Use springs included with heads or with cam kit

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Oct 21, 2017 | 10:35 PM
  #1  
I'm going to get these:

http://www.blueprintengines.com/inde...cylinder-heads

And I have a comp cams k-kit. That includes springs.

http://www.compcams.com/Company/CC/c...?csid=204&sb=2

Do I run with the pre-installed springs or take the time to swap out the springs with those included in the cam kit?

The heads are setup for .575 lift. I only need .520 for the cam.

Included springs are 295-305 lb. Comp springs are 320 lb.

GD
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Oct 22, 2017 | 07:51 AM
  #2  
Re: Use springs included with heads or with cam kit
Specs for the springs on the heads look a lot like 986 which is one of the recommendations Comp gives for that cam.

Also looks like they're set up at slightly higher installed height than Comp's recommendation, which accounts for the slightly lower pressures and slightly higher allowable lift, compared to Comp's published spec.

When the heads arrive, check the IH; reset to 1.750" if it's greater than that. Check for coil bind height and make sure you're not into the weeds.

Pressure "over the nose" isn't all that important. Seat pressure IS. Esp if you want to push the RPM envelope.
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Oct 22, 2017 | 08:59 AM
  #3  
Re: Use springs included with heads or with cam kit
You want to build around your cam essentially, I'd probably swap them out.
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Oct 22, 2017 | 01:56 PM
  #4  
Re: Use springs included with heads or with cam kit
300psi give up 7% open pressure to 320psi Comp springs but what about close press at your installed height? It's Comp camshaft and they know what they're cam needs. I guess what I'm saying is even if you bought that cam by it's self you would need a spring with spec's that Comp recommends.

Hey if you gott'm put them on and don't look back.
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Oct 22, 2017 | 08:15 PM
  #5  
Re: Use springs included with heads or with cam kit
I guess if I'm going to be checking installed height it might as well be the ones that came with the cam. Better to check the work on the Indonesian slave child labor rather than leave it to chance.....

GD
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Oct 23, 2017 | 11:23 AM
  #6  
Re: Use springs included with heads or with cam kit
Quote: I guess if I'm going to be checking installed height it might as well be the ones that came with the cam. Better to check the work on the Indonesian slave child labor rather than leave it to chance.....

GD

Yes, I hate to dwell on it. Much of the world struggles just to eat and we can worry about parts for our hot rod cars. But ya know they still manage to reproduce so life must move on for all of us.
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Oct 23, 2017 | 12:34 PM
  #7  
Re: Use springs included with heads or with cam kit
What springs came in the cam kit? 986 or 987

I like the 987's more for the increased rate. But the 986's shimmed to correct height should work.
So you could try the stock head springs since they are almost identical to the 986. In that case dont buy cam kit. Buy cam only and get your lifters separately
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Oct 23, 2017 | 08:26 PM
  #8  
Re: Use springs included with heads or with cam kit
Quote: What springs came in the cam kit? 986 or 987

I like the 987's more for the increased rate. But the 986's shimmed to correct height should work.
So you could try the stock head springs since they are almost identical to the 986. In that case dont buy cam kit. Buy cam only and get your lifters separately
Ya know - it doesn't say which ones it comes with.

Too late - I bought the cam kit thinking I would use the Vortec heads but then my machine shop says it will be about $500 to set them up and for $813 I can get the Blueprint heads. They have quite a few excellent reviews on Summit. I figured..... well for $313 I get aluminium heads and my TPI manifold will bolt on ultimately saving me from buying the Vortec TPI base.....

And now I'm leaning toward a Dart SHP block because of the machine work required on the Vortec block and if I don't I'll probably throw the crank right out the bottom with a Procharger. I.... just.... cant... win.

GD
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