Can I run single valve springs?

[norvalwilhelm]

I spot tested some of the roller springs I got with the heads just now and they far exceed what the cam calls for. The comp roller cam calls for 440# at .600 lift and I have 700# at .600
I then took the dual springs apart and tested only the single outer spring and got 210# seat and 436# at .600
That is right in the ball park for the cam BUT can I just run a single spring. For safety in the even of a broken spring I though dual is like a spare tire. I won't drop the valve, rev's would be down but no dropped valve. Also harmonics? While these don't have damper springs they are duals and interference fit.
Can I safely run a single spring or am I stuck with buying new springs?

 

[Tom Bryant]

Those dual springs sure sound like over kill unless you are going to twist high rpms. I prdict that harmonics will be a problem with just running the outer spring. If you have a set of dampers from some stock springs try them out for fit in the new ones. Use the hats too if they fit. Otherwise I'd use the spring recommended by your cam manufacturer for the cam you bought.

Tom

 

[wishuwerehere82]

Don't you need to run a higher spring rate on the intakes to compensate for the boost pressure on your blower? I would think that you would need to run as high as possible to make sure they close under maximum boost. You would be taking a big chance using just the outer spring, in my opinion. And a broken single spring can cause the hats to shake the retainers out resulting in a dropped valve.

 

[norvalwilhelm]

Those dual springs sure sound like over kill unless you are going to twist high rpms. I prdict that harmonics will be a problem with just running the outer spring. If you have a set of dampers from some stock springs try them out for fit in the new ones. Use the hats too if they fit. Otherwise I'd use the spring recommended by your cam manufacturer for the cam you bought.

Tom

I agree Tom. Those springs are rediculous but they came with the heads. I wanted to say free with the heads but I certainly did pay for them along with the titanium retainers. I will run what the cam card says but might up it 20 pounds or so to help overcome the 12 pounds of boost on the 2.300 intake valve.
Harmonics bothers me and I too feel a double spring is needed. I will go to the speed shop and try and trade them in on something closer to the specs. I do have a valve spring checker and will run every spring through it to make sure I meet specs. I spend about 1 evening assemblying each head buy checking installed height, retainer to seal clearance etc.
I also use fine valve grinding compound on each valve, take a few turns with a rubber suction cup and then measure and visually inspect each seat before assembley.
I also run seals on all 16 valves and not just the intakes like Brodix does,

 

[norvalwilhelm]

Don't you need to run a higher spring rate on the intakes to compensate for the boost pressure on your blower? I would think that you would need to run as high as possible to make sure they close under maximum boost. You would be taking a big chance using just the outer spring, in my opinion. And a broken single spring can cause the hats to shake the retainers out resulting in a dropped valve.

Again I agree. I think running a single spring is taking a gamble. What if one broke and I dropped a valve.
I will run about 20 pounds overweight for boost but I have lost interest in redlining the motor years ago. With a blower it is not necessary. I use to run to 7500 all the time. Now my rev limiter is set at 5400 and I seldom bump up agianst it.Thanks for the response wishuwerehere82