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Discussion Starter #1
is it not recommended to run a diffrent spring on an intake side than an exhaust?i would think this could be done.

wanting to run a stiffer spring on the intake valves to make up for the weight of the valve on a hydro roller setup.
 

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is it not recommended to run a diffrent spring on an intake side than an exhaust?i would think this could be done.

wanting to run a stiffer spring on the intake valves to make up for the weight of the valve on a hydro roller setup.
doesn't sound like a real necessary thing to me....how much difference are you talking? if you're talking 10 or 20 lbs you don't need different springs to do that, mine are equal, it spins to 7k no problem...
 

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Discussion Starter #4
I am putting short travel lifters in and at the same time being i have had a couple of issues with valve float on the intake side only i thought it would be the safe thing to put new springs in it anyway.you can buy the PAC springs seoperately and would n=only be increasing seat pressure by about 20 or so and probably a little over 25 open.
 

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I am putting short travel lifters in and at the same time being i have had a couple of issues with valve float on the intake side only i thought it would be the safe thing to put new springs in it anyway.you can buy the PAC springs seoperately and would n=only be increasing seat pressure by about 20 or so and probably a little over 25 open.
how high do you want to spin the motor? short travel lifters if your looking over maybe 7500....are you using a double spring now? How did you determine you have float in the intake only? not being smart ass just asking questions...a good set of double springs with the correct open and set pressure should be fine...good geometry is the key to it all with a hyd roller...
 

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Discussion Starter #6
Looking to safely spin it to 7500.

i have actually had the rocker arm come off(to the side)of the valve a few times when spinning it high.and shows the star pattern kinda on the valve tip.i have only had it happen on the intake valves.

springs now are behives with about 150 closed and i think 370 open,althou dont actually know pressure at true lift.

i wanted to put a hollow stem intake valve in it but if i can get away with it with just a spring and lifter change it would save me.
 

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Can you order a set of 8 titanium retainers and locks? Maybe go with a slightly lighter pushrod on the intake side?
 

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Looking to safely spin it to 7500.

i have actually had the rocker arm come off(to the side)of the valve a few times when spinning it high.and shows the star pattern kinda on the valve tip.i have only had it happen on the intake valves.

springs now are behives with about 150 closed and i think 370 open,althou dont actually know pressure at true lift.

i wanted to put a hollow stem intake valve in it but if i can get away with it with just a spring and lifter change it would save me.
You're playing with fire...do whatever you have to do to fix it. Lighter valves never hurt. Talk to your cam company about your lobe profile and spring requirements for what you're wanting to do.
 

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DO NOT put a lighter push rod in the motor. Push rods have been proven that biger/stonger is better as there weight isnt directly reflected on the spring. Unless you can afford special composite push rods or custom alloys but im guessing not worthy or the case. If you have to put smaller or thinner to make lighter dont do it.
 

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Can you give more details about your combination?
What's your current cam, lifters and springs?
What lifters are you changing to?
What's the installed height/coil bind specs?
What rockers?
With a hyd roller there can be several things going on that really have nothing to do with the spring pressures. I have several hyd roller engines running in the 7000+rpm range with no issues, same spring int. and ex. with standard Morel hyd. lifters, not the short travel.
ETA: just saw your springs. You need more spring pressure, closer to 200/500 if the lifters can handle it. You don't have near enough pressure to run that rpm.
 

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i am going to order some of the comp cam short travel lifters and somw springs today,well see what happens.
say waaaaaaaat?

stay with a regular lifter
and put some spring on it.

what happened to the hollow stem intake valves?
I'd do that before the limited travel lifters
 

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Looking to safely spin it to 7500.

i have actually had the rocker arm come off(to the side)of the valve a few times when spinning it high.and shows the star pattern kinda on the valve tip.i have only had it happen on the intake valves.

springs now are behives with about 150 closed and i think 370 open,althou dont actually know pressure at true lift.

i wanted to put a hollow stem intake valve in it but if i can get away with it with just a spring and lifter change it would save me.
Is that the pac 1220? Sold from a few different places(lunati ect, but under their brand name)....not to be confused with the comp cams hive that is the same spec, but not same quality.

If you wanna stay with a hive, the pac 1520 might be the only one worth looking at, and Im still not quite sure it has the kind of pressure needed to go all the way to 7500. Its a better spring with a touch more pressure than the 1220 it sounds like you are using. Even with the better hive, youd still need to make a very strong effort towards saving weight everywhere in the valve side of the valvetrain(and no light pushrods....thats a no no).

Better lifters alone are not going to increase the springs ability to control the intake valve.
 

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DO NOT put a lighter push rod in the motor. Push rods have been proven that biger/stonger is better as there weight isnt directly reflected on the spring. Unless you can afford special composite push rods or custom alloys but im guessing not worthy or the case. If you have to put smaller or thinner to make lighter dont do it.
X2
 

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DO NOT put a lighter push rod in the motor. Push rods have been proven that biger/stonger is better as there weight isnt directly reflected on the spring. Unless you can afford special composite push rods or custom alloys but im guessing not worthy or the case. If you have to put smaller or thinner to make lighter dont do it.

We have seen different results.
 

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Discussion Starter #18
Some of this is a money issue,if i could get away with a spring only change i would do that.initially i was wanting to run the hollow stem valves on the intake side only,and if that is the best awnser i will do that BUT if just a spring will do it then great.

also it has the original lifters in it plus two other Autozone lifters.thought it might be wise to put new lifters in it and if so might as well use the short travel ones by comp.

one way or another i need to change springs being i have had a valve float issue and i am sure thats not good for them.
 

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Some of this is a money issue,if i could get away with a spring only change i would do that.initially i was wanting to run the hollow stem valves on the intake side only,and if that is the best awnser i will do that BUT if just a spring will do it then great.

also it has the original lifters in it plus two other Autozone lifters.thought it might be wise to put new lifters in it and if so might as well use the short travel ones by comp.

one way or another i need to change springs being i have had a valve float issue and i am sure thats not good for them.
Are you replacing stock OEM type hyd. rollers?
 
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