Father's Day and no one is asking me to do anything so... . I ran these Variable Rate Buick Le Sabre spring through a spring rate calculator. It is a bit hard to do being a variable rate spring. I decided to null out the tighter wound "softer" part of the spring. Theoretically it would collapse at some point and only make the larger spaced "stiffer" portion of the spring effective.

When I factored the spring OD, the wire diameter and the free and compressed length (reducing "free" values to compensate for the collapsed "softer" portion) I got a spring rate of 364. The Moog CC655 is rated at 355 but that is likely a combined factor of the soft and stiffer aspects of the spring. How they factor the two spring rates together I do not know.

I ran the spring a second time using the values of the "stiffer" coils only, but this time I assumed the spring to be the full, free length and did nor reduce factors like I did before. Basically I was assuming the spring to be a constant rate and replaced the "softer" coils with a continuation of the "stiffer" coils. This gave me a spring rate of 309.

So, in the end I find the following:

The combined "soft" and "stiff" rate of the spring (before the "soft" collapses) has to be less than 309. How much less I haven't the smarts to calculate.

Once the soft portion of the spring collapses the rate is 364.

I found some information on the SDC site that listed testing of constant rate "standard" springs at 225 and "HD" springs at 270. Others stated 300 for the HD springs.

So, while my gains may be minimal I still might get something. Especially given my 150 pound weight removal from the front. And, as I said before if I cut the spring to lower the car, the rate will increase. Going from six active coils to five increased the spring rate by 50. and going from five active coils to four increased the spring rate by an additional 75. That is quite a it of change per coil.

And that is how I spent Father's Day.

Tom

[Alan]

Tom, I put a set of 655's on my spring tester and got 301 lbs. for the first inch. I can't go to the 10 1/2" ride height of the stock Stude, as my tester is only good for 500 lbs. The stock Stude 127's are .638" -.643" depending on where you mike them at and they have one more active coil at 7.