Correct valve springs?

Dominic · Sep 14, 2020

Hey guys, I was wondering if you think these valve springs for a 440 build would work for my setup... The heads I have are aluminum Trick Flow 240 (TFS-61617802-C00) with valve spring specs:

1.550" O.D. dual spring with damper (TFS-16094) 138 lbs. @ 1.950" installed height
430 lbs. @ 1.250" open
420 lbs. per inch rate
.680" maximum lift

I want to use a hydraulic roller cam (Comp Xtreme Energy 23-710-9), that will have about .574/.570 valve lift (after 1.6 roller rocker arms). Is this too much spring pressure for this setup? Would a valve spring change be necessary? Thanks

Other specs: 440 is .030 over, CR ~10.5:1, link to cam specs

69L48Z27 · Sep 14, 2020

Check the cam card for valve spring part number from Comp. Find that spring and it should have those specs. Compare and go from there. 160 installed is about all the higher you should go with hydraulics. The other numbers seem high but I do this everyday.
@PRHeads

steve340 · Sep 15, 2020

They are probably pretty close the spec they give is 430 lbs at 1.250" which if you subtract that from their installed height is 0.700" valve lift.
You only have 0.574" so the spring will not be at that spec.
The best way is to take a couple off and test them at your open height and relate that back to the Comp Cams spec spring.
With a roller you can get away with a bit more, going to soft is a bit riskier.

Dominic · Sep 15, 2020

steve340 said:
They are probably pretty close the spec they give is 430 lbs at 1.250" which if you subtract that from their installed height is 0.700" valve lift.
You only have 0.574" so the spring will not be at that spec.
The best way is to take a couple off and test them at your open height and relate that back to the Comp Cams spec spring.
With a roller you can get away with a bit more, going to soft is a bit riskier.

Thanks, and I was thinking that I also have a set of 1.7 ratio roller rockers available too. This would raise the lift to about .610ish I believe. Assuming those fit with piston clearance and all that, is there any downside to using the higher ratio rockers? Would that be more appropriate for those springs, or will the 1.7s cause more problems(like extra wear) ? Just curious since I do have a set laying around.

steve340 · Sep 15, 2020

I don't put higher ratio rocker arms in the engines I do. I know you can and like you say extra wear may be a factor. The push rods, cam lobes and the rollers will all be working harder. If I want more cam I just install that.
The only thing I would think about is do not put more cam in it than you need.
If it is a street car that Comp grind will most likely already be pretty potent.

Dominic · Sep 19, 2020

Comparing the two I have these specs:
Current Trick Flow installed valve springs-
1.550" O.D. dual spring with damper (TFS-16094)
138 lbs. @ 1.950" installed height
430 lbs. @ 1.250" open
420 lbs. per inch rate
.680" maximum lift

Recommended Comp valve springs for my cam(925-16)-
1.509" Outside Diameter of Outer Spring
1.900" Installed Height
111 lbs. Seat Pressure at Installed Height
1.200" Open Height
388 lbs. Open Pressure
1.175" Coil Bind Height
395 lbs./in. Spring Rate
1.125" Inside Diameter of Outer Spring
0.697" Inside Diameter of Inner Spring

Do you guys think this is an appropriate difference to run with my hydraulic roller cam? Like earlier stated, it should have about .574" lift all said and done.
Thanks for the help!

steve340 · Sep 20, 2020

You need to take at least 2 of the springs off the heads and measure the installed height and the pressure of the Trick Flow springs at that specific height.
I would strip and check new heads even though they say run out of the box.
Almost always you have to hone the guides and recut the seats.
If the cam is fairly aggressive and will run to 6000 - 6500 and has heavy valves - give or take I will shim to get seat pressure of 140 -160 and open 390 - 430.
You can reduce pressure somewhat if you have light valves or beehive springs.

wyrmrider · Sep 20, 2020

light valves- beehive springs jones cam has better profiles than comp which sacrafice to make them easy to grind
do a search
don't drink the kool aid

Correct valve springs?

Dominic

Well-Known Member

69L48Z27

Well-Known Member

steve340

Well-Known Member

Dominic

Well-Known Member

steve340

Well-Known Member

Dominic

Well-Known Member

steve340

Well-Known Member

wyrmrider

Well-Known Member

Similar threads