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FE Power Forums => FE Technical Forum => Topic started by: chilly460 on May 28, 2026, 10:02:50 PM

Title: Valve spring pressure
Post by: chilly460 on May 28, 2026, 10:02:50 PM

I measured install height and valve spring pressure on some C1AE heads I ported and used TFS takeout valvetrain parts for a hydraulic roller.  I’m getting 1.865” install height,plus a .100 retainer for 1.965” stack.  I’m getting right at 200-205 seat, and 475-485 open at .600”

Quick look online I think I can get a .050” taller retainer, which doing a quick test brought me to 160lb seat and 440-450lb open.  This seems much more in the ballpark. 

I’ve never setup springs before, just checking my thought process, and is there anything to look out for going with the .050” retainer?

Title: Re: Valve spring pressure
Post by: blykins on May 29, 2026, 03:59:22 AM

Just make sure that you measure with all the parts that you will be using on the engine, no spares, mock-up parts, etc., because it all makes a difference.

If your retainers are already +.100”, you won’t find one that’s +.150”. 

You can, however, use +.050” valve locks.

FWIW, I like the 160 lbs seat, but 450 lbs over the nose with a hydraulic roller could cause you problems with lifter function.  I’ve ran Morels at 425-430, and it was fine, but I don’t know about anything higher than that. 

Title: Re: Valve spring pressure
Post by: My427stang on May 29, 2026, 06:35:32 AM

Something sounds wrong there

A 16094 TFS/PAC spring should be around 175 @ 1.900 with a 427# rate.  .065 extra should put you at about 147-150 seat.

.600 lift should put you near 403 open.  You can be 5-ish lbs off any number in variance if measuring every spring, which you should, but your numbers are really high.

Check your spring micrometer with calipers, maybe check your pressures on another machine, and make sure you have a compatible retainer and spring cup.

Title: Re: Valve spring pressure
Post by: chilly460 on May 29, 2026, 07:24:23 AM

I think what I stated was unclear (and reads incorrectly).  The retainer is .100" thick, not "raised" .100...so was just specifying the dimension I used in the spring tester was total height of 1.965" (1.865" plus .100" retainer) at seat height.  My bad on that.

Thanks for the info, I'll double check tonight, I was doing this late night so I could be making some silly mistake in the calcs.