#89505, "HRC only running upgraded valve springs no cams... why?"
Ok I have my motor/tranny out of my car and am going to rebuild it. I just want to know why HRC upgraded the vavle springs but nothing else? I was under the impression that the springs only needed to be upgraded for higher lift cams or significantly higher rpm. I was originally going to go with crower stage 2's, oversized valves and crower springs but i'm starting to lean toward leaving it stock since HRC ran a 10.7@136 or w/e on the stock head. However, should I upgrade to crane springs? what gives?
Evo 8 - 12.3@113 circa 2009 (~330whp) Now with BB Xona Rotor HTZ FP Red and ~450whp 2018 MSM Civic SI Ktuner TSP stage 1 w/ Honda hacked headunit.
#89507, "RE: HRC only running upgraded valve springs no cams... why?" In response to Reply # 0
im not sure really, maybe their old ones were finally crappin out on them, or they wanted to reassurance that the valves were going to close properly, or maybe they are turning significantly higher rpm, the stock valve springs is basically what controlls that to a point.
#89508, "RE: HRC only running upgraded valve springs no cams... why?" In response to Reply # 1
Think about it.
The valve spring pulls the valve closed. Boost is trying to push the valve open. Our stock valve springs only give about 40lbs of "pull" on the valve to close it. When you're running almost 30psi, 10lbs of force isn't much to close a valve.
______________________________ If a sentence found online has 35% misspellings or greater and includes at least two racially charged expletives, chances are it is a YouTube comment.
'95 Eclipse TurboGS (garage deco) '95 TSi AWD (restoring a survivor) '97 Talon ESi-T (poor impulse control) '99 Eclipse RS-T (daily beater) '13 Evo X (mostly stock) '17 Sienna (Middle Aged Dad Mobile)
#89512, "RE: HRC only running upgraded valve springs no cams... why?" In response to Reply # 4
Originally posted by CarbonFiberRST Ah ha, I forgot about the boost pushing them open... Ok thanks for the fast replies... I always feel like the biggest dumbass after I start a thread... thanks for that feeling guys
haha i know that feeling too... the upgraded springs are to prevent valve float right? anyways, if you have the motor apart and plan to leave the head stock, why not put in some SS valves so you can run a nice shot of nitrous with the turbo??
-Chris 1999 Eclipse T-GS 2.4 Project is Officially underway
#89526, "RE: HRC only running upgraded valve springs no cams... why?" In response to Reply # 5
yea, that is the plan to save money i'll keep stock cams but run ss valves, now i am debating on wether or not the machine work will be worth it to put in 1mm oversized valves... I am doing the machine work myself. My dad is going to show me how and then let me do it... so my car may never run again (he has access to a machine shop a friend owns)
Evo 8 - 12.3@113 circa 2009 (~330whp) Now with BB Xona Rotor HTZ FP Red and ~450whp 2018 MSM Civic SI Ktuner TSP stage 1 w/ Honda hacked headunit.
#89527, "RE: HRC only running upgraded valve springs no cams... why?" In response to Reply # 0
Ummmmm....valve springs wear out...even low lift stockers. Under aggressive use with higher lift cams and turbo boost, they're gonna wear out even faster. They probably started seeing some erratic valve timing and knew it was time to upgrade. As Dark One said, boost is working against the spring trying to open the intake lessening the spring's ability to "pull" and hold the valve closed...this is not a normal situation.
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(he has access to a machine shop a friend owns)