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Discussion Starter #1
I have a question about valve springs. I have a set of Trickflow 170 heads with the .540 lift springs. I am running twin turbos and I'm having what I've been told is a vacuum leak created by weak springs. When I get into boost it won't hold it most of the time. You can hear the BOV open and close repeatedly. I hooked up my vacuum gauge and at idle the needle is fluttering really fast. I also have a very high idle of 2000 rpms. Does this sound like it could all be from weak springs that can't hold boost? What springs should I get if this is the problem. If anyone needs more info on the motor or whatever to help me I can give you that info. Thanks
 

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I dont think there talking about you valve springs. Its going to take a lot off boost to over power you head valve spring. you may be mixed up. check you blow off valve spring. If it cant hold under boost it will leak off PSI.
Also make sure you have it hooked up right and have no vacuum leaks
 

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Discussion Starter #3
Thanks for the reply,I have changed the spring in the BOV and added washers to make it stiffer with the same results. I do have a vacuum leak,after hooking up my vacuum gauge and researching what the gauge was doing it says possible weak valve springs. I can't find a leak anywhere else. So you think the springs would be strong enough?
 

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Are the springs new? Or did u run them on a previous setup and switch to turbo? Could be a tired spring but u would need alot of psi or a really weak set of springs..i would check for leaks everywhere before i tore into the motor
 

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Discussion Starter #5
My whole motor was new, I'll have to figure out where the leak is coming from. I've checked so many times, this is why the weak spring maybe made some sense.
 

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Your valve springs should be 130 [email protected] seat and 350lb at lift. Sounds like a bov issue.
 

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Thanks for the reply,I have changed the spring in the BOV and added washers to make it stiffer with the same results. I do have a vacuum leak,after hooking up my vacuum gauge and researching what the gauge was doing it says possible weak valve springs. I can't find a leak anywhere else. So you think the springs would be strong enough?
You can not have a vacuum leak and exspect it to work correctly. You BOV will count on boost PSI to help keep itself closed, if you dont have a balance of pipe PSI and vacuum line PSI it will over take the sping. The sping is to keep it closed under normal none boost driving, but not for booseted driving, that is what the vacuum sorce line is for.
Fix the leaks before you try anything els.
 

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