valve spring height question

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Not annoying at all. But the most you're talking about is .065". Stack it up on feeler gauges and see what you are lookin at.
 
CPMotorworks said:
Yes, I do.
Seat pressure means very little, base circle of the cam doesn't much care.
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So you think it's all about the base circle of the cam??? You have lots to learn my friend. There's more to the valve train than a spring and a base circle..
Here's a problem as well, you put those springs in your customers car and it wipes a lobe a week later. He takes it to another shop and they find the increased seat and open pressure, who do you think is going to be paying the bill to repair it ( whole engine strip and clean) as well as set the springs correctly??? Yeah, it's going to be you. Try arguing your "base circle don't much care" spring theory with the customer on that one..
 
Darren said:
those retainers would be good but they are for dual and triple springs.
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It should have a step to hold the outer spring in place. That is Dimension "A" of the reatainer.
Look at this.
[ame]http://www.cranecams.com/userfiles/file/348-357.pdf[/ame]
 
what about the crane retainer part# 99943-16 it states they add .100 to installed height.
but will it interfere with stock rockerarm. then i can use my #911 springs and shim to spec.
 
My response cut and pasted from your other thread...

Stick them on and go. It's fine. If you chose to have the heads done properly in the future you can look at it then. I wouldn't care about .040 less installed height. It's got another .200" before coil bind, and we're probably talking about less than 30 pounds more on the seat and over the nose. I'd be much more concerned if the stem heights differed by .040". If they're good - run it.

Additional spring pressure "within reason" is always preferred to less. In the case of a 120 pound seat pressure & 300 over the nose - increasing is not an issue IMO.
 
i will run a striaght edge over the stems and check. thanks
 
Bakerlite said:
So you think it's all about the base circle of the cam??? You have lots to learn my friend. There's more to the valve train than a spring and a base circle..
Here's a problem as well, you put those springs in your customers car and it wipes a lobe a week later. He takes it to another shop and they find the increased seat and open pressure, who do you think is going to be paying the bill to repair it ( whole engine strip and clean) as well as set the springs correctly??? Yeah, it's going to be you. Try arguing your "base circle don't much care" spring theory with the customer on that one..
Click to expand...

Yes, I do have lots more to learn. The more I do this stuff, the more questions I have and the more I find I don't know.
However, if you think 20lbs more on the seat/nose will wipe out a cam lobe, and that the numbers in the book or a spec'ed installed height is all that matters, I won't try to convince you otherwise.
As for any repair bills, a lot of the engines I do are the ones from other shops that failed for one reason or another. Keeps me pretty busy actually. And an extra 20 lbs of spring pressure has never been an issue, but the lack of that extra 20 lbs has. When you start to understand spring surge and valve train stability, you may re-think your installed height and spring theory.
If you would like to give us an in depth explanation of why that extra 20lbs will wipe a lobe, I'd be interested in discussing it.
 
It's not 20, it's almost 25... so cut the downplay..
I don't have to convince you of anything.I just have to convince the OP to set them up correctly, which I think he's going to do. If you ever took time to notice, most cam manufactures don't like to see seat pressures over 130 when running in cams. With your theory the seat pressure wouldn't matter, just the over the nose pressure. I wonder why they are concerned with the seat pressure .....
My scenario above isn't about if the 25 will or won't wipe the lobe.. maybe you got a dodgy lifter in the bunch. My point is that if you don't set them up to the recommended pressure then you won't have a leg to stand on if there is a failure. The owner and the cam manufacture would totally be within there rights to blame you for the failure.
 
Bakerlite said:
It's not 20, it's almost 25... so cut the downplay..
I don't have to convince you of anything.I just have to convince the OP to set them up correctly, which I think he's going to do. If you ever took time to notice, most cam manufactures don't like to see seat pressures over 130 when running in cams. With your theory the seat pressure wouldn't matter, just the over the nose pressure. I wonder why they are concerned with the seat pressure .....
My scenario above isn't about if the 25 will or won't wipe the lobe.. maybe you got a dodgy lifter in the bunch. My point is that if you don't set them up to the recommended pressure then you won't have a leg to stand on if there is a failure. The owner and the cam manufacture would totally be within there rights to blame you for the failure.
Click to expand...

So your whole premise is based on who to blame when it fails.
Ever wonder why the same 911 spring is used on cams from .420" lift to .525" lift?
At the same 130 seat pressure?
Because we've all seen the failed cams with the flat base circle.....
So lets compare open pressures.
130lbs @ 1.900 IH -.400" lift=272 lbs open with Comps smallest cam
-.500" lift= 309 lbs open with Comps largest cam.
38 lbs of open pressure over the nose of the lobe difference from smallest to biggest.
Seems like a lot more important than 25 lbs on the base circle when the valve is closed...
But the OP will do what he feels most comfortable with, and that's ok.
 
926 spring installed at 1.75-1.775 gives 120-130 on seat and ~305-315 over the nose.

Stock rocker? If so they aren't going to give full theoretical lift so the true over the nose pressure will be lower

No coil bind issues and a better spring rate than the 911 spring.

I get the sense this is an ask the question and want a specific answer that fits a predetermined choice because it's what's in hand.

Make sure the spring fits firmly in the cups/pads, if not, you need to run a locator for best results.
 
OP: dunno if you noticed it or not, but IQ52 posted a likely solution for your 911 springs on the first page...new locks and you can run those springs...instead of having to buy new springs...locks are cheap by comparison and you'd get to keep your new fresh better than stock springs.

Although, if you hadn't purchased the springs yet, crackedback's solution above would work well too.

here it is...

IQ52 said:
If this helps......

Just seconds ago I tried a factory retainer and lock and switched to the Comp 741-16 retainer and 627-16 (2-groove/4-groove) lock and gained .032" installed height.

Pause for thought.........is Chrysler a true 7 degree lock? Can you use Chrysler locks on Comp or Crane 7 degree retainers?
Click to expand...

...and this :)

RustyRatRod said:
I think you are over thinkin it. I would have that beeotch runnin with the 911 sprAngs by now. But that's just me.
Click to expand...
 
txstang84 said:
OP: dunno if you noticed it or not, but IQ52 posted a likely solution for your 911 springs on the first page...new locks and you can run those springs...instead of having to buy new springs...locks are cheap by comparison and you'd get to keep your new fresh better than stock springs.

Although, if you hadn't purchased the springs yet, crackedback's solution above would work well too.

here it is...



...and this :)
Click to expand...

yes i did see the post from IQ52. he bought new locks as well as new retainers. it would be nice if it added .060ish but it is still on my list of options.
 
today i went to my local speedshop to see what they had in stock. they had a set of Crane 7° retainers. so the owner of the shop let me take one home and install it with my 911 springs to see if it increased my installed height. just looking at the retainer it looked like it would. I installed it with my stock locks and it increased my height by .100". so in tossed on the rocker assembly (stock) and due to the increased height it locks like it comes pretty close to tge rocker arm. another question is are the stock 7° locks the same dimension as the Crane or Comp 7° locks? because my stock locks sink into the crane retainer. buti guess thats how they give the added hieght.
 
I think if it were me, I'd coat the locks with marking dye (dykem) and install them, move the valve a little, then take them out to see if they indeed seat properly. Or buy Crane retainers. IMO, if they were stock replacement locks made to work with factory retainers they would not change the installed hieght noticably... Since the retainer loads the locks that fit needs to be correct. I doubt it is.
 
CPMotorworks said:
So your whole premise is based on who to blame when it fails.
Ever wonder why the same 911 spring is used on cams from .420" lift to .525" lift?
At the same 130 seat pressure?
Because we've all seen the failed cams with the flat base circle.....
So lets compare open pressures.
130lbs @ 1.900 IH -.400" lift=272 lbs open with Comps smallest cam
-.500" lift= 309 lbs open with Comps largest cam.
38 lbs of open pressure over the nose of the lobe difference from smallest to biggest.
Seems like a lot more important than 25 lbs on the base circle when the valve is closed...
But the OP will do what he feels most comfortable with, and that's ok.
Click to expand...

No, not my whole premise, just the one that can hurt the most, and one people don't think about when they cut corners or ignore recommended settings..
Your comparison of the open pressures is pointless and not what the issue is here. And your comment about the "flat base circle" shows you don't understand the real issues.
First having too much seat pressure can prevent the follower from rotating during brake in. That's how your extra 25 lbs/in ( 147 lbs/in total) can wipe the lobe , and that's why cam manufactures don't like high seat pressures during run in.
Second ,the highest acceleration rate of the valvetrain occurs right off the seat. So when you add more than needed seat pressure you also add to the deflection of the pushrods and the rocker ( especially in a stock valve gear). Not to mention added heat generated and wear.
One other problem with not using correct ( lower) installed heights is that you may be preventing going to a higher lift cam at a later date because you would run into coil bind. Then you have to do the whole valve height set up again , and no one likes to do the same job twice.
 
Darren, let me ask you this. Are you coming back after assembly and tapping the end of the valve stems with a small hammer to insure the locks are properly seated? Failure to do that could be why you're getting a short installed height measurement.

And hay you two, can you take your pissin match somewhere else? It's gotten to the point it's not helpin a damn thing. I like and respect both of yall, but you should know better. Thanks.
 
RustyRatRod said:
Darren, let me ask you this. Are you coming back after assembly and tapping the end of the valve stems with a small hammer to insure the locks are properly seated? Failure to do that could be why you're getting a short installed height measurement.

x2
It's the diameter of the hole in the retainer, thickness of the locks, and angle of locks that will leave things in the right spot. That's why I'm concerned the locks themselves might be thicker and therefore sitting higher in the factory retainer. Dykem would show that point of contact.
Click to expand...
Click to expand...
 
RustyRatRod said:
Darren, let me ask you this. Are you coming back after assembly and tapping the end of the valve stems with a small hammer to insure the locks are properly seated? Failure to do that could be why you're getting a short installed height measurement.

And hay you two, can you take your pissin match somewhere else? It's gotten to the point it's not helpin a damn thing. I like and respect both of yall, but you should know better. Thanks.
Click to expand...

i will try that tonight... i will also add that the 4 springs that have the shortest heights are the ex valves that the machine shop replaced with new valves. is there a way i can have the machine shop sink those valves aproxx .025 more into head then nip the top of the valvs stems? thanks
 
Realistically, all the replaced valves should have been installed at the correct factory height at the machine shop.
 
is 1.850" the correct installed height of a sock 1968 383 spring?
 
i tapped the valve stems it brought the installed height up maybe .003.

is there a way the machine shop can sink those 3 ex valves into the seat aprox .020 by machining the valve and seat? by the way i did not have the ex seats replaced with hardened seats.
 
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