uh oh...another valve spring question...which one??? CC979 or CC980 w/CC206/206 cam
- Thread starter FJM568
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Let me start off the discussion by advising I'll send to your e-mail address spring measurement data I took a couple years ago...contains data from: CC979, CC980, LT1 (or LT-1) bought at BG, and my stock 35k mile springs.
I'd personally go with the 980 with the internal spring (as received) and without the stock cups over the 979's on a stock cam so would certainly do the same for a 206/206. Wouldn't go any stiffer than 980 until the car is faster than 11.5 range...just don't believe that we need stiffer springs to close valves faster when we are only reving to 52-5500 for example.
Regards, Bob
I'd personally go with the 980 with the internal spring (as received) and without the stock cups over the 979's on a stock cam so would certainly do the same for a 206/206. Wouldn't go any stiffer than 980 until the car is faster than 11.5 range...just don't believe that we need stiffer springs to close valves faster when we are only reving to 52-5500 for example.
Regards, Bob
A
AsphaltAnihil8r
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I have new 979 springs ,do I reuse the old cups or discard them,I have the stock cam,,please advise ,sounds like you are saying not to use the cups for added psi
Use the stock cups with 979's. I think he is saying the 980's with an internal spring are slightly higher spring pressure and may be more consistant than 979's with cups. 979's without cups, will be less than desirable in terms of spring pressure that ones with cups.
Steve Wood
Active Member
- Joined
- Jul 18, 2001
Altho I like the 980s, I would ask this.
Doesn't the cam manufacturer suggest the correct springs for a cam?
Doesn't the cam manufacturer suggest the correct springs for a cam?
Heheh...Just like Steve, cut right to the heart of the matter...I believe they recommend the 979s...BUT, would they still recommend them for cars running 20+ lbs of boost???
Reason why I'm asking, I had the 981s on there with my last cam(MM208/208 flat tappet)...wiped the #3 exh lobe...had 13k miles on it...All the other lobes looked fine, just #3 exh didn't want to be bumpy anymore ...When the heads were assembled, they were supposed to go on a motor that had the KB1txb cam in it(which they recommend seat pressure of about 104#, I think it was)..That is why I went with the 981s...plans changed and I built a completely new motor(w/MM208/208 cam) and just put the heads on it...Well, 13K miles later, wiped lobe The heads are the Stage JRs from David Chase(cnc bowl work done to them, no egr or heat crossover provisions in them), car has the PTE-51 turbo w/PTE exh housing, 50# injs, TH DP, CAS V2 FM, +.030 TRW/SpeedPro forged, steel center main caps, yada yada yada...Plans are to run in the 11s...
Keep the suggestions coming...Thanks everyone...
Reason why I'm asking, I had the 981s on there with my last cam(MM208/208 flat tappet)...wiped the #3 exh lobe...had 13k miles on it...All the other lobes looked fine, just #3 exh didn't want to be bumpy anymore
...When the heads were assembled, they were supposed to go on a motor that had the KB1txb cam in it(which they recommend seat pressure of about 104#, I think it was)..That is why I went with the 981s...plans changed and I built a completely new motor(w/MM208/208 cam) and just put the heads on it...Well, 13K miles later, wiped lobe The heads are the Stage JRs from David Chase(cnc bowl work done to them, no egr or heat crossover provisions in them), car has the PTE-51 turbo w/PTE exh housing, 50# injs, TH DP, CAS V2 FM, +.030 TRW/SpeedPro forged, steel center main caps, yada yada yada...Plans are to run in the 11s...Keep the suggestions coming...Thanks everyone...
Steve Wood
Active Member
- Joined
- Jul 18, 2001
The 980s will put you right at the top of the original factory specs but well under the danger zone from excess spring pressure in my opinion.
I think the internal damper maintains spring life longer when pushing the rpm past 5000. Don't use the cup with them, tho..just install the springs and dampers.
I think the internal damper maintains spring life longer when pushing the rpm past 5000. Don't use the cup with them, tho..just install the springs and dampers.
Steve Wood
Active Member
- Joined
- Jul 18, 2001
The factory cam probably lasted. Using springs that are 85#-90# will help. Grooving the bore to add more oil will help. Having the cam and lifters dry coated will help. Using a cam with a bit more taper ground into the lobe will help.
If you use the 979 springs I would use the stock cup to act as a shim and get the spring force up a bit. The 980 comes with an internal flat damper which adds to the overall spring rate...I'd use (and have done so on my car) 980's with their internal damper but with no cups.
A spring engineer who I used to work with, then at Peterson Spring the manufacturer of CC springs, told me that the 979 was the stock GM part number, and that the 980 spring material is better grade of Chrome-Silicon which takes heat treatment better and is more durable than the 979....plus a little stiffer. My measurements indicate that the 980's have less variation as well...no surprise if the material is indeed better.
Scooter Brothers of Comp Cams offered to trade me even his new 981's for my 980's saying they were the better spring. I declined the offer because the spring rate of the 981's is tremendous...way too much for us I think. Although if you were going to change cams frequently then would be an OK choice...certainly not a good choice for cam lobe longevity.
Regards, Bob
A spring engineer who I used to work with, then at Peterson Spring the manufacturer of CC springs, told me that the 979 was the stock GM part number, and that the 980 spring material is better grade of Chrome-Silicon which takes heat treatment better and is more durable than the 979....plus a little stiffer. My measurements indicate that the 980's have less variation as well...no surprise if the material is indeed better.
Scooter Brothers of Comp Cams offered to trade me even his new 981's for my 980's saying they were the better spring. I declined the offer because the spring rate of the 981's is tremendous...way too much for us I think. Although if you were going to change cams frequently then would be an OK choice...certainly not a good choice for cam lobe longevity.
Regards, Bob
The block that I am using started out being a NA 109 block that I built into a turbo motor...The stock NA cam came out looking okay...I have only wiped out 1 cam(MM208/208)...I am putting a CC206/206 in it now...
If this cam ends up wiping, then yes, I will end up going billet roller, but I can't right now due to being laid off of work since the first of the year...
For what it's worth, in my last post, I was actually referring to two different motors...One has a KB 1txb in it, the other had the MM cam in it...The KB cam has 30k miles on it and came out looking great(That motor is in the middle of being freshened up due to blown head gasket, replacing the NA crank with a turbo crank, and replacing questionable cast aftermarket pistons with TRW/SpeedPro forged)...It is going back together with the KB cam/lifters reinstalled back in original positions...
The motor that had the MM cam in it now has the CC 206/206...This is the motor I am asking about which valve springs to use...EXCEPT for the #3 exhaust lobe wiping, the rest of the lobes look fine having used the 981s on it...Would it hurt running a CC979 or a CC980 on just the #3 exhaust lobe???
If this cam ends up wiping, then yes, I will end up going billet roller, but I can't right now due to being laid off of work since the first of the year...
For what it's worth, in my last post, I was actually referring to two different motors...One has a KB 1txb in it, the other had the MM cam in it...The KB cam has 30k miles on it and came out looking great(That motor is in the middle of being freshened up due to blown head gasket, replacing the NA crank with a turbo crank, and replacing questionable cast aftermarket pistons with TRW/SpeedPro forged)...It is going back together with the KB cam/lifters reinstalled back in original positions...
The motor that had the MM cam in it now has the CC 206/206...This is the motor I am asking about which valve springs to use...EXCEPT for the #3 exhaust lobe wiping, the rest of the lobes look fine having used the 981s on it...Would it hurt running a CC979 or a CC980 on just the #3 exhaust lobe???
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