Thread: Valve Spring Rating for Hyd Flat Tappet

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Hey all,
I had one of my valve springs checked at the machine shop and it was 145# @seat and 377# @max lift. My cam card recommends a spring that reads as follows:

120 Lbs Seat Pressure @ 1.820 Installed Height, 340 Lbs Open Pressure @ 1.200, 1.130 Coil Bind.

There is a little lee-way on the springs (I am pretty sure), I just dont know how much and if mine exceed that "secret" boundary. I am running (getting ready to run) a .515/.530" lift, 213/219@.050 camshaft with hydraulic, flat tappet lifters in a 454cid. With a .050 offset keeper he said the seat pressure would then be around 125# (didnt do max lift).

So my question is, do these springs sound too stiff ? Will they work or should I a) get a set of offset keepers, or b) get a new set of springs?

Also, what is more important/critical...seat pressure or pressure at max lift?

I dont plan on revving past 5500 (unless I am running from somebody... )

Originally Posted by 65cayne

Hey all,
I had one of my valve springs checked at the machine shop and it was 145# @seat and 377# @max lift. My cam card recommends a spring that reads as follows:

120 Lbs Seat Pressure @ 1.820 Installed Height, 340 Lbs Open Pressure @ 1.200, 1.130 Coil Bind.

There is a little lee-way on the springs (I am pretty sure), I just dont know how much and if mine exceed that "secret" boundary. I am running (getting ready to run) a .515/.530" lift, 213/219@.050 camshaft with hydraulic, flat tappet lifters in a 454cid. With a .050 offset keeper he said the seat pressure would then be around 125# (didnt do max lift).

So my question is, do these springs sound too stiff ? Will they work or should I a) get a set of offset keepers, or b) get a new set of springs?

Also, what is more important/critical...seat pressure or pressure at max lift?

I dont plan on revving past 5500 (unless I am running from somebody... )

I would not run more than 120 on the seat pressure.

no they do not the EX will drop by 10lbs in time they are a bit much for that size cam how many shim in the spring cup ? you want to know over the nose lbs is at with the cam you are going to run.and no on the 050 keepers get some new retainers you have to watch them .050 keepers that you do not run out of stem you do not want the keepers higher then the stems topswith that cam the HO 502 springs will work

Originally Posted by pat mccarthy

no they do not the EX will drop by 10lbs in time they are a bit much for that size cam how many shim in the spring cup ? you want to know over the nose lbs is at with the cam you are going to run.and no on the 050 keepers get some new retainers you have to watch them .050 keepers that you do not run out of stem you do not want the keepers higher then the stems topswith that cam the HO 502 springs will work

I have only removed one spring because the heads are on the motor. There was no shims, just the one washer that keeps the spring from eating your heads. So you dont think that they are too stiff?...What do you mean by the exhaust dropping by 10lbs? In thinking about it, I would rather just change the springs if I was going to go thru the trouble to replace the keepers even though I have enough stem top to do it.
I would rather not change anything at all though.... ...I should have bought the correct springs way back before the motor was assembled then I would not have to question anything...

So,
1. Install Offset Keepers: cheapest solution
2. Install correct springs: not the cheapest (price range is low to insane...ditto for the retainers)
3. Re-install the spring I removed and fire that thing up: actually this is the cheapest (and easiest) solution, but could turn into the costliest if my cam gets wiped or I start punching holes in my lifters.

I am inclined to go with Erik and change the springs. I would not know which retainer (offset) to get because I do not know what I have now. My machinist said that they were titanium though so I would kind of like to keep them. That leaves the offset keepers or nothing at all. Can somebody make this decision for me???? I am the type of guy who gets hung up on paper or plastic at the cash register so this could take awhile.

BTW: lets say I did change the springs, can I change just the outer spring and leave the damper and inner spring just the way it is? Or do I do away with the whole mess and get just an outer spring?...if that were the case, wouldnt I be FORCED to get new retainers???? crap....

springs at 145 is abit to much . will i help you make your mind up NO buy new spring or try new retainers what are your springs at up 050 ? i have seen new spring drop 10 lbs so if they drop15lbs your there. more spring pressure is not any dif from a soild flat cam i know guys that run this much on boat cams. i would not brake the cam in with them springs stock type springs would work to with that cam. i set heads up all the time any thing that is under the spring is a shim or a cup/hat no washers did you try the spring with out the inner????????

ok i will tell you how i would do it put the 050 keepers in it and fukgetabout it if you have the room the competition products VTO keeper are true 050

Originally Posted by pat mccarthy

did you try the spring with out the inner????????

Yes, he said they were too light (i didnt ask him what the # was). The one (complete set, inner, outer, damper) I brought in dropped from 145 down to 125# on the seat with an extra .050. Did not measure the max lift pressure, I imagine it would decrease considerably from 377#

I am liking the keeper idea now...decisions...I'll sleep on it and think about it whilst I pull out my tranny tomorrow to investigate that oil galley plug

Thanks for your input Pat... I'll let you know what happens!