valve spring installed hight question

DynoDon

Moderator
Yes the retainer must be in place to take the measurement
 

oldasdirt

Member
The thickness of the retainer is subtracted from the total height to give you the installed spring height and also remember to include the spring pocket in the head if you have one.
 

flattop1

Dawg 89
installed height is the measurement of the spring as installed . similar to an id measurement.
From the base of the spring to the top of the spring. it does not include any shims or the retainer , although they are involed in the end result. in as much as it is from the top of the shim or head too the underside of the retainer.
 

astrowrench

Member
The "height" is how TALL THE SPRING IS ................If I am 6'3 and stand on top of new trade center with a Hat on I'M still 6'3 What is so hard to understand..... ASSEMBLED SPRING LENGTH....... If said valve spring was shimmed to a shorter installed height...... it would be--- Stronger.... and shorter..... less prone to valve float......... and longer..... than installed height.. Weaker..... more prone to valve float........It seems to be a very simple thing
 

conehead

New member
The "height" is how TALL THE SPRING IS ................If I am 6'3 and stand on top of new trade center with a Hat on I'M still 6'3 What is so hard to understand..... ASSEMBLED SPRING LENGTH....... If said valve spring was shimmed to a shorter installed height...... it would be--- Stronger.... and shorter..... less prone to valve float......... and longer..... than installed height.. Weaker..... more prone to valve float........It seems to be a very simple thing
dang astrowrench no need to get like that when some ask for some help and insight,,,and by the way it depends on where they measure u from on top of that building, from the ground or the roof , with or without the hat, lol, and that's what he was asking
 

rebsfan4

New member
is the retainer included in the hight measurement? thanks

Install height IS measured with everything in the spring assembly MINUS the spring. For the remainder of the year it will be measured with retainer and seal in place. After the first of the year it will be meausred with the retainer, seal AND any shims that may be used to achieve the install height.
 

mikey56

New member
the question i have is simple....understanding the need to measure the spring height against a known height is keeping within the rules, but sometimes it seems that the measuring seems odd. if you measure the spring height at say 1.350 inches (just throwing numbers out there, i know they aren't correct) and the rules say that it can't be more than 1.330 inches, is the extra .020 actually that much of an advantage? i know that there has to be a limit, but each spring, retainer, seal and shim made isn't going to be measured exactly what the rules are asking for. sure you have a variance (+ / - a certain amount), but does this measurement mean that much and provide that much of an advantage? by my way of thinking, the springs act only as a garage door opener.....they only hold the valve in place and apply enough pressure to keep the valve closed. does the height actually mean that it's going to open farther or close harder? i was under the impression that the cam is what limits the valve to how wide it opens and how fast it slams shut. now if your talking spring pressure, that i can understand...it will limit what you can do because it will affect power...get one too stiff and it's hard to open....get one too weak and you'll hit valve float, so it has an immediate effect on power...but does the height have that much affect?

only asking....
 

Big Iron

Member
If the spring height is supposed to be .815" but it is installed height is at .750", you will obtain a stronger seat pressure allowing the motor to turn well over 7000 rpm's. It would be like putting 18 pound springs in the head instead of 10.8 pound springs.

Measure the spring height by removing the spring and replacing it with the must go gauge between the retainer and the spring pocket (or shims if installed). JMO. Knowledgeable builders may explain more in depth and/or correct me if I am incorrect.

Tom Cole of ARC Racing made some videos about the clone engines. Here is the one about spring height. It is older and the so some of the information is outdated but the actual spring height check should still work.


http://www.ustream.tv/recorded/16472004
 
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flattop1

Dawg 89
the question i have is simple....understanding the need to measure the spring height against a known height is keeping within the rules, but sometimes it seems that the measuring seems odd. if you measure the spring height at say 1.350 inches (just throwing numbers out there, i know they aren't correct) and the rules say that it can't be more than 1.330 inches, is the extra .020 actually that much of an advantage? i know that there has to be a limit, but each spring, retainer, seal and shim made isn't going to be measured exactly what the rules are asking for. sure you have a variance (+ / - a certain amount), but does this measurement mean that much and provide that much of an advantage? by my way of thinking, the springs act only as a garage door opener.....they only hold the valve in place and apply enough pressure to keep the valve closed. does the height actually mean that it's going to open farther or close harder? i was under the impression that the cam is what limits the valve to how wide it opens and how fast it slams shut. now if your talking spring pressure, that i can understand...it will limit what you can do because it will affect power...get one too stiff and it's hard to open....get one too weak and you'll hit valve float, so it has an immediate effect on power...but does the height have that much affect?

only asking....
it would seem so. the issue would be a custom spring that fit the criteria and had a little more pressure than allowed at full lift. progresseve wound springs do this, also it would allow the valve to open just that much more when it did float. so in effect it limits vale lift probably more than the pressure problem.imho
 

racin1

New member
The reason they have an installed height rule, is so you can't run a cam with a taller lift. If you do the spring will coil bind. Alot easier to check spring than cam.
 

Kart43

Member
Valve spring installed height controls the amount of pressure the spring applies to seat the valve. This is extremely important to control the equality of engines in a class. It is always checked in multi cylinder engines to make certain all springs are applying equal force. After valve are refinished their seating positions change and do not have to be the same, you use various size valve spring shims to equalize the installed height. As far as teching an engine heck I would rather check lift than try to tech installed height.

Mikey remember this is a Go guage check, if your installed height is 1.350 the rule will state 1.330 must Go so you would be fine, but your springs would be at a disadvantage because they are applying less pressure to seat the valve.

At all cost you should avoid valve bounce off the seat and valve float in these engines, there is no gain of lift as these cams are not that aggressive, the valve train should be designed so all parts follow the camshaft profile smoothly. If not valve train parts deteriorate quickly.
 
The rest of the engine can deteriorate quickly too. Try the flathead trick to "loft" the valvetrain on an OHV and valves kiss pistons, keepers are knocked loose, pushrods eject, holes are made, etc.
 

Kart43

Member
Thanks Shelby I have tried to dispell the rumor of extra lift by floating the valve for several years now, if it was that easy why would there be so many problems associated to springs.
 

gregp07

Member
Springs are tech'd by "Must go .815" installed height block and then you have the "Dead weight" check..10.8 @ .850 and 18 @ .650..that is how the pressure is controlled..unless you can stiffen them up AFTER .650 might be possible if you are a spring maker.
 
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