Pulling the inner valve spring at cam break in?

[MopaR&D]

So how much pressure do those inner springs actually add? While my mild 440 build for my cousin's car didn't need dual springs my machinist recommended them because he's seen valve spring failures that drop the valve and cause all kinds of havoc. Looking at them the inner spring is pretty tiny looks like it has 1/4 as big a spring constant as the outer ones; how much of a difference does that really make if the springs are around 320 lbs. open? Seems like some of these dual-spring packages are more of a failsafe than a performance enhancement.

 

[j par]

So how much pressure do those inner springs actually add? While my mild 440 build for my cousin's car didn't need dual springs my machinist recommended them because he's seen valve spring failures that drop the valve and cause all kinds of havoc. Looking at them the inner spring is pretty tiny looks like it has 1/4 as big a spring constant as the outer ones; how much of a difference does that really make if the springs are around 320 lbs. open? Seems like some of these dual-spring packages are more of a failsafe than a performance enhancement.

another great question to add to this debate "not argument"

 

[fishy68]

So how much pressure do those inner springs actually add? While my mild 440 build for my cousin's car didn't need dual springs my machinist recommended them because he's seen valve spring failures that drop the valve and cause all kinds of havoc. Looking at them the inner spring is pretty tiny looks like it has 1/4 as big a spring constant as the outer ones; how much of a difference does that really make if the springs are around 320 lbs. open? Seems like some of these dual-spring packages are more of a failsafe than a performance enhancement.

I just measured some inner springs last night. They might not look like they'd do much but they added 48 psi on the seat and 110 @ .500 lift. They do a lot more than provide a fail safe.

 

[j par]

I just measured some inner springs last night. They might not look like they'd do much but they added 48 psi on the seat and 110 @ .500 lift. They do a lot more than provide a fail safe.

You measured some springs? do you know what the total open spring pressure was of both of them put together? because if so, like mine are 350 open that would have been 1/7 of my spring pressure total. so had I taking them out, I would have had one seventh less spring pressure I take it? And I guess that could have been at some point the deciding factor? Again not trying to be smart here, more on a fact finding search to this most controversial subject. Thank you for some insight .

 

[MopaR&D]

You measured some springs? do you know what the total open spring pressure was of both of them put together? because if so, like mine are 350 open that would have been 1/7 of my spring pressure total. so had I taking them out, I would have had one seventh less spring pressure I take it? And I guess that could have been at some point the deciding factor? Again not trying to be smart here, more on a fact finding search to this most controversial subject. Thank you for some insight .

No he said 110# open that's about a third which is quite a bit. BUT what springs were they that were tested? I need to check the invoice for my 440 heads I'm not sure if they have Howards springs or what...

 

[RustyRatRod]

You cannot just say the inner springs are "a third" of this or that. Since the inner and outer springs have different rates, their percentages have to be figured differently.

I am tending to agree with moper the more I read about it. I think it depends on the seat pressure. Look at the Comp 924-16. They have a seat pressure of 115 @ 1.900". That will probably be fine with the inner springs left in.

 

[j par]

:banghead: open spring pressure? spring pressure on the seat? testing a random inner spring ? probably be fine with the inner Springs left in? I'm getting more questions than answers it seems like. Not that it's anybody's duty to make answers for me, it's just I guess I need clarification for dummies? that's me! (The dummy ) I do know that certain cams or all cams call for a certain spring pressure on the seat and open, but I'm just missing I guess the borderline or if there should be a borderline? It seems like there will be a clear line drawn in the sand as far as when spring should absolutely be taken out or absolutely not be taken out? but I guess this discussion may exist due to the lack of such a absolute borderline?

 

[fishy68]

You measured some springs? do you know what the total open spring pressure was of both of them put together? because if so, like mine are 350 open that would have been 1/7 of my spring pressure total. so had I taking them out, I would have had one seventh less spring pressure I take it? And I guess that could have been at some point the deciding factor? Again not trying to be smart here, more on a fact finding search to this most controversial subject. Thank you for some insight .

Yes, 375 @ .600 lift. There are so many different springs out there with varying pressures I can't say what yours would be with the inner spring removed

No he said 110# open that's about a third which is quite a bit. BUT what springs were they that were tested? I need to check the invoice for my 440 heads I'm not sure if they have Howards springs or what...

I measured several sets and at the moment I don't remember which ones those were. A buddy of mine bought them at a estate sale and just asked me to verify if the springs matched the boxes they were in. Just for fun I pulled the inner spring on one to measure it and that's the one I was referring too. As mentioned above the open pressure of that spring combo was 375 @ .600

:banghead: open spring pressure? spring pressure on the seat? testing a random inner spring ? probably be fine with the inner Springs left in? I'm getting more questions than answers it seems like. Not that it's anybody's duty to make answers for me, it's just I guess I need clarification for dummies? that's me! (The dummy ) I do know that certain cams or all cams call for a certain spring pressure on the seat and open, but I'm just missing I guess the borderline or if there should be a borderline? It seems like there will be a clear line drawn in the sand as far as when spring should absolutely be taken out or absolutely not be taken out? but I guess this discussion may exist due to the lack of such a absolute borderline?

Uh, I didn't think this was your thread? I just threw in the spec on the inner spring for Mopekid since he commented that he thought inner springs may not really do much

I really can't understand the fuss about removing the inner springs. You assemble the heads with just the outer springs, break in the cam, then pull the valve covers and install the inner springs. About 1 to 1-1/2 hrs worth of work doesn't seem like a big deal to me!!!!!!!

 

[RustyRatRod]

:banghead: open spring pressure? spring pressure on the seat? testing a random inner spring ? probably be fine with the inner Springs left in? I'm getting more questions than answers it seems like. Not that it's anybody's duty to make answers for me, it's just I guess I need clarification for dummies? that's me! (The dummy ) I do know that certain cams or all cams call for a certain spring pressure on the seat and open, but I'm just missing I guess the borderline or if there should be a borderline? It seems like there will be a clear line drawn in the sand as far as when spring should absolutely be taken out or absolutely not be taken out? but I guess this discussion may exist due to the lack of such a absolute borderline?

You are trying to get one answer for everything. Either leave them in or leave them out. It's not that simple it seems.

The best answer is if you are worried about it (and quite obviously, you ARE) then leave the inner springs out to be sure. Really not that difficult.

The question has been answered to death. There is no one answer to fit every spring out there. Bottom line is if you want to leave them out do it. If not, just know that it is possible you could do some damage. Pretty much all there is. Not everything fits into a yes or no, black or white, do or don't situation.

A lot of times it's all about personal preference.

 

[RustyRatRod]

Yes, 375 @ .600 lift. There are so many different springs out there with varying pressures I can't say what yours would be with the inner spring removed



I measured several sets and at the moment I don't remember which ones those were. A buddy of mine bought them at a estate sale and just asked me to verify if the springs matched the boxes they were in. Just for fun I pulled the inner spring on one to measure it and that's the one I was referring too. As mentioned above the open pressure of that spring combo was 375 @ .600



Uh, I didn't think this was your thread? I just threw in the spec on the inner spring for Mopekid since he commented that he thought inner springs may not really do much

I really can't understand the fuss about removing the inner springs. You assemble the heads with just the outer springs, break in the cam, then pull the valve covers and install the inner springs. About 1 to 1-1/2 hrs worth of work doesn't seem like a big deal to me!!!!!!!

Exactly. A small amount of labor to pay for doing it right.

 

[j par]

Uh, I didn't think this was your thread? [/QUOTE]
Uh, i considered all threads OURS for sharing and learning?

 

[j par]

There is no one answer to fit every spring out there. Bottom line is if you want to leave them out do it. If not, just know that it is possible you could do some damage. Pretty much all there is. Not everything fits into a yes or no, black or white, do or don't situation.

A lot of times it's all about personal preference.

oh, that's the answer ? Thank you ! :cheers:

 

[fishy68]

Uh, I didn't think this was your thread?

Uh, i considered all threads OURS for sharing and learning?[/QUOTE]

True, but you were not the original poster so I wasn't answering anything you asked about. That's all I meant by "not your thread". If you get several guys asking questions within a thread it can get to be a mess trying to figure out who's answering who.

 

[j par]

Uh, i considered all threads OURS for sharing and learning?

True, but you were not the original poster so I wasn't answering anything you asked about. That's all I meant by "not your thread". If you get several guys asking questions within a thread it can get to be a mess trying to figure out who's answering who.[/QUOTE]


ok now I am going to be a smart ***! isn't that what the quote button is for? you're basically answering the person you're quoting?

 

[fishy68]

ok now I am going to be a smart ***! isn't that what the quote button is for? you're basically answering the person you're quoting?

Yes, using the quote button should suffice but it seems not everyone understands how things work. And not everyone uses the quote button which makes it worse

 

[MopaR&D]

You cannot just say the inner springs are "a third" of this or that. Since the inner and outer springs have different rates, their percentages have to be figured differently.

I am tending to agree with moper the more I read about it. I think it depends on the seat pressure. Look at the Comp 924-16. They have a seat pressure of 115 @ 1.900". That will probably be fine with the inner springs left in.

The springs in my cousin's 440 build are similar to those, typical "entry-level" performance springs. Just thinking out loud, the seat pressure being important makes sense since the most stress on the cam lobe and lifter is right when it first starts to open the valve and the lobe just gets "smacked" with at least 100 lbs. of force (depending on seat pressure) off the bat. Come to think of it it's even quite a bit higher than that considering the rocker ratio.

Did some quick calculations based off fishy68's numbers, those inner springs have 124 lb/in rate and both together are 442 lb/in (assuming a 110# seat pressure) so that's fairly close to a third of the rate. However looking at just the seat pressure of the inner spring 48# is almost half the seat pressure of both springs together so I think there is definitely truth behind removing the inner springs for break-in.

 

[chasonmarose]

I've always just soaked the lifters in oil for an hour before start up and never touched the springs... Jair made sure there was fresh oil and dumped it after 20 mins of 2500 rpm... Never had a problem have rebuilt and fired over 100 motors big cams to small ones rollers to flat tappet

 

[OldmanRick]

I've always just soaked the lifters in oil for an hour before start up and never touched the springs... Jair made sure there was fresh oil and dumped it after 20 mins of 2500 rpm... Never had a problem have rebuilt and fired over 100 motors big cams to small ones rollers to flat tappet

Been just about where you have been, other then I didn't soak my hydraulics. I don't want to get into the drama here, especially since the OP has decided to pull his inner springs.

Granted all my break-ins were in the 70's to mid 80's that even included some moderately sprung solids, and one very large BBC race engine. Even so, I never lost a cam at startup. I know times have changed...oil composition, aggressive lobes, etc. But if we can simulate those same conditions today, I don't see why a good solid startup cant produce the same results.

In my time, a good swipe on the lifter base & lobes with a good moly, plus a can of GM/EOS or STP in the crankcase was good enough. The main focus then as today was a,

Quick startup
2500/3000 rpm's
A box fan
And a garden hose just incase, for temp control

I see no reason why we cant duplicate those same conditions today with some good lube and a quality oil like the Penn/Gibbs, etc.

It really comes down to your choice, but I'm not as scared as some may be.....After all, how many "lost cam" threads have been posted here.....

Ok, so now you guys all hate me . Sorry, just a "Oldman" posting his thought's from yesteryear.

 

[RustyRatRod]

Yup I cannot disagree ^^^^^

 

[j par]

Been just about where you have been, other then I didn't soak my hydraulics. I don't want to get into the drama here, especially since the OP has decided to pull his inner springs.

Granted all my break-ins were in the 70's to mid 80's that even included some moderately sprung solids, and one very large BBC race engine. Even so, I never lost a cam at startup. I know times have changed...oil composition, aggressive lobes, etc. But if we can simulate those same conditions today, I don't see why a good solid startup cant produce the same results.

In my time, a good swipe on the lifter base & lobes with a good moly, plus a can of GM/EOS or STP in the crankcase was good enough. The main focus then as today was a,

Quick startup
2500/3000 rpm's
A box fan
And a garden hose just incase, for temp control

I see no reason why we cant duplicate those same conditions today with some good lube and a quality oil like the Penn/Gibbs, etc.

It really comes down to your choice, but I'm not as scared as some may be.....After all, how many "lost cam" threads have been posted here.....

Ok, so now you guys all hate me . Sorry, just a "Oldman" posting his thought's from yesteryear.

drama lol ! Your old school with many years of experience . it seems as anytime I challenge someone's thinking I'm causing drama. anytime I agree with the minority opinion I'm just shopping for someone to agree with my thinking. As far as I know this is an open forum to help people to the best of your ability at any point people should be able to take what advice they want or don't want and I sure appreciated yours. I didn't take out my springs and I put 100 Street miles on the car so far and several dragstrip passes and everything's holding together great! and when I say that it's not a NA-NA it's just my experience. Take it for what its worth!
I think the best part of being an old man would be say whatever the heck you want and not giving a rat what people think! Drama! Lol!
if anyone on this forum wants to know real drama I'll introduce you to my ex wife!!!