Mopar Battleship Triple Springs. Go big or go home. lol
Valve Spring Pressure Discussion
- Thread starter SpeedThrills
- Start date
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mopowers
Well-Known Member
That makes sense. Thank you!
Assuming you have enough installed height, do you install them to a specific installed height, or do you shim them to get the seat pressures or open pressures equal (or close to)?
PRH
Well-Known Member
It can be any or all of that…..
Sometimes if there is enough spread between the 8 stiff/ 8 soft springs, I’ll adjust the IH slightly to compensate.
But much of the time it comes down to how serious of an effort the build is, what the cam is, the available space for lift, etc……..which will kind of dictates how fussy one needs to be.
Like on my friends NHRA stocker, the springs are set up to minimum coil bind clearance…….which I have at .050”.
So, for each particular spring, it’s coil bind height, plus .050”, plus net lift = IH.
For street/strip type stuff, I don’t usually run things that tight.
Generally I’m shooting for an installed height.
If the springs are all close to each other, the closed/open pressures will also be close.
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mopowers
Well-Known Member
Thank you for such a detailed response.
PRH
Well-Known Member
I will add this……
If you’re setting up spring that will use all of its lift capacity………you really need to measure the actual coil bind height on every spring.
There are often a few outliers within the set that end up not meeting the coil bind spec……by enough to matter.
I’ve only run into a situation a few times where the offenders went into coil bind at a tall enough height where they had to be substituted for some that were closer to spec.
If you’re setting up spring that will use all of its lift capacity………you really need to measure the actual coil bind height on every spring.
There are often a few outliers within the set that end up not meeting the coil bind spec……by enough to matter.
I’ve only run into a situation a few times where the offenders went into coil bind at a tall enough height where they had to be substituted for some that were closer to spec.
A lot to take in here. 
Not having much experience, I did think that the pressures are all over. I'm figuring new springs, because several seat pressures are so low now. I'll check installed height after the valve job. (Taking them to the shop the 14th.)
I'll check back here when I have a plan regarding spring rate, and how to go about shimming them.
Not having much experience, I did think that the pressures are all over. I'm figuring new springs, because several seat pressures are so low now. I'll check installed height after the valve job. (Taking them to the shop the 14th.)
I'll check back here when I have a plan regarding spring rate, and how to go about shimming them.
The guides and valve job are done.
I re-checked all the installed heights, pressures, etc. I was getting varying results. I found that A) I needed practice getting a feel for the height mic and B) My method of checking pressures wasn't reliable and C) the machinist put the springs back on, though I said not to. I don't know if he mixed them up.
I have practiced both many times, and I'm confident in my results. My apologies to those who put effort into the previous numbers.
My chart now includes calculated spring rate; thanks to PRH for providing that formula.
The intakes are 5.050", and the exhausts are 5.075". That would account for the exhaust installed heights being higher than the intakes. Do I need two different springs to get the pressures (110-300 ish) because of the different heights? Would different retainers or locks be feasible, as @Locomotion suggested? My head's spinnin'.
Again, it's a street/strip engine. I don't require Stock Elim. type accuracy. I'd just like to get 6500 rpm's out of it.
I re-checked all the installed heights, pressures, etc. I was getting varying results. I found that A) I needed practice getting a feel for the height mic and B) My method of checking pressures wasn't reliable and C) the machinist put the springs back on, though I said not to. I don't know if he mixed them up.
I have practiced both many times, and I'm confident in my results. My apologies to those who put effort into the previous numbers.
My chart now includes calculated spring rate; thanks to PRH for providing that formula.
The intakes are 5.050", and the exhausts are 5.075". That would account for the exhaust installed heights being higher than the intakes. Do I need two different springs to get the pressures (110-300 ish) because of the different heights? Would different retainers or locks be feasible, as @Locomotion suggested? My head's spinnin'.
Again, it's a street/strip engine. I don't require Stock Elim. type accuracy. I'd just like to get 6500 rpm's out of it.
PRH
Well-Known Member
This doesn’t help you at this point, but……My preference is to update factory heads to use small OD seals and spring cups when they’re getting reworked, which opens up more spring options.
What you’ve got there is a pretty big disparity in heights……..maybe more than what you can easily shim for….enough to even up the IH……. and still have a means for locating the springs.
Looking at your notes…….the IH on the chart is without any shims?
If I had to pick a single spring for that……as it is……. I’d consider the intake valves as “close enough” to 1.800” to target that as the height I’m looking at springs for. Then shim the exhaust accordingly.
Something like a Howard’s 98511, or a PAC-1927.
Edit- aside from the few dead ones……looks to me like the old springs would have been about right if installed at the factory IH of 1.670-ish.
What you’ve got there is a pretty big disparity in heights……..maybe more than what you can easily shim for….enough to even up the IH……. and still have a means for locating the springs.
Looking at your notes…….the IH on the chart is without any shims?
If I had to pick a single spring for that……as it is……. I’d consider the intake valves as “close enough” to 1.800” to target that as the height I’m looking at springs for. Then shim the exhaust accordingly.
Something like a Howard’s 98511, or a PAC-1927.
Edit- aside from the few dead ones……looks to me like the old springs would have been about right if installed at the factory IH of 1.670-ish.
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I did have the shop install Viton seals. Even the umbrellas had about .125" clearance. (I'm also about .100" from coil bind at full lift.)
What would cause varying heights? Is that something that should be considered when grinding valves and seats? These valves aren't buried.
Yes, the IH's on the chart are without the shims.
Thanks for the spring ideas. I am hoping to get something that works, without getting too involved. I've learned a lot for my next heads.
And I appreciate your experience regarding how these springs would work at a stock IH.
PRH
Well-Known Member
My comments about updating the heads for cups and seals was to facilitate the use of dual springs.
You’re past that point now.
I don’t recall what the deal is with your particular heads/valves wrt IH, but “typically”(for in line valve wedge heads), the exhaust valve being longer than the intake is to make up for the ex valve having a thicker margin.
And then some heads don’t come with the int/ex seats cut to the exact same depth.
Often, When using other than oe replacement parts, if you want the tip heights to be close to each other, you have to machine the seats in a way that achieves that result……… although it’s not always doable depending on the particular heads and valves being used.
“Would’ve” worked……. Past tense.
They’re trash now imo.
Dual springs:
You’re past that point now.
I don’t recall what the deal is with your particular heads/valves wrt IH, but “typically”(for in line valve wedge heads), the exhaust valve being longer than the intake is to make up for the ex valve having a thicker margin.
And then some heads don’t come with the int/ex seats cut to the exact same depth.
Often, When using other than oe replacement parts, if you want the tip heights to be close to each other, you have to machine the seats in a way that achieves that result……… although it’s not always doable depending on the particular heads and valves being used.
“Would’ve” worked……. Past tense.
They’re trash now imo.
Dual springs:
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PRH
Well-Known Member
And then sometimes poor decisions are made and you get stuff like this:
(How many things stand out here?)
(How many things stand out here?)
Oh my
PRH
Well-Known Member
They’re a story all onto themselves, but I won’t litter up your thread with too many details.
They were new Ede heads built from bare castings.
Different length valves that had different tip lengths too……… and then there was the one different beehive spring on them(installed at a short enough height to go into coil bind at less than .500” lift).
They were new Ede heads built from bare castings.
Different length valves that had different tip lengths too……… and then there was the one different beehive spring on them(installed at a short enough height to go into coil bind at less than .500” lift).
The intake IH averages 1.794
The exhaust IH averages 1.842
I'm going with your idea. I'll get springs for a 1.800 IH. I'll try shimming the exhausts with the .054-.061 shims that I have and see where I stand.
My head is spinnin' much slower now.
I just finished installing the new springs. It ain't "race car" perfect, but I think it'll do the job.
After doing all of this, I now know the pressure checker I have is not precise. (Howards Cams Chinese-ium.) It's range is 0-600#. I did some of them a few times until I developed a feel for the gauge. The range would be about 15#. Not ultimate. If I do this more, I'd have to get a better gauge. The Rimac is all I see, and that's too much money for how often I do this.
My long block is assembled, the heads will go on when I get the springs on. That'll finish what started last November as a spun rod repair. I'm going to paint it and cover it up. (Well lubed, and fogged.) And while the car it's going back into (in my avatar) has been on the street and track for about 3 years, I need to paint it while the engine's out, and who knows how long that'll take. I don't even know who's going to do it, and how much labor ($) I'll chip in.
Thanks to all on this thread who helped me, I learned a LOT!
After doing all of this, I now know the pressure checker I have is not precise. (Howards Cams Chinese-ium.) It's range is 0-600#. I did some of them a few times until I developed a feel for the gauge. The range would be about 15#. Not ultimate. If I do this more, I'd have to get a better gauge. The Rimac is all I see, and that's too much money for how often I do this.
My long block is assembled, the heads will go on when I get the springs on. That'll finish what started last November as a spun rod repair. I'm going to paint it and cover it up. (Well lubed, and fogged.) And while the car it's going back into (in my avatar) has been on the street and track for about 3 years, I need to paint it while the engine's out, and who knows how long that'll take. I don't even know who's going to do it, and how much labor ($) I'll chip in.
Thanks to all on this thread who helped me, I learned a LOT!
PRH
Well-Known Member
Uuuummm…..”Crane” 98511?
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