[Ecotec] Correct valve springs for roller rockers

[PappaYeet]

Assuming both are brand new, what would perform better with high ratio roller rockers: 90lb stock springs or 105lb upgraded springs?

I’ve seen mixed opinions from people, some claiming that stock springs will float at high RPM, some saying this is only true for old springs, and others saying that it doesn’t matter.

Is there a proper way to work this out? Is the added resistance of a stronger spring too small to worry about with regards to engine performance?

Thanks.

 

[Immortality]

It depends on what you want to do and what other mods you have. Stock high mileage springs aren't recommended if you like to rev the nuts of the motor but then it's a supercharged motor so in theory there is no need to rev it hard.

I believe the stock spring is only about 55lbs seat pressure. a 90lbs spring would be a entry level performance spring and more than fine for high ratio rockers.

 

[Vin999]

Higher springs would put more load on standard valves/train and cam shaft lobe, depending what you want to do as Immortality said, standard ecotec springs aren't to bad really for the power of engine.

 

[Vin999]

at higher rpm I would be more concerned for our friend rodney in the bottom end that the top end.

 

[losh1971]

I believe the stock spring is only about 55lbs seat pressure. a 90lbs spring would be a entry level performance spring and more than fine for high ratio rockers.

Would the stock lifters keep up with high revs and stiffer springs?

 

[Immortality]

I wouldn't be to worried about the rods but the stock timing chain tensioner is suspect. For 105lbs springs I would upgrade to a double row for sure. For the 90lbs springs it's toss up.

Would the stock lifters keep up with high revs and stiffer springs?

The job of the spring is to keep the valve train motion under control, with a roller cam follower it's more critical that the roller follower stays on the cam lobe or the bearings in the follower will get pounded to death. There is some info that the stock lifter hydraulic internals are a bit weak and collapse at higher revs but It's not something that I have seen first hand.

 

[delcowizzid]

Stock springs are around 90- 95lb seat pressure

 

[PappaYeet]

55? 90? I’m lost.

 

[woteva]

Just checked V6 Ecotec standard valve springs from crow cams part number 4021-12 specs show pressure 55 and previous V6 stock spring pressure is 80 ???