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Cam break in Springs??

threewood

threewood

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If this has been beaten to death, link me to the threads. Getting ready to break in my cam. It is a single spring and a damper. Does the damper need to come out? And as far as the spring, below is the cam card with pressures, open and on the seat. Maybe I'm over thinking it but was considering buying lower pressure springs to break in the cam.

I'm using Driven break in grease and Driven break in oil.
Screenshot_20250504_192348_Adblock Browser.jpg
 
The “recommended” springs on that cam card are way too stiff for break in.

I’d suggest 100-120 on the seat and under 300 open.
 
PRHeads said:
The “recommended” springs on that cam card are way too stiff for break in.

I’d suggest 100-120 on the seat and under 300 open.
Click to expand...
That's what I thought. I found some "stock" springs that show 121lbs/192lbs which I will use. Thanks!
 
Make sure whatever spring you use has enough travel to accommodate the higher lift.
At least .050” from coil bind at full lift.
 
Absolutely. These heads were put together by Modern Cylinder Head. I only gave them cam card specs to do the valve train so I don'tknow the current spring specs. The springs I ordered coil bind at 1.350" but I will check once installed.
 
So the springs I bought wouldn't work. They were Elgin RV-869S springs. I did see that mine had inner springs and a damper, so I pulled the inner spring. At max lift on #1 exhaust (.588") there is no spring stack. Going with it.
20250510_100318.jpg


Side note, people go crazy about not wiping off the assembly lube from the lobes and fire it quickly, but how do you stop it from happening when turning the crank to lash valves? I did this my last cam and it was fine.
 
20250510_163803.jpg
20250510_132727.jpg


All back together. Used intake gaskets under the pan gasket and sealed everything using Hylomar. Oil and new filter. Have water in the radiator for now. Set my timing right on my old mark and it fired right up. Revved between 2k and 3k for 25 minutes, got a little hot so I shut it down. No leaks. Pulled valve covers off and everything looks good. Took it out for a spin and it sounds good.
Screenshot_20250510_185208_Gallery.jpg
Screenshot_20250510_185137_Gallery.jpg


At what point do I need to put the inner springs back in?
 
I would put your inner springs back in now since you did the cam break-in. Change oil filter, and add more break in oil to bring level back to full. Cut open old filter and have a look.
 
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